Maxillofacial injuries in multiply injured patients

I

Maxillofacial

I

injuries in multiply injured patients

H. Cannell, A. Paterson, R. Loukota Depurtment

qf Orul

and

Mrr.uihfircial

Surgrq:

Rood London Hospital, UK

SUMMAR Y. Experience in team management of multiply injured patients with maxillofacial injuries is reported. During 1992, out of 169 patients transferred to the Royal London Hospital, UK by the Helicopter Emergency Medical Service 38 (22.4%) had injuries to the maxillofacial region, 17 of whom were scored on the Abbreviated Injury Scale (AIS) as having sustained facial AIS > 2. The median Injury Severity Score (ISS) was 22, while the ISS was 17.7 for survivors and 34.5 for those who died v=7.3, 0.05~ P>O.O2). Facial AIS (median 4) and facial AIS contribution to ISS were found to be poor indicators of severity of injury. Revised Trauma Score (RTS) and percentage probability of survival (P,%) were found to be useful discriminators of severity of overall injuries. RTS compared between survivors and those who died was 0.05

0.02 @), while P,% was 0.01~ P> 0.001 v). It was concluded that the severity of maxillofacial injuries, and hence their contribution to total injury assessments, tended to be underscored. We propose that refined facial injury assessment methods be tested.

INTRODUCTION

called at the resuscitation phase but usually attended for secondary survey or at computerized tomography (CT) scanning. Our previously described protocol for control of posteriorly displayed airway and for arrest of maxillofacial haemorrhage2 was carried out in some cases by staff of the Accident and Emergency Department and then consolidated by maxillofacial staff. The cervical collar was removed only after neck injury was excluded by radiographic views of the cervical spine and thorough examination by an experienced surgeon.

A retrospective survey was carried out of multiply injured patients with maxillofacial injuries brought in 1992 to the Royal London Hospital (RLH) by the Helicopter Emergency Medical Service (HEMS). This paper describes management and early outcome in a group of 38 patients with maxillofacial injuries admitted by HEMS. HEMS was called out on 973 occasions and these flights resulted in 169 patients being triaged and brought back to RLH, mainly for management of multiple injuries, including to the head. face and chest. Of the 169 patients, 38 (22.4%) had maxillofacial injuries but only half of these had facial injuries of sufficient severity for the immediate call out of our on duty team.

MATERIALS

Coding of injuries Injuries were categorized using the Abbreviated Injury Scale (AIS),” which allows scoring of injury severity in the range 1 (minor) to 6 (fatal). Calculation of the Injury Severity Score ( 1SS)4 was carried out in the normal way by addition of the sum of the squares of the AIS for the three most severely injured body regions. The AIS scores for the maxillofacial area as detailed in AIS 90” ranged from 1 to 4, where 1 described a closed fracture of the mandible, 2 a closed fracture of the zygoma or maxilla or a compound mandibular fracture and 3 a Le Fort III level fracture. Only if 20% or more of the total circulating blood volume is lost in addition can a score of 4 apply. The Revised Trauma Score (RTS)’ was calculated at accident scenes from age-weighted values, GCS, systolic blood pressure and respiratory rate. Percentage probability of survival (P,‘%) was calculated according to US data2. It appears that UK figures for P, differ markedly from US figures. The differences in the values for P, were non-linear. US values were used throughout.

AND METHODS

A doctor trained in anaesthesia and Advanced Trauma Life Support (ATLS)’ was taken by HEMS to accident scenes. Thus, early records of physiological measurements such as blood pressure, respiration rate and Glasgow Coma Scale (GCS) were available for later comparison. Stabilization of patients before transfer by HEMS was by control of airway, control of haemorrhage and restoration of circulating volume. Cervical collars were placed on all patients at accident scenes and were not removed until neck injury could be excluded. The multiply injured patients were received at the resuscitation room at RLH by a trauma team led by an ATLS-trained senior surgeon’. Unlike the first 16 months of HEMS, maxillofacial staff were not always 303

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1 - Survivors and deaths with causes of injuries: (n = 38) facial abbreviated injury score (AIS) and total injury severity score (KS) in relation to Revised Trauma Score (RTS) and probability of survival (P.%). There were significant differences between values for RTS and P,% between cohorts of survivors and those who died (x2)

