Oxygen consumption (V˙o₂) is a measurement used to determine the metabolic rate, and is affected by environmental temperature, body temperature, physical activity, blood flow, and nutrition. Measurements of V˙o₂ have been used to study energy balance in newborn infants and to determine the optimal thermal environment for nursing preterm babies.¹ More recently it has been suggested that measurements of peripheral V˙o₂ may provide an indication of the need for circulatory support during critical care.

Methods used to assess V˙o₂ are either based on the Fick’s principle or a gas exchange technique. The standard units used to express V˙o₂ are ml O₂/kg/min. Neonatal cerebral V˙o₂ values using near infrared spectroscopy (NIRS) and jugular venous occlusion have been reported² and have been expressed in ml/100 g/min. NIRS has been …