子宮筋腫核出術におけるバソプレッシン使用による心拍機能変化の検討

Analysis of heart rate's alterations by the intramyometrial injection of vasopressin during myomectomy

◆要旨：腹腔鏡補助下子宮筋腫核出術でバソプレッシン（以下，VP）の注入直後に心停止した症例を経験した．そこで投与直後の心機能の影響を調べ安全な使用法を検討した．対象は2005年6月～2009年12月までの徐脈群9例と非徐脈群121例である．徐脈群のVP投与量は9.0±3.9単位，非徐脈群は6.6±1.4単位で両者に有意差はないが，徐脈群は非徐脈群に比べ137％と増量傾向を認めた．またVP 6.6～6.8単位以下の投与では有意に徐脈症例数が低下した．VPの過剰投与を避けるために注入濃度は0.2単位/ml以下で総投与量は6.8単位以下とし，使用前に麻酔科へ事前に注意を喚起し，徐脈が生じた場合は回復に努めることが重要である．

　Since we once experienced a patient who underwent sudden cardiac arrest immediately after intramyomerial injection of low-concentration vasopressin during a laparoscopically-assisted myomectomy（LAM）, we evaluated the safer usage of vasopressin. Between June 2005 and December 2009, nine bradycardia patients and 121 non-bradycardia patients underwent LAM. Bradycardia was observed within 2.3±0.9 minutes after the intramyomerial injection of vasopressin, and it took 6.3±4.4 minutes until recovery. There was no change in the blood pressure. The dosage of dilute vasopressin used in the bradycardia group was 9.0±3.9 units, while 6.6±1.4 units of dilute vasopressin were used in the non-bradycardia group. No statistically significant difference was observed between the two groups. However, the total dosage increased by 137%in the bradradycardia group. In addition, the number of bradycardia patients significantly decreased after the dosage was reduced to less than 6.6-6.8 units in our patients. We therefore recommend that the administration of an excessive dose of vasopressin should be avoided, the dilute concentration should be under 0.2 unit/ml, and the maximal amount should be less than 6 .8 units. At the same time, close monitoring by means of electrocardiography is also considered to be essential to avoid any problems.