Plasma prostanoids in neonates with pulmonary hypertension treated with conventional therapy and with extracorporeal membrane oxygenation.

Thromboxane may be a mediator of pulmonary hypertension in the neonate. Acute thromboxane-mediated pulmonary hypertension has been described in sheep receiving extracorporeal membrane oxygenation, which raises concerns about a potential thromboxane-mediated exacerbation of pulmonary hypertension in human neonates with severe pulmonary hypertension who are treated with extracorporeal membrane oxygenation. We measured plasma levels of thromboxane, prostaglandin F2 alpha, and 6-keto-prostaglandin F1 alpha in infants with pulmonary hypertension, some of whom were treated medically and some of whom were treated with extracorporeal membrane oxygenation. Plasma levels of all three prostanoids were elevated in infants with pulmonary hypertension and decreased with time, whether the neonates were treated with extracorporeal membrane oxygenation or with medical management alone. In infants treated with extracorporeal membrane oxygenation, we collected samples simultaneously from preoxygenator sites, postoxygenator sites, and umbilical artery catheter. We could demonstrate no significant difference in plasma prostanoid levels across the oxygenator. In two patients, plasma thromboxane and prostaglandin F2 alpha levels measured shortly after a platelet transfusion were distinctly higher in the umbilical artery catheter than in venous samples.

Plasma prostanoids in neonatal extracorporeal membrane oxygenation. Influence of meconium aspiration.

Thromboxane B2 may be a mediator of neonatal persistent pulmonary hypertension. Elevated levels of plasma thromboxane and prostacyclin have been described previously in hypoxic newborn infants with neonatal pulmonary hypertension. We measured serial plasma levels of thromboxane B2 and 6-keto-prostaglandin F1 alpha (stable metabolite of prostacyclin) in 21 newborn infants with severe respiratory failure and pulmonary hypertension who required extracorporeal membrane oxygenation support. We sought to study (1) the evolution of plasma prostanoids in pulmonary hypertensive infants treated with extracorporeal membrane oxygenation and (2) whether different pulmonary hypertensive diagnostic subgroups have distinctive prostanoid profiles. Our data indicated that infants with meconium aspiration had significantly lower levels of plasma thromboxane B2 and 6-keto-prostaglandin F1 alpha while receiving extracorporeal membrane oxygenation than did infants with persistent pulmonary hypertension but no meconium aspiration. Levels of all infants decreased progressively as extracorporeal membrane oxygenation support continued.

Long-term prognosis (15 to 26 years) after repair of tetralogy of Fallot: I. Survival and symptomatic status.

One hundred eighty-two patients with tetralogy of Fallot repaired before or during 1967 were studied by interview, physical examination, and noninvasive testing. Twenty were excluded from the final analysis because review of cineangiograms and operative reports disclosed that they had had double-chambered right ventricle rather than tetralogy of Fallot. On follow-up ranging from 15 to 26 years (mean, 20.2 years), there were 86 patients in New York Heart Association Functional Class I, 53 in Class II, 5 in Class III, and none in Class IV. There were 9 late deaths. Functional classification was not ascertained in the remaining 9 patients. Cumulative survival at 25 years postoperatively was 94.4%. There was no significant relationship between survival and year of operation, age at operation, sex, or presence of a prior shunt. The 9 late deaths occurred between 6 and 23 years after operation and were due to late-onset complete heart block in 2 patients, congestive failure in 4, suicide in 1, accident in 1, and an unknown cause in 1. We conclude that long-term survival after repair of tetralogy of Fallot is excellent and not influenced by prior shunt.

Extracorporeal membrane oxygenation and neonatal respiratory failure: experience from the extracorporeal life support organization.

Extracorporeal membrane oxygenation (ECMO) has rescued moribund infants with respiratory failure from a variety of causes. We report the experience from 58 United States and 7 overseas ECMO centers between 1980 and 1989. Voluntarily submitted data forms provided details of diagnosis, clinical condition, ECMO indications, morbidity, and mortality. Of 3,528 infants with a predicted mortality greater than 80% treated with ECMO, 83% survived. Entry diagnoses and aggregate survival were: meconium aspiration syndrome (MAS) 1,356 (93%), persistent pulmonary hypertension of the newborn (PPHN) 480 (83%); congenital diaphragmatic hernia (CDH) 585 (62%); hyaline membrane disease (HMD) 532 (84%); sepsis 416 (77%); and other 185 (77%). ECMO indications were a-AdO2 greater than 600 for 6 to 8 hours (22%), oxygenation index greater than 40 for 4 hours (18%), acute deterioration (14%), maximal therapy failure (34%), and barotrauma (1%). Annual survival improved over 9 years except for CDH, which decreased from 70% (1987) to 56% (1989) P less than .01). Survivors differed from non-survivors (P less than .05) by birth weight (greater than 2 kg), gestational age (greater than 37 weeks), entry diagnosis (MAS, PPHN, HMD, sepsis v CDH), inborn versus outborn, pre-ECMO pH, and ECMO duration. Technical complications in 25% of patients and medical complications in 75% adversely affected survival. Annual sepsis survival improved to 75% (1989) but had significantly greater complication rates (P less than .05) than other diagnoses. Multicenter data yield information not available from single institution experience. Although entry criteria and conventional therapy continue to evolve, ECMO currently improves survival from an estimated 20% to 83% overall. Individual prognosis depends on entry diagnosis, clinical condition, and complications.

