The effect of pre-ECLS ventilation time on survival and respiratory morbidity in the neonatal population

Updates in Neonatal Extracorporeal Membrane Oxygenation and the Artificial Placenta

Extracorporeal life support, initially performed in neonates, is now commonly used for both pediatric and adult patients requiring pulmonary and/or cardiac support. Data suggests the clinical feasibility of Extracorporeal Membrane Oxygenation for premature infants (29-33 weeks estimated gestational age [EGA]). For extremely premature infants less than 28 weeks EGA, an artificial placenta has been developed to recreate the fetal environment. This approach is investigational but clinical translation is promising. In this article, we discuss the current state and advances in neonatal and "preemie Extracorporeal Membrane Oxygenation" and the development of an artificial placenta and its potential use in extremely premature infants.

Pediatric and neonatal extracorporeal life support: current state and continuing evolution

The use of extracorporeal life support (ECLS) for the pediatric and neonatal population continues to grow. At the same time, there have been dramatic improvements in the technology and safety of ECLS that have broadened the scope of its application. This article will review the evolving landscape of ECLS, including its expanding indications and shrinking contraindications. It will also describe traditional and hybrid cannulation strategies as well as changes in circuit components such as servo regulation, non-thrombogenic surfaces, and paracorporeal lung-assist devices. Finally, it will outline the modern approach to managing a patient on ECLS, including anticoagulation, sedation, rehabilitation, nutrition, and staffing.

In-Hospital Outcomes Following Extracorporeal Membrane Oxygenation in a Retrospective Cohort of Infants

Objective

We sought to characterize associations between infant characteristics and extracorporeal membrane oxygenation (ECMO) survival using electronic health records data.

Study Design

We examined a cohort study of infants ≥32 weeks of gestational age and ≥1,800 g birth weight supported with ECMO in a Pediatrix Medical Group neonatal intensive care unit from 1998 to 2013.

Results

We identified 268 infants, of which 45 (17%) were <37 weeks of gestational age. Survival to discharge was 87% but was lower in premature compared with term infants (76 vs. 89%, p = 0.03). In multivariable analysis, acute kidney injury (odds ratio [OR] = 4.00; 95% confidence interval [CI] = 1.05, 15.24), postnatal age at cannulation of 7 to 13 days (OR = 5.86; 95% CI = 1.21, 28.44), and venoarterial ECMO cannulation (OR = 4.33; 95% CI = 1.77, 10.60) were associated with lower survival.

Conclusion

ECMO cannulation type, postnatal age, and acute kidney injury were associated with lower ECMO survival, while prematurity was not. Future studies are needed to identify risk factors and strategies to improve outcomes.

Extracorporeal life support: updates and controversies

The use of Extracorporeal Life Support (ECLS) in children and adults has markedly increased during the past few years with over 4000 patients placed on ECLS every year in over 200 centers. This article focuses on updates to the physiology and mechanics of ECLS with use of magnetically levitated centrifugal pumps, hollow-fiber gas-exchange devices, and bi-caval dual-lumen catheters. We also explore controversies in management including indications, cannulation approaches, renal replacement, monitoring of anticoagulation, early ambulation, and termination of ECLS. Finally, we present changes in the systems that provide ECLS including the single-provider model and regionalization of care.

Advances in neonatal extracorporeal support: the role of extracorporeal membrane oxygenation and the artificial placenta

This review addresses the history and evolution of neonatal extracorporeal membrane oxygenation (ECMO), with a discussion of the indications, contraindications, modalities, outcomes, and impact of ECMO. Controversies surrounding novel uses of ECMO in neonates, namely ECMO for premature infants and ex utero intrapartum therapy with transition to ECMO, are discussed. The development of an extracorporeal artificial placenta for support of premature infants is presented, including the rationale, research, and challenges. ECMO has had a dramatic effect on the care of critically ill neonates over the past 4 decades, and there is great potential to expand these benefits in the future.

The impact of mechanical ventilation time before initiation of extracorporeal life support on survival in pediatric respiratory failure: a review of the Extracorporeal Life Support Registry

OBJECTIVE

To evaluate the relationship between duration of mechanical ventilation before the initiation of extracorporeal life support and the survival rate in children with respiratory failure. Extracorporeal life support has been used as a rescue therapy for >30 yrs in children with severe respiratory failure. Previous studies suggest patients who received >7-10 days of mechanical ventilation were not acceptable extracorporeal life support candidates as a result of irreversible lung damage.

