[A case of prolonged hypercapnea after interscalene brachial plexus block].

An 83-year-old woman was scheduled for surgery of the left upper and lower extremity fracture. She had past history of lung partial resection for lung cancer and rheumatoid arthritis, and recent history of pneumonia. She also had fluid retention in the thoracic cavity. Open resection of the femoral neck fracture was first performed uneventfully under spinal anesthesia with bupivacaine 0.5% 2 ml. Then, interscalene blaxioplexus block was performed with 0.75% ropivacaine 15 ml and 1% lidocaine 10 ml for tension band wiring of the fractured olecranon. Midazolam 1 mg and propofol 1.5 mg x kg(-1) x hr(-1) were administered for sedation. Thirty minutes after the block, oxgen saturation decreased to 92% under O2 3 l x min(-1) by a mask. She was intubated and arterial carbon dioxide tension was above 150 mmHg. A few hours later, she became conscious and mask CPAP was used after extubation for one day. Pa(CO2) was 90-100 mmHg for 3 days and decreased to 56.9 mmHg on the 6th day, but her consciousness had been clear. Phrenic nerve palsy and sedation in the patient with decreased lung function might have induced prolonged hypercapnea.