北本 憲永

手術室において臨床工学技士がどのように医師や看護師と連携し、働き方改革に寄与できるか検討してきた。その中で特に医療機器が多く使用される内視鏡外科手術や各種治療装置、手術中のナビゲーション装置、整形外科関連のインプラント業務などの医療機器の準備や機器の接続、手術中の進行に合わせた操作介助などを中心に対応を進めてきた。また、その延長線上に清潔野での操作介助も実施されるようになり、臨床工学技士が得意とする分野で、清潔補助業務を看護から移行し、手術室を安全で効率的に運用することで手術室全体の働き方改革に寄与できる。公益社団法人日本臨床工学技士会から厚生労働省に提出している周術期管理の働き方改革の中に、麻酔科医不足をサポートする麻酔補助業務、外科医不足をサポートする内視鏡外科手術時の内視鏡用カメラを保持するスコピスト業務がある。いずれも医師の業務を補助することで麻酔科医と外科医に対する働き方改革になると確信している。いずれの業務も自施設で承認した上で実施していくこと。今後は各関連学会(日本麻酔学会、外科学会、内視鏡外科学会、日本手術看護学会、日本手術医学会など)と共同で教育をさらに構築し対応していく必要がある。(著者抄録)

BACKGROUND: Total hemoglobin (tHb) measurement is indispensable for determining the patient's condition (hemorrhagic vs. ischemic) and need for blood transfusion. Conductivity- and absorbance-based measurement methods are used for blood gas analysis of tHb. For conductivity-based measurement, tHb is calculated after converting blood conductivity into a hematocrit value, whereas absorbance measurement is based on light absorbance after red blood cell hemolysis. Due to changes in plasma electrolytes and hemolysis, there is a possibility that conductivity- and absorbance-based measurement methods may cause a difference in tHb. METHODS: In this study, test samples with controlled electrolyte changes and hemolysis were created by adding sodium chloride, distilled water or hemolytic blood to blood samples collected from healthy volunteers, and tHb values were compared between both methods. RESULTS: Conductivity-based measurement revealed reduced tHb value (from 15.49 to 13.05 g/dl) following the addition of 10% sodium chloride, which was also reduced by the addition of hemolysate. Conversely, the addition of distilled water significantly increased tHb value than the expected value. In the absorbance method, there was no significant change in tHb value due to electrolyte change or hemolysis. CONCLUSIONS: We have to recognize unexpected conductivity changes occur at all times when tHb is measured via conductivity- and absorbance-based measurement methods. The absorbance method should be used when measuring tHb in patients with expected blood conductivity changes. However, when using this method, the added contribution of hemoglobin from hemolytic erythrocytes lacking oxygen carrying capacity must be considered. We recognize that discrepancy can occur between conductivity- and absorbance-based measurement methods when tHb is measured.