http://informahealthcare.com/jmf ISSN: 1476-7058 (print), 1476-4954 (electronic) J Matern Fetal Neonatal Med, Early Online: 1–4 ! 2015 Taylor & Francis. DOI: 10.3109/14767058.2015.1067295
ORIGINAL ARTICLE
The safety of postnatal transport of newborns prenatally diagnosed with duct-dependent congenital heart disease J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by University of Pennsylvania on 08/31/15 For personal use only.
Rajesh U. Shenoy1,2 and Michael DiLorenzo2 1
Division of Pediatric Cardiology and 2Department of Pediatrics, The Children’s Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA Abstract
Keywords
Objective: Critical congenital heart disease is increasingly recognized prenatally. Following the diagnosis, families are advised to deliver in a facility where neonatal cardiac interventions are available. We studied the safety of transport of neonates who had been prenatally diagnosed with duct-dependent congenital heart lesions. Methods: We performed a retrospective chart review of all fetuses diagnosed with ductdependent congenital heart disease in our fetal program between 2007 and 2011. Demographic data, dose of prostaglandin infusion, respiratory status, blood gas data, as well as complications of the transport were collected. Results: Twenty-nine neonates qualified for inclusion in the study. Ten were intubated (7 electively) prior to the transport. One of these required intervention for desaturation during the transport. One of the 19 unintubated patients required emergent intubation during the transport. Thus, the overall rate of incidents was 6.9%. All 4 patients who developed apnea requiring intubation did so within 1 h of starting prostaglandin. Conclusions: Elective postnatal transport of neonates prenatally diagnosed with duct-dependent congenital heart lesions is safe. Prophylactic intubation of these infants may not be necessary. It would be advantageous to schedule the elective transport an hour after starting prostaglandin or later.
Congenital heart disease, neonatal transport, prenatal diagnosis
Introduction Advances in the field of fetal cardiology have resulted in the routine prenatal diagnosis of very complex congenital cardiac lesions. Duct-dependent lesions, in which either the systemic or pulmonary circulation is solely perfused by the patent ductus arteriosus, constitute a significant subset of these lesions. Many centers recommend that a fetus that has been prenatally diagnosed with a duct-dependent congenital heart lesion be delivered at a facility contiguous with a children’s hospital that offers congenital heart surgery, the so-called ‘‘antenatal transport’’. The rationale for this approach is the avoidance of the morbidity of an inter-facility transport, which includes thermal dysregulation, respiratory failure, need for increased respiratory support, glycemic dysregulation or even death [1,2]. These risks are accentuated when transportation times are prolonged [3,4]. However, recent literature has suggested that postnatal diagnosis or birth at a community medical center [5] does not result in increased Address for correspondence: Rajesh U. Shenoy, M.D., Division of Pediatric Cardiology, Mount Sinai – Kravis Children’s Hospital, 1 Gustave L. Levy Place, Box 1201, New York, NY 10029, USA. Tel: +212 241 0424. Fax: +646 537 9307. E-mail: [email protected]
History Received 22 April 2015 Revised 24 June 2015 Accepted 25 June 2015 Published online 13 August 2015
severity of illness within the first 24 h of life or result in worse outcomes. Patients with duct-dependent cardiac lesions are maintained on an intravenous prostaglandin (PGE1) infusion which by keeping the ductus arteriosus patent, ensures oxygenation and adequate systemic perfusion until corrective surgery can be performed [6]. While the use of PGE1 is life-saving, it has well-described risks, including apnea, vasodilation, arrhythmia, fever and hypotension [7]. To avoid the morbidity related to an in-transport apneic episode, newborns on PGE1 infusions are often electively intubated and ventilated for the transport. The few studies on transport of newborns on PGE1 infusions have shown that the rate of complications in unintubated patients is minimal and, in some cases is far lower than in electively intubated patients [8]. This has prompted some groups to avoid electively intubating these patients [9] and to use specialized transport teams to reduce the morbidity of an inter-facility transport [10]. Transfer of care to another facility might pose a significant burden to a woman carrying a fetus with critical congenital heart disease, as well as to her family. This is further compounded if this facility is located far away from where she lives and works. We sought to study the safety of neonatal transport of patients prenatally diagnosed with
2
R. U. Shenoy & M. DiLorenzo
duct-dependent congenital heart disease within our tertiary care facility. The obstetric programs and both of the level III neonatal intensive care units (NICU) affiliated with this system are located at a distance of 3.5–4 miles from the Children’s Hospital. The policy of the fetal cardiac program is to deliver almost all neonates with cardiac lesions at the obstetric facilities, start the neonates with duct-dependent lesions on a PGE1 infusion, and then transfer them electively to the Children’s Hospital. This protocol provides an ideal study group to determine the risks and complications associated with the postnatal transport of newborns prenatally diagnosed with a duct-dependent cardiac lesion.
