Probability of survival after prolonged extracorporeal membrane oxygenation in pediatric patients with acute respiratory failure. Extracorporeal Life Support Organization

Impact of Extracorporeal Membrane Oxygenation Bridging Duration on Lung Transplant Outcomes

BACKGROUND

We sought to characterize the association between venovenous extracorporeal membrane oxygenation (VV-ECMO) bridging duration and outcomes in patients listed for lung transplantation.

METHODS

A retrospective observational study was conducted using the Organ Procurement and Transplantation Network (OPTN) database to identify adults (aged ≥18 years) who were listed for lung transplantation between 2016 and 2020 and were bridged with VV-ECMO. Patients were then stratified into groups, determined by risk inflection points, depending on the amount of time spent on pretransplant ECMO: group 1 (≤5 days), group 2 (6-10 days), group 3 (11-20 days), and group 4 (>20 days). Waiting list survival between groups was analyzed using Fine-Gray competing risk models. Posttransplant survival was compared using Cox regression.

RESULTS

Of 566 eligible VV-ECMO bridge-to-lung-transplant patients (median age, 54 years, 49% men), 174 (31%), 124 (22%), 130 (23%), and 138 (24%) were categorized as groups 1, 2, 3, and 4, respectively. Overall, median duration of VV-ECMO was 10 days (interquartile range, 1-211 days), and 178 patients (31%) died on the waiting list. In the Fine-Gray model, compared with group 1, patients bridged with longer ECMO durations in group 2 (subdistribution hazard ratio [SHR], 2.95; 95% CI, 1.63-5.35), group 3 (SHR, 3.96; 95% CI, 2.36-6.63), and group 4 (SHR, 4.33; 95% CI, 2.59-7.22, all P < .001) were more likely to die on the waiting list. Of 388 patients receiving a transplant, pretransplant ECMO duration was not associated with 1-year survival in Cox regression.

CONCLUSIONS

Prolonged duration of ECMO bridging was associated with worse waiting list mortality but did not impact survival after lung transplant. Prioritization of very early transplantation may improve waiting list outcomes in this population.

Seven-day in vivo testing of a novel, low-resistance, pumpless pediatric artificial lung for long-term support

INTRODUCTION

For children with end-stage lung disease that cannot wean from extracorporeal life support (ECLS), a wearable artificial lung would permit extubation and provide a bridge to recovery or transplantation. We evaluate the function of the novel Pediatric MLung-a low-resistance, pumpless artificial lung developed specifically for children-in healthy animal subjects.

METHODS

Adolescent "mini sheep" weighing 12-20 kg underwent left thoracotomy, cannulation of the main pulmonary artery (PA; inflow) and left atrium (outflow), and connection to the MLung.

RESULTS

Thirteen sheep were studied; 6 were supported for 7 days. Mean PA pressure was 23.9 ± 6.9 mmHg. MLung blood flow was 633±258 mL/min or 30.0 ± 16.0% of CO. MLung pressure drop was 4.4 ± 3.4 mmHg. Resistance was 7.2 ± 5.2 mmHg/L/min. Device outlet oxygen saturation was 99.0 ± 3.3% with inlet saturation 53.8 ± 7.3%. Oxygen delivery was 41.1 ± 18.4 mL O₂/min (maximum 84.9 mL/min) or 2.8 ± 1.5 mL O₂/min/kg. Platelet count significantly decreased; no platelet transfusions were required. Plasma free hemoglobin significantly increased only on day 7, at which point 2 of the animals had plasma free hemoglobin levels above 50 mg/dL.

CONCLUSION

The MLung provides adequate gas exchange at appropriate blood flows for the pediatric population in a PA-to-LA configuration. Further work remains to improve the biocompatibility of the device.

LEVEL OF EVIDENCE

N/A.

A pumpless artificial lung without systemic anticoagulation: The Nitric Oxide Surface Anticoagulation system

BACKGROUND

Artificial lungs have the potential to serve as a bridge to transplantation or recovery for children with end-stage lung disease dependent on extracorporeal life support, but such devices currently require systemic anticoagulation. We describe our experience using the novel Nitric Oxide (NO) Surface Anticoagulation (NOSA) system-an NO-releasing circuit with NO in the sweep gas-with the Pediatric MLung-a low-resistance, pumpless artificial lung.

METHODS

NO flux testing: MLungs (n = 4) were tested using veno-venous extracorporeal life support in a sheep under anesthesia with blood flow set to 0.5 and 1 L/min and sweep gas blended with 100 ppm NO at 1, 2, and 4 L/min. NO and NO₂ were measured in the sweep and exhaust gas to calculate NO flux across the MLung membrane. Pumpless implants: Sheep (20-100 kg, n = 3) underwent thoracotomy and cannulation via the pulmonary artery (device inflow) and left atrium (device outflow) using cannulae and circuit components coated with an NO donor (diazeniumdiolated dibutylhexanediamine; DBHD-N₂O₂) and argatroban. Animals were connected to the MLung with 100 ppm NO in the sweep gas under anesthesia for 24 h with no systemic anticoagulation after cannulation.

RESULTS

NO flux testing: NO flux averaged 3.4 ± 1.0 flux units (x10^-10 mol/cm²/min) (human vascular endothelium: 0.5-4 flux units). Pumpless implants: 3 sheep survived 24 h with patent circuits. MLung blood flow was 716 ± 227 mL/min. Outlet oxygen saturation was 98.3 ± 2.6%. Activated clotting time was 151±24 s. Platelet count declined from 334,333 ± 112,225 to 123,667 ± 7,637 over 24 h. Plasma free hemoglobin and leukocyte and platelet activation did not significantly change.

CONCLUSIONS

The NOSA system provides NO flux across a gas-exchange membrane of a pumpless artificial lung at a similar rate as native vascular endothelium and achieves effective local anticoagulation of an artificial lung circuit for 24 h.

Mortality trends in neonatal ECMO for pulmonary hypoplasia: A review of the Extracorporeal Life Support Organization database from 1981 to 2016

BACKGROUND

The purpose of this review is to provide ECMO outcome data for medical personnel who counsel families of patients with pulmonary hypoplasia (PH), often secondary to renal abnormalities. We report diagnoses and outcomes associated with PH in neonates that were treated with ECMO over the past 35 years.

METHODS

Retrospective cohort study using the ELSO database for neonates born between 1981 and 2016 with a primary or secondary diagnosis of PH. Five patient groups were created based on ICD-9 codes. Mortality rates were compared and trends over time were investigated.

