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Survey of intussusception reduction in England, Scotland and Wales: How and why we could do better
ClinicalRadiology(1999) 54, 452-458
Survey of Intussusception Reduction in England, Scotland and Wales: How and why we could do better K. ROSENFELD,
K. M c H U G H
Radiology Department, Great Ormond Street Hospital for Children, London WC1N 3JH, U.K. Received: 2 October 1998
Revised: 28 January 1999
Accepted: 8 February 1999
AIM: The aim of our study was to assess the variation in technique among hospitals in England, Wales and Scotland. In addition, local in hospital variation among paediatric radiologists at our own institution was assessed. M E T H O D : Postal questionnaires were distributed to the radiology departments of 301 hospitals. RESULTS: 183 (60.8%) replies were received. 122 institutions reduced intnssusceptions and 61 did not. A lack of paediatric surgical and/or anaesthetic cover, and a lack of radiologicai experience were the major reasons cited by the departments which did not attempt intussusception reduction. Sixtyfive hospitals use barium for hydrostatic reduction, 43 employ pneumatic reduction, 10 use watersoluble enemas and four use ultrasound. Of the 65 centres using barium 16 (25%) reported a success rate of less than 50%, 24 (37%) had a 50-70% success rate, seven (11%) reduce greater than 70% of intussusceptions and 18 (27%) did not know. In the 43 institutions employing air reduction, one (2%) had a success rate less than 50%, 20 (47%) had a 50-70% success rate, 17 (40%) a success rate greater than 70% and five (11%) did not know. Overall, of the total number of hospitals which replied to our survey, 28 (23%) reported that they were not aware of their success rates. Within the pneumatic reduction group in particular there was marked variation in the methods and duration of attempted reduction - between different hospitals and within the same institution. In six departments the machine used for pneumatic reduction did not measure intraluminal pressure. CONCLUSIONS: Ultrasound is underutilized despite being a sensitive method in diagnosis. There is almost certainly an over-reliance on plain radiographs and on the use of sedation, antibiotics and anti-spasmodics in general. We believe a 70% or greater success rate should be achievable in most institutions whether by pneumatic or hydrostatic reduction, and all departments should strive to achieve success rates in this range. Less than a quarter of centres who replied currently achieve this standard. Successful reduction rates below 50% are unacceptable in our opinion. Not surprisingly, success rates are generally highest in those centres treating more than 20 cases per annum. Twentyeight (23%) of hospitals performing intussusception reductions did not know their success rates. Regular audits of intussesception figures should take place in all institutions. Unacceptably wide variations in intussusception reduction techniques currently exist. An accurate pressure release valve at least, and preferably intraluminal pressure monitoring should be an integral component of all pneumatic reduction devices. The British Paediatric Radiology and Imaging Group or the Royal College of Radiology should address these issues and introduce some standardization of practice. Rosenfeld, K. and McHugh, K. (1999) Clinical Radiology 54, 452-458. Key words: intussusception, pneumatic reduction, barium, ultrasounds.
Reduction of an intussusception is a relatively common therapeutic radiological procedure performed in young children. Intussusception predominantly occurs in the 6-24 month age group with a higher prevalence in the spring and autumn months. The diagnosis is suspected on clinical history and examination and can be confirmed in the majority of cases on ultrasound examination [1]. Although there are classical plain radiographic findings on abdominal radiographs, this examination is often unhelpful in the diagnosis of intussusception [2,3]. Plain films are Correspondence to: Dr K. McHugh, Radiology Department, Great Ormond Street Hospital for Children, London WC1N 3JH, U.K. 0009-9260/99/070452+07 $12.00/0
generally performed to exclude alternative diagnoses or a complication such as a perforation. Management of a confirmed intussusception is usually by radiological reduction after adequate resuscitation, if this fails surgical reduction or resection is needed. The technique of radiological reduction varies from centre to centre, with no uniform technique being applied. METHOD Postal questionnaires (Table 1) were sent to the radiology departments of 301 hospitals within England, Wales and © 1999 The Royal College of Radiologists
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SURVEY OF INTUSSUSCEPTION REDUCTION IN ENGLAND, SCOTLAND AND WALES Table 1 - Intussusception questionnaire
INTUSSUSCEPTION QUESTIONNAIRE 1. What is the status of your hospital? Teaching [] District General hospital []
Children's hospital []
2.
Do you treat intussusceptions radiologically? yes [] no [] if yes, please answer questions 4-17 if no, please answer question 3
3.
Why not? No surgical cover [] no anaesthetic cover [] No radiology expertise [] other [] specify ........................................................................................................................................................................
4.
What method do yon primarily use for reductions? Air enema [] Barium enema [] Water soluble enema [] Ultrasound and water [] Ultrasound and saline [] Ultrasound and water soluble contrast [] Other [] .............................................................................................................................................................
5.
Do you perform plain abdominal radiographs routinely in all suspected cases? yes [] no []
6.
Do you perform an ultrasound routinely on suspected cases? Y e s [ ] n o [ ] if yes, do you usecolourdoppIer? y e s [ ] n o [ ]
6.
If you perform air enemas what maximum pressure do you use? N/A [] no pressure measurement [] 80mmHG [] 100mmHg []
7.
What type of device do you use for air reductions? Made locally []
purchased []
120mmHg []
other []
specify .......................................................................
if yes manufacturer? .........................................................................................................................................................
8.
How many attempts do you use at each pressure? l[3 2[] 3• >3[]
9.
How long at each attempt? lminD 2min[] 3mind
>3min[]
10.
Do you sedate patients? always [] almost always []
sometimes []
11.
Do you routinely use antibiotic cover? yes [] no [] if yes, what antibiotic? ..................................................................................................................................................................................
12.
Do you use antispasmodics? no [] yes [] if yes, buscopan []
13.
What catheter do you use? standard rectal catheter [] balloon catheter []
14.
How many cases do you manage per year? <10[] 10-20[] >20[]
15.
What is your approximate success rate, if known? < 5 0 % [ ] 5 0 - 7 0 % [ ] > 7 0 % [ ] don't k n o w [ ]
16.
What complications have you had in past 5 years? none [] perforation [] other [] specify ...........................................................................................................................................................................
17.
Any other comments?