J Matern Fetal Neonatal Med, Early Online: 1–4
Table 1. Patient population (n ¼ 29). Gestational age (weeks) Male (n) Birth weight (g) Type of cardiac disease (n) Pulmonary atresia/stenosis Transposition of the great arteries Hypoplastic left or right heart Aortic atresia/stenosis Coarctation of the aorta Double outlet right ventricle Coarctation of the aorta with hypoplastic aortic valve Ebstein’s anomaly Tetralogy of Fallot with pulmonary atresia Hypoplastic aortic arch
37.4 ± 2.8 15 (52%) 3099 ± 670 6 5 5 3 3 3 1 1 1 1
(21%) (17%) (17%) (10%) (10%) (10%) (3.5%) (3.5%) (3.5%) (3.5%)
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by University of Pennsylvania on 08/31/15 For personal use only.
Methods The study was approved by the Institutional Review Board of Montefiore Medical Center. All patients prenatally diagnosed in the Fetal Cardiac Program with duct-dependent congenital cardiac lesions who delivered either at the Weiler Hospital of the Albert Einstein College of Medicine or at Jacobi Medical Center (both regional perinatal centers) between 2007 and 2011 were identified. The newborns with duct-dependent lesions who were transported to the Children’s Hospital on a PGE1 infusion were included in the study. Patients who were diagnosed prenatally in our program, but who were delivered at the Children’s Hospital itself, or at obstetrical facilities other than Weiler Hospital or Jacobi Medical Center were excluded from the study. The following data were obtained for each patient: demographic data (gestational age, sex, birth weight, maternal history and complications of pregnancy), cardiac anatomy and echocardiographic findings (both pre- and postnatal), dose of PGE1 infusion, other prescribed medications, respiratory status at the time of transport, pre- and post-transport blood gases, details of transport (age at transport and duration of transport), and any transport complications and interventions. Paired T-test was used to compare pre- and post-transport blood gases.
Results Patient demographics Forty-six patients were diagnosed prenatally with a ductdependent complex congenital cardiac lesion during the study period. Of these, 17 were excluded for the following reasons: termination of pregnancy [7], intrauterine fetal demise [3], transfer of care to another institution [4], elective birth at the Children’s Hospital at Montefiore for emergent catheterization [2] based on prenatal assessment, and compassionate care for the infant [1]. The 29 remaining patients were included in the study. The baseline demographic data and cardiac diagnosis are listed in Table 1. Four patients had minor differences between preand postnatal echocardiograms; however, none of these differences affected neonatal management and decision to start prostaglandin. Transport results All patients were transported by a dedicated neonatal transport team staffed by a neonatologist or neonatal nurse
Table 2. Transport data (n ¼ 29). Age at transport (median hr, range) PGE1 dose at transport (mcg/kg/min) Transport time (min) n¼26 Respiratory status when leaving NICU (n) Intubated (n ¼ 10) Elective Apnea Poor perfusion Respiratory distress CPAP Room Air
5, 21632 0.06 ± 0.02 22 ± 9.5 4 3 1 2 3 16
(14%) (10%) (4%) (7%) (10%) (55%)
practitioner, as well as a certified neonatal nurse. All members of the transport team were NRP trained. Transport characteristics, including age at transport, PGE1 dose, transport time and respiratory status are listed in Table 2. All patients except for 1 were transported within the first 3 days of life. The 1 patient who was transported at 1632 h remained in the NICU due to premature status, and was transported when she attained appropriate weight for surgical correction. Twelve of the 29 patients were on ampicillin and gentamicin while awaiting results of a sepsis work-up. Only 2 patients were on inotropic agents for blood pressure support, both of whom were intubated for transport. Ten patients were intubated prior to transport. Of these, 3 were intubated because of apnea after starting PGE1 infusion. The only transport incident among these patients was a desaturation to 60% in 1 patient, which improved after increasing the PGE1 dose and adjusting ventilator settings. Among the 19 patients who were not intubated before the transport, 1 patient initially transported on room air developed hypotension and apnea during transport, requiring emergent intubation en-route. This patient was started on PGE1 within 1 h prior to transport. Overall transport complication rate was 6.9%. Pre- and post-transport blood gases were available for 14 patients. There was a statistically significant increase in pH (7.33 ± 0.06–7.39 ± 0.08, p ¼ 0.05) and decrease in pCO2 (45 ± 9.9–38 ± 10, p ¼ 0.02). Intubated and nonintubated patients displayed no significant difference in change of pH or pCO2 from pre- to post-transport blood gases.