RESULTS

Thirty-three percent of the 1385 patients survived to discharge. Congenital diaphragmatic hernia (CDH) patients had significantly higher mortality than PH patients secondary to renal dysplasia (p < 0.001). Mortality decreased significantly over time for all groups (p < 0.001). The proportion of patients alive at discharge increased over time for CDH patients (p < 0.001), whereas survival decreased for patients with PH secondary to renal dysplasia (p = 0.012).

CONCLUSIONS

Neonates with PH that require ECMO have high mortality rates, which have generally decreased over the past 35 years; however, mortality for neonates with PH secondary to renal dysplasia continues to increase. We speculate that the apparent rise in mortality for these patients is because of changes in patient selection subsequent to improvements in non-ECMO ventilatory support.

LEVEL OF EVIDENCE

II.

Long-term Respiratory Extracorporeal Membrane Oxygenation and Prognosis: A Retrospective Analysis

The duration of extracorporeal membrane oxygenation (ECMO) treatments increases, however, data presented from prolonged support is limited. We retrospectively analyzed all patients during a 4-year period undergoing respiratory ECMO for duration of therapy, demographics, therapy-associated parameters, and outcome according to ECMO duration (<28 days and ≥28 days = long-term ECMO). Out of 55 patients undergoing ECMO for ARDS or during bridging to lung transplantation, 18 were on ECMO for ≥28 days (33%). In the long-term group, median ECMO run time was 40 days (interquartile range 34-54 days). Hospital survival was not significantly different between the groups (54% in short-term and 50% in long-term ECMO patients). There was a significantly higher proportion of patients suffering from malignancy in the group of long-term nonsurvivors. Recovery occurred after more than 40 days on ECMO in 3 patients. The longest ECMO run time in a hospital survivor was 65 days. Duration of ECMO support alone was no prognostic factor and should not represent a basis for decision-making. In patients suffering from malignancy, long-term ECMO support seems to be a factor of adverse prognosis, if not futile.

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.

Outcomes and associated ethical considerations of long-run pediatric ECMO at a single center institution

PURPOSE

Survival of neonatal and pediatric patients undergoing extracorporeal membrane oxygenation (ECMO) ≥ 21 days has not been well described. We hypothesized that patients would have poor survival and increased long-term complications.

METHODS

Retrospective, single center, review and case analysis. Tertiary-care university children's hospital including neonatal, pediatric and cardiac intensive care units. After institutional review board approval, the charts of all patients < 18 years of age undergoing ECMO for ≥ 21 continuous days were performed, and they were compared to comparative patients undergoing shorter runs. Overall survival, incidence of complications, and post-discharge recovery were recorded.

RESULTS

Overall survival was 36% in patients undergoing ≥ 21 days of ECMO (N = 14). 5/8 patients with cardiopulmonary failure from acquired etiologies survived versus 0/6 patients with congenital anomalies. 1/5 survivors achieved complete recovery with no neurologic deficits. The remaining survivors suffer from multiple medical and neurodevelopmental morbidities.

CONCLUSION

ECMO support for ≥ 21 days is associated with poor survival, particularly in neonates with congenital anomalies. Long-term outcomes for survivors ought to be carefully weighed and discussed with parents given the high incidence of neurologic morbidities in this population.

Viral Infection in the Development and Progression of Pediatric Acute Respiratory Distress Syndrome

Viral infections are an important cause of pediatric acute respiratory distress syndrome (ARDS). Numerous viruses, including respiratory syncytial virus (RSV) and influenza A (H1N1) virus, have been implicated in the progression of pneumonia to ARDS; yet the incidence of progression is unknown. Despite acute and chronic morbidity associated with respiratory viral infections, particularly in "at risk" populations, treatment options are limited. Thus, with few exceptions, care is symptomatic. In addition, mortality rates for viral-related ARDS have yet to be determined. This review outlines what is known about ARDS secondary to viral infections including the epidemiology, the pathophysiology, and diagnosis. In addition, emerging treatment options to prevent infection, and to decrease disease burden will be outlined. We focused on RSV and influenza A (H1N1) viral-induced ARDS, as these are the most common viruses leading to pediatric ARDS, and have specific prophylactic and definitive treatment options.

Adenovirus pneumonia complicated with acute respiratory distress syndrome: a case report

Severe adenovirus infection in children can manifest with acute respiratory distress syndrome (ARDS) and respiratory failure, leading to the need for prolonged mechanical support in the form of either mechanical ventilation or extracorporeal life support. Early extracorporeal membrane oxygenation (ECMO) intervention for children with ARDS should be considered if selection criteria fulfill.We report on a 9-month-old boy who had adenovirus pneumonia with rapid progression to ARDS. Real-time polymerase chain reaction tests of sputum and pleural effusion samples confirmed adenovirus serotype 7. Chest x-rays showed progressively increasing infiltrations and pleural effusions in both lung fields within 11 days. Because conventional ARDS therapies failed, we initiated ECMO with high-frequency oscillatory ventilation (HFOV) for 9 days. Chest x-rays showed gradual improvements in lung expansion.This patient was subsequently discharged after a hospital stay of 38 days. Post-ECMO and adenovirus sequelae were followed in our outpatient department.Adenovirus pneumonia in children can manifest with severe pulmonary morbidity and respiratory failure. The unique lung recruitment by HFOV can be a useful therapeutic option for severe ARDS patients when combined with sufficient lung rest provided by ECMO.

Prolonged extracorporeal membrane oxygenator support among neonates with acute respiratory failure: a review of the Extracorporeal Life Support Organization registry

The objective of this study was to identify types of neonatal diseases associated with prolonged (≥21 days) extracorporeal membrane oxygenation (ECMO), characteristics of survivors and nonsurvivors among those requiring prolonged ECMO, and factors associated with mortality. Data were obtained from the Extracorporeal Life Support Organization registry over the period from January 1, 1998, through December 31, 2011, for all neonates (age <31 days), with respiratory failure as the indication for ECMO. The primary outcome was survival to hospital discharge. Survivors and nonsurvivors were compared for 1) patient demographics, 2) primary diagnosis, 3) pre-ECMO clinical course and therapies, and 4) ECMO course and associated complications. The most common diagnosis associated with prolonged ECMO support in neonates is congenital diaphragmatic hernia (CDH; 69%). Infants with meconium aspiration syndrome had the highest survival rate (71%) compared with other diagnoses analyzed (26.3%; p < 0.001). Nonsurvivors were more likely to experience complications on ECMO, and multivariate analysis showed that the need for inotropes while on ECMO support (odds ratio, 2.2 [95% confidence interval, 1.3-3.7]; p = 0.003) was independently associated with mortality. Neonates requiring prolonged ECMO support have a 24% survival to discharge. Many of these cases involve CDH. Complications are common with prolonged ECMO, but only receipt of inotropes was shown to be independently associated with mortality. This report may help guide clinical decision making and family counseling for neonates requiring prolonged ECMO support.

