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Home oxygen therapy following neonatal intensive care
Early Human Development, 26 (1991) 29-35 Elsevier Scientific Publishers Ireland Ltd.
29
EHD 01150
Home oxygen therapy following neonatal intensive care A. Greenough, Department of Child Health. (Received
15 August
M.F. Hird and H.R. Gamsu King‘.s College Hospitul. London SE5 YRS ( U.K.)
1990; revision
received
I2 April
1991; accepted
I7 April
1991)
Summary
In a 12-month period 28 of 164 consecutive very low birthweight (VLBW) infants receiving intensive care within 48 h of birth at King’s College Hospital developed chronic lung disease, (oxygen dependence beyond 28 days of age). Fifteen of the 28 infants were eligible for home oxygen therapy, but this was only practical, because of home circumstances, in 8 infants (4.9%). These 8 infants received home oxygen therapy. One further infant, born at term and suffering from pulmonary hypoplasia was also discharged home on oxygen therapy. Two infants subsequently required readmission due to a deterioration in their respiratory status and died. Three others required re-admissions (total duration 32 days) for respiratory problems. The median duration of home oxygen therapy was 17 weeks (range ““86 days). We conclude that home oxygen therapy is needed by only a very small number of preterm infants and is appropriate for only a proportion of them. Parents need to be counselled carefully regarding the possibility that the need for oxygen might be protracted. chronic lung disease; prematurity;
oxygen
Introduction
Prolonged hospital admission in those infants suffering from chronic lung disease who require continuous oxygen therapy may be avoided by oxygen administration at home [7]. Earlier discharge from neonatal intensive care is likely to result in improved parent-child relationships [4] and is certainly less costly [2,7]. It has been Correspondence IO: Dr Anne Greenough. 9RS. U.K.
Dept of Child Health,
0378-378219163.50 0 1991 Elsevier Scientific Published and Printed in Ireland
Publishers
Ireland
King’s College
Ltd.
Hospital,
London
SE5
30
reported that home oxygen therapy is generally required for a median period of 3 months [7]. We have recently begun to use home oxygen routinely for infants with chronic lung disease. We had learned that some infants required home oxygen for longer than 3 months and considered that this prolonged duration of therapy might have implications for the family by causing additional work and anxiety. In addition, the increasing survival of very preterm infants [3] and a reported incidence of chronic lung disease (CLD) of 40% in one series [5] implied that large numbers of infants might be eligible for home management. Such numbers when taken together with a protracted course of oxygen therapy could overstretch already limited community resources. We have therefore reviewed the outcome of VLBW infants admitted to this regional neonatal intensive care unit (NICU) at King’s College Hospital (KCH) over a l-year period when home oxygen therapy was routinely available. Our aim was to determine the proportion of infants for whom home oxygen therapy would be applicable and practical, the duration of such therapy, and if adequate supervision could be provided by existing hospital personnel. Methods and Patients Consecutive VLBW infants were reviewed prospectively. They were all inborn or required intensive care at KCH within 48 h of birth. Infants were defined as having chronic lung disease if they continued to require added oxygen or other respiratory support after 28 days of age and in addition had an abnormal chest radiograph [5]. Infants were considered eligible for home oxygen therapy if: (1) the infants were feeding well by mouth and they were steadily gaining weight (2) the infants required more than 25% inspired oxygen to maintain an arterial oxygen tension (PAoz) of 2 55 mmHg (3) the mother was supported during the programme, agreeable to it and capable of carrying it out (4) the infants lived within travelling distance of KCH and so could be supervised by the KCH team. The infants all received oxygen via dual nasal cannulae (De Vilbiss Health Care, Feltham, U.K.). Oxygen was administered via extension tubing from a concentrator (De Vilbiss Health Care) which was equipped with a regulator and flow meter (SLE, Croydon, U.K.) capable of delivering oxygen of a low flow (0.01-l l/min). The equipment a.nd system of oxygen delivery was carefully explained to the parents and the same system installed in the home. At home the parents also had oxygen cylinders both for use in an emergency if the concentrator failed (Size F, obtained on prescription from the chemist) and for transport purposes (230 1 Saber oxygen cylinders). Prior to discharge the infant was observed while breathing room air and the response to the fall in inspired oxygen was demonstrated to their parents. The parents were instructed in the techniques of monitoring their infant’s condition, by observing the infant’s colour, respiratory rate, ability to feed and genera] behaviour. Parents were also shown how to use an oxgyen saturation monitor (Ohmeda, Flex 2 probe) [8,10]. Two saturation monitors were bought by the NICU specifically for