DOI: 10.3109/14767058.2015.1067295
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by University of Pennsylvania on 08/31/15 For personal use only.
Discussion In this study, we have demonstrated that neonatal transport of infants with complex duct-dependent cardiac lesions can be performed safely and effectively. Our study demonstrated a 6.9% incidence of complications during transport, with all the infants arriving at the PICU at the Children’s Hospital safely, which is consistent with previously reported studies on neonatal transport of infants with congenital cardiac disease [10,11]. Woods et al. [12] showed 24.8% rate of transportrelated adverse events; however, the vast majority of these were due to medication error or transporter error, and were not due to clinical changes. We had two instances of adverse events during our transport: one occurrence of apnea while on room air, and one occurrence of desaturation in an intubated patient. In all, 4 patients (14%) developed apnea and required intubation (three prior to transport and one during transport), all of which occurred within 1 h of starting PGE1 infusion. This rate of apnea and temporal occurrence to the start of PGE1 infusion is similar to that reported by Browning Carmo [11], in which 18% of non-ventilated patients developed apnea within the first hour of starting PGE-1 therapy. Meckler reported a reduction in incidence of PGE1 related apnea when transporting infants at least 3 h after beginning the infusion [8]. Additionally, 3 of the 4 patients who developed apnea were on PGE-1 infusion rates of 0.1 mcg/kg/min, which, while within the approved infusion rates to maintain ductal patency, are at the higher end of this range. In this series, there was a 4-fold greater risk of adverse events with PGE1 doses 40.05 mcg/kg/min. Browning Carmo similarly demonstrated a significantly higher risk of adverse events with higher PGE1 dosages; however, their cut-off was 0.015 mcg/kg/min, a dose which is nearly the lower limit of recommended maintenance dose [11]. An adverse event occurred in 1 patient (10%) who was intubated prior to transport. No mechanical or ventilatorassociated incidents were noted in our population. The argument could be made that this would support prophylactic intubation prior to PGE1 therapy; however, we believe that our findings were partially because of our small sample size. In the study by Browning Carmo, only 2 infants (2.6%) transported on PGE1 without mechanical ventilation developed apnea [11]. One of these infants required bag and mask ventilation, and neither required intubation during transport. Meckler determined that elective intubation was a ‘‘significant predictor of major transport complications’’, including endotracheal displacement, desaturation and hypoventilation [8]. Prophylactic intubation ‘‘exposes the infant to the potential for mechanical malfunction’’ [2]. The study by Lee from Singapore further supports this, showing no occurrences of adverse events in 22 patients transported on PGE1, only 18% of which were intubated prior to transport [9]. Despite these findings, however, the decision to not electively intubate requires that the members of a transport team, as in our study, are highly trained in neonatal resuscitation and are prepared to intubate if necessary. There are several limitations to this study. This paper is a retrospective study, and variables such as the dose of PGE1, as well as the decision to intubate were not randomized.
