Abstract
BACKGROUND AND AIMS: The position of the tip of the central venous catheter (CVC) is important to minimise complications. The aim of our study was to compare modified Peres' height formula and landmark method using distance between puncture site and right third intercostal space (PS-RTICS) and to develop a reliable formula for correct positioning of tip of the CVC. METHODS: This prospective, randomised study was conducted on 400 patients of either gender, of age 18 years and older, scheduled to undergo right internal jugular venous cannulation. Depending on the technique used for deciding the length of CVC to be inserted, the patients were randomly allocated into two groups: Group A, using modified Peres' height formula, that is, height of patient (cm)/10-2 and Group B, using distance between PS-RTICS and subtracting one from it, that is (PS-RTICS)-1. The carina was taken as the landmark for optimum insertion of CVC, which was confirmed on postprocedure chest X-ray. Data so obtained were tabulated and analysed. P<.05 was considered statistically significant for correlation and regression coefficients. RESULTS: In group A, the mean length of catheter inserted was 15.18 ± 0.73 cm and the catheter tip was found to be 2.41 ± 0.85 cm distal to carina (P =0.001). Over-insertion was found in 98.45% patients in group A. In group B, the mean length of catheter inserted was 14.12 ± 0.85 cm and the catheter tip was found to be 0.20 ± 1.18 cm distal to carina. CONCLUSION: Though both landmark and modified Peres' height formula has low accuracy, landmark technique is superior in predicting correct depth of right internal jugular venous cannulation catheter.