Prolonged duration ECMO for ARDS: futility, native lung recovery, or transplantation?

Extracorporeal membrane oxygenation (ECMO) is recommended as a treatment modality for severe acute respiratory distress syndrome (PaO2/FiO2 ≤ 100 mm Hg with positive end-expiratory pressure ≥ 5 cm H2O) as defined by the Berlin definition. The reported usual duration of ECMO in these patients is 7-10 days. However, increasing reports of prolonged duration ECMO (>14 days) for respiratory failure document survival rates of 50-70% with native lung recovery, and ECMO bridge to lung transplantation has been performed at many centers. At present, there are no established national criteria for when to consider futility or lung transplantation in adult patients requiring ECMO for acute respiratory failure. We report a case of prolonged duration venovenous-ECMO (1,347 hours, 56.13 days), with native lung recovery and discuss treatment strategies to optimize native lung recovery in ECMO patients. The lung may have unexpected regenerative capacity with native lung recovery after prolonged mechanical support, similar to acute kidney injury and native renal recovery. We recommend redefining irreversible lung injury and futility in ECMO.

Is age at initiation of extracorporeal life support associated with mortality and intraventricular hemorrhage in neonates with respiratory failure?

OBJECTIVE

To describe differences in characteristics among neonates treated with extracorporeal life support (ECLS) in the first week of life for respiratory failure compared with later in the neonatal period and to assess risk factors for central nervous system (CNS) hemorrhage and mortality among the two groups.

STUDY DESIGN

Review of the Extracorporeal Life Support Organization registry from 2001 to 2010 of neonates ⩽30 days comparing two age groups: those ⩽7 days (Group 1) to those >7 days (Group 2) at ECLS initiation.

RESULT

Among 4888 neonates, Group 1 (n=4453) had significantly lower mortality (17 vs 39%, P<0.001) but greater CNS hemorrhage (11 vs 7%, P=0.02) than Group 2 (n=453). Mortality and CNS hemorrhage improved significantly with increasing gestational age only for Group 1 patients. CNS hemorrhage occurred more frequently in Group 1 patients receiving venoarterial (VA) than with venovenous ECLS (15 vs 7%, P<0.001). In Group 1, lower birth weight and pre-ECLS pH and VA mode were independently associated with mortality. In Group 2, higher mean airway pressure was independently associated with mortality. Complications of ECLS therapy, including CNS hemorrhage and renal replacement therapy were independently associated with mortality for both groups.

CONCLUSION

Neonates cannulated for ECLS after the first week of life had greater mortality despite lower CNS hemorrhage than neonates receiving ECLS earlier. Premature infants cannulated after 1 week had fewer CNS hemorrhages than premature infants treated with extracorporeal membrane oxygenation starting within the first week of life.

Current knowledge of acute lung injury and acute respiratory distress syndrome

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) continues to be a major cause of mortality in adult and pediatric critical care medicine. This article discusses the pulmonary sequelae associated with ALI and ARDS, the support of ARDS with mechanical ventilation, available adjunctive therapies, and experimental therapies currently being tested. It is hoped that further understanding of the fundamental biology, improved identification of the patient's inflammatory state, and application of therapies directed at multiple sites of action may ultimately prove beneficial for patients suffering from ALI/ARDS.

Prolonged extracorporeal membrane oxygenation for children with respiratory failure

OBJECTIVE

Extracorporeal membrane oxygenation is used to support children with respiratory failure. When extracorporeal membrane oxygenation duration is prolonged, decisions regarding ongoing support are difficult as a result of limited prognostic data.

DESIGN

Retrospective case series.

SETTING

Multi-institutional data reported to the Extracorporeal Life Support Organization Registry.

PATIENTS

Patients aged 1 month to 18 yrs supported with extracorporeal membrane oxygenation for respiratory failure from 1993 to 2007 who received support for ≥ 21 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 3213 children supported with extracorporeal membrane oxygenation during the study period, 389 (12%) were supported ≥ 21 days. Median patient age was 9.1 months (interquartile range, 2.5-41.7 months). Median weight was 6.7 kg (interquartile range, 3.5-15.8 kg). Survival for this group was 38%, significantly lower than survival reported for children supported ≤ 14 days (61%, p < .001). Among children supported with extracorporeal membrane oxygenation for ≥ 21 days, no differences were found between survivors and nonsurvivors with regard to acute pulmonary diagnosis, pre-extracorporeal membrane oxygenation comorbidities, pre-extracorporeal membrane oxygenation adjunctive therapies, or pre-extracorporeal membrane oxygenation blood gas parameters. Only peak inspiratory pressure was significantly different in survivors. Complications occurring on extracorporeal membrane oxygenation were more common among nonsurvivors. The use of inotropic infusion (odds ratio 1.64; 95% confidence interval 1.07-2.52), acidosis (pH <7.2) during extracorporeal membrane oxygenation (odds ratio 2.62; 95% confidence interval 1.51-4.55), and male gender (odds ratio 1.95; 95% confidence interval 1.21-3.15) were independently associated with increased odds of death.

CONCLUSION

Survival declines with duration of extracorporeal membrane oxygenation. Male gender and inadequate cardiorespiratory status during extracorporeal membrane oxygenation increased the risk of death. Prolonged support with extracorporeal membrane oxygenation appears reasonable unless multiorgan failure develops.

Use of extracorporeal life support in adults with severe acute respiratory failure

Extracorporeal membrane oxygenation (ECMO) is a recognized and accepted therapeutic option in the treatment of neonatal and pediatric respiratory failure. However, early studies in adults did not demonstrate a survival benefit associated with the utilization of ECMO for severe acute respiratory failure. Despite this historical lack of benefit, use of ECMO in adult patients has seen a recent resurgence. Local successes and a recently published randomized trial have both demonstrated promising results in an adult population with high baseline mortality and limited therapeutic options. This article will review the history of ECMO use for respiratory failure; investigate the driving forces behind the latest surge in interest in ECMO for adults with refractory severe acute respiratory failure; and describe potential applications of ECMO that will likely increase in the near 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.

