Maynard N, Bihari D, Beale R, Smithies M, Baldock G, Mason R, McColl I
Department of Surgery, Guy's Hospital, London, England.
JAMA. 1993 Sep 8;270(10):1203-10.
To investigate the importance of splanchnic ischemia in patients with acute circulatory failure by comparing gastric intramucosal pH as measured by tonometry with conventional methods of assessing adequacy of tissue oxygenation.
Prospective cohort of patients with acute circulatory failure in first 24 hours after admission to the intensive care unit.
Two general intensive care units in London, England.
Consecutive sample of 83 patients of varying diagnostic categories that required pulmonary artery catheterization.
Gastric intramucosal pH and hemodynamic, oxygen transport, and metabolic variables were measured on admission and at 12 hours and 24 hours after admission. Prediction of outcome (death or survival) by each measurement was assessed by sensitivity, specificity, and logistic regression analysis.
Mean 24-hour Acute Physiology and Chronic Health Evaluation (APACHE II) score was 20.3. There were significant differences in mean gastric intramucosal pH between survivors and nonsurvivors on admission and at 24 hours, (7.40 vs 7.28, 7.40 vs 7.24, respectively; P < .001). Admission heart rate was higher (116 vs 101 beats per minute; P < .003) and mean arterial pressure lower (82 vs 97 mm Hg; P < .01) in nonsurvivors. There were no consistent differences in cardiac index, oxygen delivery, and oxygen uptake between survivors and nonsurvivors. Admission arterial pH was significantly lower (7.3 vs 7.36; P < .003), base excess more negative (-5.3 vs -1.9; P < .001), and lactate concentration higher (3.14 vs 1.91 mmol/L; P < .03) in nonsurvivors. Gastric intramucosal pH had a sensitivity of 88% for predicting death and a likelihood ratio of 2.32, higher than for any other variable. Only gastric intramucosal pH at 24 hours independently predicted outcome.
Gastric intramucosal pH was the most reliable indicator of adequacy of tissue oxygenation in this group of patients. Inadequate regional blood flow as detected by a reduction in gastric intramucosal pH, but not by systemic measures, is an important contributor to morbidity and mortality in intensive care units.
通过比较用张力测定法测量的胃黏膜内pH值与评估组织氧合是否充足的传统方法，研究内脏缺血在急性循环衰竭患者中的重要性。
对入住重症监护病房后最初24小时内的急性循环衰竭患者进行前瞻性队列研究。
英国伦敦的两个普通重症监护病房。
连续选取83例不同诊断类型且需要进行肺动脉导管插入术的患者。
入院时、入院后12小时和24小时测量胃黏膜内pH值以及血流动力学、氧输送和代谢变量。通过敏感性、特异性和逻辑回归分析评估每次测量对结局（死亡或存活）的预测情况。
24小时急性生理与慢性健康状况评分（APACHE II）平均值为20.3。存活者与非存活者入院时和24小时时的胃黏膜内pH值平均值存在显著差异（分别为7.40对7.28，7.40对7.24；P <.001）。非存活者入院时心率较高（116次/分钟对101次/分钟；P <.003），平均动脉压较低（82 mmHg对97 mmHg；P <.01）。存活者与非存活者在心脏指数、氧输送和氧摄取方面没有一致的差异。非存活者入院时动脉pH值显著较低（7.3对7.36；P <.003），碱剩余更负（-5.3对-1.9；P <.001），乳酸浓度更高（3.14 mmol/L对1.91 mmol/L；P <.03）。胃黏膜内pH值预测死亡的敏感性为88%，似然比为2.32，高于任何其他变量。只有24小时时的胃黏膜内pH值能独立预测结局。
胃黏膜内pH值是该组患者组织氧合是否充足的最可靠指标。通过胃黏膜内pH值降低检测到的局部血流不足，但不是通过全身指标检测到的，是重症监护病房发病率和死亡率的重要促成因素。
