Respiratory Performance after Upper Abdominal Surgery. A Comparison of Pain Relief with Intercostal Blocks and Centrally Acting Analgesics

The respiratory capacity was studied during the first 2 days postoperatively in 94 patients, aged 19 to 75 years and undergoing surgery through an upper abdominal incision. Postoperative pain relief was randomly administered, either by intercostal block (i.c.b.) and centrally acting analgesics on demand, or by centrally acting analgesics alone. Respiratory studies comprising forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEF) and analysis of arterial blood gases were made. Bilateral i.c.b. given after surgery performed through a midline incision did not improve the respiratory function, whereas unilateral i.c.b. after surgery through a subcostal incision had positive effects. Thus postoperative i.c.b. following cholecystectomy performed through a subcostal incision resulted in higher FVC, FEV1 and PEF values than without i.c.b. at least during the time of effective nerve block. I.c.b. after subcostal incision also improved arterial oxygen tension. The patients undergoing cholecystectomy and receiving a second i.c.b. 8 h after the first one had better respiratory function than the patients without any block during the first 2 days postoperatively.