31
this purpose and a third was bought from funds raised by the local population, again specifically to monitor such infants. Parents were advised at home to keep the oxygen saturation between 90% and 92%. The alarm levels were set from 88% to 95%. Initially parents complained that they were disturbed by alarms due to movement artefacts (once or twice a day) but after the first week with increasing use and experience of the monitor this very infrequently caused problems. Reduction in the oxygen flow rate was made if oxygen saturations were consistently above 92%. The oxygen flow rate was reduced by 0.1 l/min per day if oxygen saturations were maintained and the infant continued to gain weight satisfactorily. Following discharge, clinical care was provided by close liaison between the health visitor, general practitioner and consultant paediatrician. Community services are extremely stretched in the area around KCH. It was thus envisaged that all supervision of the infants’ home oxygen treatment, and problems arising from it, would be provided by the NICU staff, although no extra personnel could be provided by the NICU specifically for this purpose. Both the general practitioner and health visitor were requested to provide their routine surveillance and encouraged to contact the consultant paediatrician should they have any concerns regarding the infant. Any extra visits by the health visitor or general practitioner requested by the parents, above usual clinical practice and, in particular, specifically related to the home oxygen management, were documented by the parents and reported to us at hospital visits. The purpose of such visits was then verified by later telephone contact with the general practitioner or health visitor as appropriate. Parents were also questioned regarding problems encountered with administration of the home oxygen. The infants and their parents were seen at home on a daily basis over the first few days after discharge by the health visitor attached to the NICU. Their health was subsequently reviewed at weekly intervals by the paediatrician. Infants were brought to the hospital, if necessary by car. If this was unavailable, hospital transport was arranged. At each visit the infant’s clinical status and growth were assessed and the daily record of oxygen saturations kept by the parents was reviewed. The accuracy of oxygen saturation monitoring was assessed by comparison with 0, saturation in an arterial blood gas sample. The parents were asked to notify the paediatrician immediately if any change was noted in their infant’s clinical status at home and, if there was concern, the infant was then seen as soon as possible. The parents were encouraged to try and establish as normal a pattern of family life as possible. Use of portable oxygen cylinders allowed the infants to be taken out in a pushchair for shopping or leisure activities. Parents were advised, however, to avoid taking their infants into crowded or smoky atmospheres. They were also advised to avoid other children with respiratory infections and if attending hospital clinics were kept in a separate waiting area. Patients During the l-year period 164 VLBW infants were consecutively admitted to the regional NICU at KCH within 48 h of birth. Their median birthweight was 1079 kg (range 5061500) and gestational age 28 weeks (range 23-38). In the 1Zmonth period 28 of the 164 infants developed chronic lung disease (medi-
32
