Journal of Applied Physiology, Vol 66, Issue 1 210-216, Copyright © 1989 by American Physiological Society
Oxygen delivery rate and sufficiency of oxygenation during ECMO in newborn baboons
J. D. Cornish, D. R. Gerstmann, D. M. Null Jr, M. D. Smith and T. J. Kuehl
Department of Pediatrics, Wilford Hall US Air Force Medical Center, Lackland AFB 78236.
Minimum acceptable O2 delivery (DO2) during extracorporeal membrane
oxygenation (ECMO) remains to be defined in a newborn primate model. The
right atrium, carotid artery, and femoral artery were cannulated, and the
ductus arteriosus, aorta, and pulmonary artery ligated in neonatal baboons
(Papio cynocephalus) under a combination of ketamine, diazepam, and
pancuronium. The internal jugular vein was also cannulated retrograde to
the level of the occipital ridge. We measured hemoglobin, pH, arterial and
venous PO2 (both from the pump circuit and from the cerebral venous site),
serum lactate and bicarbonate concentrations, and pump flow, and we
calculated hemoglobin saturations, (DO2), O2 consumption (VO2), systemic O2
extraction, and cerebral O2 extraction. Six baboons were studied during
each of two phases of the experiment. In the first, flow rates were varied
sequentially from 200 to 50 ml.kg-1.min-1 with saturation maximized. In the
second, flow was maintained at 200 ml.kg-1.min-1 and saturation was reduced
sequentially from 100 to 38%. VO2 fell significantly below baseline at a
flow rate of 50 ml.kg-1.min-1 and a DO2 of 8 +/- 2 (SE) ml.kg-1.min-1 in
phase 1 and at DO2 of 12 +/- 5 in phase 2. Both systemic and cerebral O2
extraction rose significantly at a flow of 100 ml.kg-1.min-1 and DO2 of 17
+/- 4 ml.kg-1.min-1 in phase 1, whereas neither rose with decreasing DO2 in
phase 2. In fact, cerebral extraction fell significantly DO2 of 16 +/- 6
ml.kg-1.min-1.(ABSTRACT TRUNCATED AT 250 WORDS)
