PCA（patient-controlled analgesia）を用いた持続硬膜外麻酔（PCEA）による人工膝関節置換術後の疼痛管理

Patient-controlled Epidural Analgesia after Total Knee Arthroplasty

　人工膝関節置換術後（TKA）の疼痛管理にはPCEA（patient-controlled epidural analgesia）が有効であるが，その適切な投与量について明らかにされていない．われわれは，TKA術後に基礎持続投与4ml/時間，ボーラス投与2ml（4ml/h群）と基礎持続投与2ml/時間，ボーラス投与4ml（2ml/h群）にてPCA（patient-controlled analgesia）を行った．どちらの投与法が望ましいかを調べるため，両群について，ボーラス投与の回数，坐剤の使用個数，術後6時間，24時間の疼痛，合併症について検討を行った．2ml/h群では術後24時間の疼痛が少なく，尿閉を生じた症例は認められず，2ml/h群がよりよい投与法と考えられた．

　PCEA (patient-controlled epidural analgesia) is effective for pain control after TKA (total knee arthroplasty), however, the proper dose of to use for background infusion and bolus injection was unclear. We use PCEA after TKA with a background infusion of 4ml/hour and a bolus injection of 2ml (4ml/h group) and a background infusion of 2ml/hour and a bolus injection of 4ml (2ml/h group). We evaluated times of bolus injection, quantity of pain killers other than PCEA, severity of pain 6 hour or 24 hour postoperatively, and side effects. No patients in the 2ml/h group had ischuria, and they had less pain 24 hour postoperatively. A background infusion of 2ml/h and a bolus injection of 4ml are preferable doses of PCEA after TKA.