脊髓麻醉下施行全髖關節置換術並使用骨泥引起延遲性低血氧症之病例報告

Delayed Hypoxemia after Bone Cement Insertion during Total Hip Replacement under Spinal Anesthesia-- A Case Report

本病例為一在脊髓麻醉下施行全骻關節置換術的病患，發生延遲性低血氧症之報告。我們分析其可能機轉主要與其骨泥成分polymethylmethacrylate和固定人工關節施打骨泥有關。病患為七十九歲男性，麻醉體位分級第二級，且無肺病病史，手術在脊髓麻醉下順利完成。手術後（約相當於骨泥施打後兩小時），呼吸逐漸變得急促，二小時之後由脈搏血氧儀發現有低飽和現象，聽診發現有輕微哮喘現象，初步診斷為支氣管痙攣。動脈血氧分析發現，吸入氧氣分 數為35％時，血氧分壓為71毫米汞柱，飽和度91％。於是給予病患吸入性氣管擴張劑及氧氣治療（氧氣分率增為50％），病患哮喘改善，但仍持續呼吸急促及輕微滴血氧，轉至加護病房進一步的治療。隔天，進行肺臟換氣──灌流攝影檢查，結果高度懷疑肺栓塞。由過去文獻之報告與本病例之經驗，我們推測可能是因為骨泥的放置，引起肺栓塞及支氣管痙攣，造成此病人產生延遲性低血氧症。

We report a case of delayed hypoxemia in an aged healthy male patient, which developed 2 hours after cementation of the prosthesis in total hip replacement (THR) under spinal anesthesia. The patient was doing well throughout the operation but unfortunately, progressive tachypnea was noted 1 h after he was transferred to the recovery room (i.e. 2 h after the application of bone cement into the femur). An hour further, distinct wheeze was heard bilaterally on auscultation, which signified bronchospasm. Arterial blood gases analysis revealed a low PaO2 of 71 mmHg and a decrease of oxygen saturation to 91% with supplement of fractional oxygen of 35%. Aerosolization of bronchodilator with terbutaline was administered and supplemental fractional oxygen was increased to 50%. Although wheezing soon subsided, tachypnea and desaturation persisted. He was then transferred to the surgical intensive care unit for further management. Ventilation-perfusion lung scan was performed, which was suggestive of multiple pulmonary embolism.