Prolonged venovenous extracorporeal membrane oxygenation in a child with leukemia and persistent bacteremia

OBJECTIVE

In patients who require extracorporeal membrane oxygenation for prolonged periods, it is uncertain whether nosocomial bacteremia that persists throughout an entire extracorporeal membrane oxygenation run can be associated with good outcomes.

DESIGN

Case report.

SETTING

Tertiary pediatric intensive care unit.

PATIENT

A 6-yr-old boy with acute myeloid leukemia and prolonged mechanical ventilatory support.

INTERVENTIONS

Venovenous extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

The patient required extracorporeal membrane oxygenation for refractory hypoxia secondary to nosocomial pneumonia. On day 2 of the extracorporeal membrane oxygenation run and every day thereafter, blood cultures were consistently positive for Stenotrophomonas maltophilia despite combination therapy with intravenous polymyxin B and cotrimoxazole. Excluding the cannulae, the extracorporeal membrane oxygenation circuit was electively changed once during the run but without any effect on bacteremia. After 38 days of extracorporeal membrane oxygenation, the patient was successfully decannulated and the bacteremia ceased. He remains completely well and disease-free at 6-month follow-up.

CONCLUSIONS

Sustained bacteremia during an extracorporeal membrane oxygenation run should not be regarded as a reason to withdraw extracorporeal support, although efforts are clearly warranted to identify possible sources of sepsis and wean off extracorporeal membrane oxygenation at the earliest opportunity.

Glial fibrillary acidic protein as a brain injury biomarker in children undergoing extracorporeal membrane oxygenation

OBJECTIVE

To determine whether, in children, plasma glial fibrillary acidic protein is associated with brain injury during extracorporeal membrane oxygenation and with mortality.

DESIGN

Prospective, observational study.

SETTING

Pediatric intensive care unit in an urban tertiary care academic center.

PATIENTS

Neonatal and pediatric patients on extracorporeal membrane oxygenation (n = 22).

INTERVENTIONS

Serial blood sampling for glial fibrillary acidic protein measurements.

MEASUREMENTS AND MAIN RESULTS

Prospective patients age 1 day to 18 yrs who required extracorporeal membrane oxygenation from April 2008 to August 2009 were studied. Glial fibrillary acidic protein was measured using an electrochemiluminescent immunoassay developed at Johns Hopkins. Control samples were collected from 99 healthy children (0.5-16 yrs) and 59 neonatal intensive care unit infants without neurologic injury. In controls, the median glial fibrillary acidic protein concentration was 0.055 ng/mL (interquartile range, 0-0.092 ng/mL) and the 95th percentile of glial fibrillary acidic protein was 0.436 ng/mL. In patients on extracorporeal membrane oxygenation, plasma glial fibrillary acidic protein was measured at 6, 12, and every 24 hrs after cannulation. We enrolled 22 children who underwent extracorporeal membrane oxygenation. Median age was 7 days (interquartile range, 2 days to 9 yrs), and primary extracorporeal membrane oxygenation indication was: cardiac failure, six of 22 (27.3%); respiratory failure, 12 of 22 (54.5%); extracorporeal cardiopulmonary resuscitation, three of 22 (13.6%); and sepsis, one of 22 (4.6%). Seven of 22 (32%) patients developed acute neurologic injury (intracranial hemorrhage, brain death, or cerebral edema diagnosed by imaging). Fifteen of 22 (68%) survived to hospital discharge. In the extracorporeal membrane oxygenation group, peak glial fibrillary acidic protein levels were higher in children with brain injury than those without (median, 5.9 vs. 0.09 ng/mL, p = .04) and in nonsurvivors compared with survivors to discharge (median, 5.9 vs. 0.09 ng/mL, p = .04). The odds ratio for brain injury for glial fibrillary acidic protein >0.436 ng/mL vs. normal was 11.5 (95% confidence interval, 1.3-98.3) and the odds ratio for mortality was 13.6 (95% confidence interval, 1.7-108.5).

CONCLUSIONS

High glial fibrillary acidic protein during extracorporeal membrane oxygenation is significantly associated with acute brain injury and death. Brain injury biomarkers may aid in outcome prediction and neurologic monitoring of patients on extracorporeal membrane oxygenation to improve outcomes and benchmark new therapies.

Development of a collaborative program to provide extracorporeal membrane oxygenation for adults with refractory hypoxemia within the framework of a pandemic

OBJECTIVE

We report the process used to rapidly develop a collaborative adult respiratory extracorporeal membrane oxygenation program as a response to caring for young adult patients with refractory hypoxemia in the setting of the pH1N1 pandemic.

DESIGN

Interdisciplinary response of a complex medical system to a public health crisis. PATIENTS, INTERVENTIONS, MEASUREMENTS, AND MAIN RESULTS: After the successful use of extracorporeal membrane oxygenation in young adults with pH1N1-induced acute respiratory distress syndrome refractory to conventional therapies, an adult venovenous extracorporeal membrane oxygenation program was implemented over an 8-wk period. Implementation of this program involved a number of key steps that were crucial in the development process, including administrative and institutional support, multidisciplinary leadership and collaboration, extensive interdisciplinary educational initiatives, and substantial technical modifications.

CONCLUSIONS

In the setting of the pH1N1 influenza pandemic, an adult respiratory extracorporeal membrane oxygenation program was successfully developed to complement an established neonatal-pediatric program. This program expansion integrated all of the necessary components involved in the development process from start to finish and confirms that a healthcare system can respond very quickly and successfully to an urgent healthcare need.

Extracorporeal membrane oxygenation for pediatric respiratory failure: Survival and predictors of mortality

OBJECTIVE

The last multicentered analysis of extracorporeal membrane oxygenation in pediatric acute respiratory failure was completed in 1993. We reviewed recent international data to evaluate survival and predictors of mortality.

DESIGN

Retrospective case series review.

SETTING

The Extracorporeal Life Support Organization Registry, which includes data voluntarily submitted from over 115 centers worldwide, was queried. The work was completed at the Division of Pediatric Critical Care, Department of Pediatrics, Primary Children's Medical Center, University of Utah, Salt Lake City, UT.