never []
glucagon [] feeding tube []
Table 2 - Method of reduction
Teaching hospital
District general hospital
Children's hospital
Total Table 3 - Abdominal X-ray
Barium 8 Air 15 Water soluble 1 contrast medium Ultrasound 0
56 19 9
1 9 0
65 43 10
3
1
4
Total
87
11
122
24
Teaching hospital
District general hospital
Children's hospital
Total
No Yes
3 21
12 75
3 8
18 104
Total
24
87
11
122
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CLINICAL RADIOLOGY
Table 4 - Ultrasound
No Yes Doppler Yes No Not indicated
Table 8 - Catheter
Teaching hospital
District general hospital
Children's hospital
Total
10 14
39 48
1 10
50 72
6 5 3
7 31 10
6 3 1
19 39 14
STD rectal Balloon (Foley) Feeding tube Total
Table 9 - Number
Teaching hospital
District general hospital
Children's hospital
Total
8 15 1 24
25 53 9 87
4 7 0 11
37 75 10 122
of cases per year
Table 5 - Sedation
Always Almost always Sometimes Never Total
Teaching hospital
District general hospital
Children's hospital
Total
4 5 8 7 24
16 20 33 18 87
5 1 2 3 11
25 26 43 28 122
< 10 10-20 >20 Total
Teaching hospital
District general hospital
Children' s hospital
Total
12 5 7 24
77 9 1 87
2 4 5 11
91 18 13 122
Teaching hospital
District general hospital
Children's hospital
Total
2 7 10 5 24
16 39 10 22 87
0 3 7 1 11
18 49 27 28 122
Table 10 - Success rate Table 6 - Antibiotic cover
Yes No Total
Teaching hospital
District general hospital
Children's hospital
Total
6 18 24
4 83 87
2 9 11
12 110 122
Table 7 - Anti-spasmodics
No Yes Total
<50% 50-70% >70% Don't know Total
T a b l e 11 - S u c c e s s r a t e v s t e c h n i q u e
Teaching hospital
District general hospital
Children's hospital
Total
22 2 24
68 19 87
11 0 11
101 21 122
Scotland. The names and addresses were obtained from the 1997 Medical Directory and all hospitals with both a radiological and paediatric department were included. In addition, the questionnaire was circulated among six consultant paediatric radiologists at our institution.
RESULTS One hundred and eighty-three (60.8%) replies were received of which 122 institutions reduced intussusceptions and 61 did not. O f the 61 departments that did not attempt intussusception reduction eight were from teaching hospitals and 53 from district general hospitals. In the teaching hospital group, six had no in-patient paediatrics, one had no paediatric surgeon and
Barium Air Water soluble contrast Ultrasound Total
< 50%
50-70%
> 70%
Don't know
Total
16 1 0
24 20 5
7 17 0
18 5 5
65 43 t0
1 18
0 49
3 27
0 28
4 122
one referred their cases to a local Paediatric hospital. In the district general hospital group, 31 had no paediatric surgeon, 15 reported no anaesthetic cover for paediatrics and seven stated there was no radiology experience. Seventeen had no in-patient paediatrics and in three the paediatricians apparently preferred to send their cases elsewhere for reduction. Fifteen respondents felt it was the radiologists' role to make the diagnosis and then refer to a more experienced unit for reduction. One response felt that radiologists should play no part in therapy, only in diagnosis. In seven cases it was remarked that they used to perform intussusception reduction until the Royal College of Anaesthetics changed their guidelines regarding paediatric anaesthetic cover for surgery. In the group performing intussusception reduction, 24
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SURVEY OF INTUSSUSCEPTIONREDUCTIONIN ENGLAND,SCOTLAM)AND WALES Table 12 - Success rate vs n u m b e r cases per year
< 10 10-20 >20 Total
Table 14 - N u m b e r of attempts at each pressure
< 50%
50-70%
> 70%
Don't know
Total
16 1 1 18
38 10 1 49
10 7 10 27
27 0 1 28
91 18 13 122
(19.7%) replies were from teaching hospitals (TH), 87 (71.1%) from district general hospitals (DGH) and 11 (9%) from children's hospitals (CH). Sixty-five hospitals (53.3%) use barium for hydrostatic reduction (eight TH, 56 DGH, one CH), 43 (35.2%) use pneumatic reduction (15 TH, 19 DGH, nine CH), 10 (12.2%) use water-soluble enemas (one TH, nine DGH) and four (3.3%) use ultrasound (three DGH, one CH). In the latter group, three use water-soluble contrast medium and one air. In the pneumatic reduction group two centres use carbon dioxide (Table 2). The results with regard to the use of plain radiographs, ultrasound and Doppler evaluation are tabulated in Tables 3 and 4 and the results on use of sedation, antibiotics, antispasmodics and the type of catheter in Tables 5-8. With regard to the use of a balloon catheter, most places indicated that the balloon was not necessarily inflated during the procedure. Ninety-one (74.6%) hospitals (12 TH, 77 DGH, two CH) performed less than 10 procedures per year, 18 (14.7%) 10-20 per year (five TH, nine DGH, four CH) and only 13 (10.7%) greater than 20 per year (seven TH, one DGH, five CH) (Table 9). Eighteen (14.8%) centres (two TH, 16 DGH) estimated their success rate to be less than 50%, 49 (40.2%) between 50-70% (seven TH, 39 DGH, three CH) and 27 (22%) greater than 70% (10 TH, 10 DGH, seven CH). Twenty-eight (23%) hospitals (five TH, 22 DGH, and one CH) did not know their success rate of which three indicated it would be the subject of a forthcoming audit (Table 10). When comparing success rate to the technique used, of the 65 centres using barium, 16 (25%) reported a success rate of less than 50%, 24 (37%) had a 50-70% success rate, seven (11%) greater than 70% and 18 (27%) did not know. In the air reduction group (n = 43), one (2%) had a success rate less than 50%, 20 (47%) had a 50-70% success rate, 17 (40%) a success rate greater than 70% and five (11%) did not know. In those hospitals that used water-soluble enemas, five (50%) had success rates between 50-70% and five (50%) did not know. Of the four hospitals that use ultrasound one (25%) had a less
1 2 3 >3 Total
Teaching hospital
Districtgeneral hospital
Children's Total hospital
1 1 8 5 15
0 2 12 5 19
0 0 5 4 9
1 3 25 14 43
than 50% success rate and three (75%) had a rate in excess of 70% (Table 11). When comparing success rate to the number of cases performed, a less than 50% success rate was achieved in 16 centres who performed less than 10 cases per year, a 50-70% success rate in 38 centres with less than 10 per year and a greater than 70% in 10 centres. Twenty-seven centres that perform less than 10 per year did not know their success rate. In those centres that perform between 10-20 per year, one had a success rate less than 50%, 10 between 50-70% and seven greater than 70%. In the hospitals who perform more than 20 cases per year, only one had a success rate less than 50% (a DGH using barium), one between 50-70% (a children's hospital that often try to reduce intussusceptions when other referring hospitals have failed) and 10 had success rates greater than 70%. One hospital did not know their success rate, which will be the subject of an audit (Table 12). Only 14 serious complications were experienced and reported in the previous 5 years. Thirteen of these were perforations and one child developed septic shock and arrested during the procedure (DGH using water-soluble enema). Of the 13 perforations, four were in a TH, three in a DGH and six in a CH. In 12 cases, air pneumatic reduction was used and in only one (DGH) barium was used. The techniques of pneumatic reduction were compared in the 43 centres that used this method. No pressure measurement is used in six hospitals (all DGH). A maximum pressure of 80mmHg is used in seven hospitals (five DGH, two CH), 100 mmHg in seven hospitals (two TH, four DGH, one CH) and 120mmHg in 23 hospitals (13 TH, four DGH, six CH). No hospital uses more than 120mmHg (Table 13). One hospital uses only one attempt at each pressure (TH), three use two attempts (one TH, two DGH), 25 use three attempts (eight TH, 12 DGH, five CH) and 14 (five TH, five DGH, four CH) use more than three attempts at each pressure (Table 14). The time at each attempt is also variable. Three (one TH, one DGH, one
Table 13 - M a x i m u m pressure ( m m Hg) Table 15 - Time at each attempt
Teaching hospital No pressure measured 80 100 120 Total
Districtgeneral hospital
Children's hospital
Total
0
6
0
6
0 2 13 15
5 4 4 19
2 l 6 9
7 7 23 43
1rain 2rain 3 rain > 3 rnin Total
Teaching hospital
Districtgeneral hospital
Children's Total hospital
1 3 8 3 15
1 4 11 3 19
1 1 5 2 9
3 8 24 8 43
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CLINICAL RADIOLOGY
CH) apply pressure for only I rain, eight for 2 min (three TH, four DGH, one CH), 24 for 3 min (eight TH, 11 DGH, five CH) and eight for longer than 3 min (three TH, three DGH, two CH) (Table 15). The device used wasmade at the insitution in 36 places (12 TH, 16 DGH, eight CH) and purchased (three TH, three DGH, one CH) either from the nearest children's hospital or from the institution in which the radiologist trained. The above results did not include our own institution. At the Great Ormond Street Hospital for Children, London, six paediatric consultant radiologists were surveyed. All use the same locally made air device. Five routinely perform plain radiographs and one does not. Three use ultrasound and three do not. Of the three who perform ultrasound only two use Doppler. Sedation is never used by five and only occasionally used by one. Antibiotics are only used by one radiologist, who also works on another site. None of the six use anti-spasmodics. Standard rectal catheters are used by three, paediatric feeding tubes by two and a balloon catheter by one radiologist. Five radiologists perform between 10-20 cases per year and one, who covers paediatric radiology at another London hospital, greater than 20 cases. The success rate among four is greater than 70%, one 50-70% and one does not know. In the technique of air reduction five use a maximum pressure of 120mmHg and one 100mmHg. One radiologist only uses a single attempt at each pressure, one has two attempts, three have three attempts and one has more than three attempts. The time duration for each attempt also varies with one using only 1 rain, one 2 min and four use 3 rain.
