Technical aspects in the management of the meconium aspiration syndrome with extracorporeal circulation.

Sixteen neonatal patients diagnosed as having the meconium aspiration syndrome were selected for management with extracorporeal circulation with a membrane oxygenator (ECMO) with 8 survivors over 4 yr. All patients weighed greater than 2 kg. Each was placed in the 100% mortality group according to a Neonatal Pulmonary Insufficiency Index (NPII) based on hourly pH and FiO2 determinations. The typical patient course on ECMO was stabilization for the first 12 hr then improvement on high bypass flow rates for 12-24 hr to maintain a pAO2 for 50-60 mm Hg with minimal ventilator settings with an FiO2 of 0.3-0.4. Bypass flow rates were reduced to maintain adequate pAO2 with similar ventilator settings for another 24 hr. Survivors were taken off bypass and decannulated while on similar ventilator settings. Nonsurvivors did stabilize or improve but usually exhibited symptoms of intracranial hemorrhage by 48 hr. Intracranial hemorrhage appeared to be related to the degree of prebypass acidosis. Successful ECMO support reduced the expected mortality from severe meconium aspiration from 100% to 50%. Early institution of ECMO, before acidosis worsens, seems to be indicated to reduce the morbidity of conventional ventilator management and to prevent intracranial hemorrhage from severe prebypass acidosis. Long term followup indicates that these patients have progressed satisfactorily according to developmental testing for as long as 4 yr.