From the Department of Surgery (U.P.I., K.P., K.E.M., G.J.B.), and School of Medicine (T.C.), University of Minnesota, Minneapolis; and Technomics Research (T.N.), LLC, Medina, Minnesota.
J Trauma Acute Care Surg. 2014 Mar;76(3):809-16. doi: 10.1097/TA.0b013e3182ab07a4.
Near-infrared spectroscopy-derived tissue hemoglobin saturation (StO2) is a noninvasive measurement that reflects changes in microcirculatory tissue perfusion. Previous studies in trauma patients have shown a correlation between low StO2 levels and mortality, organ failure, and severity of injury. The goals of this study were to identify the incidence of low StO2 in the critically ill patient population of a surgical intensive care unit (SICU) and evaluate the relationship of low StO2 and clinical outcomes.
We conducted a prospective cohort study at the University of Minnesota Medical Center. After institutional review board approval, 620 patients admitted to the SICU between July 2010 and July 2011 were screened for enrollment. Patients with an expected ICU length of stay of less than 24 hours were excluded. In the 490 patients who met inclusion criteria, StO2 measurements were obtained from the thenar eminence one to three times daily for the length of the ICU stay, up to 14 days. Outcome data included 28-day hospital mortality; ICU readmission; ventilator-free, ICU-free, and hospital-free days; and the need for lifesaving interventions.
The overall incidence of low StO2 (<70%) was 11% of the patients per day. Patients with at least 1 day in the SICU with an StO2 measurement of less than 70% had higher rates of ICU readmission and fewer ventilator-free, ICU-free, and hospital-free days compared with those who did not. Mortality (28-day in-hospital) trended higher for these patients but was not statistically significant. An increase in the number of days with StO2 less than 70% was also associated with fewer ventilator-free, ICU-free, and hospital-free days.
Low StO2 (<70%) is common and associated with poor outcomes in SICU patients. Near-infrared spectroscopy represents a potentially useful, noninvasive adjunct to monitoring of critically ill patients.
Prognostic study, level II.
近红外光谱衍生的组织血红蛋白饱和度（StO2）是一种非侵入性测量方法，可反映微循环组织灌注的变化。先前在创伤患者中的研究表明，低 StO2 水平与死亡率、器官衰竭和损伤严重程度之间存在相关性。本研究的目的是确定外科重症监护病房（SICU）中危重症患者人群中低 StO2 的发生率，并评估低 StO2 与临床结局的关系。
我们在明尼苏达大学医学中心进行了一项前瞻性队列研究。在机构审查委员会批准后，筛选了 2010 年 7 月至 2011 年 7 月期间入住 SICU 的 620 名患者以进行入组。排除预计 ICU 住院时间少于 24 小时的患者。在符合纳入标准的 490 名患者中，在 ICU 住院期间每天从大鱼际肌测量 StO2 一次到三次，最长可达 14 天。结局数据包括 28 天院内死亡率；ICU 再入院率；无呼吸机、无 ICU 和无医院天数；以及需要救生干预的情况。
每天低 StO2（<70%）的患者总体发生率为 11%。与未发生这种情况的患者相比，在 SICU 至少有一天 StO2 测量值<70%的患者 ICU 再入院率更高，无呼吸机、无 ICU 和无医院天数更少。这些患者的死亡率（28 天院内）趋势更高，但无统计学意义。StO2 测量值<70%的天数增加也与无呼吸机、无 ICU 和无医院天数减少相关。
低 StO2（<70%）在 SICU 患者中很常见，并与不良结局相关。近红外光谱代表了一种潜在有用的、非侵入性的监测危重症患者的辅助手段。
预后研究，II 级。