DISCUSSION
This study confirms that there is a wide variation in the techniques of radiological reduction of intussusception within the U.K. Air reduction techniques are predominantly used in Children's and Teaching Hospitals, while barium is still the main method preferred in the District General Hospital. Many DGH stated that they would like to switch to pneumatic reduction. The number of cases in their institutions are so small, however, the radiologists believed they would not gain sufficient experience and justifiably prefered to stick to a method with which they were familiar. In addition, many cases occurred out of hours and the radiologists felt that these times were not suitable for experimenting with new techniques. Although the younger radiologists in these departments were generally familiar with pneumatic reduction, most departments preferred, however, to have a uniform protocol for reduction. In a previous smaller U.K. study of 76 hospitals a similar trend was observed with paediatric radiologists preferring a pneumatic method of reduction and general radiologists still using barium [4]. In a study from the United States of 58 centres (published in 1992 but probably reflecting practice in 1991) more than one method was used in 90% of centres with changing trends depending on the duty radiologists' experience [5]. Barium was used in 97% of centres, water-soluble contrast in 83% and air in 50% [5]. In high risk cases water-soluble contrast medium was the preferred method in 71% [5]. In a recent review it is suggested that more centres in America are converting to air reduction techniques and those centres that
still doubt the efficacy of air have little or no experience with the technique [6]. Although there have been no randomized trial comparing the two methods, air reduction is generally regarded as easier, quicker, and cleaner, with a lower radiation dose than barium [4-8]. There have, however, been conflicting reports with regard to irradiation during fluoroscopic reduction and in one study the assumption of a lower radiation dose was not confirmed using a dose area product meter to measure effective dose [9]. More recently reports are appearing of high success rates using ultrasound-guided reduction with either saline or water [10-12]. This method is particularly popular in the Far East where intussusception is common and the leading cause of an acute abdomen in young children. A reduction in radiation is cited as the major benefit in addition to high success rates, possible lower recurrence rates and the benefit of clearly observing the patients' clinical condition throughout the procedure possibly due to easier access to the patient in an ultrasound room. Only four centres in our study reported using ultrasound-guided reduction. Abdominal radiographs have been shown to have a role in ruling out other diagnoses and not in the diagnosis of intussusception [2,21]. Daneman and Alton could find no cases of free air or perforation before attempted reduction [2]. We would question, therefore, the routine use of plain abdominal radiographs in children in whom the diagnosis of intussusception is likely. The plain radiograph should be reserved for doubtful cases or where there is concern with regard to peritonism or marked small bowel obstruction. Ultrasound is used as an aid to diagnosis in only 59% of our hospitals. The radiologists who use ultrasound as a diagnostic tool remarked on its high sensitivity and this has been confirmed in a number of studies [13,14,21]. We have found a similar experience in our practice. Daneman and Alton suggest that the current state-of-the-art management of intussusception should be sonography for diagnosis and air for reduction [2]. One limitation with sonography, however, that should be borne in mind is that false-positive diagnoses of intussusception from bowel wall thickening due to lymphoma or Crohn's disease are possible. On Doppler examination, if there is lack of colour flow within the tip of the intussusceptum it has been suggested that it indicates a reduced chance of successful reduction, this finding, however, should not prevent a reduction attempt [21]. The use of sedation varies considerably in our study. The policy of utilizing sedation often appears to be determined by the local paediatricians or surgeons rather than by the radiologists, which is not ideal. In the North American study only 3% always sedated patients compared with our 21% [5]. Seven percent always used sedation compared with our 21% [5]. Sedation was sometimes used in 45% and never used in 45% of their group compared with 35% and 23% in our group, respectively. Touloukian [15] found a 35% higher reduction rate in sedated patients in his study. It is generally felt, however, that sedation is best avoided as it serves primarily to quieten the patient but does not afford pain relief, and can mask the signs of shock or hypotension. In addition, the Valsalva manoeuvre is thought to be protective against perforation during air but not hydrostatic enemas [6,16]. By reducing the ability to mount a Valsalva manouevre sedating children may actually increase the perforation rate with pneumatic
SURVEY OF INTUSSUSCEPTION REDUCTION IN ENGLAND, SCOTLAND AND WALES
reduction. We feel sedation alone is not justified. There is some justification for analgesic use but this should be determined by local paediatric practice. Antibiotic cover was given in only 9.8% of our group compared with 16% of the North American study [5]. Antibiotic prophylaxis is frequently given depending on the attitude of the surgeon or paediatrician. In a study by Somekh et al. the risk of bacteraemia following air enema reduction was shown to be very low [17]. The rationale for giving antibiotics is mainly to protect the patient if a perforation occurs although there is little evidence to support the use of antibiotics in the vast majority of cases. Anti-spasmodics were used in 17% of our cases compared with 10% in the North American group [5]. Some authors have suggested that anti-spasmodics may be of some use if previous attempts at reduction have failed [18]. Interestingly it is not used in any of our Children's hospitals. Franken et al. [19] found that glucagon was not efficacious in the hydrostatic reduction of intussusception in a double-blind study of 30 patients and we believe there is little justification for its continued use. A wide variation in the catheter used was noted and it largely depended on personal preference. Most respondents (61%) employ a balloon catheter, only inflating the balloon in cases of a poor seal which was reported to be uncommon. The use of a balloon catheter in the rectum engenders much controversy particularly in adult radiology practice and while many centres worldwide are happy to use a balloon catheter in reducing childhood intussusceptions, others prefer to achieve a rectal seal with taping and/or a rubber disc [20,21]. We could find no proof that balloon catheters with the balloon inflated increase the perforation rate in children during an attempted intussusception reduction. The success rate for radiological reduction appeared higher in those units performing more cases confirming that experience with a particular technique increases the success rate. The success rate in most CHs are higher than in DGHs, although in one CH they remark that their success rate