The Effect of PEEP on Cross Sectional Area of Right Internal Jugular Vein in Anaesthetised Patients Using Ultrasonography - An Observational Study

BACKGROUND Central Venous Cannulation is a very important technique needed intra operatively and in critical care setting. Most commonly accessed is the right internal jugular vein due to lesser incidence of complications and easy accessibility. Ultrasound guidance improves the successful insertion rate than blind technique. Increasing the cross-sectional area (CSA) of IJV improves the success rate and decreases complications. Several manoeuvres such as Trendelenburg’s position, Valsalva’s manoeuvre, hepatic compression and positive end-expiratory pressure have been used to increase the diameter of the IJV. Application of PEEP of 10–12 cm H2O in supine position has been found to increase the CSA of right IJV in various studies. The aim of the study is to determine the optimal PEEP which increases size of IJV without complications. METHODS This is an observational study conducted in the Government Medical College, Thrissur. The groups were chosen from instances where three different levels of PEEP were used. A total of 90 ASA PS 1 & 2 patients who received general anaesthesia for elective surgeries where assigned to three groups - P0, P5 and P10 with different values of PEEP- 0, 5, and 10 cm of H2O respectively. Patients with obesity, raised intracranial pressure, previous neck surgery were excluded from the study. After application of PEEP for 2 minutes, the diameter of Right Internal Jugular was sonologically measured. The increase in cross sectional area of IJV in each group was analysed. Application of PEEP affects heart rate and mean arterial pressure in patients. So, the heart rate and mean arterial pressure readings were taken at the time of measurement of IJV. These were also analysed statistically. RESULTS The three groups P0, P5 and P10 were comparable in demographic parameters like age and weight. Cross-sectional area of three groups was compared. The mean CSA in P0 was 1.3345, P5 was 1.399 and P10 was 1.443 cm2. (p .001). There was a statistically significant increase in cross-sectional area of IJV when PEEP was applied. Increase in CSA was significantly higher with higher PEEP (p .001). CONCLUSIONS The application of PEEP of 5 to 10 cm of H2O is a safe method to increase the area of IJV for successful cannulation. This value of PEEP did not cause clinically significant haemodynamic effects. KEYWORDS PEEP, Cross-Sectional Area of IJV, Sonoanatomy, IJV Cannulation