Effects of four different positive airway pressures on right internal jugular vein catheterisation.

CONTEXT: The right internal jugular vein (RIJV) is often used for central venous catheterisation in patients undergoing major surgery. The efficacy of this route correlates with the diameter of the vein which can be influenced by airway pressure. OBJECTIVE: To investigate four positive airway pressures (PAPs) in mechanically ventilated patients and to determine the most suitable of these for RIJV catheterisation. DESIGN: Prospective, randomised, controlled study. SETTING: Two Chinese medical centres. PATIENTS: Two hundred and forty patients scheduled for gastrointestinal tract surgery under general anaesthesia (male-to-female ratio, 135 : 105; American Society of Anesthesiologists' physical status class, I-III; age range, 19-81 years); patients were excluded from the study if they had a history of haematological disease, external neck injury, RIJV catheterisation, severe cardiovascular disease, RIJV thrombosis, injection-site infection, pneumothorax and pulmonary bulla. INTERVENTIONS: They were randomised into four groups of 60, each to undergo RIJV catheterisation at a PAP of 0 (1 cmH2O = 0.098 kPa, group A); 15 (group B); 20 (group C); and 25 cmH2O (group D). MAIN OUTCOME MEASURES: Primary outcomes were central venous pressure (CVP) and RIJV cross-sectional area which were measured before and during PAP; the number of catheterisations completed in 30 s; the number of first pass punctures; heart rate and mean arterial pressure which were monitored continuously; and the incidence of complications which included local haematoma, pneumothorax and internal carotid artery (ICA) puncture. RESULTS: Two patients were excluded following ICA puncture, leaving 238 for analysis. In groups C and D, the CVP and the cross-sectional area of RIJV were significantly larger; the number completing catheterisation within 30 s and the number of first pass punctures increased significantly and was comparable between these two groups. Compared with groups A and B, the incidences of hypotension and bradycardia were significantly increased in groups C and D. The incidence of local haematoma was significantly increased in group D compared with other groups. RIJV catheterisation was completed successfully in all but two patients in group A. CONCLUSION: A PAP of 20 cmH2O seems most suitable for successful RIJV catheterisation in mechanically ventilated patients. It is associated with an increase in cross-sectional RIJV area and CVP, which facilitate cannulation, and results in fewer puncture-related complications. However, meticulous haemodynamic monitoring is needed to avoid hypotension and bradycardia.