EFFECTS OF INCREASED RED-CELL MASS ON SUBCLINICAL TISSUE ACIDOSIS IN HYALINE-MEMBRANE DISEASE

Aim-To determine whether there are subclinical deficits in oxygen deli very in ventilated premature neonates. Method-Ventilated premature neo nates weighing less than 1500 g, who were transfused for anaemia or wh o were given colloids for clotting abnormalities (or oedema), were hae modynamically monitored during the first week of life. Calf muscle sur face pH (tpH) was measured in conjunction with peripheral limb blood f low by occlusion plethysmography. Results-Packed red blood cell transf usions corrected a subclinical regional tissue acidosis (low tpH) with out affecting arterial pH or limb blood flow. This observation also co rrelated with an increase in regional oxygen delivery. The data were a lso suggestive of a pattern of pathological, supply dependent, oxygen delivery and are similar to other observations made in adults with adu lt respiratory distress syndrome. Conclusions-Packed red blood cells i ncrease regional oxygen delivery and tissue surface pH. In contrast, c olloid infusion provided no substantial cardiovascular or metabolic be nefit to these patients and should be avoided when oxygen delivery is at issue and when there may be leaky pulmonary capillaries.