Transport of newborns with duct-dependent CHD
3
Our sample size was limited. Additionally, our study excluded infants who were diagnosed with complex congenital cardiac lesions after birth. While advancements in fetal echocardiography have improved detection of complex cardiac lesions, it remains dependent on appropriate prenatal care and referrals from obstetricians. Tworetzky showed a prenatal diagnosis rate of 37% for hypoplastic left heart syndrome [13]. While a more recent study by Levey showed a prenatal diagnosis rate of 67% for all the congenital cardiac diseases [14], it is clear that a significant proportion of congenital cardiac disease remains undiagnosed prenatally. Although we expect that transport of these infants can still be performed safely and with minimal morbidity, possible emergent interventions would be delayed due to the need for transport. Finally, while our study showed no adverse outcomes during or immediately after transport, we did not examine long-term outcome in our patients and the role that transport may have in these outcomes. Future prospective studies looking at these outcomes may be beneficial. Since the distance the neonates had to be transported was 4 miles or less in this study, it would not be correct to assume the same will hold true for longer distances. However, Yaeger showed no significant difference in rate of adverse incidents based on distance of transport [2]. In summary, this study demonstrates that neonates who are prenatally diagnosed with duct-dependent congenital heart disease can be safely transported in an elective fashion after institution of a PGE1 infusion. The incidence of PGE1-related apnea might be reduced by delaying the transport to at least an hour after instituting the PGE1 infusion, and decreasing the dose to 0.05 mcg/kg/min, or less. In addition, an accurate prenatal diagnosis as well as the availability of a trained neonatal transport team is necessary to ensure a successful outcome.
Declaration of interest The authors report no conflicts of interest.
References 1. Chance GW, O’Brien MJ, Swyer PR. Transportation of sick neonates, 1972: an unsatisfactory aspect of medical care. Can Med Assoc J 1973;109:847–51. 2. Yeager SB, Horbar JD, Greco KM, et al. Pretransport and posttransport characteristics and outcomes of neonates who were admitted to a cardiac intensive care unit. Pediatrics 2006;118: 1070–7. 3. Vietra ALP, dos Santos AMN, Okuyama MK, et al. Factors associated with clinical complications during intra-hospital transports in a neonatal unit in Brazil. J Trop Pediatr 2011;57: 368–74. 4. Mori R, Fujimura M, Shiraishi J, et al. Duration of inter-facility neonatal transport and neonatal mortality: systematic review and cohort study. Pediatr Int 2007;49:452–8. 5. Simpson LL, Harvey-Wilkes K, D’Alton ME. Congenital heart disease: the impact of delivery in a tertiary care center on SNAP scores. Am J Obstet Gynceol 2000;182:184–91. 6. Olley PM, Coceani F, Bodach A. E-type prostaglandins: a new emergency therapy for certain cyanotic congenital heart malformations. Circulation 1976;53:728–31. 7. Lewis AB, Freed MD, Heymann MA, et al. Side effects of therapy with prostaglandin E1 in infants with critical congenital heart disease. Circulation 1981;64:892–8. 8. Meckler GD, Lowe C. To intubate or not to intubate? Transporting infants on prostaglandin E1. Pediatrics 2009;123:e25–30.
4
R. U. Shenoy & M. DiLorenzo
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by University of Pennsylvania on 08/31/15 For personal use only.
9. Lee JH, Puthucheary J. Transport of critically ill neonates with cardiac conditions. Air Med J 2010;29:320–2. 10. Hellstrom-Westas L, Hanseus K, Jogi P, et al. Long-distance transport of newborn infants with congenital heart disease. Pediatr Cardiol 2001;22:380–4. 11. Browning Carmo KA, Barr P, West M, et al. Transporting newborn infants with suspected duct dependent congenital heart disease on low-dose prostaglanding E1 without routine mechanical ventilation. Arch Dis Child Fetal Neonatal Ed 2007;92:F117–19.