Multicenter comparison of conventional venoarterial access versus venovenous double-lumen catheter access in newborn infants undergoing extracorporeal membrane oxygenation.

A multicenter trial was designed to compare standard venoarterial (VA) access versus single-catheter, venovenous access using the double-lumen catheter (VV-DLC) for newborns with respiratory failure undergoing extracorporeal membrane oxygenation (ECMO). Twenty-seven ECMO centers participated, each submitting data from the center's most recent VA cases, and data from VV-DLC cases completed upon entering the study. Data from 135 VA ECMO cases and 108 VV-DLC cases were submitted. All diagnoses resulting in neonatal respiratory failure were submitted, including patients with congenital diaphragmatic hernia (24 patients VA bypass, 11 patients VV-DLC bypass). Overall survival in patients undergoing VA bypass was 87%, while survival in patients undergoing VV-DLC bypass was 95%. Eleven patients required conversion from VV-DLC bypass to VA bypass because of insufficient support--10 of these patients survived (91% survival). Average bypass time for newborns undergoing VA bypass was 132 +/- 7.4 hours versus 100 +/- 5.1 hours for those undergoing VV-DLC bypass. Neurologic complications were more common in the VA bypass patients, although the VV patients were more stable. Hemorrhagic, cardiopulmonary, and mechanical complications, other than kinking of the DLC, occurred with approximately equal frequency in each group. In conclusion, in newborns with adequate cardiac function, venovenous ECMO using the DLC can provide the same level of support as conventional VA ECMO, without ligation of the carotid artery.

Extracorporeal membrane oxygenation: support for overwhelming pulmonary failure in the pediatric population. Collective experience from the extracorporeal life support organization.

Data from the Extracorporeal Life Support Organization (ELSO) regarding the use of extracorporeal membrane oxygenation (ECMO) in pediatric patients with respiratory failure are reviewed. Two hundred eighty-five children between the ages of 14 days and 18 years were supported with ECMO between January 1982 and September 1991. Although these data represent the experience of 52 ECMO centers, seven centers accounted for over 50% of the total. The patients had a mean age of 33 +/- 48 months with a median age of 13 months: 137 (48%) were male and 148 (52%) were female. There were numerous primary pulmonary diagnoses: the two most common were presumed viral pneumonia (32%) and adult respiratory distress syndrome (28%). Entry criteria for ECMO, although poorly defined and specific to each institution, attempted to identify children with an 85% to 100% predicted mortality. The survival rate with ECMO was 47% (135/285). Pre-ECMO mechanical ventilatory support was extreme with an FIO2 .97 +/- .07 and a mean airway pressure (MAP) 23.6 +/- 8 cm H2O used to achieve PaO2 of 50 +/- 39 and PaCO2 51 +/- 22 mm Hg. The MAP was significantly higher in nonsurvivors versus survivors (25.3 +/- 8.7 v 22.0 +/- 7.1 cm H2O, P < .01). The duration of ECMO was 4 hours to 35.5 days with a mean of 245 +/- 165 hours, which is approximately 10 days. Duration for survivors was 222 +/- 151 hours compared with 266 +/- 176 hours for nonsurvivors. ECMO complications are divided into two categories: mechanical (directly related to the ECMO circuit) and medical (patient related).(ABSTRACT TRUNCATED AT 250 WORDS)

Recruitment experience in the Nocturnal Oxygen Therapy Trial.

The Nocturnal Oxygen Therapy Trial was a randomized controlled clinical trial sponsored by the National Heart, Lung, and Blood Institute and carried out by six clinics. The primary objective was to compare, in patients with advanced chronic obstructive pulmonary disease, the effectiveness of 24 hours of oxygen administration to that of 12 hours of oxygen administration including the patient's usual period of sleep. Some patients entering the period of baseline observation were not eligible for randomization at the end of the baseline period. Such attrition is discussed relative to setting goals for the number of patients to enter such an observation period. The impact of an enrollment rate less than what was originally projected is discussed relative to changes in the eligibility criteria and relative to the decision as to whether to extend the recruitment period.

National experience with extracorporeal membrane oxygenation for newborn respiratory failure. Data from 715 cases.

In a national registry, data were collected on 715 newborn patients with severe respiratory failure supported by extracorporeal membrane oxygenation (ECMO) in 18 neonatal centers. This represents almost all infants treated with ECMO between 1980 and 1987. Eighty-one percent of the patients survived. This result is statistically significantly better than any other treatment which produces less than 78.4% survival. The most common diagnoses were meconium aspiration (310 patients, 91% survived), respiratory distress syndrome (96 patients, 78% survived), diaphragmatic hernia (121 patients, 65% survived), and sepsis (64 patients, 72% survived). Average pre-ECMO characteristics were: age 59 hours; PaO2 42 torr, PaCO2 41 torr, pH 7.40; ventilator settings FiO2 1.0, pressure 45/4 cmH2O, rate 93. Technical complications occurred in 23.1%, and physiologic complications occurred in 65.6%. Results improved with experience. Survival rate for the first ten patients from each center was 73.5% compared to 83.7% for all subsequent patients. Survival rate did not, however, significantly differ after an institutional experience of 20 patients. These observations were made on a large cohort that could not be accumulated at an individual center. These results indicate that ECMO and lung rest is appropriate and successful treatment for newborn respiratory failure unresponsive to other means of management, and that almost all respiratory failure is reversible in near-term neonates.