may be lower as they often try to reduce patients that are clinically stable and have had a failed attempt at a referring hospital. The overall success rate is higher in those hospitals using air reduction but this may reflect both the greater experience in hospitals using air, more cases per annum or a better overall technique. Many centres having switched to pneumatic reduction of intussusception are reporting higher success rates than they previously had with hydrostatic reduction [22]. There is a wide variation between different centres performing air reductions with regard to the maximum pressure used, number of attempts at each pressure and the time allowed at each attempt. The classical teaching of three attempts for 3 rain (at three pressures to a maximum of 120mmHg) does not universally apply. In six DGH departments the machine used does not measure the pressure given and not surprisingly their success rates are low. This lack of pressure monitoring is far from ideal and may not be defensible from a medico-legal viewpoint [23]. To our knowledge, however, no machine is yet commercially manufactured in Europe for intussusception reduction; most units have a locally assembled device. The American College of Radiology has recently issued a new standard relating to intussusception reduction which states that
457
if a radiologist elects to use air, carbon dioxide or oxygen as a medium for reduction, a manometer must be used to ensure that pressures do not exceed 120 mmItg [23]. This seems sensible but no such consensus nor standardization exists in this country. There is a need for a safe device with a pressure release valve and accurate pressure monitoring to be widely available. The success rates appear better in those hospitals that use a maximum pressure of 120 mmHg for 3 rain than those who use lower pressures. We acknowledge the limitations of a retrospective postal survey in that frequently the questionnaire was answered by one individual on behalf of the whole department and so it cannot be entirely representative of all radiologists. In England and Wales acute intussusception has an incidence of 1-2/1000 live births and accounts for around 700 hospital admissions each year [24]. Although our reported figures are not entirely comprehensive, the complication rates appear low with only 13 perforations recorded in 5 years. 12 of these cases were when using air reduction and only one with barium confirming a general impression that pneumatic reductions lead to more perforations [25]. In another case in which the child developed septic shock and suffered a cardiac arrest, the radiologist felt that there might have been a missed perforation prior to the attempted reduction. It is impossible to determine accurately the perforation and success rates when the total number of attempted reductions is not known. It may be that those centres with higher perforation rates try harder, thus having a better overall reduction rate whilst accepting a higher perforation rate [21]. When reviewing the practices within our own institution we found a variation in the techniques of air reduction by our six paediatric radiologists confirming the difficulties in obtaining uniform management of these cases. Although a few centres report success rates approaching 90%, we believe successfully reducing greater than 70% of intussusceptions encountered is a realistic standard that should be achievable in all institutions. A worrying finding in our study was that 18 centres (16 using barium reduction), who undertake less than 10 reductions per year, reported a success rate of less than 50%. It is difficult to know the nature of the information given to the parents in these cases when seeking consent to the attempted reduction. In addition, 28 (18 using barium, five air, five water-soluble) centres did not know their success rates. Although up to 75% of centres perform less than 10 reductions per annum which may be divided between a number of colleagues further diluting experience, we believe it is mandatory that these departments perform self-audit as a matter of urgency and if the figures are poor, then some re-training or transfer of all cases of intussusception to larger or more experienced units should be considered. It is noteworthy that seven departments reported they no longer attempt reduction as a result of the recommendations by the Royal College of Anaesthetists with regard to adequate local paediatric anaesthetic cover. Although we have not addressed this in our survey, we suspect there are a few radiologists bravely performing intussusception reduction without local surgical back-up which in the event of an iatrogenic perforation is also of some concern. In the successful management of intussusception radiologically, teamwork between the radiologist, paediatricians, surgeons and nursing staff is essential in providing the optimal environment for a
458
CLL~CAL RADIOLOGY
successful attempt at radiological reduction. This includes adequate clinical assessment, resuscitation and explanation to parents. O f particular importance is adequate fluid replacement as inadequate fluid replacement has been implicated as a major factor in 20% of deaths. In conclusion, this is the largest survey of the U.K. practice of experience in the management of intussusception confirming that there is still wide variation in the technique of radiological reduction of intussusception between different centres and to a lesser degree within one institution. Neither the Royal College of Radiologists nor the British Paediatric Radiology and Imaging Group has issued any formal guidelines with regard to intussusception reduction and this should probably be rectified. The technique used depends on the radiologists' experience and in many centres the low number of cases per year make them reluctant to try a new technique. Pneumatic reduction seems to be growing in popularity but we should stress that a properly performed hydrostatic reduction is a perfectly satisfactory alternative [25]. The overall success rate depends largely on the number of examinations performed per year rather than on a specific technique. The complication rate for these procedures appears low, although all centres performing pneumatic reduction should do so with intraluminal pressure monitoring. Ultrasound has been shown to have a high sensitivity and specificity in the diagnosis of intussusception and should be more widely utilized in doubtful cases. The newest technique of water/saline reduction under ultrasound control still requires evaluation, as the number of centres employing this technique is low. Sedation and antispasmodics are best avoided. There is little evidence to support the routine use of antibiotics.
Acknowledgements. The authors would like to thank all those radiologists who took time to complete their questionnaire.
REFERENCES 1 Caffeys Paediatrie X-ray Diagnosis 9th edn. Mosby 1993; pp 10761084. 2 Daneman A, Alton DJ. Intussusception: issues and controversies related to diagnosis and reduction. Radiol Clin N Am 1996;34:743-756. 3 Ratcliffe JF, Fong S, Cheong I, O'Connell P. The plain abdominal film in intussusception: the accuracy and incidence of radiographic signs. Pediatr Radiol 1992;22:110-111. 4 Jewell FM, Roobottom C, Duncan A. Variations in the management of intussusception: restdts of a postal survey. Br J Radiol 1995;68:13-18.
