ECMO-treated Patients Research Articles

Probability of survival after prolonged extracorporeal membrane oxygenation in pediatric patients with acute respiratory failure

Extracorporeal membrane oxygenation (ECMO) has been used with increasing frequency for respiratory failure that is unresponsive to conventional therapy. We examined the relationship between duration of ECMO and outcome to understand whether prolonged ECMO (duration of the procedure for > 14 days) was more commonly associated with futile therapy or eventual recovery. A cohort study of all patients reported to the Pediatric ECMO Registry for Acute Respiratory Failure of the Extracorporeal Life Support Organization. Tertiary hospitals (n = 83) capable of providing extracorporeal support for pediatric patients. Children (n = 382) between the ages of 1 wk and 18 yrs of age with severe respiratory failure. Extracorporeal membrane oxygenation. The death or live hospital discharge of ECMO-treated patients, together with the post-ECMO mechanical ventilation course, were examined as a function of duration of ECMO and of pre-ECMO respiratory status. The occurrence of complications and the causes of death were also noted. The criteria used to initiate ECMO, as well as the determination of the futility of further ECMO, were determined by local practice at individual centers. There were 382 patients treated with ECMO, of whom 184 (48%) survived. The proportional survival in the patients treated for the longest duration was similar to the overall group. The cause of death was given for 168 patients: 32 neurologic deaths; nine deaths due to ECMO complications; and 30 deaths due to nonpulmonary organ failure. There were 97 deaths due to elective ECMO termination; 80 of these deaths occurred after the determination of the futility of anticipating pulmonary recovery. The latter deaths occurred at widely varying durations of ECMO, with a median of 282 hrs. However, at that same duration, 47 eventual survivors (26% of all survivors) continued to receive ECMO. By discriminant analysis, the survival rate was independently related (r2 = .18; p < .0001) to peak ventilator inspiratory pressure before ECMO and duration of intubation before ECMO, patient age, and the occurrence of several complications. While the survival rate in pediatric patients receiving ECMO appears related to the severity of lung disease and to the occurrence of ECMO complications, the survival rate in patients treated with ECMO courses of > 2 wks was similar to the survival rate of patients treated for shorter periods of time. ECMO was terminated in some patients for pulmonary futility at durations of ECMO associated with survival in substantial numbers of patients in whom ECMO was continued.

Respiratory deadspace measurements in neonates with congenital diaphragmatic hernia.

To apply the technique of respiratory deadspace measurement to consecutive infants with congenital diaphragmatic hernia, who were referred to our institution, in order to assess the efficiency of gas exchange. A cohort study evaluating the utility of deadspace measurements in neonates with congenital diaphragmatic hernia. Tertiary care pediatric intensive care unit in a university hospital. Thirty infants with congenital diaphragmatic hernia were studied on presentation to our institution, either before the institution of extracorporeal membrane oxygenation (ECMO) or after stabilization on ECMO. The CO2 concentration of expired gas sampled at the exhaust port of the test ventilator was continuously measured and transformed to mixed expired CO2 by the following formula that corrects for compressible volume measured by the ventilatory pneumotachometer: mixed expired CO2 = (PCO2 in exhaust gas) x (ventilatory pneumotachometer minute volume)/(minute volume at the proximal airway). We then utilized the Bohr-Enghoff method to calculate the deadspace/tidal volume ratio: deadspace/tidal volume ratio = (PaCO2 - mixed expired PCO2)/PaCO2. Deadspace/tidal volume ratio was calculated either before the institution of ECMO or during temporary separation from ECMO support as the patients demonstrated improvements in gas exchange and lung compliance. One hundred two measurements were made in 30 patients, with a mean of four measurements per patient (range 1 to 10). There was a significant (p = .005) difference between the first deadspace/tidal volume ratio measured, in survivors vs. nonsurvivors. The mean of the highest deadspace/tidal volume ratio in survivors was 0.47 compared with 0.62 in nonsurvivors (p = .003). A deadspace/tidal volume ratio of > or = 0.60 predicted mortality, with a positive predictive value of 80%, a negative predictive value of 79%, and an odds ratio of 15. The mean pre-ECMO deadspace/tidal volume ratio in those infants who ultimately required ECMO was significantly greater than the mean value for infants not requiring ECMO (0.65 vs. 0.43; p = .004). In patients who were treated with ECMO, survivors demonstrated a significant decrease in deadspace/tidal volume ratio during the course of ECMO. This decrease was not seen in the ECMO-treated patients who did not survive. Predictors of outcome in infants with congenital diaphragmatic hernia have been complicated and contradictory, particularly in the ECMO era. We demonstrated that the respiratory deadspace can be easily quantified in these infants, and that a physiologic deadspace of > 0.60 is associated with a 15-fold increase in mortality rate. We also demonstrated that in those infants treated with ECMO, the survivors manifested a significant decrease in their deadspace/tidal volume ratio before ECMO decannulation.

