BACKGROUND: Central venous cannulation is technically challenging in obese patients. We hypothesized that positive end-expiratory pressure (PEEP) increases the size of the internal jugular vein (IJV) in obese adults.
METHODS: The circumference and cross-sectional area of the IJV were measured in obese patients under general anesthesia at PEEP 0, 5, and 10 cm H2O. Results are reported as means ± SE.
RESULTS: PEEP at 10 cm H2O was tolerated by 18 of 24 obese patients. Each 5 cm H2O of PEEP increased the cross-sectional area by 0.16 ± 0.02 cm2 (P < 0.0001) and the circumference by 0.23 ± 0.03 cm (P < 0.0001).
CONCLUSIONS: PEEP modestly increases the size of the IJV in obese adults but was poorly tolerated because of hypotension.