The Effects of Positive End-Expiratory Pressure on Cross-Sectional Area of Internal Jugular Vein in Obese Patients

Abstract

Introduction: Obesity is one of the most important risk factors for complications of internal jugular vein (IJV) cannulation. The efficacy and safety of positive end-expiratory pressure (PEEP) are still under debate in obese patients. The aim of this prospective randomized ultrasound study was to investigate effects of different PEEP levels on the cross-sectional area (CSA) of right IJV and overlap with carotid artery (CA) in anesthetized obese patients. Materials and Methods: Seventy-two obese patients undergoing various elective surgeries under general endotracheal anesthesia were enrolled. We measured CSA of right IJV, margin of safety (MOS), and degree of overlap between CA and IJV at PEEP 0 (P0), 5 (P5), and 12 (P12) cm H2O levels. We defined a ≥20% increase in CSA as clinically relevant. Results: Data were collected for all the 72 patients enrolled in the study. Application of 12, but not 5 cm H2O PEEP, resulted in a clinically significant increase in CSA of right IJV. When compared to P0, application of P5 and P12 increased both degree of overlap (p < 0.001 each) and MOS (p < 0.001 each). None of the patients experienced severe hypotension or bradycardia. Conclusions: Application of 12 cm H2O PEEP provides a clinically significant increase in CSA of right IJV without relevant reduction of MOS in anesthetized obese patients.