ICUにおける気管内チューブの抜管基準

Extubation criteria after weaning from postopcrative mechanical ventilation

　人工呼吸器で呼吸管理を行なっている患者から気管内チューブを抜管する際，現在では種々の基準や，評価法^1〜6）が設けられているが，実際には経験豊富な医師による主観的判断で抜管されることが多い。

　我々は，その判断に少しでも客観性をもたせるために，誰でもがベッドサイドで簡単に行なえるいくつかの項目を選んで，その評価を点数化し，抜管の成功と不成功とをその総合点数である程度予測できないかどうかを検討してみたところ，抜管の目安として有効と思われる結果を得たので報告する。

In attempt to define extubation criteria that everyone could practice easily and estimate objec-tively, we tried to score twelve factors of our cri-teria.

Between successed group in extubation and failed one, significant difference was found on six factors; 1. Normality on X-ray photograph of chest 2. Ability of lifting one's head 3. Normal respiratory rate (10/min≦R. R.≦30min) 4. Enough forced vital capacity (F.V.C.≧12/ml/kg) 5. R-index under 0.8 (R-index= AaDO₂/PaO₂) 6. Good ge-neral impression (They were scored 0 point.) In order to simplify the calculation of the score, a value of either 0 or 1 point was assigned to each of the six factors. Total scores of the six factors ranged from 0 to 6 points, increasing with severity of symptoms and signs. Total scores were signifi-cantly different (p<0.01) between successed group (1.11±1.0) and failed one (3.13±1.15). In successed group patients with total score under 2 points accounted for 90 percent and in failed one over 3 to 6 points accounted for 70 percent.

We concluded that patients with total scores under 2 points could be extubated successfully.