SUBJECTS

Patients aged 1 month to 18 yrs supported with extracorporeal membrane oxygenation for acute respiratory failure from 1993 to 2007.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 3,213 children studied. Overall survival remained relatively unchanged over time at 57%. Considerable variability in survival was found based on pulmonary diagnosis, ranging from 83% for status asthmaticus to 39% for pertussis. Comorbidities significantly decreased survival to 33% for those with renal failure (n = 329), 16% with liver failure (n = 51), and 5% with hematopoietic stem cell transplantation (n = 22). The proportion of patients with comorbidities increased from 19% during 1993 to 47% in 2007. Clinical factors associated with mortality included precannulation ventilatory support longer than 2 wks and lower precannulation blood pH.

CONCLUSIONS

Although the survival of pediatric patients with acute respiratory failure treated with extracorporeal membrane oxygenation has not changed, this treatment is currently offered to increasingly medically complex patients. Mechanical ventilation in excess of 2 wks before the initiation of extracorporeal membrane oxygenation is associated with decreased survival.

Management of acute lung injury/ARDS

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are disorders of pulmonary inflammation characterized by hypoxemia and respiratory failure. Children have varying incidence of ALI/ARDS from 2.2 to 16 per 100,000 pediatric population associated with high morbidity, mortality, and financial burden. The diagnostic criteria include: acute onset, severe arterial hypoxemia resistant to oxygen therapy alone (PaO₂/FIO₂ ratio ≤ 200 for ARDS and ≤ 300 for ALI), diffuse pulmonary inflammation (bilateral infiltrates on chest radiograph) and No evidence of left atrial hypertension. Management includes ventilatory therapy including lower tidal volume, relatively high PEEP and supportive care. Guidelines for diagnosis, ventilator management, rescue therapies and supportive care are being discussed in the protocol.

Factors associated with survival in pediatric extracorporeal membrane oxygenation--a single-center experience

AIM

We aimed to examine outcomes of extracorporeal membrane oxygenation (ECMO) therapy in the pediatric population and identify pre-ECMO and on-ECMO characteristics that are associated with survival.

METHODS

We retrospectively reviewed the ECMO records at our institution between 1999 and 2008 and selected pediatric patients who were cannulated for respiratory failure or hemodynamic instability resistant to conventional interventions. We recorded details of pre-ECMO clinical characteristics, including blood gas variables and mechanical ventilatory support, and details of ECMO therapy including survival off ECMO and to hospital discharge. Predictors of survival were analyzed using logistic regression modeling and a prediction algorithm was developed.

RESULTS

Of the 445 ECMO runs, data from 58 consecutive patients were analyzed: 57% were successfully decannulated, and 48% survived to discharge from the hospital. The cohort included 32 (55%) female patients, 22 postoperative patients (38%), and 15 (26%) with an immunosuppressive condition, with a median age of 5 years and weight 19.5 kg, The mean duration of pre-ECMO respiratory support was 3 days, in the form of high-frequency oscillatory ventilation (n = 28, 48%) and conventional mechanical ventilation (n = 13, 22%). The median duration (interquartile range) of ECMO support was 142 hours (60, 321) or 5.9 days. Pre-ECMO pH above 7.2 (P < .001) and oxygenation index below 35 (P = .021) were associated with the highest survival rates. Pre-ECMO PaCO(2) and duration of mechanical ventilation were not associated with survival.

CONCLUSIONS

Based on our results, ECMO therapy should be considered early in children with oxygenation index greater than 35 with worsening metabolic status. The restriction of ECMO based on ventilator days alone needs to be revisited in this era of lung protective ventilation.

Management of acute lung injury and acute respiratory distress syndrome in children

BACKGROUND

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS), are devastating disorders of overwhelming pulmonary inflammation and hypoxemia, resulting in high morbidity and mortality.

AIM

To provide the clinician with a summary of the literature on the epidemiology, diagnosis, and an evidence-base for management of ALI/ARDS in children.

DATA SELECTION

PubMed search for clinical trials, selected literature review of other relevant studies on epidemiology and diagnosis. DATA SYNTHESIS AND RECOMMENDATIONS: Lower mortality combined with a relatively lower frequency of ALI/ARDS in children makes performance of clinical trials challenging. Based on expert opinion, the following are recommended: 1) avoid tidal volumes > or =10 mL/kg body weight; 2) keep plateau pressure < or =30 cm H2O, arterial pH at 7.30 to 7.45, and Pao2 60 to 80 torr (8 to 10.7 kPa) (Spo2 > or =90%); 3) provide sedation, analgesia, and stress ulcer prophylaxis; and 4) use a 10 g/dL hemoglobin threshold for packed red blood cell transfusion in unstable patients (shock or profound hypoxia). Evidence supports dropping the hemoglobin transfusion threshold to 7 g/dL once profound hypoxia and shock have resolved. Promising therapies for pediatric ALI/ARDS based on pediatric studies include endotracheal surfactant, high-frequency oscillatory ventilation, noninvasive ventilation, and use of extracorporeal membrane oxygenation as a rescue therapy. Promising therapies based on adult trials include use of corticosteroids for lung inflammation and fibrosis, use of 4 to 6 mL/kg tidal volumes and restrictive fluid management. Prone positioning, bronchodilators, inhaled nitric oxide, tight glucose control, and high-flow nasal cannula (HFNC) oxygen are therapies that require further study before they can be recommended for children with ALI/ARDS.

Extracorporeal membrane oxygenation for cardiopulmonary failure in pediatric patients: is a second course justified?

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is accepted therapy for cardiorespiratory failure. Even after a successful ECMO course, patient deterioration may occur and a second course of ECMO may be contemplated. Although data regarding second ECMO courses exist in neonates, there are no reports describing second ECMO courses in pediatric patients. We hypothesized that data from a national ECMO registry would be useful in identifying which pediatric patients would be optimal candidates for a second course of ECMO.

METHODS

We obtained data from the national Extracorporeal Life Support Organization registry from 1981 to 2007 on all patients 1-18 years old who required single-run ECMO (SRE) or multiple-run ECMO (MRE). Primary outcome measures were complications and survival. Continuous variables were assessed for distribution normality by using a Shaprio-Wilk statistic to guide nonparametric testing. SRE and MRE patients were compared by using chi2 tests (Fisher's exact and McNemar's) to assess differences in categorical variables; continuous data were assessed by using Mann-Whitney U or Wilcoxon signed-rank testing. Two multivariate regression models were constructed to identify independent predictors of survival and complications in MRE patients. Statistical significance was assumed at P < 0.05.