J Matern Fetal Neonatal Med, Early Online: 1–4
12. Woods P, Browning Carmo K, Wall M, et al. Transporting newborns with transposition of the great arteries. J Paediatr Child Health 2013;49:E68–73. 13. Tworetzky W, McElhinney DB, Reddy VM, et al. Improved surgical outcome after fetal diagnosis of hypoplastic left heart syndrome. Circulation 2001;103:1269–73. 14. Levey A, Glickstein JS, Kleinman CS, et al. The impact of prenatal diagnosis of complex congenital heart disease on neonatal outcomes. Pediatr Cardiol 2010;31:587–97.
ORIGINAL ARTICLE
The safety of postnatal transport of newborns prenatally diagnosed with duct-dependent congenital heart disease J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by University of Pennsylvania on 08/31/15 For personal use only.
Rajesh U. Shenoy1,2 and Michael DiLorenzo2 1
Division of Pediatric Cardiology and 2Department of Pediatrics, The Children’s Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA Abstract
Keywords
Objective: Critical congenital heart disease is increasingly recognized prenatally. Following the diagnosis, families are advised to deliver in a facility where neonatal cardiac interventions are available. We studied the safety of transport of neonates who had been prenatally diagnosed with duct-dependent congenital heart lesions. Methods: We performed a retrospective chart review of all fetuses diagnosed with ductdependent congenital heart disease in our fetal program between 2007 and 2011. Demographic data, dose of prostaglandin infusion, respiratory status, blood gas data, as well as complications of the transport were collected. Results: Twenty-nine neonates qualified for inclusion in the study. Ten were intubated (7 electively) prior to the transport. One of these required intervention for desaturation during the transport. One of the 19 unintubated patients required emergent intubation during the transport. Thus, the overall rate of incidents was 6.9%. All 4 patients who developed apnea requiring intubation did so within 1 h of starting prostaglandin. Conclusions: Elective postnatal transport of neonates prenatally diagnosed with duct-dependent congenital heart lesions is safe. Prophylactic intubation of these infants may not be necessary. It would be advantageous to schedule the elective transport an hour after starting prostaglandin or later.
Congenital heart disease, neonatal transport, prenatal diagnosis
Introduction Advances in the field of fetal cardiology have resulted in the routine prenatal diagnosis of very complex congenital cardiac lesions. Duct-dependent lesions, in which either the systemic or pulmonary circulation is solely perfused by the patent ductus arteriosus, constitute a significant subset of these lesions. Many centers recommend that a fetus that has been prenatally diagnosed with a duct-dependent congenital heart lesion be delivered at a facility contiguous with a children’s hospital that offers congenital heart surgery, the so-called ‘‘antenatal transport’’. The rationale for this approach is the avoidance of the morbidity of an inter-facility transport, which includes thermal dysregulation, respiratory failure, need for increased respiratory support, glycemic dysregulation or even death [1,2]. These risks are accentuated when transportation times are prolonged [3,4]. However, recent literature has suggested that postnatal diagnosis or birth at a community medical center [5] does not result in increased Address for correspondence: Rajesh U. Shenoy, M.D., Division of Pediatric Cardiology, Mount Sinai – Kravis Children’s Hospital, 1 Gustave L. Levy Place, Box 1201, New York, NY 10029, USA. Tel: +212 241 0424. Fax: +646 537 9307. E-mail: [email protected]
History Received 22 April 2015 Revised 24 June 2015 Accepted 25 June 2015 Published online 13 August 2015
severity of illness within the first 24 h of life or result in worse outcomes. Patients with duct-dependent cardiac lesions are maintained on an intravenous prostaglandin (PGE1) infusion which by keeping the ductus arteriosus patent, ensures oxygenation and adequate systemic perfusion until corrective surgery can be performed [6]. While the use of PGE1 is life-saving, it has well-described risks, including apnea, vasodilation, arrhythmia, fever and hypotension [7]. To avoid the morbidity related to an in-transport apneic episode, newborns on PGE1 infusions are often electively intubated and ventilated for the transport. The few studies on transport of newborns on PGE1 infusions have shown that the rate of complications in unintubated patients is minimal and, in some cases is far lower than in electively intubated patients [8]. This has prompted some groups to avoid electively intubating these patients [9] and to use specialized transport teams to reduce the morbidity of an inter-facility transport [10]. Transfer of care to another facility might pose a significant burden to a woman carrying a fetus with critical congenital heart disease, as well as to her family. This is further compounded if this facility is located far away from where she lives and works. We sought to study the safety of neonatal transport of patients prenatally diagnosed with
2
R. U. Shenoy & M. DiLorenzo
duct-dependent congenital heart disease within our tertiary care facility. The obstetric programs and both of the level III neonatal intensive care units (NICU) affiliated with this system are located at a distance of 3.5–4 miles from the Children’s Hospital. The policy of the fetal cardiac program is to deliver almost all neonates with cardiac lesions at the obstetric facilities, start the neonates with duct-dependent lesions on a PGE1 infusion, and then transfer them electively to the Children’s Hospital. This protocol provides an ideal study group to determine the risks and complications associated with the postnatal transport of newborns prenatally diagnosed with a duct-dependent cardiac lesion.
