Ultrasound-guided central venous cannulation in bariatric patients.

BACKGROUND: Central venous catheterization may be difficult in morbidly obese patients because anatomic landmarks are often obscured.

METHODS: We evaluated the efficacy and safety of ultrasound-guided central venous cannulation in 55 patients undergoing bariatric surgery. The usefulness of ultrasonic examination combined with intraatrial electrocardiogram as a diagnostic tool for catheter misplacement was studied.

RESULTS: Preliminary ultrasound examination of the neck vessels demonstrated anatomical variations in the position of internal jugular vein in 19 cases and four unrecognized asymptomatic thromboses of the right internal jugular vein. Central venous catheterization was successful in all 55 patients, in 51 with single skin puncture, and in 42 with single vein puncture. In three cases in whom the catheter was misplaced, this was detected by bedside ultrasonic examination during the procedure and immediately corrected by real-time echographic visualization. No arterial puncture, no hematoma, and no pneumothorax occurred in any patient. Successful catheter placement was also confirmed in all patients by post-operative chest X-ray. No evidence of infection or thrombosis subsequently was noted.

CONCLUSIONS: The use of ultrasound guidance may increase the success rate and decrease the incidence of complications associated with central venous cannulation. The advantages of this approach is visualization of the anatomical structures at puncture site prior to skin puncture and the ability to track needle and guide-wire placement during the procedure. With its high accuracy in detecting catheter misplacement, bedside ultrasonic examination combined with intraatrial electrocardiogram may further decrease morbidity associated with misplaced central venous catheters.