The aim of this study was to assess whether blood sampling from umbilical artery catheters reduces cerebral blood volume and cerebral oxygenation in very low birthweight infants. A total of 20 infants, median birthweight 890 g (530-1,500 g), median gestation age 26 +4 wk (range: 22 +5 to 30 +6 wk) were studied from 10 min before until 10 min after routine blood sampling from umbilical artery catheters placed in the high position. Using near infrared spectroscopy, changes in concentrations of cerebral oxygenated and deoxygenated haemoglobin were measured, and changes in cerebral blood volume and cerebral oxygenation index were calculated. Heart rate, oxygen saturation, transcutaneous PO2 and PCO2 were registered continuously. Mean arterial blood pressure was measured before and after sampling. Oxygenated haemoglobin decreased significantly from baseline during blood sampling, whereas deoxygenated haemoglobin did not change significantly. This resulted in a decrease in cerebral blood volume and cerebral oxygenation index. Heart rate increased slightly, but significantly, from baseline. Oxygen saturation, blood pressure, transcutaneous PO2 and PCO2 did not change significantly.
Conclusion: Blood sampling from umbilical artery catheters induces a significant decrease in cerebral blood volume and cerebral oxygenation.