Table

Age

Sex

16

M F F F M M M F M M M M M M M M M F M M F M M F M M M F

34

13 60 44 35 22 9

14 45 59 43 27 54 34 42 39 26 21

11 18 59 30 36

18 32 40 30

AIS Face

ISS total

RTS

P, %

4

17

5.91

II

4 4

17 22

1 1

10 10

4

99 94 93 99 99 71

4

8 34 2 24

1.84 5.91 6.9 7.84 6.9 5.03

1

11

4 4

29 33 5 5

16 1

1 1 1 9

1 9

1 1 1 4

1 1 4 4

1 4

-1

9 5 9 38 43

16 99 51 53 99 99

10 97 99

-1

-1 4.45 3.36 7.84 7.84 7.84 7.84 2.93 4.74 7.84 7.84

10 22

1 26 24 36 5 22

Fall RTA RTA RTA HIT RTA Suicide attempt RTA RTA Homicide Fall Suicide attempt RTA RTA HIT Assault Fall RTA RTA RTA RTA RTA RTA RTA RTA RTA Fall Suicide attempt

-1 4.45 7.84 5.91 4.09 7.84 7.84 0.58 5.97 7.84

19

Cause

52 21 99 93 99 98 42 62 99 99

Deaths 92 66 45

10 82 29 40

16 60 77

F M M F M F M M F M

4

1 1 4 4

1 1 4 4 4

-1

21 30 27 29 27 24 50 33 45 59

The timing of emergency or urgent operations was recorded, as were decisions affecting management. In general, decisions regarding the priorities of treatment were made after consensus had been reached among the various surgical disciplines involved. Occasionally, treatment priorities had to be changed in response to fresh haemorrhage or loss of control of the airway.

RESULTS Biases within the sample

The survey was retrospective and of an unpaired cohort. Although x2 statistical tests were applied the results may not correctly represent the relationship between parameters measured.‘j Confounding errors may have affected results of observed data. Such errors were ignored, as the majority of observational reports of injuries in the medical literature suffer from the same disadvantage.

-1 5.97 3.87 3.57 4.09 3.36

RTA RTA Fall Hit Suicide RTA RTA RTA RTA RTA

56 59 28 21 52

-1

-1 5.39 5.03 5.39

79 14 7

Patients

Thirty-eight patients with maxillofacial injuries who had been transported by HEMS were managed during 1992 (Table 1). The median ISS was 22 (range l-59). Twenty-eight patients survived and 10 died (Table 2). One patient with an ISS of 43 survived a helicopter crash and three other survivors had ISS>30. Median P, was 71%, and for 16 out of 38 patients it was >90%. Survivors had a median P, of 97% and those who died had a median P, of 21%. Most of the deaths occurred at the resuscitation phase or soon Table 2-Total injury severity score (ISS) as an expression of severity of injury-survivors and those who died (n = 38)

Total ISS

>l

Total Survivors Those who died

> 16

>19

37 28

25 15

22 12

10 5

4

10

10

10

5

3

m=13.28+10.93, v=119.6, median=22. No significance between values (x2).

>29

b-39

1

Maxillofacial Table 3 - Facial injury severity score (KS) severity of injurysurvivors and those who Facial

as an expression died (n = 38)

of

ISS

1

4

9

16

Total Survivors Those who

18 14 4

17 11 6

2 2

1 1

died

m=3.16+2.98, No significance

v=8.89, between

Table 4 - Maxillofacial treatments

median=4. values (~2). injuries

Injury Diagnostic peritoneal Abdominal operation Laparotomy Thoracic Chest drain Thoracotomy Neurosurgical ICP Haematoma Other

(n = 38)

and

other

injuries

or

II lavage

14 14 8 7 6 1 9 4 5 2

after admission (l-2 h after initial stabilization); one patient died 24 h after admission. In 13 cases the maxillofacial team was asked to attend the resuscitation phase to assist with diagnoses at secondary survey and to help establish priorities in surgical management. Twenty two of the 38 cases had previously been intubated at accident scenes by the HEMS medical team’ were intubated at resuscitation after a fall in their GCS. Fractures to the maxillofacial region were found in 20 of 38 cases and soft tissue injuries in the remainder. Twelve patients had injuries classified as less than severe (ISS < 16) but had been triaged by the HEMS team to RLH. In each case the potential for life-threatening injury was present, for example because of entrapment at RTA scenes, falls of over 3.66 m or alleged severe assault. Combined head and face injuries with ISS > 2 for each region were present in about 50% of cases. Table 3 shows facial ISS. Abdominal interventions for diagnosis (diagnostic peritoneal lavage) or for treatment of abdominal haemorrhage (laparotomy) were necessary in 14 of the cases with maxillofacial injuries. The commonest injury (n = 15) associated with maxillofacial trauma was fracture(s) of long bones. Other associations of multiple injuries are noted in Table 4. Emergency Operations While most patients with crania-maxillofacial injuries (n=38) underwent planned operations with the least possible delay, in six patients emergency surgery to the maxillofacial area was undertaken as part of a multidisciplinary intervention. Two patients suffered continued life-threatening haemorrhage, four had grossly displaced mandibular fragments and all six patients had tracheostomies to complete airway stabilization prior to ventilation.

