Prior to ECMO all infants demonstrated severe gas exchange abnormalities, with the mean lowest Pa02 being 32 ±3 mm Hg while on maximal mechanical ventilator settings such as FIo2 of 1.0 and the MAP being 18.7 +1.2 cm H20 (Table 1). One infant had cardiac arrest requiring resuscitation prior to ECMO. The mean highest OI was 79 ±20, and therefore all study subjects met the institutional criteria of a greater than 80 percent mortality on conventional therapy (OI >40) prior to ECMO.
The primary pediatrician taking care of the infant, from the time of discharge from NICU until 6 months of age, treated these infants with supplemental oxygen, diuretics and/or bronchodilators if necessary based on clinical signs and symptoms (elevated respiratory rate, rales, noninvasive oxygen and carbon dioxide monitoring and arterial blood gas levels). At 6 months of age, 10 out of 19 of these infants, or 52 percent, were still being treated with aerosolized ($2 agonist bronchodilators, and 6 (32 percent) were being treated with oral diuretics (Diuril and Dyrenium). Four infants (21 percent) received diuretics and bronchodilators.
Table 1 – Clinical and Demographic Data of Study Infants
|No. of infants||19|
|Gestational age at birth (weeks)||39.8 ±0.5|
|Birth weight (kg)||3.3±0.1|
|Study weight (kg)||6.9 ±0.2|
|MAP (cm HaO)||18.7± 1.2|
|Last Pa02 before ECMO (mm Hg)||32 ±3|
|Pa02 – Pa02 (mm Hg)||636 ±3|
|Age at starting ECMO (h)||43.4 ±9.1|
|Duration of ECMO (h)||91 ±11|
|Duration of assisted mechanical ventilation after ECMO (h)||212 ±44|