RESULTS

A total of 3937 pediatric patients received ECMO for cardiac or respiratory failure. Of them, 3810 (96.8%) children underwent a single course of ECMO, whereas 127 (3.2%) required multiple ECMO runs. Compared with SRE patients, the first ECMO course in MRE patients was notable for higher rates of cardiac ECMO (61% versus 44%, P < 0.001), venoarterial ECMO (88% versus 78%, P = 0.04), and central cannulation (28% versus 17%, P = 0.007). There was no survival difference between MRE and SRE patients (44% versus 49%, P = 0.28). Median time between MRE courses was 9.0 days (interquartile range = 5-20 days). The mean number of complications per MRE patient was higher in the second ECMO run compared with the first (3.93 versus 3.12, P = 0.008). Multivariate regression identified 2 variables as independent predictors of survival in MRE patients: (1) renal complications during first ECMO run (P = 0.04); and (2) total number of complications during second ECMO run (P = 0.005). A separate multivariate analysis identified 3 variables independently predictive of complications in MRE patients: (1) age (P < 0.001); (2) duration of second run (P < 0.001); and (3) total number of complications during first ECMO run (P < 0.001).

CONCLUSIONS

ECMO therapy achieves 49% survival in children 1-18 years of age. When a second ECMO course becomes necessary, survival rates comparable to the first ECMO course are possible. Patients developing renal complications during their first ECMO course have worse outcome with a second ECMO course. Patients are at greater risk for complications during a second ECMO course if they experience a high number of first-run complications, are >3 years old, or undergo a prolonged second ECMO course. These data are useful when deciding whether to offer a second ECMO course to an eligible pediatric patient.

Versatile use of extra-corporeal life support to resuscitate acute respiratory distress patients

Extra-corporeal life support (ECLS) has been applied successfully to congenital respiratory defects but less optimally to acquired pulmonary failure. We extended this support to certain extreme complexities of patients with acute respiratory distress. From January 2003 to June 2005, 16 (nine men and seven women) patients refractory to ventilator support were treated with ECLS. Their median age was 32.4 years (1.5-70). The triggering events were pulmonary haemorrhage (n = 4), pneumonia (n = 7), aspiration (n = 2) and pancreatitis (n = 3). The indications for support were hypoxaemia in 13 and hypercapnia in three patients. Ten (63%) met the criteria of fast entry. Thirteen (81%) received veno-venous (V-V) mode support and the other three received veno-arterial mode support initially, but then converted to V-V mode after sufficient oxygenation stabilised haemodynamics. Initial pump flow was maximised to improve (mean 3250 +/- 1615 ml/min) to improve the oxygenation. Four patients with active pulmonary haemorrhage were heparin free in the first 12-24 h of support without complications. Excluding one prematurely terminated patient because of brain permanent damage, the duration of support was 162 +/- 95 h (67-363). Eleven (69%) weaned successfully from ECLS and 10 (63%) discharged and regained normal pulmonary performance in a median of 26.8 months follow-up. Pulmonary support using ECLS was feasible in selected patients with acute respiratory distress. Modification of guidelines for liberal use, early deployment before secondary organ damage and prevention of complications during support were the key to final success.

Surfactant application during extracorporeal membrane oxygenation improves lung volume and pulmonary mechanics in children with respiratory failure

Introduction

This study was performed to determine whether surfactant application during extracorporeal membrane oxygenation (ECMO) improves lung volume, pulmonary mechanics, and chest radiographic findings in children with respiratory failure or after cardiac surgery.

Methods

This was a retrospective chart review study in a pediatric intensive care unit (PICU). Seven patients received surfactant before weaning from ECMO was started (group S). They were compared to six patients treated with ECMO who did not receive surfactant (group C). These control patients were matched based on age, weight, and underlying diagnosis. Demographic data, ventilator settings, tidal volume, compliance of respiratory system (calculated from tidal volume/(peak inspiratory pressure – positive end-expiratory pressure), and ECMO flow were extracted. Chest radiographs were scored by two blinded and independent radiologists. Changes over time were compared between groups by repeated-measures analysis of variance (time*group interaction). Values are given as percentages of baseline values.

Results

The groups did not differ with regard to demographic data, duration of ECMO, ventilator settings, PICU and hospital days. After application of surfactant, mean tidal volume almost doubled in group S (from 100% before to 186.2%; p = 0.0053). No change was found in group C (100% versus 98.7%). Mean compliance increased significantly (p = 0.0067) in group S (from 100% to 176.1%) compared to group C (100% versus 97.6%). Radiographic scores tended to decrease in group S within 48 h following surfactant application. ECMO flow tended to decrease in group S within 10 h following surfactant application but not in group C. Mortality was not affected by treatment.

Conclusion

Surfactant application may be of benefit in children with respiratory failure treated with ECMO, but these findings need confirmation from prospective studies.

A review of 100 patients transported on extracorporeal life support

Between May 1990 and January 1999, 100 patients (68 adult, 32 pediatric) with severe respiratory or cardiac instability were successfully transported to the University of Michigan Medical Center on extracorporeal life support. Diagnoses included adult respiratory distress syndrome (n = 78), cardiac failure (n = 7), sepsis (n = 7), asthma (n = 5), respiratory distress syndrome (of newborn) (n = 2), and airway compromise (n = 1). Of the patients, 53 were supported with venovenous bypass and 47 with venoarterial bypass. Patients were transported by ground ambulance (n = 80), helicopter (n = 15), or fixed-wing aircraft (n = 5). The median transport distance was 44 miles (range 2-790 miles), and the median transport time was 5 hours and 30 minutes (range: 1 h 33 min to 16 h 6 min). Sixty-six patients (66%) survived to discharge. One death occurred during cannulation, and two patients died before cannulation began. Complications that occurred during transport included 10 cases of electrical failure, 3 cases of circuit tubing leakage, and 1 case each of circuit rupture, membrane lung thrombosis, and membrane lung leakage. None of the complications occurring during transport had an adverse effect on outcome. We conclude that the long distance transport of patients on extracorporeal life support can be safely accomplished and is an effective option for the unstable patient with severe respiratory or cardiac failure.