Extracorporeal membrane oxygenation for pediatric respiratory failure: Five-year experience at the University of Pittsburgh

To describe the etiology, respiratory severity of illness, and outcome in patients with pediatric respiratory failure who were treated with extracorporeal membrane oxygenation (ECMO). To identify predictors of death, and to compare our morbidity and mortality rates with those rates of a previously reported series of patients with pediatric respiratory failure managed conventionally. Survey, case series. Intensive care unit in a tertiary care pediatric hospital. Twenty-eight pediatric patients (3 wks to 20 yrs of age) who underwent ECMO for pediatric respiratory failure between 1985 and 1991. Thirteen (46%) of the 28 patients survived. The most common diagnoses were adult respiratory distress syndrome and nonspecific pneumonitis. Multiple organ system failure occurred in only four (14%) patients; most patients died of respiratory failure. The occurrence of persistent airleak during ECMO was significantly greater in nonsurvivors than in survivors. Furthermore, nonsurvivors had significantly less response to lung reexpansion maneuvers compared with survivors, as measured by a calculated compliance index (effective tidal volume/mean airway pressure x 100). The mortality rate was comparable with those rates of other published studies of conventionally managed and ECMO-treated patients with pediatric respiratory failure. Moreover, our patients appeared to exhibit more severe respiratory failure at the start of ECMO than those patients in other studies. ECMO appears to be a rational therapy for patients with pediatric respiratory failure who are likely to die with continued conventional management. Recovery of lung function by the end of the first week of ECMO may be a favorable prognostic indicator. Persistent airleak may be a nonfavorable prognostic indicator.

Cerebrovascular lesions in infants and children dying after extracorporeal membrane oxygenation

The neuropathologic autopsy findings of a group of infants and children at Children's Hospital of Pittsburgh who died after treatment with extracorporeal membrane oxygenation (ECMO) were reviewed and tabulated. The study surveyed an 11-year period (February, 1980 to May, 1991); of 268 children receiving ECMO therapy for severe cardiopulmonary failure, 94 patients died, 70 of whom were autopsied and permission for brain examination was granted in only 44. The frequency of ischemic neuronal necrosis (50%), focal cerebral infarcts (50%), intracerebral hemorrhages (52%), and periventricular leukomalacia (41%) was higher in this group of ECMO-treated patients than that observed in the general autopsy population from which the study patients were selected. The frequency of ischemic and hemorrhagic brain lesions was similar among neonates and older infants and children. This documentation of cerebrovascular lesions in children dying after ECMO may provide a better understanding of potential brain damage in the larger population of infants and children who survive this invasive procedure.

Experience with delayed repair of congenital diaphragmatic hernia during extracorporeal membrane oxygenation in a European center

In high-risk patients with congenital diaphragmatic hernia (CDH), we conducted a strategy of delayed repair following preoperative stabilization, including ECMO if necessary. From January 1991 to July 1992, preoperative ECMO treatment was delivered to 6 out of 14 high-risk patients with CDH. In this study, we report our experience with this policy of preoperative stabilization in six ECMO-treated patients in whom the diaphragmatic defect was repaired on ECMO. In all patients bleeding complications occurred. Three of the six ECMO-treated patients died, in two cases due to recurrent persistent pulmonary hypertension. Overall mortality was 43%.