DESIGN

A retrospective review encompassing the past 10 yrs of the International Extracorporeal Life Support Organization Registry (January 1, 1999, to December 31, 2008).

SETTING

Extracorporeal Life Support Organization Registry database.

PATIENTS

A total of 1325 children (≥ 30 days and ≤ 18 yrs) met inclusion criteria.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The following pre-extracorporeal life support variables were identified as independently and significantly related to the chance of survival: 1) >14 days of ventilation vs. 0-7 days was adverse (odds ratio, 0.32; p < .001); 2) the presence of a cardiac arrest was adverse (odds ratio, 0.56; p = .001); 3) pH per 0.1-unit increase was protective (odds ratio, 1.15; p < .001); 4) oxygenation index, per 10-unit increase was adverse (odds ratio, 0.95; p = .002); and 5) any diagnosis other than sepsis was related to a more favorable outcome. Patients requiring >7-10 or >10-14 days of pre-extracorporeal life support ventilation did not have a statistically significant decrease in survival as compared with patients who received 0-7 days.

CONCLUSIONS

There was a clear relationship between the number of mechanical ventilation days before the initiation of extracorporeal life support and survival. However; there was no statistically significant decrease in survival until >14 days of pre-extracorporeal life support ventilation was reached regardless of underlying diagnosis. We found no evidence to suggest that prolonged mechanical ventilation should be considered as a contraindication to extracorporeal life support in children with respiratory failure before 14 days.

Is it possible to predict outcome in pulmonary ECMO? Analysis of pre-operative risk factors

Serious pulmonary failure may be treated with extracorporeal membrane oxygenation (ECMO) when other treatment has failed. The aim of this study was to analyze pre-operative risk factors of early mortality in patients who underwent either veno-arterial (VA) ECMO or veno-venous (VV) ECMO for pulmonary failure. We studied a total of 26 risk factors in 72 patients with severe pulmonary insufficiency treated with ECMO. All consecutive cases treated at our institution between Sept 1990 and Aug 2007 were included. Univariate analysis and multiple logistic regression analysis were performed on 26 risk factors. The end point was early mortality (any death within 30 days of ECMO treatment). Thirty-six (50%) of the patients died within 30 days of treatment. Age, gender, body mass index(BMI)(adults), cause of pulmonary failure, pre-ECMO treatment with nitric oxide(NO), intra-aortic balloon pump(IABP), and type of ventilation did not significantly influence early mortality. Neither pre-operative blood gas results, oxygenation index or pre-operative PaO(2)/FiO(2) ratio, nor mean ventilator days prior to ECMO gave any indications on early mortality. Liver function did not predict early mortality, but pre-ECMO serum creatinine levels were significantly lower in patients who survived. Treatment with ECMO in patients with severe pulmonary failure may save lives. It is, however, difficult to predict outcome when initiating ECMO. In this analysis, only pre-operative serum creatinine levels correlated with survival. None of the other parameters, including those which were used to select patients for ECMO treatment, could significantly predict the outcome.

Extracorporeal life support

Extracorporeal life support (ECLS) denotes the use of prolonged extracorporeal cardiopulmonary bypass in patients with acute, reversible cardiac or respiratory failure. As technology has advanced, organ support functions other than gas exchange, such as liver, renal, and cardiac support, have been provided by ECLS, and others, such as immunologic support, will be developed. The future of ECLS will include improvements in devices accompanied by circuit simplification and auto-regulation. Such enhancements in technology will allow application of ECLS to populations currently excluded from such support; for example, thromboresistant circuits will eliminate the need for systemic anticoagulation and lead to the use of this technique in premature newborns. As the ECLS technique becomes safer and simpler, and as morbidity and mortality are minimized, criteria for application of ECLS will be relaxed. New approaches to ECLS, such as pumpless arteriovenous bypass, the artificial placenta, arteriovenous CO(2) removal (AVCO(2)R), and intravenous oxygenators (IVOX), will become more commonly applied. Such advances in technology will allow broader and more routine application of ECLS for lung and other organ system failure.