Pediatric Extracorporeal Life Support After High Frequency Ventilation: Predictors of Survival

Previous studies of extracorporeal life support in pediatric patients have identified variables associated with survival. However, none of these studies focused on extracorporeal life support after failure of high frequency ventilation (HFV). In the present study, we determined variables associated with survival for pediatric respiratory failure patients who received HFV prior to extracorporeal life support, using data reported to the Extracorporeal Life Support Organization Registry from 1992 to 1998. Patients with neonatal diagnoses, immune compromising conditions, or congenital cardiac defects were excluded. The 243 patients who met inclusion criteria had a 58% survival rate (95% CI 48-66%). The mean age was 22 +/- 39 months. Mean duration of mechanical ventilation prior to extracorporeal life support was 6.6 +/- 5.8 days. Venoarterial extracorporeal life support was used in 72% of the patients; venovenous in 28%. The survival rate for the subset of patients with an oxygenation index greater than 42 cm H2O/torr on HFV (n = 122) was not significantly different from the overall sample. We determined that lower mean airway pressure, lower pressure amplitude, decreased oxygenation index, increased PaO2, and increased oxygen saturation on HFV were associated with increased survival in patients who were subsequently treated with extracorporeal life support.

Artificial lungs: a new inspiration

An estimated 16 million Americans are afflicted with some degree of chronic obstructive pulmonary disease (COPD), accounting for 100,000 deaths per year. The only current treatment for chronic irreversible pulmonary failure is lung transplantation. Since the widespread success of single and double lung transplantation in the early 1990s, demand for donor lungs has steadily outgrown the supply. Unlike dialysis, which functions as a bridge to renal transplantation, or a ventricular assist device (VAD), which serves as a bridge to cardiac transplantation, no suitable bridge to lung transplantation exists. The current methods for supporting patients with lung disease, however, are not adequate or efficient enough to act as a bridge to transplantation. Although occasionally successful as a bridge to transplant, ECMO requires multiple transfusions and is complex, labor-intensive, time-limited, costly, non-ambulatory and prone to infection. Intravenacaval devices, such as the intravascular oxygenator (IVOX) and the intravenous membrane oxygenator (IMO), are surface area limited and currently provide inadequate gas exchange to function as a bridge-to-recovery or transplant. A successful artificial lung could realize a substantial clinical impact as a bridge to lung transplantation, a support device immediately post-lung transplant, and as rescue and/or supplement to mechanical ventilation during the treatment of severe respiratory failure.

Extracorporeal membrane oxygenation for severe respiratory failure

The use of extracorporeal technology to accomplish gas exchange with or without cardiac support is based on the premise that "lung rest" facilitates repair and avoids the baso- or volutrauma of mechanical ventilator management. Extracorporeal membrane oxygenation (ECMO), a modified form of cardiopulmonary bypass, has been shown to decrease mortality of neonatal, pediatric and adult respiratory failure and is capable of total gas exchange. In neonates, over 20,638 patients have been treated with an overall survival of 77% in a population thought to have 78% mortality.

Survival and renal function in pediatric patients following extracorporeal life support with hemofiltration

OBJECTIVE: To determine variables associated with survival in pediatric patients treated with hemofiltration while receiving extracorporeal life support and to determine the probability for recovery of renal function among survivors. DESIGN: Retrospective database analysis. SETTING: University of Michigan pediatric nephrology database. PATIENTS: All pediatric patients treated with continuous hemofiltration while on extracorporeal life support at the University of Michigan between January 1990 and May 1999. A pediatric patient was defined as any child between birth and 18 yrs of age, including children treated in both the pediatric intensive care unit and neonatal intensive care unit. Indications for extracorporeal life support included both cardiac and pulmonary failure. INTERVENTIONS: Data analysis of patients who were treated with hemofiltration while on extracorporeal life support. Hemofiltration includes both ultrafiltration and hemofiltration with countercurrent dialysis. MEASUREMENTS AND MAIN RESULTS: Thirty-five patients with a mean age of 39 +/- 65 months (median, 3 months) underwent hemofiltration while on extracorporeal life support. Forty-three percent survived to hospital discharge (95% CI, 26%-60%). All deaths occurred in the intensive care unit. Recovery of renal function occurred in 93% of survivors (95% CI, 79%-108%). Mean duration of hemofiltration in survivors, including time during and after extracorporeal life support, was 9 +/- 6 days. All nonsurvivors were on renal replacement therapy at the time of death. In this analysis, decreased survival was significantly associated with the use of vasopressor infusions (p =.01) and the presence of complications (p =.006). Vasopressor infusions were required in 89% of patients, and 37% of patients experienced complications. CONCLUSIONS: In patients receiving hemofiltration while on extracorporeal life support, survival is comparable to that reported in other extracorporeal life support or hemofiltration populations. Decreased survival in these patients may be associated with the use of vasopressor infusions and the occurrence of complications. Recovery of renal function occurs in most survivors.

Extracorporeal life support outcome for 128 pediatric patients with respiratory failure

PURPOSE

The aim of this study was to describe a single-center experience with pediatric extracorporeal life support (ECLS) and to determine variables predictive of outcome in pediatric patients, both before the institution of ECLS and while on support.

METHODS

From October 1985 to September 1998 the authors supported 128 children with severe acute hypoxemic respiratory failure(n = 121, Pao2/FIo2 ratio = 58+/-29) or acute hypercarbic respiratory failure (n = 7, Paco2 = 128+/-37), despite maximal conventional ventilation. Mode of access included venoarterial bypass (VA, n = 64), venovenous bypass (VV, n = 53), and VV to VA bypass (n = 11). The techniques used included lung rest, pulmonary physiotherapy, diuresis to dry weight using hemofiltration if needed, minimal anticoagulation, and optimal systemic oxygen delivery.

