COMPARATIVE SONOANATOMY OF CLASSIC "SHORT AXIS" PROBE POSITION WITH A NOVEL "MEDIAL-OBLIQUE" PROBE POSITION FOR ULTRASOUND-GUIDED INTERNAL JUGULAR VEIN CANNULATION: A CROSSOVER STUDY

Background: Ultrasound (US)-guided short-axis approach for internal jugular vein (IJV) cannulation does not fully protect patients from inadvertent carotid artery (CA) puncture. Carotid puncture is not rare (occurring in up to 4% of all IJV cannulations) despite the use of US. Objectives: Compare the sonoanatomy of the "medial-oblique approach" probe position with the classic US-guided "short-axis" probe position, specifically: relation of internal CA and IJV; vertical and horizontal diameter of IJV; and degree of overlapping of IJV with CA. Methods: One hundred consecutive patients between the ages of 18 and 50 years, both male and female, and American Society of Anesthesiologists Physical Status classification system (ASA PS) I-II undergoing elective surgery under general anesthesia were recruited in this prospective, randomized, crossover, parallel-group study. Results: The transverse diameter of the IJV was found to be significantly higher in the medial-oblique probe position (p = 0.000, mean difference 0.43 cm; 95% confidence interval [CI] 0.34-0.52). The percentage of overlap was also significantly lower in the medial-oblique probe position (48.7 +/- 10.7% in short-axis vs. 36.3 +/- 13.2% in medialoblique probe position; p = 0.000; mean difference 12.4%, 95% CI 9.1-15.8). However, there was no statistically significant difference in the anteroposterior diameter of the IJV between the two probe positions (1.11 +/- 0.26 cm in short axis vs 1.07 +/- 0.25 cm in medial oblique; p = 0.631). Conclusion: The medial-oblique probe position for IJV cannulation provides sonoanatomic superiority over the classic short-axis probe position. Further randomized, controlled trials may confirm the medial-oblique view's clinical benefit in the future. (C) 2015 Elsevier Inc.