Negative pressure versus loss of resistance technique for interpleural block.
BACKGROUND
Loss of resistance is a commonly practiced technique among the trainees. But, for performing interpleural block (IPB), negative-pressure identification techniques have been popularized. This study was designed to evaluate the two techniques in trainee anaesthetists.


METHODS
Sixty American society of anaesthesiologist (ASA) grade 1 and 2 women scheduled for elective breast surgeries under general anaesthesia were recruited for the study. The patients were randomly assigned to receive IPB (25 mL of 0.5% bupivacaine with adrenaline 5 mg/mL) with either loss of resistance technique (group LR, n=45) or the negative-pressure technique (group NP, n=45). The success rate and ease of performance was evaluated by the number of attempts and time taken.


RESULTS
Higher first attempt success rate was observed in group LR (90%) when compared with group NP (80%), with a significantly shorter mean time to successful identification of interpleural space in the group LR (5 min) than in the group NP (5.8 min), P<0.01log rank test. All patients had satisfactory IPB and the median numbers of segments blocked were 7 (5-9) and 6 (5-7) in groups LR and NP, respectively. No significant complications were observed in any of the patients.


CONCLUSIONS
Both techniques are safe and effective, but the loss of resistance technique is associated with a higher first attempt success rate performed in a shorter time by trainee anaesthetists.
Department of Anaesthesiology and Critical Care, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, Tamil Nadu, India.
Pankaj
P
Kundra
Karuppiah
K
Ajeetha