Neonatal extracorporeal life support: impact of new therapies on survival

OBJECTIVE

To evaluate the effects of pre-extracorporeal life support (ECLS) management with nitric oxide (NO), high frequency ventilation (HFV), and surfactant on mortality among neonates supported with ECLS.

STUDY DESIGN

Extracorporeal Life Support Organization (ELSO) data on 7017 neonates cannulated for respiratory reasons between 1996 and 2003 were analyzed using chi2, analysis of variance, and logistic regression.

RESULTS

The use of ECLS declined by 26.6% over the study period with no significant change in mortality. Unadjusted ECLS mortality for NO-treated patients was lower than for infants not treated with NO (25.1% vs 28.6%, P = .0012) and for infants treated with surfactant than for infants not treated with surfactant (18.7% vs 30.3%, p <.0001.) Unadjusted mortality for HFV-treated patients was no different than for non-HFV-treated patients (26.0% vs 26.6%, P = .56). After adjusting for confounders (primary diagnosis, age at cannulation, ECMO year 1996-1999 vs 2000-2003), surfactant use was associated with decreased mortality. NO-treated neonates were less likely to have a pre-ECLS cardiopulmonary arrest than infants not treated with NO. NO, HFV, and surfactant were not associated with prolongation of ECLS or mechanical ventilation.

CONCLUSIONS

NO, HFV, and surfactant were not associated with increased mortality in neonates who require ECLS for hypoxic respiratory failure.

Extracorporeal membrane oxygenation in infants with meconium aspiration syndrome: a decade of experience with venovenous ECMO

BACKGROUND

Despite the emergence of new therapies for respiratory failure of the newborn with meconium aspiration syndrome (MAS), extracorporeal membrane oxygenation (ECMO) has a significant role as a rescue modality in these infants. Our objective was to compare the use of venovenous (VV) vs venoarterial (VA) ECMO in newborns with MAS who need ECMO and to ascertain the impact of new therapies in these infants during the last decade. We also evaluated how disease severity or time of ECMO initiation affected mortality and morbidity.

METHODS

A report of 12 years experience (1990-2002) of a single center, comparing VV and VA ECMO, is given. Venovenous ECMO was the preferred rescue modality for respiratory failure unresponsive to maximal medical therapy. Venoarterial ECMO was used only when the placement of a VV ECMO 14-F catheter was not possible; 128 patients met ECMO criteria, 114 were treated with VV ECMO, and 12 with VA ECMO. Two patients were converted from VV to VA ECMO.

RESULTS

Venovenous and VA ECMO patients had comparable birth weight (mean +/- SEM, 3.48 +/- 0.05 vs 3.35 +/- 0.15 kg) and gestational age (40.3 +/- 0.1 vs 40.7 +/- 0.3 weeks). Before ECMO, there was no difference between VV and VA ECMO patients in oxygenation index (60 +/- 3 vs 63 +/- 8), mean airway pressure (19.5 +/- 0.4 vs 20.8 +/- 1.5 cm H2O), alveolar-arterial O2 gradient (630 +/- 2 vs 632 +/- 4 torr), ECMO cannulation age (median [25th-75th percentiles], 23 [14-47] vs 26 [14-123] hours), or in the % of patients who needed vasopressors/inotropes (98% vs 100%). From November 1994, inhaled nitric oxide (NO) was available. Before VV ECMO, 67% of the patients received NO, 24% received surfactant, and 48% were treated with high-frequency ventilation (HFV). There was no significant difference between VV and VA ECMO patients in survival rate (94% vs 92%), ECMO duration (88 [64-116] vs 94 [55-130] hours), time of extubation (9 [7-11] vs 14 [9-15] days), age at discharge (23 [18-30] vs 27 [15-41] days), or incidence of short-term intracranial complications (5.3% vs 16.7%). For the total cohort of 126 infants, indices of disease severity (oxygenation index, alveolar-arterial O 2 gradient, mean airway pressure) did not correlate with outcome measures. Delay in ECMO initiation (> 96 hours) was associated with prolonged mechanical ventilation and hospitalization (P < .01). New therapies (NO, HFV, surfactant) in the second part of the decade were associated with a longer ECMO duration (98 [80-131] vs 87 [60-116] hours; P < .05), no delay in ECMO initiation time (23 [10-40] vs 24 [14-52] hours), and no significant change in survival (97% vs 92.5%). No patient was treated with VA ECMO after 1994.