5 Meyer JS. The current radiologic management of intussusception: a survey and review. Pediatr Radiol 1992;22:323-325. 6 Kirks DR. Air intussusception reduction: 'the winds of change'. Paediatr Radiol 1995;25:89-91. 7 Wong I-IF, Kong MS, Ng SH, et al. Pneumetic reduction of intussusception in children. J Formosan Med Assoc 1995;94:702-704. 8 Gorenstein A, Rancher A, Serour F, Witzling M, Katz R. Intussusception in children: reduction with repeated, delayed air enema. Radiology 1998;206:721-724. 9 Thomas RD, Fairhurst JJ, Strife JL. Effective dose during screening monitored intussusception reduction. Clin Radiol 1993;48:189-191. 10 Rohrschneider WK, Troger J. Hydrostatic reduction of intussusception under U/S guidance. Pediatr Radiol 1995;25:530-534. 11 Soun DS, Choy PC, Tok TS, Chiu CY. Reduction of intussusception by ultrasound guided saline enema. Acta Paediatrica Sinica 1996;37:257262. 12 Choi SO, Park WH, Woo SK. Ultrasound guided water enema: an alternative method of non-operative treatment for children with intussusception. J Pediatr Surg 1994;29:498-500. 13 Stanley A, Logan H, Bate TW, Nicholson AJ. Ultrasound in the diagnosis and exclusion of intussusception. Irish Med J 1997;90:64-65. 14 Lim HK, Sang HB, Lee KH, et al. Assessment of reducibility of ileocolic intussusception in children: usefulness of color doppler sonography. Radiology 1994; 191:781-785. 15 Touloukian RJ, O'Connell JB, Markowitz RI, et al. Analgesic premedication in the management of ileocolic intussusception. Pediatrics 1987;79:432-434. 16 Shiels WE, Kirks DR, Keller GL, et al. Colonic perforation by air and liquid enemas: comparison study in young pigs. Am J Roentgenol 1993;160:931-935. 17 Somekh E, Serour F, Goncalves D, Gorenstein A. Air enema for reduction of intussusception in children: risk of bacteraemia. Radiology 1996;200:217-218. 18 Mortenson W, Eklof O, Laurin S. Hydrostatic reduction of childhood intussusception: the role of adjuvant glucagon medication. Acta Radiol Diagn 1984;25:261-264. 19 Franken EA Jr, Smith WL, Chernish SM, et al. The use of glucagon in hydrostatic reduction of intussusception: a double-blind study of 30 patients. Radiology 1983;146:687-689. 20 Meyer JS, Dangman BC, Buonomo C, Berlin JA. Air and liquid contrast agents in the management of intussusception: a controlled, randomized trial. Radiology 1993;188:507-511. 21 McAlister WH. Intussusception: even Hippocrates did not standardize his technique of enema reduction. Radiology 1998;206:595-598. 22 Stein M, Alton DJ, Daneman A. Pneumatic reduction of intussusception: 5-year experience. Radiology 1992;183:681-684. 23 Berlin L. Malpractice issues in radiology. Reducing the intussuscepted colon. Am J Roentgenol 1998;170:1161-1163. 24 Stringer MD, Pledger G, Drake DP. Childhood deaths from intussusception in England and Wales, 1984-9. Br Med J 1992;304:737739. 25 Poznanski AK. Why I still use barium for intussusception. Pediatr Radiol 1995;25:92-93.
Survey of Intussusception Reduction in England, Scotland and Wales: How and why we could do better K. ROSENFELD,
K. M c H U G H
Radiology Department, Great Ormond Street Hospital for Children, London WC1N 3JH, U.K. Received: 2 October 1998
Revised: 28 January 1999
Accepted: 8 February 1999
AIM: The aim of our study was to assess the variation in technique among hospitals in England, Wales and Scotland. In addition, local in hospital variation among paediatric radiologists at our own institution was assessed. M E T H O D : Postal questionnaires were distributed to the radiology departments of 301 hospitals. RESULTS: 183 (60.8%) replies were received. 122 institutions reduced intnssusceptions and 61 did not. A lack of paediatric surgical and/or anaesthetic cover, and a lack of radiologicai experience were the major reasons cited by the departments which did not attempt intussusception reduction. Sixtyfive hospitals use barium for hydrostatic reduction, 43 employ pneumatic reduction, 10 use watersoluble enemas and four use ultrasound. Of the 65 centres using barium 16 (25%) reported a success rate of less than 50%, 24 (37%) had a 50-70% success rate, seven (11%) reduce greater than 70% of intussusceptions and 18 (27%) did not know. In the 43 institutions employing air reduction, one (2%) had a success rate less than 50%, 20 (47%) had a 50-70% success rate, 17 (40%) a success rate greater than 70% and five (11%) did not know. Overall, of the total number of hospitals which replied to our survey, 28 (23%) reported that they were not aware of their success rates. Within the pneumatic reduction group in particular there was marked variation in the methods and duration of attempted reduction - between different hospitals and within the same institution. In six departments the machine used for pneumatic reduction did not measure intraluminal pressure. CONCLUSIONS: Ultrasound is underutilized despite being a sensitive method in diagnosis. There is almost certainly an over-reliance on plain radiographs and on the use of sedation, antibiotics and anti-spasmodics in general. We believe a 70% or greater success rate should be achievable in most institutions whether by pneumatic or hydrostatic reduction, and all departments should strive to achieve success rates in this range. Less than a quarter of centres who replied currently achieve this standard. Successful reduction rates below 50% are unacceptable in our opinion. Not surprisingly, success rates are generally highest in those centres treating more than 20 cases per annum. Twentyeight (23%) of hospitals performing intussusception reductions did not know their success rates. Regular audits of intussesception figures should take place in all institutions. Unacceptably wide variations in intussusception reduction techniques currently exist. An accurate pressure release valve at least, and preferably intraluminal pressure monitoring should be an integral component of all pneumatic reduction devices. The British Paediatric Radiology and Imaging Group or the Royal College of Radiology should address these issues and introduce some standardization of practice. Rosenfeld, K. and McHugh, K. (1999) Clinical Radiology 54, 452-458. Key words: intussusception, pneumatic reduction, barium, ultrasounds.
Reduction of an intussusception is a relatively common therapeutic radiological procedure performed in young children. Intussusception predominantly occurs in the 6-24 month age group with a higher prevalence in the spring and autumn months. The diagnosis is suspected on clinical history and examination and can be confirmed in the majority of cases on ultrasound examination [1]. Although there are classical plain radiographic findings on abdominal radiographs, this examination is often unhelpful in the diagnosis of intussusception [2,3]. Plain films are Correspondence to: Dr K. McHugh, Radiology Department, Great Ormond Street Hospital for Children, London WC1N 3JH, U.K. 0009-9260/99/070452+07 $12.00/0
generally performed to exclude alternative diagnoses or a complication such as a perforation. Management of a confirmed intussusception is usually by radiological reduction after adequate resuscitation, if this fails surgical reduction or resection is needed. The technique of radiological reduction varies from centre to centre, with no uniform technique being applied. METHOD Postal questionnaires (Table 1) were sent to the radiology departments of 301 hospitals within England, Wales and © 1999 The Royal College of Radiologists
453
SURVEY OF INTUSSUSCEPTION REDUCTION IN ENGLAND, SCOTLAND AND WALES Table 1 - Intussusception questionnaire
INTUSSUSCEPTION QUESTIONNAIRE 1. What is the status of your hospital? Teaching [] District General hospital []
Children's hospital []
2.
Do you treat intussusceptions radiologically? yes [] no [] if yes, please answer questions 4-17 if no, please answer question 3
3.
Why not? No surgical cover [] no anaesthetic cover [] No radiology expertise [] other [] specify ........................................................................................................................................................................
4.
What method do yon primarily use for reductions? Air enema [] Barium enema [] Water soluble enema [] Ultrasound and water [] Ultrasound and saline [] Ultrasound and water soluble contrast [] Other [] .............................................................................................................................................................
5.
Do you perform plain abdominal radiographs routinely in all suspected cases? yes [] no []
6.
Do you perform an ultrasound routinely on suspected cases? Y e s [ ] n o [ ] if yes, do you usecolourdoppIer? y e s [ ] n o [ ]
6.
If you perform air enemas what maximum pressure do you use? N/A [] no pressure measurement [] 80mmHG [] 100mmHg []
7.
What type of device do you use for air reductions? Made locally []
purchased []
120mmHg []
other []
specify .......................................................................
if yes manufacturer? .........................................................................................................................................................
8.