an gestational age 26 weeks, range 23-29 weeks). Seven of the 28 infants subsequently died and 6 others were transferred back to their referring hospitals. These latter 6 infants came from different districts in the South East Thames regions, none were discharged from their local hospital on home oxygen. Though 15 infants fulfilled the criteria which made them eligible for home oxygen therapy, in 7 cases the parents did not wish to take part in the home oxygen programme; 4 mothers were unsupported; both parents of two infants were working and in the seventh case the family were visiting from overseas. Seven infants were discharged home on oxygen therapy at a median age of 25 weeks (range 17-37). The eighth infant was discharged home without oxygen therapy but 8 weeks later when reviewed as an outpatient was found to be hypoxic and was then given home oxygen therapy when aged 27 weeks. During the l-year period a further infant received home oxygen therapy. She was born at term and had pulmonary hypoplasia. This child was discharged home in oxygen aged 37 weeks. Results
Comparison of the infants with CLD who did or did not receive home oxygen therapy revealed that there was no significant difference between the two groups in the number of infants who had a patent ductus ligation (2 home oxygen cohort; 1 non-home oxygen cohort or pneumothorax (one infant only, who had pulmonary hypoplasia). The median gestational age of the two groups was not significantly different, being 25 (median, range 23-40 weeks) in the home oxygen group and 26 (median, range 23-29 weeks) in the non-home oxygen group. The median duration of oxygen therapy prior to discharge was significantly shorter in the infants who did not receive home oxygen therapy (median 89 days, range 30-182) compared to that received by the 8 infants who did receive home oxygen therapy (median 164 days, range 119-256) (P < 0.01, Wilcoxon Rank Sum test) (Fig. 1). The median duration of home oxygen therapy was 17 weeks, range 4-486 days (Fig. 1). One infant, however, remained oxygen-dependent after 48 weeks of home oxygen therapy. One infant returned to hospital after only 4 days, his respiratory status having deteriorated due to infection. Unfortunately, this child remained in hospital until his death at 43 weeks from Branhamella catarrhalis pneumonitis and chronic lung disease. One other child in the series died, the primary diagnosis being severe pulmonary hypoplasia. The total duration of home oxygen therapy in this case was 17 weeks and she died when aged 99 weeks. Three other infants were readmitted for a total of 32 days with additional respiratory problems: four of these admissions were due to infection and the remaining two because of respiratory distress associated with wheezing episodes. Although 9 infants required home oxygen management there was only one short period when there were more than three infants at home in oxygen. Thus three oxygen saturation monitors were sufficient to provide adequate home monitoring. No transport problems were experienced by the parents. One unmarried mother required hospital transport and one infant lived so close to the hospital he was brought in a pushchair with a portable oxygen cylinder attached. The remaining infants were brought to the hospital by private car, either belonging to their parents or their
16 15 14 13 12 11 ul lo E 9 a a 'S $7
6 5 4 3 2 1 0
50
100 150 200 250 300 350 400 450 500 550 600 650 700 750 800
02 dependency (days) Fig. I. The duration
of oxygen
dependence
of the patients
who were eligible for home oxygen therapy.
friends. Parents experienced very few problems with home oxygen management. These included, initially getting accustomed to the noise of the oxygen concentrator and, throughout the period of home oxygen management, the difficulty of obtaining suitable baby-sitters, although frequently nurses from the NICU volunteered. No increase in visiting frequency or emergency call-out by the health visitor or general practitioner, respectively, were required. Parents did, however, make frequent phone calls to the consultants, particularly when the infants were initially discharged home. Discussion
Pulse oximetry was chosen to monitor oxygen requirements. It has been claimed that transcutaneous PO, monitoring may be useful in home management [6]. Rome et al. [9], however, have demonstrated that transcutaneous PO, always underestimated Pao, after 10 weeks of postnatal life, although they suggested that transcutaneous monitoring in older infants may be useful for estimating Pao, providing an appropriate correction was made. Others [8,10] have suggested that pulse oximetry is the more accurate method of monitoring. Additional advantages are that pulse oximeters do not require repeated calibration and as the sensor is unheated it will not cause skin burns, nor require to be frequently re-applied to another area of skin. Two of our infants required home oxygen therapy for more than 1 year. Such protracted courses of home management have previously been described [l]. Gestational age, birthweight and length of hospital stay did not predict those infants who remained oxygen-dependent beyond 1 year either in the previous [1] or the present