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In one multiply injured patient, a significant orofacial haemorrhage recurred during the operation. despite appropriate and successful first-aid measures at admission. Copious oral and nasal bleeding recommenced, possibly caused by coagulation consumption problems. Multiple transfusions had been necessary during repair of a lacerated liver and of a fixation of a fractured left humerus, which had led to an absent pulse at the wrist. The facial bleeding became sufficiently alarming for the surgical priorities to change. Further stabilization of a displaced mandibular fracture was undertaken together with intraoral repair of lacerations and tracheostomy. Reduction and fixation of the next most urgent priority-the bilateral fractured femurs-was then continued by orthopaedic surgical colleagues. The requirement for a patientmanagement team leader, usually a general surgeon. was always apparent. The AIS system did not include a score correctly indicative in these cases of a compromised airway caused by a displaced maxilla, a cornminuted mandible or a multiply lacerated oral cavity. DISCUSSION The HEMS Aerospatiale Dauphin SH 365H helicopter was equipped with portable monitoring and intensive care apparatus. It transported an anaesthetist trained in emergency life support and a paramedic to serious accident scenes within a radius of 50 nautical miles from RLH.7 This enabled the two medical staff to achieve stabilization of the airway, the cervical spine and the circulating volume in severely injured patients (until more formal treatment could begin at RLH). There were fewer patients (12.4%) with significant to severe maxillofacial injuries in 1992, compared with the 18% treated in the first 16 months of HEMS at RLH’. The total percentage of maxillofacial injuries managed was 22.4”/0. The low figure for significant crania-maxillofacial injuries was thought to be due to changes in call-out skills for HEMS at London Ambulance Services (LAS) Headquarters. During the autumn of 1992, a computer system was made responsible for each of the 2200 calls per day received at LAS. Unfortunately, the system for the disposal of the calls was found to be less efficient than the older manual system. The level of inappropriate call-outs for HEMS rose and when the computer system had to be abandoned it took some time before manually controlled call-out skills became re-established. Coding of injuries Objective criteria for the measurement of injury are used in codified form as indices of severity with the purpose of encouraging comparison of outcome between accident centres. Most systems in current use have disadvantages and most fail to allow proper comparisons on both practical and intellectual grounds. Further examples of the limitations of the

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systems commonly in use for maxillofacial injuries and in the multiply injured patients are described below. The AIS is used to award scores from 1 to 5 for each injury found, where 1 is minor and 5 major. Although useful in a majority of cases, the AIS does have anomalies: 1. Lacerations to the facial area may be coded as minor (superficial), where AIS = 1, or major if the laceration is greater than 10 cm or if fullthickness avulsion is greater than 25 cm2 but blood loss less than 20% by volume equals AIS of 2. A score of 3 is awarded for blood loss greater than 20%. 2. Different anatomical areas score differently for the same apparent degree of injury. 3. Two or more injuries to the same anatomical area, one possibly very severe, are counted as one score. One case particularly illustrated the erratic nature of the AIS scoring system for maxillofacial injuries. The patient, aged 9 years, had been hit by falling glass from a window 9.9 m above. There were three lacerations in the maxillofacial area, scalp and neck greater than 10 cm, and several others of almost that size. The difficulty with the AIS coding for these areas was that it was impossible to ascribe blood loss as being more from one extensive laceration, for example the one on the scalp than any other laceration of the whole area. It was apparent that considerable blood loss had accompanied a severed jugular vein. Equally evident was the rich arterial supply to the scalp. In the same case, AIS allowed for a tongue laceration described as deep or intensive and suggested a score of 2. The entire root of the patient’s tongue and larynx had been severed, thus confirming that this injury was not described by the ordinal rather than interval AIS Even if the facial AIS had been squared it was not necessarily incorporated into a total ISS. Thus the ISS also seemed an unsatisfactory measure of injuries for the purposes of comparison. In our view both AIS and ISS as descriptors of facial injury should be abandoned. Other techniques for describing anatomical injury such as anatomical profile (AP)8, have been suggested. The purpose of an accurate description is in some way to assist management or measurement, for example measurement by statistical analysis of outcome of morbidity, mortality or even of costs. Therefore, accuracy of description of an injury or of an intervention forms the data upon which all the forecasting calculations are then based. Considerable unease concerning the validity of current injuryscoring systems has been expressed by Rutledge et al., who commented that their simplified system of grading of trauma improved accuracy of forecasts in terms of sensitivity, specificity, false positives and false negatives. Their system used the International Classification of Disease Ninth Revision, which is the main code agreed for use within National Health Service Trusts, pending assessment of Read Codes”.