How many attempts do you use at each pressure? l[3 2[] 3• >3[]
9.
How long at each attempt? lminD 2min[] 3mind
>3min[]
10.
Do you sedate patients? always [] almost always []
sometimes []
11.
Do you routinely use antibiotic cover? yes [] no [] if yes, what antibiotic? ..................................................................................................................................................................................
12.
Do you use antispasmodics? no [] yes [] if yes, buscopan []
13.
What catheter do you use? standard rectal catheter [] balloon catheter []
14.
How many cases do you manage per year? <10[] 10-20[] >20[]
15.
What is your approximate success rate, if known? < 5 0 % [ ] 5 0 - 7 0 % [ ] > 7 0 % [ ] don't k n o w [ ]
16.
What complications have you had in past 5 years? none [] perforation [] other [] specify ...........................................................................................................................................................................
17.
Any other comments?
never []
glucagon [] feeding tube []
Table 2 - Method of reduction
Teaching hospital
District general hospital
Children's hospital
Total Table 3 - Abdominal X-ray
Barium 8 Air 15 Water soluble 1 contrast medium Ultrasound 0
56 19 9
1 9 0
65 43 10
3
1
4
Total
87
11
122
24
Teaching hospital
District general hospital
Children's hospital
Total
No Yes
3 21
12 75
3 8
18 104
Total
24
87
11
122
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CLINICAL RADIOLOGY
Table 4 - Ultrasound
No Yes Doppler Yes No Not indicated
Table 8 - Catheter
Teaching hospital
District general hospital
Children's hospital
Total
10 14
39 48
1 10
50 72
6 5 3
7 31 10
6 3 1
19 39 14
STD rectal Balloon (Foley) Feeding tube Total
Table 9 - Number
Teaching hospital
District general hospital
Children's hospital
Total
8 15 1 24
25 53 9 87
4 7 0 11
37 75 10 122
of cases per year
Table 5 - Sedation
Always Almost always Sometimes Never Total
Teaching hospital
District general hospital
Children's hospital
Total
4 5 8 7 24
16 20 33 18 87
5 1 2 3 11
25 26 43 28 122
< 10 10-20 >20 Total
Teaching hospital
District general hospital
Children' s hospital
Total
12 5 7 24
77 9 1 87
2 4 5 11
91 18 13 122
Teaching hospital
District general hospital
Children's hospital
Total
2 7 10 5 24
16 39 10 22 87
0 3 7 1 11
18 49 27 28 122
Table 10 - Success rate Table 6 - Antibiotic cover
Yes No Total
Teaching hospital
District general hospital
Children's hospital
Total
6 18 24
4 83 87
2 9 11
12 110 122
Table 7 - Anti-spasmodics
No Yes Total
<50% 50-70% >70% Don't know Total
T a b l e 11 - S u c c e s s r a t e v s t e c h n i q u e
Teaching hospital
District general hospital
Children's hospital
Total
22 2 24
68 19 87
11 0 11
101 21 122
Scotland. The names and addresses were obtained from the 1997 Medical Directory and all hospitals with both a radiological and paediatric department were included. In addition, the questionnaire was circulated among six consultant paediatric radiologists at our institution.
RESULTS One hundred and eighty-three (60.8%) replies were received of which 122 institutions reduced intussusceptions and 61 did not. O f the 61 departments that did not attempt intussusception reduction eight were from teaching hospitals and 53 from district general hospitals. In the teaching hospital group, six had no in-patient paediatrics, one had no paediatric surgeon and
Barium Air Water soluble contrast Ultrasound Total
< 50%
50-70%
> 70%
Don't know
Total
16 1 0
24 20 5
7 17 0
18 5 5
65 43 t0
1 18
0 49
3 27
0 28
4 122
one referred their cases to a local Paediatric hospital. In the district general hospital group, 31 had no paediatric surgeon, 15 reported no anaesthetic cover for paediatrics and seven stated there was no radiology experience. Seventeen had no in-patient paediatrics and in three the paediatricians apparently preferred to send their cases elsewhere for reduction. Fifteen respondents felt it was the radiologists' role to make the diagnosis and then refer to a more experienced unit for reduction. One response felt that radiologists should play no part in therapy, only in diagnosis. In seven cases it was remarked that they used to perform intussusception reduction until the Royal College of Anaesthetics changed their guidelines regarding paediatric anaesthetic cover for surgery. In the group performing intussusception reduction, 24
455
SURVEY OF INTUSSUSCEPTIONREDUCTIONIN ENGLAND,SCOTLAM)AND WALES Table 12 - Success rate vs n u m b e r cases per year
< 10 10-20 >20 Total
Table 14 - N u m b e r of attempts at each pressure
< 50%
50-70%
> 70%
Don't know
Total
16 1 1 18
38 10 1 49
10 7 10 27
27 0 1 28
91 18 13 122
(19.7%) replies were from teaching hospitals (TH), 87 (71.1%) from district general hospitals (DGH) and 11 (9%) from children's hospitals (CH). Sixty-five hospitals (53.3%) use barium for hydrostatic reduction (eight TH, 56 DGH, one CH), 43 (35.2%) use pneumatic reduction (15 TH, 19 DGH, nine CH), 10 (12.2%) use water-soluble enemas (one TH, nine DGH) and four (3.3%) use ultrasound (three DGH, one CH). In the latter group, three use water-soluble contrast medium and one air. In the pneumatic reduction group two centres use carbon dioxide (Table 2). The results with regard to the use of plain radiographs, ultrasound and Doppler evaluation are tabulated in Tables 3 and 4 and the results on use of sedation, antibiotics, antispasmodics and the type of catheter in Tables 5-8. With regard to the use of a balloon catheter, most places indicated that the balloon was not necessarily inflated during the procedure. Ninety-one (74.6%) hospitals (12 TH, 77 DGH, two CH) performed less than 10 procedures per year, 18 (14.7%) 10-20 per year (five TH, nine DGH, four CH) and only 13 (10.7%) greater than 20 per year (seven TH, one DGH, five CH) (Table 9). Eighteen (14.8%) centres (two TH, 16 DGH) estimated their success rate to be less than 50%, 49 (40.2%) between 50-70% (seven TH, 39 DGH, three CH) and 27 (22%) greater than 70% (10 TH, 10 DGH, seven CH). Twenty-eight (23%) hospitals (five TH, 22 DGH, and one CH) did not know their success rate of which three indicated it would be the subject of a forthcoming audit (Table 10). When comparing success rate to the technique used, of the 65 centres using barium, 16 (25%) reported a success rate of less than 50%, 24 (37%) had a 50-70% success rate, seven (11%) greater than 70% and 18 (27%) did not know. In the air reduction group (n = 43), one (2%) had a success rate less than 50%, 20 (47%) had a 50-70% success rate, 17 (40%) a success rate greater than 70% and five (11%) did not know. In those hospitals that used water-soluble enemas, five (50%) had success rates between 50-70% and five (50%) did not know. Of the four hospitals that use ultrasound one (25%) had a less
1 2 3 >3 Total
Teaching hospital
Districtgeneral hospital
Children's Total hospital
1 1 8 5 15
0 2 12 5 19
0 0 5 4 9
1 3 25 14 43
than 50% success rate and three (75%) had a rate in excess of 70% (Table 11). When comparing success rate to the number of cases performed, a less than 50% success rate was achieved in 16 centres who performed less than 10 cases per year, a 50-70% success rate in 38 centres with less than 10 per year and a greater than 70% in 10 centres. Twenty-seven centres that perform less than 10 per year did not know their success rate. In those centres that perform between 10-20 per year, one had a success rate less than 50%, 10 between 50-70% and seven greater than 70%. In the hospitals who perform more than 20 cases per year, only one had a success rate less than 50% (a DGH using barium), one between 50-70% (a children's hospital that often try to reduce intussusceptions when other referring hospitals have failed) and 10 had success rates greater than 70%. One hospital did not know their success rate, which will be the subject of an audit (Table 12). Only 14 serious complications were experienced and reported in the previous 5 years. Thirteen of these were perforations and one child developed septic shock and arrested during the procedure (DGH using water-soluble enema). Of the 13 perforations, four were in a TH, three in a DGH and six in a CH. In 12 cases, air pneumatic reduction was used and in only one (DGH) barium was used. The techniques of pneumatic reduction were compared in the 43 centres that used this method. No pressure measurement is used in six hospitals (all DGH). A maximum pressure of 80mmHg is used in seven hospitals (five DGH, two CH), 100 mmHg in seven hospitals (two TH, four DGH, one CH) and 120mmHg in 23 hospitals (13 TH, four DGH, six CH). No hospital uses more than 120mmHg (Table 13). One hospital uses only one attempt at each pressure (TH), three use two attempts (one TH, two DGH), 25 use three attempts (eight TH, 12 DGH, five CH) and 14 (five TH, five DGH, four CH) use more than three attempts at each pressure (Table 14). The time at each attempt is also variable. Three (one TH, one DGH, one