J Matern Fetal Neonatal Med, Early Online: 1–4
Table 1. Patient population (n ¼ 29). Gestational age (weeks) Male (n) Birth weight (g) Type of cardiac disease (n) Pulmonary atresia/stenosis Transposition of the great arteries Hypoplastic left or right heart Aortic atresia/stenosis Coarctation of the aorta Double outlet right ventricle Coarctation of the aorta with hypoplastic aortic valve Ebstein’s anomaly Tetralogy of Fallot with pulmonary atresia Hypoplastic aortic arch
37.4 ± 2.8 15 (52%) 3099 ± 670 6 5 5 3 3 3 1 1 1 1
(21%) (17%) (17%) (10%) (10%) (10%) (3.5%) (3.5%) (3.5%) (3.5%)
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by University of Pennsylvania on 08/31/15 For personal use only.
Methods The study was approved by the Institutional Review Board of Montefiore Medical Center. All patients prenatally diagnosed in the Fetal Cardiac Program with duct-dependent congenital cardiac lesions who delivered either at the Weiler Hospital of the Albert Einstein College of Medicine or at Jacobi Medical Center (both regional perinatal centers) between 2007 and 2011 were identified. The newborns with duct-dependent lesions who were transported to the Children’s Hospital on a PGE1 infusion were included in the study. Patients who were diagnosed prenatally in our program, but who were delivered at the Children’s Hospital itself, or at obstetrical facilities other than Weiler Hospital or Jacobi Medical Center were excluded from the study. The following data were obtained for each patient: demographic data (gestational age, sex, birth weight, maternal history and complications of pregnancy), cardiac anatomy and echocardiographic findings (both pre- and postnatal), dose of PGE1 infusion, other prescribed medications, respiratory status at the time of transport, pre- and post-transport blood gases, details of transport (age at transport and duration of transport), and any transport complications and interventions. Paired T-test was used to compare pre- and post-transport blood gases.
Results Patient demographics Forty-six patients were diagnosed prenatally with a ductdependent complex congenital cardiac lesion during the study period. Of these, 17 were excluded for the following reasons: termination of pregnancy [7], intrauterine fetal demise [3], transfer of care to another institution [4], elective birth at the Children’s Hospital at Montefiore for emergent catheterization [2] based on prenatal assessment, and compassionate care for the infant [1]. The 29 remaining patients were included in the study. The baseline demographic data and cardiac diagnosis are listed in Table 1. Four patients had minor differences between preand postnatal echocardiograms; however, none of these differences affected neonatal management and decision to start prostaglandin. Transport results All patients were transported by a dedicated neonatal transport team staffed by a neonatologist or neonatal nurse
Table 2. Transport data (n ¼ 29). Age at transport (median hr, range) PGE1 dose at transport (mcg/kg/min) Transport time (min) n¼26 Respiratory status when leaving NICU (n) Intubated (n ¼ 10) Elective Apnea Poor perfusion Respiratory distress CPAP Room Air
5, 21632 0.06 ± 0.02 22 ± 9.5 4 3 1 2 3 16
(14%) (10%) (4%) (7%) (10%) (55%)
practitioner, as well as a certified neonatal nurse. All members of the transport team were NRP trained. Transport characteristics, including age at transport, PGE1 dose, transport time and respiratory status are listed in Table 2. All patients except for 1 were transported within the first 3 days of life. The 1 patient who was transported at 1632 h remained in the NICU due to premature status, and was transported when she attained appropriate weight for surgical correction. Twelve of the 29 patients were on ampicillin and gentamicin while awaiting results of a sepsis work-up. Only 2 patients were on inotropic agents for blood pressure support, both of whom were intubated for transport. Ten patients were intubated prior to transport. Of these, 3 were intubated because of apnea after starting PGE1 infusion. The only transport incident among these patients was a desaturation to 60% in 1 patient, which improved after increasing the