Arterial oxygen desaturation during peripheral venous cannulation in children.

Arterial oxygen saturation (SpO2) was measured to determine oxygen desaturation during peripheral venous cannulation prior to induction of anaesthesia in 40 consecutive patients in each of the three age groups; Group I: 1-4 mo, Group II: 4-12 mo, Group III: 12-24 mo. Following premedication with oral trimeprazine tartarate 3 mg.kg-1, one to two hours before operation, baseline SpO2 was noted with child breathing room air. Continuous monitoring during peripheral venous cannulation was done and maximum decrease and duration of SpO2 < 90% was noted. Decreases in mean SpO2, 3.2 +/- 1.4 in Group I, 2.6 +/- 2.0 in Group II and 1.7 +/- 1.9 in Group III, were observed (P < 0.001). Desaturation > or = 4% was noted in 17 patients in Group I, ten patients in Group II and six patients in Group III. Two children, one each in Groups I and II, experienced SpO2 < 90% for 30 sec and 80 sec respectively. We conclude that clinically undiagnosed desaturation occurs during peripheral venous cannulation in healthy children. The authors suggest that continuous monitoring of SpO2 using pulse oximetry should be performed routinely during peripheral venous cannulation.