Context: The study was designed to compare the characteristics and hemodynamic effects subclavian central venous catheterisation done under spontaneous respiration versus mechanical ventilation. Aims: To compare the characteristics and hemodynamic effects of infraclavicular subclavian central venous catheterisation done under spontaneous respiration versus mechanical ventilation. Settings and Design: prospective cross-sectional study. Methods and Material: A prospective randomised cross-sectional study was undertaken in 100 patients requiring subclavian venous catheterisation. They were randomised by computer generated random number table to receive the venous cannulation either during spontaneous or mechanical ventilation. The characteristics i.e success or failure, successful cannulation in first attempt, number of attempts, time taken ; and hemodynamic effects i.e heart rate, systolic blood pressure, diastolic blood pressure and mean arterial pressure were measured in patients with spontaneous respiration and with mechanical ventilation. Hemodynamic variables were measured every 2 minutes till successful catheterisation and till 10 minutes after successful catheterisation. Statistical analysis used: Statistical Package for Social Sciences (SPSS) version 21.0. Results: The demographic variables were comparable in both the groups. Failure to cannulate occurred in total of 8 patients and were comparable among the groups. Successful catheterisation in first attempt was possible in 66% patients breathing spontaneously versus 72% in mechanically ventilated patients (p=0.517). Time to successful catheterisation were also comparable between groups (145.42 ± 56.54 secvs 133.38 ± 36.78 sec, p = 0.582). Heart rate variability >20% of baseline occurred in 22% vs 4% in spontaneously breathing and mechanically ventilated patients ( p = 0.015 ). The systolic, diastolic and MAP were comparable between the groups. Conclusions: The characteristics of infraclavicular subclavian central venous catheterisation are similar regardless of mechanical ventilation and spontaneous respiration. The infraclavicular subclavian venous catheterisation done under spontaneous respiration may result in significant heart rate variability.

Keymessages: The characteristics of infraclavicular subclavian central venous catheterisation are similar regardless of mechanical ventilation and spontaneous respiration. The infraclavicular subclavian venous catheterisation done under spontaneous respiration may result in significant heart rate variability.