PGE1 dose and adjusting ventilator settings. Among the 19 patients who were not intubated before the transport, 1 patient initially transported on room air developed hypotension and apnea during transport, requiring emergent intubation en-route. This patient was started on PGE1 within 1 h prior to transport. Overall transport complication rate was 6.9%. Pre- and post-transport blood gases were available for 14 patients. There was a statistically significant increase in pH (7.33 ± 0.06–7.39 ± 0.08, p ¼ 0.05) and decrease in pCO2 (45 ± 9.9–38 ± 10, p ¼ 0.02). Intubated and nonintubated patients displayed no significant difference in change of pH or pCO2 from pre- to post-transport blood gases.
DOI: 10.3109/14767058.2015.1067295
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by University of Pennsylvania on 08/31/15 For personal use only.
Discussion In this study, we have demonstrated that neonatal transport of infants with complex duct-dependent cardiac lesions can be performed safely and effectively. Our study demonstrated a 6.9% incidence of complications during transport, with all the infants arriving at the PICU at the Children’s Hospital safely, which is consistent with previously reported studies on neonatal transport of infants with congenital cardiac disease [10,11]. Woods et al. [12] showed 24.8% rate of transportrelated adverse events; however, the vast majority of these were due to medication error or transporter error, and were not due to clinical changes. We had two instances of adverse events during our transport: one occurrence of apnea while on room air, and one occurrence of desaturation in an intubated patient. In all, 4 patients (14%) developed apnea and required intubation (three prior to transport and one during transport), all of which occurred within 1 h of starting PGE1 infusion. This rate of apnea and temporal occurrence to the start of PGE1 infusion is similar to that reported by Browning Carmo [11], in which 18% of non-ventilated patients developed apnea within the first hour of starting PGE-1 therapy. Meckler reported a reduction in incidence of PGE1 related apnea when transporting infants at least 3 h after beginning the infusion [8]. Additionally, 3 of the 4 patients who developed apnea were on PGE-1 infusion rates of 0.1 mcg/kg/min, which, while within the approved infusion rates to maintain ductal patency, are at the higher end of this range. In this series, there was a 4-fold greater risk of adverse events with PGE1 doses 40.05 mcg/kg/min. Browning Carmo similarly demonstrated a significantly higher risk of adverse events with higher PGE1 dosages; however, their cut-off was 0.015 mcg/kg/min, a dose which is nearly the lower limit of recommended maintenance dose [11]. An adverse event occurred in 1 patient (10%) who was intubated prior to transport. No mechanical or ventilatorassociated incidents were noted in our population. The argument could be made that this would support prophylactic intubation prior to PGE1 therapy; however, we believe that our findings were partially because of our small sample size. In the study by Browning Carmo, only 2 infants (2.6%) transported on PGE1 without mechanical ventilation developed apnea [11]. One of these infants required bag and mask ventilation, and neither required intubation during transport. Meckler determined that elective intubation was a ‘‘significant predictor of major transport complications’’, including endotracheal displacement, desaturation and hypoventilation [8]. Prophylactic intubation ‘‘exposes the infant to the potential for mechanical malfunction’’ [2]. The study by Lee from Singapore further supports this, showing no occurrences of adverse events in 22 patients transported on PGE1, only 18% of which were intubated prior to transport [9]. Despite these findings, however, the decision to not electively intubate requires that the members of a transport team, as in our study, are highly trained in neonatal resuscitation and are prepared to intubate if necessary. There are several limitations to this study. This paper is a retrospective study, and variables such as the dose of PGE1, as well as the decision to intubate were not randomized.