RESULTS

The median age was 1.4 years (range, 2 weeks to 17 years). The mean duration of ECLS was 288+/-240 hours (range, 4 to 1148 hours or 0.2 to 47.8 days). Lung compliance increased from 0.32+/-0.02 mL/cm H2O/kg to 0.59+/-0.03 mL/cm H2O/kg in survivors, but only increased from 0.34+/-0.02 mL/cm H2O/kg to 0.35+/-0.02 mL/cm H2O/kg in nonsurvivors (P<.002 comparing change between survivors and nonsurvivors). Mean body weight decreased from 9%+/-2% over dry weight to 4%+/-2% in survivors, whereas in nonsurvivors the mean body weight increased from 25%+/-5% over dry weight to 35%+/-7% (P<.001). Outcome results by diagnosis were pneumonia, 73%; acute respiratory distress syndrome, 67%; and airway support, 60%, with overall lung recovery occurring in 77%, and hospital survival in 71%. Multivariate logistic regression modelling of patients with hypoxemic respiratory failure found the only pre-ECLS variable significantly associated with outcome to be pH (P<.05). Variables during the course of ECLS significantly associated with decreased survival were the presence of creatinine greater than 3.0 (P<.01), the need for inotropes (P<.04), failure to return the patient to dry weight (P<.04), and lung compliance that did not improve significantly. (P<.01).

CONCLUSIONS

ECLS provides life support in severe respiratory failure in children, allowing time for injured lungs to recover. Pre-ECLS predictors, such as pH and variables during ECLS, such as presence of renal failure, improvement in compliance, return to dry weight, and the need for inotropes on ECLS, may be useful for predicting outcome.

Advances in conventional and innovative therapies for respiratory distress syndrome in children

Adult respiratory distress syndrome is a phenomenon encountered by many pediatric critical care nurses. Care of these complex patients is multifaceted and requires an in-depth understanding of pathophysiology and therapeutic intervention. Several innovative treatments are now available as biomedical and technical advances have evolved. Outcomes will improve as clinicians improve patient selection, identify therapeutic endpoints, and risk/benefits. This article addresses the current understanding of pathophysiology, innovative treatments, and nursing care issues.

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

Although mechanical ventilation for more than 7 to 10 days has been considered a contraindication to the application of extracorporeal life support (ECLS) in neonates, the outcome and respiratory morbidity for newborns placed on ECLS after more than 7 days of ventilation have not been well characterized. The purpose of this study was to determine the impact of pre-ECLS ventilation time on the rate of survival, the likelihood of the development of bronchopulmonary dysplasia (BPD), and the need for supplemental oxygen at the time of discharge. Examination of the Extracorporeal Life Support Organization (ELSO) Registry showed that 6,110 neonates were treated for respiratory failure with a pre-ECLS ventilation time of less than 14 days between January 1990 and May 1995. Gestational age (GA), birth weight (BW), indication for ECLS, and diagnosis were compared with the rate of survival, the discharge diagnosis of BPD, and the need for home oxygen. The GA and BW of neonates placed on ECLS during the first week of life (n = 5,888) did not differ significantly from those of neonates whose ECLS was begun in the second week of life (n = 222). The neonates were divided into two groups (early, ventilation time of 3 to 6 days; late, ventilation time of 7 to 10 days) to determine the odds ratios for survival, BPD, and home oxygen. Logistic regression analysis was used to develop a model to predict the rate of survival, the risk for the development of BPD, and the need for home oxygen given the length of pre-ECLS ventilation time. The late group was less likely to survive (odds ratio, 1.8; 95% confidence interval [CI], 1.21 to 2.68). The late group also had approximately twice the risk for the development of BPD (odds ratio, 1.9; 95% CI, 1.2 to 3.04) and a trend toward an increased incidence of home oxygen use (odds ratio, 1.55; 95% CI, 0.92 to 2.60). The authors conclude that (1) there is a greater risk of mortality and BPD and a trend toward an increased need for home oxygen with increased time on the ventilator before ECLS; (2) at 14 days the predicted probability of survival is still 53% (95% CI, 31% to 74%); (3) at 14 days the predicted probability of BPD is 54% (95% CI, 28% to 78%); and (4) based on these data, it is reasonable to consider application of ECLS to patients who have had mechanical ventilation for up to 14 days.

Risks of extracorporeal membrane oxygenation: is there a role for use in the management of the acutely poisoned patient?

OBJECTIVE

To review the use of extracorporeal membrane oxygenation in the support of poisoned patients and provide a basis for comparison to other methods of respiratory support for these patients.

METHODS

The medical literature was reviewed and selected cases of poisoning supported by extracorporeal membrane oxygenation and mechanical ventilation highlighted. Data from published outcome studies were reviewed. All cases found were included in the database. Case experiences were critiqued based on available clinical literature. Outcome studies were critiqued with respect to relevancy and bias. Many cases do not provide strong evidence of direct patient benefit. There are no data to support an improvement in outcome among poisoned patients.

CONCLUSION

The use of extracorporeal membrane oxygenation for respiratory failure following ingestion has the same limited indications as for other patients with respiratory failure. Data supporting an improvement in outcome are not available. Extracorporeal membrane oxygenation support for reversible cardiac toxicity has a sound basis but clinical experience is limited. Good supportive care for the poisoned patient is essential before considering extracorporeal membrane oxygenation.

Benefits of extracorporeal membrane oxygenation for hydrocarbon pneumonitis

OBJECTIVE

To review the therapeutic benefits of extracorporeal membrane oxygenation for the management of hydrocarbon pneumonitis.

METHODS

A search of the medical literature was conducted through Medline and the bibliographies of relevant articles and a search of patient databases maintained by the Extracorporeal Life Support Organization and the American Association of Poison Control Centers was performed. All articles and case reports on the use of extracorporeal membrane oxygenation in patients with hydrocarbon pneumonitis were selected. The data were abstracted without judgments about study design.

RESULTS

There is some evidence that pulmonary parenchymal tissue can recover from hydrocarbon pneumonitis, but the degree of injury and recovery are variable. In the Extracorporeal Life Support Organization Registry 19 children with hydrocarbon pneumonitis were treated with extracorporeal membrane oxygenation during 1985 to 1994 and 68% survived compared to the 52% overall survival of 883 pediatric cases who had a diagnosis of a respiratory condition. A review of the American Association of Poison Control Centers data for 1993 and 1994 identified five cases of hydrocarbon pneumonitis in which extracorporeal membrane oxygenation was used and two survived. There are two full case descriptions in the literature with both children surviving, but one child developed persistent moderate left hemiparesis and seizure activity.

CONCLUSIONS

The need for extracorporeal membrane oxygenation is rare owing to the generally good outcome of most cases of hydrocarbon ingestions and pneumonitis. Only with further research on the nature and clinical course of severe hydrocarbon pneumonitis, refinement of extracorporeal membrane oxygenation criteria, and evaluation of alternative therapies, will the benefits of extracorporeal membrane oxygenation be better defined.