34
study. Overall, the average duration of home oxygen therapy was longer than that described by Pinney et al. [7], this difference might be explained by the greater immaturity of the infants we treated. We have found that the occurrence of CLD in our patients (17%) is much lower than that recently reported from the U.S.A. [5]. The incidence, however, is very similar to an earlier report from the U.K. [3]. This variation in incidence between the U.K. and the U.S.A. may reflect differences in the population treated or in the techniques of mechanical ventilation. It does, however, suggest that smaller numbers of infants would require home oxygen management in the U.K. than in the U.S.A. All of our parents preferred home oxygen over hospital oxygen therapy, encountering very few and relatively minor problems. It is interesting to note that infants who received home oxygen therapy had received a significantly longer duration of oxygen therapy in hospital than infants with CLD whose parents were unwilling or unable to take up this programme. It seems possible that the duration of hospital oxygen may influence the parental decision regarding home oxygen therapy. King’s College Hospital is a level three NICU and, as a consequence, cares for infants at greatest risk of CLD and chronic oxygen dependency. Thus, we were providing an adequate challenge to assess if existing services could indeed cope with the workload of home oxygen therapy programmes. We were able to supervise home oxygen adequately without any extra use of community services or having to provide hospital staff dedicated specifically and only to this project. The cost of home oxygen was provision of oxygen concentrators, two oxygen saturation monitors and hospital transport for one patient. Since, without home oxygen, these infants would have remained in hospital for many weeks or even months (Fig. 1) this project represents a large financial saving. We did not include in our home management programme infants who were transferred back to their referring hospital. Such infants lived too far from KCH to allow adequate supervision but, as they came from different districts in our region, these chronically oxygen-dependent infants did not represent a significant workload to a particular hospital. Of those infants living within the district surrounding KCH only a small number (8) and proportion (14.9%) of VLBW infants required home oxygen therapy. Despite the protracted duration of home oxygen management their small numbers mean that they will not represent a significant workload for the community and that close supervision would be possible by the hospital paediatric staff. Acknowledgements Dr Michael Hird, Research Fellow, is supported by the Children Nationwide Medical Research Fund. We are grateful to Diana Singh (Liaison Health Visitor) for her invaluable assistance in the care of these patients. We thank MS Sue Williams for secretarial assistance. References 1
Abman, S.H., Accurso, F.J. and Koops. B.L. (1984): Experience with home oxygen in the management of infants with brochopulmonary dysplasia. Clin. Paediatr.. 23. 471476.
2
4 5
Donn, S. (1982): Cost-effectiveness of home management of brochopulmonary dysplasia. Pediatrics, 70, 330-33 I. Greenough, A. and Roberton, N.R.C. (1985): Morbidity and mortality in neonates ventilated for the respiratory distress syndrome. Br. Med. J., 290. 597-600. Hall, D. (1975): Effects of illness in the neonate. In: Comprehensive Pediatric Nursing. Editor: G.M. Scysien. McGraw Hill, New York. HlFl Study Group. (1989): High frequency oscillation ventilation compared with conventional mechanical ventilation in the treatment of respiratory failure in preterm infants. N. Engl. J. Med., 320, 88-93. Philip, A.G.S., Peabody, J.L. and Lucey, J.F. (1978): Transcutaneous PO, monitoring in the home management of bronchopulmonary dysplasia. Pediatrics. 61, 655-657. Pinney, M.A and Cotton, E.K. (1976): Home management of bronchopulmonary dysplasia. Pediatrics, 58, 85&859. Ramanathan. R., Durand, M. and Larrrazabal, C. (1987): Pulse oximetry in low birthweight infants with acute and chronic lung disease. Pediatrics, 79. 612-617. Rome, E.S., Stork, E.K., Carlo, W.A. and Martin, R.J. (1984): Limitations of transcutaneous PO? and PCO, monitoring in infants with bronchopulmonary dysplasia. Pediatrics, 74. 217-220. Solimano, A.J., Smyth, J.A., Mann, T.K. and Albersheim, S.G. (1986): Pulse oximetry advantages in infants with bronchopulmonary dysplasia. Pediatrics, 78. 844-849.