CONCLUSIONS

Venovenous ECMO is as reliable as VA ECMO in newborns with MAS in severe respiratory failure who need ECMO. Delay in ECMO initiation may result in prolonged mechanical ventilation and increased length of hospital stay. The emergence of new conventional therapies (NO, HFV, surfactant) and particularly increased experience enable sole use of VV ECMO with no significant change in survival in infants with MAS.

Delayed institution of extracorporeal membrane oxygenation is associated with increased mortality rate and prolonged hospital stay

BACKGROUND/PURPOSE

Severe meconium aspiration syndrome (MAS) is a frequent indication for extracorporeal membrane oxygenation (ECMO). Trials of less invasive cardiopulmonary support may result in fewer infants treated with ECMO but could delay institution of ECMO. The authors hypothesized that those infants with severe MAS who are treated with ECMO early will have a lower mortality rate and a shorter hospital course than those who receive delayed ECMO.

METHODS

A retrospective review of all patients with MAS in the national extracorporeal life support (ELSO) registry for the decade 1989 through 1998 was performed. Data from the ELSO registry were examined for demographics, clinical parameters, and treatment course. Patients were divided into 3 groups based on the time from birth to institution of ECMO: group 1, 0 to 23 hours; group 2, 24 to 96 hours; and group 3, greater than 96 hours. These groups were compared for survival, duration of extracorporeal support, and duration of ventilatory support after ECMO. Statistical relevance was determined by analysis of variance (ANOVA) and Tukey's post-hoc test.

RESULTS

A total of 3,235 of 4,002 patients with MAS had complete information on duration of mechanical ventilation. Overall mortality rate was 5.8%. The mortality rate in group 1 (n = 1,266) was 4.8%, group 2 (n = 1,568) 6.0%, and group 3 (n = 401) 7.7%. An increased time to ECMO was associated with a significant increase in mortality rate (P <.05). This also was associated with significant increases in the length of the ECMO run (157 +/- 4 v 130 +/- 2 hours, P =.02) and duration of post-ECMO ventilation (157 +/- 17 v 118 +/- 3 hours; P <.001). Those patients in groups 1 and 2 who did not respond to a trial of high-frequency oscillatory ventilation had significantly longer ECMO runs (129 +/- 2 v 113 +/- 1 hours; P =.001) and longer post-ECMO ventilator courses (137 +/- 2 v 114 +/- 1 hours; P =.002) than those who did not.

CONCLUSIONS

Delay in institution of ECMO for MAS results in prolonged ECMO and need for post-ECMO ventilation. Consideration should be given to instituting ECMO earlier in patients with severe MAS.

Outcome of infants with bronchopulmonary dysplasia who receive extracorporeal membrane oxygenation therapy

BACKGROUND/PURPOSE

Extracorporeal membrane oxygenation (ECMO) is an accepted therapy for acute respiratory failure but more recently has been used in infants with bronchopulmonary dysplasia (BPD) and superimposed acute pulmonary insults. The purpose of this study was to review the outcomes of such infants.

METHODS

Charts of infants at The Children's Hospital of Philadelphia (CHOP) who had a diagnosis of BPD before ECMO were reviewed. In addition, to obtain survival data in a larger population, the Extracorporeal Life Support Organization (ELSO) Registry was searched for infants with BPD before ECMO.

RESULTS

Of 204 patients who received noncardiac ECMO at CHOP, 9 had BPD before ECMO. Of 7 survivors, 4 were still ventilator dependent at 9 to 39 months of corrected age. Developmentally, 4 had significant global delays, whereas 3 had significant language and motor delays with average to mildly delayed cognitive abilities. The ELSO Registry search showed 76 patients with BPD before ECMO, with a 78% survival.

CONCLUSIONS

The survival rate of infants with BPD who receive ECMO is comparable to, or better than, the survival rates in most other ECMO populations. However, there appears to be a high risk of severe pulmonary and neurodevelopmental sequelae.