Fleischmann Edith, Herbst Friedrich, Kugener André, Kabon Barbara, Niedermayr Monika, Sessler Daniel I, Kurz Andrea
Department of Anesthesia and Intensive Care, Medical University Vienna, Austria.
Anesthesiology. 2006 May;104(5):944-9. doi: 10.1097/00000542-200605000-00009.
Supplemental perioperative oxygen increases tissue oxygen tension and decreases incidence of wound infection in colorectal surgery patients. Mild intraoperative hypercapnia also increases subcutaneous tissue oxygen tension. However, the effect of hypercapnia in patients already receiving supplemental oxygen is unknown, as is the effect of mild hypercapnia on intestinal oxygenation in humans-although the intestines are presumably the tissue of interest for colon surgeries. The authors tested the hypothesis that mild intraoperative hypercapnia increases both subcutaneous tissue and intramural intestinal oxygen tension in patients given supplemental oxygen.
Patients undergoing elective colon resection were randomly assigned to normocapnia (n = 15, end-tidal carbon dioxide tension 35 mmHg) or mild hypercapnia (n = 15, end-tidal carbon dioxide tension 50 mmHg). Intraoperative inspired oxygen concentration was 80%. The authors measured subcutaneous tissue oxygen tension in the right upper arm and intramural oxygen tension in the left colon. Measurements were averaged over time within each patient and, subsequently, among patients. Data were compared with chi-square, unpaired t, or Mann-Whitney rank sum tests; P < 0.05 was significant.
Morphometric characteristics and other possible confounding factors were similar in the groups. Intraoperative tissue oxygen tension in hypercapnic patients was significantly greater in the arm (mean +/- SD: 116 +/- 29 mmHg vs. 84 +/- 25 mmHg; P = 0.006) and colon (median [interquartile range]: 107 [81-129] vs. 53 [41-104] mmHg; P = 0.020).
During supplemental oxygen administration, mild intraoperative hypercapnia increased tissue oxygen tension in the arm and colon. Previous work suggests that improved tissue oxygenation will reduce infection risk via the proposed pathomechanism, although only an outcome study can confirm this.
围手术期补充氧气可提高组织氧张力，并降低结直肠手术患者伤口感染的发生率。术中轻度高碳酸血症也可提高皮下组织氧张力。然而，在已接受补充氧气的患者中高碳酸血症的作用尚不清楚，轻度高碳酸血症对人体肠道氧合的影响也不清楚——尽管肠道可能是结肠手术中关注的组织。作者检验了以下假设：在给予补充氧气的患者中，术中轻度高碳酸血症可提高皮下组织和肠壁内肠道的氧张力。
接受择期结肠切除术的患者被随机分为正常碳酸血症组（n = 15，呼气末二氧化碳分压35 mmHg）或轻度高碳酸血症组（n = 15，呼气末二氧化碳分压50 mmHg）。术中吸入氧浓度为80%。作者测量了右上臂的皮下组织氧张力和左结肠的肠壁内氧张力。对每位患者在一段时间内的测量值进行平均，随后在患者之间进行平均。数据采用卡方检验、不成对t检验或曼-惠特尼秩和检验进行比较；P < 0.05具有统计学意义。
两组患者的形态学特征和其他可能的混杂因素相似。高碳酸血症患者术中组织氧张力在手臂（平均值±标准差：116±29 mmHg对84±25 mmHg；P = 0.006）和结肠（中位数[四分位间距]：107 [81 - 129]对53 [41 - 104] mmHg；P = 0.020）显著更高。
在补充氧气期间，术中轻度高碳酸血症可提高手臂和结肠的组织氧张力。先前的研究表明，改善组织氧合将通过所提出的病理机制降低感染风险，尽管只有一项结局研究才能证实这一点。