29
EHD 01150
Home oxygen therapy following neonatal intensive care A. Greenough, Department of Child Health. (Received
15 August
M.F. Hird and H.R. Gamsu King‘.s College Hospitul. London SE5 YRS ( U.K.)
1990; revision
received
I2 April
1991; accepted
I7 April
1991)
Summary
In a 12-month period 28 of 164 consecutive very low birthweight (VLBW) infants receiving intensive care within 48 h of birth at King’s College Hospital developed chronic lung disease, (oxygen dependence beyond 28 days of age). Fifteen of the 28 infants were eligible for home oxygen therapy, but this was only practical, because of home circumstances, in 8 infants (4.9%). These 8 infants received home oxygen therapy. One further infant, born at term and suffering from pulmonary hypoplasia was also discharged home on oxygen therapy. Two infants subsequently required readmission due to a deterioration in their respiratory status and died. Three others required re-admissions (total duration 32 days) for respiratory problems. The median duration of home oxygen therapy was 17 weeks (range ““86 days). We conclude that home oxygen therapy is needed by only a very small number of preterm infants and is appropriate for only a proportion of them. Parents need to be counselled carefully regarding the possibility that the need for oxygen might be protracted. chronic lung disease; prematurity;
oxygen
Introduction
Prolonged hospital admission in those infants suffering from chronic lung disease who require continuous oxygen therapy may be avoided by oxygen administration at home [7]. Earlier discharge from neonatal intensive care is likely to result in improved parent-child relationships [4] and is certainly less costly [2,7]. It has been Correspondence IO: Dr Anne Greenough. 9RS. U.K.
Dept of Child Health,
0378-378219163.50 0 1991 Elsevier Scientific Published and Printed in Ireland
Publishers
Ireland
King’s College
Ltd.
Hospital,
London
SE5
30
reported that home oxygen therapy is generally required for a median period of 3 months [7]. We have recently begun to use home oxygen routinely for infants with chronic lung disease. We had learned that some infants required home oxygen for longer than 3 months and considered that this prolonged duration of therapy might have implications for the family by causing additional work and anxiety. In addition, the increasing survival of very preterm infants [3] and a reported incidence of chronic lung disease (CLD) of 40% in one series [5] implied that large numbers of infants might be eligible for home management. Such numbers when taken together with a protracted course of oxygen therapy could overstretch already limited community resources. We have therefore reviewed the outcome of VLBW infants admitted to this regional neonatal intensive care unit (NICU) at King’s College Hospital (KCH) over a l-year period when home oxygen therapy was routinely available. Our aim was to determine the proportion of infants for whom home oxygen therapy would be applicable and practical, the duration of such therapy, and if adequate supervision could be provided by existing hospital personnel. Methods and Patients Consecutive VLBW infants were reviewed prospectively. They were all inborn or required intensive care at KCH within 48 h of birth. Infants were defined as having chronic lung disease if they continued to require added oxygen or other respiratory support after 28 days of age and in addition had an abnormal chest radiograph [5]. Infants were considered eligible for home oxygen therapy if: (1) the infants were feeding well by mouth and they were steadily gaining weight (2) the infants required more than 25% inspired oxygen to maintain an arterial oxygen tension (PAoz) of 2 55 mmHg (3) the mother was supported during the programme, agreeable to it and capable of carrying it out (4) the infants lived within travelling distance of KCH and so could be supervised by the KCH team. The infants all received oxygen via dual nasal cannulae (De Vilbiss Health Care, Feltham, U.K.). Oxygen was administered via extension tubing from a concentrator (De Vilbiss Health Care) which was equipped with a regulator and flow meter (SLE, Croydon, U.K.) capable of delivering oxygen of a low flow (0.01-l l/min). The equipment a.nd system of oxygen delivery was carefully explained to the parents and the same system installed in the home. At home the parents also had oxygen cylinders both for use in an emergency if the concentrator failed (Size F, obtained on prescription from the chemist) and for transport purposes (230 1 Saber oxygen cylinders). Prior to discharge the infant was observed while breathing room air and the response to the fall in inspired oxygen was demonstrated to their parents. The parents were instructed in the techniques of monitoring their infant’s condition, by observing the infant’s colour, respiratory rate, ability to feed and genera] behaviour. Parents were also shown how to use an oxgyen saturation monitor (Ohmeda, Flex 2 probe) [8,10]. Two saturation monitors were bought by the NICU specifically for