Physiological parameters as a response to injury provide the basis for the calculation of probability of survival. P,% was used to forecast morbidity and mortality in the present report and in our earlier paper2 and was also suggested in the survey of injury severity measurements by Ali and Shepherd.” The RTS is another physiologically derived figure. It is calculated from the GCS, which has a span of 3-15, the respiratory rate and the systolic blood pressure. However, each of these three physiological parameters is banded in one of four categories and therefore becomes restricted in sensitivity. The final RTS is achieved by multiplying the measured parameters by certain weighted numbers, which were derived from previous experience of trauma cases in the USA. Examples of commonly occurring RTSs in the patients with maxillofacial injuries (Table 1) were: l

l

l

7.84: this was a normal physiological measurement 6.90: this usually meant that the respiratory rate and blood pressure were normal but there was likely to have been a GCS of between 11 and 13 5.97: respiratory rate and blood pressure were normal but GCS decreased to between 9 and 11.

The sensitivity of RTS as a predictor of final outcome suffered not only from the limitations imposed by insensitive banding, but also by changes in physiological parameters following rapid resuscitation at accident scenes. The most important limitation noted was that the GCS became meaningless if the patient had to be intubated and anaesthetized. In the present series, a GCS of 8 or less (if correct) at the accident scene usually led to an oroendotracheal intubation by the HEMS doctor. It was our experience that intubated patients were the more seriously injured cases. Most also had a high ISS. Their survival depended upon rapid and precise resuscitation and treatment. In the current series, seven patients who had been intubated at accident scenes survived but 10 others died. The Trauma Score and Injury Severity Score (TRISS)' is used to calculate P, and hence measure and compare outcome. Unfortunately, the RTS ‘counts’ any loss of consciousness in that score as part of the GCS, which is in turn part of the RTS. Therefore, in the absence of proven imaging evidence or of pathological evidence of head injury (e.g. nuclear magnetic resonance imaging or CT scans, fractures on plain films or nasal cerebrospinal fluid leak, etc.) a small brain injury may be entirely excluded from the coding and the TRISS score. The methodology of TRISS does not allow for a calculation or a numerical weight to be awarded for suspected injuries or as a result of such comments in the notes as ‘suspicious of’, ‘consistent with’ or ‘developing’. Thus, the rigorous definitions within TRISS and within most other injury assessment codes may not be fully descriptive from a clinician’s viewpoint and may lead to underscoring. The resultant forecast is thus an underestimate of the risk to life from the various injuries. Only large numbers of patients compared by

Maxillofacial

various injury-scoring systems under conditions applying within the UK will allow their proper evaluation. The Major Trauma Outcome Study (MTOS) in the UK” is designed to achieve this. Figures for MTOS (USA) have different regression analysis coefficients from those obtained for MTOS in the UK, possibly because of inclusion of patients with penetrating rather than solely blunt trauma. Some parameters of injury, including outcome and costs, were measured by Nicholl et al., whose study undertook to use identical criteria to compare cohorts of patients transported from accident scenes by land ambulance with those transported by HEMS. Emergency interventions at the resuscitation phase Emergency interventions in the maxillofacial area were for confirmation of airway control and for arrest of haemorrhage. The accident and emergency general trauma teams had previously been trained by our department in the selective use of intra-oral rubber props and nasal Epistats*. In most cases their use of these aids for airway and haemorrhage control was good. In one case a fractured displaced maxilla was not at first recognized. Bleeding from the nose, despite Epistats, continued as a brisk ooze caused by the downward pressure destabilizing the fracture. The maxillofacial duty team were able to correct the situation by deflating the Epistats, propping the maxilla in the correct position and then reflating the Epistats. In two other cases, the correct use of props and Epistats by medical staff successfully controlled a compromised upper airway and haemorrhage from the nasal area. Operations carried out immediately on admission Hospital policy was first to stabilize and then, where possible, to achieve immediate reduction and fixation of fractures and to repair injuries to soft tissue. Concurrent or sequential multidisciplinary operations often took place after treatment priorities had been agreed. Gross or increased swelling sometimes prevented such an intervention in the maxillofacial region, particularly around the orbit. Intracranial bleeding and swelling of the brain constituted neurosurgical emergenciesI and were a major factor in achieving consensus of treatment priorities. Outcome following head injuries was not studied separately but it was noted that many interventions took place within 1 hour of admission. Several cases served to illustrate the use of definitive early stabilization of fractured facial bones by long plates of 10 holes or more for fixation. The plates were used across heavily cornminuted main fracture areas in buttress bones, principally at the mandible. Their use reduced operating time at later operation and often enabled intermaxillary fixation to be avoided in critically injured patients.

