Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function.
Interscalene block may cause phrenic nerve block and decreased diaphragmatic motion. We evaluated the effect of continuous interscalene block on ventilatory function and diaphragmatic motion. We studied ten patients scheduled for surgery or manipulation of the shoulder. Preoperatively, the patients underwent spirometry and double-exposure chest radiography. They received an interscalene block with 0.75% bupivacaine. Thereafter, 0.25% bupivacaine was infused into the interscalene space for 24 h. Spirometry was repeated three times and double-exposure radiography twice. The maximal inspiratory and expiratory pressures were measured repeatedly. Haemoglobin oxygen saturation (SPO2) was monitored with pulse oximetry. The block provided adequate anaesthesia for surgery or manipulation. All patients had a marked ipsilateral paresis of the diaphragm in the radiographs 3 h after the initial block. Twenty-one hours later five patients had diaphragmatic motility comparable to the situation before the block. In the other five patients, the amplitude of diaphragmatic motility on the side of the block was only 4-37% of the values before the block. All patients had a clear reduction in forced vital capacity (FVC), forced expiratory volume in 1s (FEV1) and peak expiratory flow (PEF) 3 and 8 h after the block without signs of dyspnoea. In conclusion, in all our patients interscalene block caused an ipsilateral hemidiaphragm paresis, which in five of ten patients persisted until the end of the continuous block.
Pere
P
P
Department of Anaesthesia, Surgical Hospital, Helsinki University Central Hospital, Finland.
Pitkänen
M
M
Rosenberg
P H
PH
Björkenheim
J M
JM
Linden
H
H
Salorinne
Y
Y
Tuominen
M
M
D000328:Adult; D001917:Brachial Plexus; D002045:Bupivacaine / Q000009:adverse effects; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects; D010100:Oxygen / Q000097:blood; D010366:Peak Expiratory Flow Rate / Q000187:drug effects / Q000502:physiology; D010791:Phrenic Nerve / Q000187:drug effects; D012123:Pulmonary Ventilation / Q000187:drug effects / Q000502:physiology; D011859:Radiography; D012119:Respiration / Q000187:drug effects / Q000502:physiology*; D012133:Respiratory Paralysis / Q000209:etiology*; D012782:Shoulder; D013147:Spirometry; D014797:Vital Capacity / Q000187:drug effects / Q000502:physiology
D010100:Oxygen; D002045:Bupivacaine