31
this purpose and a third was bought from funds raised by the local population, again specifically to monitor such infants. Parents were advised at home to keep the oxygen saturation between 90% and 92%. The alarm levels were set from 88% to 95%. Initially parents complained that they were disturbed by alarms due to movement artefacts (once or twice a day) but after the first week with increasing use and experience of the monitor this very infrequently caused problems. Reduction in the oxygen flow rate was made if oxygen saturations were consistently above 92%. The oxygen flow rate was reduced by 0.1 l/min per day if oxygen saturations were maintained and the infant continued to gain weight satisfactorily. Following discharge, clinical care was provided by close liaison between the health visitor, general practitioner and consultant paediatrician. Community services are extremely stretched in the area around KCH. It was thus envisaged that all supervision of the infants’ home oxygen treatment, and problems arising from it, would be provided by the NICU staff, although no extra personnel could be provided by the NICU specifically for this purpose. Both the general practitioner and health visitor were requested to provide their routine surveillance and encouraged to contact the consultant paediatrician should they have any concerns regarding the infant. Any extra visits by the health visitor or general practitioner requested by the parents, above usual clinical practice and, in particular, specifically related to the home oxygen management, were documented by the parents and reported to us at hospital visits. The purpose of such visits was then verified by later telephone contact with the general practitioner or health visitor as appropriate. Parents were also questioned regarding problems encountered with administration of the home oxygen. The infants and their parents were seen at home on a daily basis over the first few days after discharge by the health visitor attached to the NICU. Their health was subsequently reviewed at weekly intervals by the paediatrician. Infants were brought to the hospital, if necessary by car. If this was unavailable, hospital transport was arranged. At each visit the infant’s clinical status and growth were assessed and the daily record of oxygen saturations kept by the parents was reviewed. The accuracy of oxygen saturation monitoring was assessed by comparison with 0, saturation in an arterial blood gas sample. The parents were asked to notify the paediatrician immediately if any change was noted in their infant’s clinical status at home and, if there was concern, the infant was then seen as soon as possible. The parents were encouraged to try and establish as normal a pattern of family life as possible. Use of portable oxygen cylinders allowed the infants to be taken out in a pushchair for shopping or leisure activities. Parents were advised, however, to avoid taking their infants into crowded or smoky atmospheres. They were also advised to avoid other children with respiratory infections and if attending hospital clinics were kept in a separate waiting area. Patients During the l-year period 164 VLBW infants were consecutively admitted to the regional NICU at KCH within 48 h of birth. Their median birthweight was 1079 kg (range 5061500) and gestational age 28 weeks (range 23-38). In the 1Zmonth period 28 of the 164 infants developed chronic lung disease (medi-
32
an gestational age 26 weeks, range 23-29 weeks). Seven of the 28 infants subsequently died and 6 others were transferred back to their referring hospitals. These latter 6 infants came from different districts in the South East Thames regions, none were discharged from their local hospital on home oxygen. Though 15 infants fulfilled the criteria which made them eligible for home oxygen therapy, in 7 cases the parents did not wish to take part in the home oxygen programme; 4 mothers were unsupported; both parents of two infants were working and in the seventh case the family were visiting from overseas. Seven infants were discharged home on oxygen therapy at a median age of 25 weeks (range 17-37). The eighth infant was discharged home without oxygen therapy but 8 weeks later when reviewed as an outpatient was found to be hypoxic and was then given home oxygen therapy when aged 27 weeks. During the l-year period a further infant received home oxygen therapy. She was born at term and had pulmonary hypoplasia. This child was discharged home in oxygen aged 37 weeks. Results
