REDUCING RESPIRATORY VARIATIONS IN INTERNAL JUGULAR VEIN CROSS-SECTIONAL AREA USING PEEP AND TRENDELENBURG POSITION

Introduction: The respiratory cycle influences the size of the right internal jugular vein (RIJV). We evaluated the changes in RIJV size during the respiratory cycle in patients on positive pressure ventilation. Additionally, we investigated the impact of positive end-expiratory pressure (PEEP) and the Trendelenburg position on these respiratory fluctuations. Methods: The study involved 24 patients who underwent general endotracheal anesthesia. Images of the right internal jugular vein (RIJV) were captured in the supine position (baseline, S0) and during three randomized maneuvers: applying a positive end-expiratory pressure (PEEP) of 10 cmH2O (S10), positioning the patient in a 10° Trendelenburg tilt (T0), and combining the Trendelenburg tilt with PEEP (T10). The aim was to measure the cross-sectional area (CSA), anteroposterior diameter, and transverse diameter of the RIJV at both its smallest and largest observed sizes during each maneuver. Results: The study found that all maneuvers significantly reduced the fluctuation in the size of the right internal jugular vein (RIJV) (p = 0.0004). Specifically, compared to the supine position (S0), the maneuvers resulted in the following decreases in the cross-sectional area (CSA) from the smallest to the largest observed sizes: • S0: Decrease by 28.3% • S10: Decrease by 8.5% • T0: Decrease by 8.0% T10: Decrease by 4.4% Additionally, compared to S0, the combination of a 10° Trendelenburg tilt position with a positive end-expiratory pressure (PEEP) of 10 cmH2O significantly increased the CSA: • In the largest observed areas by 83.8% • In the smallest observed areas by 169.4% These findings suggest that the Trendelenburg tilt combined with PEEP was particularly effective in increasing the CSA of the RIJV, both at its largest and smallest observed sizes, compared to other maneuvers and the baseline supine position. Conclusions: A 10° Trendelenburg tilt position combined with a PEEP of 10 cmH2O not only increases the size of the RIJV but also reduces fluctuation by the respiratory cycle.