* Epistat. Xomed-Treace, Florida 32216. USA.

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Jacksonville,

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CONCLUSIONS We conclude that profuse bleeding from the maxillofacial region from blunt injuries is a recurring problem, because the haemorrhage could initially be life threatening and also because haemorrhage could recur at operation after changes in coagulation factor consumption. Early intervention to stabilize grossly displaced or comminuted facial bone fragments did have the positive benefit of producing easier management of convalescent patients and avoided temporary or permanent facial deformity. To allow such emergency interventions, trained staff should be readily available to participate in multidisciplinary decisions and operations. Comparison of patient management and outcome between major trauma centres depends upon accurate injury description, disclosure of that information and agreed protocols for management.‘” We conclude that most techniques for description of maxillofacial injury and for forecast of outcome of multiply injured patients were flawed. Our current studies are aimed at description of anatomical and physiological disturbance and hence proper adjudication of the severity of a maxillofacial injury, within a total injury assessment. The relationship between timing of neurosurgical and timing of maxillofacial interventions in severely injured patients is also under current study.

References I. American College of Surgeons, Committee on Trauma. Chicago, Illinois: Advanced Trauma Life Support Care Course, 1989. 2. Cannel1 H, Silvester KC, O’Regan MB. Early management ol multiply injured patients with maxillofacial injuries transferred to hospital by helicopter. Br J Oral Maxillofac Surg 1993; 31: 207-212. Abbreviated Injury Scale Booklet (AIS 90) revision. Des Plaines. Illinois. Association for the Advancement 01 Automotive Medicine, 1990. Baker SP, O’Neill B. The injury severity score: an update. J Trauma 1976; 16: 882-885. Boyd CR, Tolson MA. Copes WS. Evaluating trauma care: The TRISS Method. J Trauma 1987: 27: 370-378. Brennan P. Croft P. Interpreting the results of observational research: chance is not such a fine thing B M J 1994: 309: 727-730. Hospital Daily Express I. Rock A. In: The Royal London Helicopter Emergency Medical Service. R. Earlam ted.). Bishops Stortford. Herts. UK: Saldatore 1990; 8. sc Copes WS. Champion HR, Sacco WJ et rrl. Progress in characterising anatomic injury. J Trauma 1990; 30: 1200~1207. S. Baker C, Oller D. Injury severit) 9. Rutledge R, Fakhry II simplified technique based grading in trauma patients upon ICD-Y coding: J Trauma 1993; 35: 497?507. IO. Read Codes and the teams projects: a brief guide. Pub. Information Management Group. NHS Executive, Feb. 1905. of injury severity. BI II. Ali T, Shepherd JP. The mcasuremcnt J Oral Maxillofac Surg 1994; 3: 13 18. 12. Major Trauma Outcome Study ( UK ) 1995. Personal Communication. Professor D. Yates. 13. Nicholl JP. Brazier JE, Snooks HA. Lees-Mlatqa S. Costs and health benefits of the London Helicopter Emergency Medical Service, Part II Report to the D.O.H. 1994. 14 Howard JM. Trauma -the disease that was neglected. Progress: past and that to be. JR Coil Surg Edlnb 1994: 39: 335 343.

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15. Sakellariou A, McDonald PJ, Lane RHS. The trauma team concept and its implementation in a district general hospital. Ann R Co11 Surg Engl 1995; II: 45-52.

R. Loukota, FRCS, FDSRCS Consultant Leeds Dental Hospital

The Authors

Correspondence and requests for offprints to Mr Hugh Cannell, MD FDSRCS, Department of Oral and Maxillofacial Surgery, The Royal London Hospital, Whitechapel, London El 1BB.

Hugh Cannell, MD, FDSRCS Consultant and Reader Royal London Hospital A. Paterson, FRCS, FDSRCS Consultant Carlisle Hospital

Paper received 20 December 1994 Accepted 14 March 1995