Comparison of the infants with CLD who did or did not receive home oxygen therapy revealed that there was no significant difference between the two groups in the number of infants who had a patent ductus ligation (2 home oxygen cohort; 1 non-home oxygen cohort or pneumothorax (one infant only, who had pulmonary hypoplasia). The median gestational age of the two groups was not significantly different, being 25 (median, range 23-40 weeks) in the home oxygen group and 26 (median, range 23-29 weeks) in the non-home oxygen group. The median duration of oxygen therapy prior to discharge was significantly shorter in the infants who did not receive home oxygen therapy (median 89 days, range 30-182) compared to that received by the 8 infants who did receive home oxygen therapy (median 164 days, range 119-256) (P < 0.01, Wilcoxon Rank Sum test) (Fig. 1). The median duration of home oxygen therapy was 17 weeks, range 4-486 days (Fig. 1). One infant, however, remained oxygen-dependent after 48 weeks of home oxygen therapy. One infant returned to hospital after only 4 days, his respiratory status having deteriorated due to infection. Unfortunately, this child remained in hospital until his death at 43 weeks from Branhamella catarrhalis pneumonitis and chronic lung disease. One other child in the series died, the primary diagnosis being severe pulmonary hypoplasia. The total duration of home oxygen therapy in this case was 17 weeks and she died when aged 99 weeks. Three other infants were readmitted for a total of 32 days with additional respiratory problems: four of these admissions were due to infection and the remaining two because of respiratory distress associated with wheezing episodes. Although 9 infants required home oxygen management there was only one short period when there were more than three infants at home in oxygen. Thus three oxygen saturation monitors were sufficient to provide adequate home monitoring. No transport problems were experienced by the parents. One unmarried mother required hospital transport and one infant lived so close to the hospital he was brought in a pushchair with a portable oxygen cylinder attached. The remaining infants were brought to the hospital by private car, either belonging to their parents or their
16 15 14 13 12 11 ul lo E 9 a a 'S $7
6 5 4 3 2 1 0
50
100 150 200 250 300 350 400 450 500 550 600 650 700 750 800
02 dependency (days) Fig. I. The duration
of oxygen
dependence
of the patients
who were eligible for home oxygen therapy.
friends. Parents experienced very few problems with home oxygen management. These included, initially getting accustomed to the noise of the oxygen concentrator and, throughout the period of home oxygen management, the difficulty of obtaining suitable baby-sitters, although frequently nurses from the NICU volunteered. No increase in visiting frequency or emergency call-out by the health visitor or general practitioner, respectively, were required. Parents did, however, make frequent phone calls to the consultants, particularly when the infants were initially discharged home. Discussion
Pulse oximetry was chosen to monitor oxygen requirements. It has been claimed that transcutaneous PO, monitoring may be useful in home management [6]. Rome et al. [9], however, have demonstrated that transcutaneous PO, always underestimated Pao, after 10 weeks of postnatal life, although they suggested that transcutaneous monitoring in older infants may be useful for estimating Pao, providing an appropriate correction was made. Others [8,10] have suggested that pulse oximetry is the more accurate method of monitoring. Additional advantages are that pulse oximeters do not require repeated calibration and as the sensor is unheated it will not cause skin burns, nor require to be frequently re-applied to another area of skin. Two of our infants required home oxygen therapy for more than 1 year. Such protracted courses of home management have previously been described [l]. Gestational age, birthweight and length of hospital stay did not predict those infants who remained oxygen-dependent beyond 1 year either in the previous [1] or the present