Table 13 - M a x i m u m pressure ( m m Hg) Table 15 - Time at each attempt
Teaching hospital No pressure measured 80 100 120 Total
Districtgeneral hospital
Children's hospital
Total
0
6
0
6
0 2 13 15
5 4 4 19
2 l 6 9
7 7 23 43
1rain 2rain 3 rain > 3 rnin Total
Teaching hospital
Districtgeneral hospital
Children's Total hospital
1 3 8 3 15
1 4 11 3 19
1 1 5 2 9
3 8 24 8 43
456
CLINICAL RADIOLOGY
CH) apply pressure for only I rain, eight for 2 min (three TH, four DGH, one CH), 24 for 3 min (eight TH, 11 DGH, five CH) and eight for longer than 3 min (three TH, three DGH, two CH) (Table 15). The device used wasmade at the insitution in 36 places (12 TH, 16 DGH, eight CH) and purchased (three TH, three DGH, one CH) either from the nearest children's hospital or from the institution in which the radiologist trained. The above results did not include our own institution. At the Great Ormond Street Hospital for Children, London, six paediatric consultant radiologists were surveyed. All use the same locally made air device. Five routinely perform plain radiographs and one does not. Three use ultrasound and three do not. Of the three who perform ultrasound only two use Doppler. Sedation is never used by five and only occasionally used by one. Antibiotics are only used by one radiologist, who also works on another site. None of the six use anti-spasmodics. Standard rectal catheters are used by three, paediatric feeding tubes by two and a balloon catheter by one radiologist. Five radiologists perform between 10-20 cases per year and one, who covers paediatric radiology at another London hospital, greater than 20 cases. The success rate among four is greater than 70%, one 50-70% and one does not know. In the technique of air reduction five use a maximum pressure of 120mmHg and one 100mmHg. One radiologist only uses a single attempt at each pressure, one has two attempts, three have three attempts and one has more than three attempts. The time duration for each attempt also varies with one using only 1 rain, one 2 min and four use 3 rain.
DISCUSSION
This study confirms that there is a wide variation in the techniques of radiological reduction of intussusception within the U.K. Air reduction techniques are predominantly used in Children's and Teaching Hospitals, while barium is still the main method preferred in the District General Hospital. Many DGH stated that they would like to switch to pneumatic reduction. The number of cases in their institutions are so small, however, the radiologists believed they would not gain sufficient experience and justifiably prefered to stick to a method with which they were familiar. In addition, many cases occurred out of hours and the radiologists felt that these times were not suitable for experimenting with new techniques. Although the younger radiologists in these departments were generally familiar with pneumatic reduction, most departments preferred, however, to have a uniform protocol for reduction. In a previous smaller U.K. study of 76 hospitals a similar trend was observed with paediatric radiologists preferring a pneumatic method of reduction and general radiologists still using barium [4]. In a study from the United States of 58 centres (published in 1992 but probably reflecting practice in 1991) more than one method was used in 90% of centres with changing trends depending on the duty radiologists' experience [5]. Barium was used in 97% of centres, water-soluble contrast in 83% and air in 50% [5]. In high risk cases water-soluble contrast medium was the preferred method in 71% [5]. In a recent review it is suggested that more centres in America are converting to air reduction techniques and those centres that
still doubt the efficacy of air have little or no experience with the technique [6]. Although there have been no randomized trial comparing the two methods, air reduction is generally regarded as easier, quicker, and cleaner, with a lower radiation dose than barium [4-8]. There have, however, been conflicting reports with regard to irradiation during fluoroscopic reduction and in one study the assumption of a lower radiation dose was not confirmed using a dose area product meter to measure effective dose [9]. More recently reports are appearing of high success rates using ultrasound-guided reduction with either saline or water [10-12]. This method is particularly popular in the Far East where intussusception is common and the leading cause of an acute abdomen in young children. A reduction in radiation is cited as the major benefit in addition to high success rates, possible lower recurrence rates and the benefit of clearly observing the patients' clinical condition throughout the procedure possibly due to easier access to the patient in an ultrasound room. Only four centres in our study reported using ultrasound-guided reduction. Abdominal radiographs have been shown to have a role in ruling out other diagnoses and not in the diagnosis of intussusception [2,21]. Daneman and Alton could find no cases of free air or perforation before attempted reduction [2]. We would question, therefore, the routine use of plain abdominal radiographs in children in whom the diagnosis of intussusception is likely. The plain radiograph should be reserved for doubtful cases or where there is concern with regard to peritonism or marked small bowel obstruction. Ultrasound is used as an aid to diagnosis in only 59% of our hospitals. The radiologists who use ultrasound as a diagnostic tool remarked on its high sensitivity and this has been confirmed in a number of studies [13,14,21]. We have found a similar experience in our practice. Daneman and Alton suggest that the current state-of-the-art management of intussusception should be sonography for diagnosis and air for reduction [2]. One limitation with sonography, however, that should be borne in mind is that false-positive diagnoses of intussusception from bowel wall thickening due to lymphoma or Crohn's disease are possible. On Doppler examination, if there is lack of colour flow within the tip of the intussusceptum it has been suggested that it indicates a reduced chance of successful reduction, this finding, however, should not prevent a reduction attempt [21]. The use of sedation varies considerably in our study. The policy of utilizing sedation often appears to be determined by the local paediatricians or surgeons rather than by the radiologists, which is not ideal. In the North American study only 3% always sedated patients compared with our 21% [5]. Seven percent always used sedation compared with our 21% [5]. Sedation was sometimes used in 45% and never used in 45% of their group compared with 35% and 23% in our group, respectively. Touloukian [15] found a 35% higher reduction rate in sedated patients in his study. It is generally felt, however, that sedation is best avoided as it serves primarily to quieten the patient but does not afford pain relief, and can mask the signs of shock or hypotension. In addition, the Valsalva manoeuvre is thought to be protective against perforation during air but not hydrostatic enemas [6,16]. By reducing the ability to mount a Valsalva manouevre sedating children may actually increase the perforation rate with pneumatic
SURVEY OF INTUSSUSCEPTION REDUCTION IN ENGLAND, SCOTLAND AND WALES