Transport of newborns with duct-dependent CHD
3
Our sample size was limited. Additionally, our study excluded infants who were diagnosed with complex congenital cardiac lesions after birth. While advancements in fetal echocardiography have improved detection of complex cardiac lesions, it remains dependent on appropriate prenatal care and referrals from obstetricians. Tworetzky showed a prenatal diagnosis rate of 37% for hypoplastic left heart syndrome [13]. While a more recent study by Levey showed a prenatal diagnosis rate of 67% for all the congenital cardiac diseases [14], it is clear that a significant proportion of congenital cardiac disease remains undiagnosed prenatally. Although we expect that transport of these infants can still be performed safely and with minimal morbidity, possible emergent interventions would be delayed due to the need for transport. Finally, while our study showed no adverse outcomes during or immediately after transport, we did not examine long-term outcome in our patients and the role that transport may have in these outcomes. Future prospective studies looking at these outcomes may be beneficial. Since the distance the neonates had to be transported was 4 miles or less in this study, it would not be correct to assume the same will hold true for longer distances. However, Yaeger showed no significant difference in rate of adverse incidents based on distance of transport [2]. In summary, this study demonstrates that neonates who are prenatally diagnosed with duct-dependent congenital heart disease can be safely transported in an elective fashion after institution of a PGE1 infusion. The incidence of PGE1-related apnea might be reduced by delaying the transport to at least an hour after instituting the PGE1 infusion, and decreasing the dose to 0.05 mcg/kg/min, or less. In addition, an accurate prenatal diagnosis as well as the availability of a trained neonatal transport team is necessary to ensure a successful outcome.
Declaration of interest The authors report no conflicts of interest.
References 1. Chance GW, O’Brien MJ, Swyer PR. Transportation of sick neonates, 1972: an unsatisfactory aspect of medical care. Can Med Assoc J 1973;109:847–51. 2. Yeager SB, Horbar JD, Greco KM, et al. Pretransport and posttransport characteristics and outcomes of neonates who were admitted to a cardiac intensive care unit. Pediatrics 2006;118: 1070–7. 3. Vietra ALP, dos Santos AMN, Okuyama MK, et al. Factors associated with clinical complications during intra-hospital transports in a neonatal unit in Brazil. J Trop Pediatr 2011;57: 368–74. 4. Mori R, Fujimura M, Shiraishi J, et al. Duration of inter-facility neonatal transport and neonatal mortality: systematic review and cohort study. Pediatr Int 2007;49:452–8. 5. Simpson LL, Harvey-Wilkes K, D’Alton ME. Congenital heart disease: the impact of delivery in a tertiary care center on SNAP scores. Am J Obstet Gynceol 2000;182:184–91. 6. Olley PM, Coceani F, Bodach A. E-type prostaglandins: a new emergency therapy for certain cyanotic congenital heart malformations. Circulation 1976;53:728–31. 7. Lewis AB, Freed MD, Heymann MA, et al. Side effects of therapy with prostaglandin E1 in infants with critical congenital heart disease. Circulation 1981;64:892–8. 8. Meckler GD, Lowe C. To intubate or not to intubate? Transporting infants on prostaglandin E1. Pediatrics 2009;123:e25–30.
4
R. U. Shenoy & M. DiLorenzo
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by University of Pennsylvania on 08/31/15 For personal use only.
9. Lee JH, Puthucheary J. Transport of critically ill neonates with cardiac conditions. Air Med J 2010;29:320–2. 10. Hellstrom-Westas L, Hanseus K, Jogi P, et al. Long-distance transport of newborn infants with congenital heart disease. Pediatr Cardiol 2001;22:380–4. 11. Browning Carmo KA, Barr P, West M, et al. Transporting newborn infants with suspected duct dependent congenital heart disease on low-dose prostaglanding E1 without routine mechanical ventilation. Arch Dis Child Fetal Neonatal Ed 2007;92:F117–19.
J Matern Fetal Neonatal Med, Early Online: 1–4
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