34
study. Overall, the average duration of home oxygen therapy was longer than that described by Pinney et al. [7], this difference might be explained by the greater immaturity of the infants we treated. We have found that the occurrence of CLD in our patients (17%) is much lower than that recently reported from the U.S.A. [5]. The incidence, however, is very similar to an earlier report from the U.K. [3]. This variation in incidence between the U.K. and the U.S.A. may reflect differences in the population treated or in the techniques of mechanical ventilation. It does, however, suggest that smaller numbers of infants would require home oxygen management in the U.K. than in the U.S.A. All of our parents preferred home oxygen over hospital oxygen therapy, encountering very few and relatively minor problems. It is interesting to note that infants who received home oxygen therapy had received a significantly longer duration of oxygen therapy in hospital than infants with CLD whose parents were unwilling or unable to take up this programme. It seems possible that the duration of hospital oxygen may influence the parental decision regarding home oxygen therapy. King’s College Hospital is a level three NICU and, as a consequence, cares for infants at greatest risk of CLD and chronic oxygen dependency. Thus, we were providing an adequate challenge to assess if existing services could indeed cope with the workload of home oxygen therapy programmes. We were able to supervise home oxygen adequately without any extra use of community services or having to provide hospital staff dedicated specifically and only to this project. The cost of home oxygen was provision of oxygen concentrators, two oxygen saturation monitors and hospital transport for one patient. Since, without home oxygen, these infants would have remained in hospital for many weeks or even months (Fig. 1) this project represents a large financial saving. We did not include in our home management programme infants who were transferred back to their referring hospital. Such infants lived too far from KCH to allow adequate supervision but, as they came from different districts in our region, these chronically oxygen-dependent infants did not represent a significant workload to a particular hospital. Of those infants living within the district surrounding KCH only a small number (8) and proportion (14.9%) of VLBW infants required home oxygen therapy. Despite the protracted duration of home oxygen management their small numbers mean that they will not represent a significant workload for the community and that close supervision would be possible by the hospital paediatric staff. Acknowledgements Dr Michael Hird, Research Fellow, is supported by the Children Nationwide Medical Research Fund. We are grateful to Diana Singh (Liaison Health Visitor) for her invaluable assistance in the care of these patients. We thank MS Sue Williams for secretarial assistance. References 1
Abman, S.H., Accurso, F.J. and Koops. B.L. (1984): Experience with home oxygen in the management of infants with brochopulmonary dysplasia. Clin. Paediatr.. 23. 471476.
2
4 5
Donn, S. (1982): Cost-effectiveness of home management of brochopulmonary dysplasia. Pediatrics, 70, 330-33 I. Greenough, A. and Roberton, N.R.C. (1985): Morbidity and mortality in neonates ventilated for the respiratory distress syndrome. Br. Med. J., 290. 597-600. Hall, D. (1975): Effects of illness in the neonate. In: Comprehensive Pediatric Nursing. Editor: G.M. Scysien. McGraw Hill, New York. HlFl Study Group. (1989): High frequency oscillation ventilation compared with conventional mechanical ventilation in the treatment of respiratory failure in preterm infants. N. Engl. J. Med., 320, 88-93. Philip, A.G.S., Peabody, J.L. and Lucey, J.F. (1978): Transcutaneous PO, monitoring in the home management of bronchopulmonary dysplasia. Pediatrics. 61, 655-657. Pinney, M.A and Cotton, E.K. (1976): Home management of bronchopulmonary dysplasia. Pediatrics, 58, 85&859. Ramanathan. R., Durand, M. and Larrrazabal, C. (1987): Pulse oximetry in low birthweight infants with acute and chronic lung disease. Pediatrics, 79. 612-617. Rome, E.S., Stork, E.K., Carlo, W.A. and Martin, R.J. (1984): Limitations of transcutaneous PO? and PCO, monitoring in infants with bronchopulmonary dysplasia. Pediatrics, 74. 217-220. Solimano, A.J., Smyth, J.A., Mann, T.K. and Albersheim, S.G. (1986): Pulse oximetry advantages in infants with bronchopulmonary dysplasia. Pediatrics, 78. 844-849.