reduction. We feel sedation alone is not justified. There is some justification for analgesic use but this should be determined by local paediatric practice. Antibiotic cover was given in only 9.8% of our group compared with 16% of the North American study [5]. Antibiotic prophylaxis is frequently given depending on the attitude of the surgeon or paediatrician. In a study by Somekh et al. the risk of bacteraemia following air enema reduction was shown to be very low [17]. The rationale for giving antibiotics is mainly to protect the patient if a perforation occurs although there is little evidence to support the use of antibiotics in the vast majority of cases. Anti-spasmodics were used in 17% of our cases compared with 10% in the North American group [5]. Some authors have suggested that anti-spasmodics may be of some use if previous attempts at reduction have failed [18]. Interestingly it is not used in any of our Children's hospitals. Franken et al. [19] found that glucagon was not efficacious in the hydrostatic reduction of intussusception in a double-blind study of 30 patients and we believe there is little justification for its continued use. A wide variation in the catheter used was noted and it largely depended on personal preference. Most respondents (61%) employ a balloon catheter, only inflating the balloon in cases of a poor seal which was reported to be uncommon. The use of a balloon catheter in the rectum engenders much controversy particularly in adult radiology practice and while many centres worldwide are happy to use a balloon catheter in reducing childhood intussusceptions, others prefer to achieve a rectal seal with taping and/or a rubber disc [20,21]. We could find no proof that balloon catheters with the balloon inflated increase the perforation rate in children during an attempted intussusception reduction. The success rate for radiological reduction appeared higher in those units performing more cases confirming that experience with a particular technique increases the success rate. The success rate in most CHs are higher than in DGHs, although in one CH they remark that their success rate may be lower as they often try to reduce patients that are clinically stable and have had a failed attempt at a referring hospital. The overall success rate is higher in those hospitals using air reduction but this may reflect both the greater experience in hospitals using air, more cases per annum or a better overall technique. Many centres having switched to pneumatic reduction of intussusception are reporting higher success rates than they previously had with hydrostatic reduction [22]. There is a wide variation between different centres performing air reductions with regard to the maximum pressure used, number of attempts at each pressure and the time allowed at each attempt. The classical teaching of three attempts for 3 rain (at three pressures to a maximum of 120mmHg) does not universally apply. In six DGH departments the machine used does not measure the pressure given and not surprisingly their success rates are low. This lack of pressure monitoring is far from ideal and may not be defensible from a medico-legal viewpoint [23]. To our knowledge, however, no machine is yet commercially manufactured in Europe for intussusception reduction; most units have a locally assembled device. The American College of Radiology has recently issued a new standard relating to intussusception reduction which states that
457
if a radiologist elects to use air, carbon dioxide or oxygen as a medium for reduction, a manometer must be used to ensure that pressures do not exceed 120 mmItg [23]. This seems sensible but no such consensus nor standardization exists in this country. There is a need for a safe device with a pressure release valve and accurate pressure monitoring to be widely available. The success rates appear better in those hospitals that use a maximum pressure of 120 mmHg for 3 rain than those who use lower pressures. We acknowledge the limitations of a retrospective postal survey in that frequently the questionnaire was answered by one individual on behalf of the whole department and so it cannot be entirely representative of all radiologists. In England and Wales acute intussusception has an incidence of 1-2/1000 live births and accounts for around 700 hospital admissions each year [24]. Although our reported figures are not entirely comprehensive, the complication rates appear low with only 13 perforations recorded in 5 years. 12 of these cases were when using air reduction and only one with barium confirming a general impression that pneumatic reductions lead to more perforations [25]. In another case in which the child developed septic shock and suffered a cardiac arrest, the radiologist felt that there might have been a missed perforation prior to the attempted reduction. It is impossible to determine accurately the perforation and success rates when the total number of attempted reductions is not known. It may be that those centres with higher perforation rates try harder, thus having a better overall reduction rate whilst accepting a higher perforation rate [21]. When reviewing the practices within our own institution we found a variation in the techniques of air reduction by our six paediatric radiologists confirming the difficulties in obtaining uniform management of these cases. Although a few centres report success rates approaching 90%, we believe successfully reducing greater than 70% of intussusceptions encountered is a realistic standard that should be achievable in all institutions. A worrying finding in our study was that 18 centres (16 using barium reduction), who undertake less than 10 reductions per year, reported a success rate of less than 50%. It is difficult to know the nature of the information given to the parents in these cases when seeking consent to the attempted reduction. In addition, 28 (18 using barium, five air, five water-soluble) centres did not know their success rates. Although up to 75% of centres perform less than 10 reductions per annum which may be divided between a number of colleagues further diluting experience, we believe it is mandatory that these departments perform self-audit as a matter of urgency and if the figures are poor, then some re-training or transfer of all cases of intussusception to larger or more experienced units should be considered. It is noteworthy that seven departments reported they no longer attempt reduction as a result of the recommendations by the Royal College of Anaesthetists with regard to adequate local paediatric anaesthetic cover. Although we have not addressed this in our survey, we suspect there are a few radiologists bravely performing intussusception reduction without local surgical back-up which in the event of an iatrogenic perforation is also of some concern. In the successful management of intussusception radiologically, teamwork between the radiologist, paediatricians, surgeons and nursing staff is essential in providing the optimal environment for a
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CLL~CAL RADIOLOGY
successful attempt at radiological reduction. This includes adequate clinical assessment, resuscitation and explanation to parents. O f particular importance is adequate fluid replacement as inadequate fluid replacement has been implicated as a major factor in 20% of deaths. In conclusion, this is the largest survey of the U.K. practice of experience in the management of intussusception confirming that there is still wide variation in the technique of radiological reduction of intussusception between different centres and to a lesser degree within one institution. Neither the Royal College of Radiologists nor the British Paediatric Radiology and Imaging Group has issued any formal guidelines with regard to intussusception reduction and this should probably be rectified. The technique used depends on the radiologists' experience and in many centres the low number of cases per year make them reluctant to try a new technique. Pneumatic reduction seems to be growing in popularity but we should stress that a properly performed hydrostatic reduction is a perfectly satisfactory alternative [25]. The overall success rate depends largely on the number of examinations performed per year rather than on a specific technique. The complication rate for these procedures appears low, although all centres performing pneumatic reduction should do so with intraluminal pressure monitoring. Ultrasound has been shown to have a high sensitivity and specificity in the diagnosis of intussusception and should be more widely utilized in doubtful cases. The newest technique of water/saline reduction under ultrasound control still requires evaluation, as the number of centres employing this technique is low. Sedation and antispasmodics are best avoided. There is little evidence to support the routine use of antibiotics.
Acknowledgements. The authors would like to thank all those radiologists who took time to complete their questionnaire.
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