Ipsilateral hemidiaphragmatic paresis after a supraclavicular and costoclavicular brachial plexus block

OBJECTIVES The current study compared the incidence of ipsilateral hemidiaphragmatic paresis, and thus PNP, between a supraclavicular and costoclavicular BPB.

PATIENTS Forty patients undergoing right-sided upper extremity surgery.

INTERVENTION All patients received either a supraclavicular group or costoclavicular group BPB using 20 ml of an equal mixture of 0.5% bupivacaine and 2% lidocaine with 1 : 200 000 epinephrine.

MAIN OUTCOME MEASURES Measurements included ipsilateral hemidiaphragmatic excursion and peak expiratory flow rate (PEFR) taken before and at 30 min after the BPB. Diaphragmatic excursion was measured using M-mode ultrasound during normal breathing, deep breathing and with the sniff manoeuvre. Ipsilateral PNP was defined as a reduction in hemidiaphragmatic excursion by at least 50% during deep breathing at 30 min after the BPB.

RESULTS The incidence of ipsilateral PNP was lower (P = 0.008) in the costoclavicular group (5%) than in the supraclavicular group (45%). Fewer (P = 0.04) patients in the costoclavicular group [1(5%)] exhibited a positive sniff test, with paradoxical movement of the diaphragm, than in the supraclavicular group [7(35%)]. PEFRs were similar (P = 0.09) between the groups. When ipsilateral hemidiaphragmatic paresis was present, the median reduction in PEFR was 32% (interquartile range 23.6 to 45.5%).

CONCLUSION Costoclavicular BPB produces a lower incidence of ipsilateral PNP than a supraclavicular BPB.