Phrenic palsy and analgesic quality of continuous supraclavicular vs. interscalene plexus blocks after shoulder surgery.
BACKGROUND
Hemidiaphragmatic palsy is a common consequence of the interscalene brachial plexus block. It occurs less commonly with the supraclavicular approach. Register data suggest that the analgesic quality of a supraclavicular blockade is sufficient for arthroscopic shoulder surgery, although data on the post-operative analgesic effect are lacking.


METHODS
After approval by the ethics committee, patients having arthroscopic shoulder surgery under general anaesthesia were randomized to receive a continuous interscalene or supraclavicular blockade. Phrenic nerve function was evaluated through ultrasound examination of the diaphragm in combination with spirometry. Pain scores at rest and activity etc. were determined before catheter insertion, during observation in the post- anaesthesia care unit (PACU) and on post-operative day 1 (POD1). The initial application of 10 ml of ropivacaine 0.2% was followed by continuous application of 4 ml of ropivacaine 0.2%, plus a patient controlled analgesia (PCA) bolus of 4 ml/h.


RESULTS
One hundred and twenty patients were randomized, of which 114 data sets were analysed. Complete hemidiaphragmatic paresis occurred in 43% of the interscalene group vs. 24% in the supraclavicular group during PACU stay. Rates of dyspnoea and hoarseness were similar. Horner's syndrome occurred in 21% of the interscalene but only 3% of the supraclavicular group on POD1. Pain scores were comparable for pain at rest and during stress at each time point.


CONCLUSIONS
This trial showed a significantly greater incidence of phrenic nerve palsy of the interscalene group in PACU, but not on POD1. Post-operative analgesic quality was similar in both groups. Continuous supraclavicular blockade is a suitable alternative to the continuous interscalene technique.
Department of Anesthesia and Intensive Care Medicine, University Hospital Giessen and Marburg, Marburg, Germany.
T
T
Wiesmann
Department of Anesthesia and Intensive Care Medicine, University Hospital Giessen and Marburg, Marburg, Germany.
C
C
Feldmann
Institute of Medical Biometry and Epidemiology, Philipps University, Marburg, Germany.
H H
HH
Müller
Department of Anesthesia and Intensive Care Medicine, University Hospital Giessen and Marburg, Marburg, Germany.
L
L
Nentwig
Department of Anesthesia and Intensive Care Medicine, University Hospital Giessen and Marburg, Marburg, Germany.
A
A
Beermann
Center for Orthopedics and Trauma Surgery, University Hospital Giessen and Marburg, Marburg, Germany.
B F
BF
El-Zayat
Department of Anesthesia and Intensive Care Medicine, University Hospital Giessen and Marburg, Marburg, Germany.
M
M
Zoremba
Department of Anesthesia and Intensive Care Medicine, University Hospital Giessen and Marburg, Marburg, Germany.
H
H
Wulf
Department of Anesthesia and Intensive Care Medicine, University Hospital Giessen and Marburg, Marburg, Germany.
T
T
Steinfeldt
D000328:Adult; D000368:Aged; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000627:therapeutic use; D001182:Arthroscopy; D065527:Brachial Plexus Block / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D010149:Postoperative Pain / Q000517:prevention & control*; D010791:Phrenic Nerve / Q000502:physiology*; D012782:Shoulder / Q000601:surgery*; D013147:Spirometry
D000701:Analgesics, Opioid