Effect of limb cooling on peripheral and global oxygen consumption in neonates
- 1Neonatal Unit, City General Hospital, Stoke on Trent, UK
- 2Centre for Science and Technology in Medicine, University of Keele, UK
- Correspondence to:
Dr Spencer, Neonatal Unit, Maternity Building, North Staffordshire Hospital (City General), Newcastle Road, Stoke on Trent ST4 6QG, UK;
andy.spencer{at}nstaffsh.wmids.nhs.uk
- Accepted 11 July 2002
Abstract
Aim: To evaluate peripheral oxygen consumption (Vo2) measurements using near infrared spectroscopy (NIRS) with arterial occlusion in healthy term neonates by studying the effect of limb cooling on peripheral and global Vo2.
Subjects and methods: Twenty two healthy term neonates were studied. Peripheral Vo2 was measured by NIRS using arterial occlusion and measurement of the oxyhaemoglobin (HbO2) decrement slope. Global Vo2 was measured by open circuit calorimetry. Global and peripheral Vo2 was measured in each neonate before and after limb cooling.
Results: In 10 neonates, a fall in forearm temperature of 2.2°C (mild cooling) decreased forearm Vo2 by 19.6% (p < 0.01). Global Vo2 did not change. In 12 neonates, a fall in forearm temperature of 4°C (moderate cooling) decreased forearm Vo2 by 34.7% (p < 0.01). Global Vo2 increased by 17.6% (p < 0.05).
Conclusions: The NIRS arterial occlusion method is able to measure changes in peripheral Vo2 induced by limb cooling. The changes are more pronounced with moderate limb cooling when a concomitant rise in global Vo2 is observed. Change in peripheral temperature must be taken into consideration in the interpretation of peripheral Vo2 measurements in neonates.
- Vo2, oxygen consumption
- NIRS, near infrared spectroscopy
- HbO2, oxygenated haemoglobin
- HbT, total haemoglobin
- CI, confidence interval
