Effect of acute moderate changes in Paco2 on global hemodynamics and gastric perfusion
Effect of acute moderate changes in Paco2 on global hemodynamics and gastric perfusion
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DOI：
10.1097/00003246-200002000-00012
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发表时间：
2000-02-01
影响因子：
8.8
通讯作者：
Fernández, R
中科院分区：
文献类型：
--
作者：
Mas, A;Saura, P;Fernández, R
目的：描述血流动力学稳定患者对Paco（2）急性调整的整体血流动力学和内脏灌注变化。设计：前瞻性、随机交叉研究。设置：社区医院的内科-外科重症监护室（400，000名居民）。患者：10名重症患者，他们接受了镇静剂、瘫痪和机械通气。高碳酸血症和低碳酸血症通过以随机顺序增加和减少仪器死腔来获得。每次干预后，患者恢复到基础状态。每个阶段持续80 min：20 min达到稳定Paco（2），60 min用于眼压计平衡。在每个阶段，收集总体血流动力学变量和眼压数据。使用方差分析比较这些时期。测量和主要结果：急性高碳酸血症（Paco（2）从40 +/-3升到52 +/-3升，p <0.05）增加心脏指数（3.43 +/-0.37 vs. 3.97 +/-0.43 mL/min/m（2），p <.05），心率（95 +/-6 vs. 105 +/-3次加热/分钟，p <.05），以及平均肺动脉压（21 +/-1 vs. 24 +/-1 mm Hg，p <.05）和降低的全身血管阻力（992 +/-98对813 +/-93达因·秒/厘米（5），p <.05）和氧提取率（27 +/-3%对22 +/-2%，p <.05）。标准化粘膜内Pco（2）从49 +/-2增加到61 +/-3托（p <0.05），计算的粘膜内pH值相应下降（[pHi] 7.35 +/-0.03 vs. 7.25 +/-0.02，p <0.05），但胃动脉Pco（2）梯度（Delta Pco（2））没有变化。急性低碳酸血症（Paco（2）从41 +/-3至34 +/-3 mmHg，p <0.05; pH 7.41 +/-0.01至7.47 +/-0.02，p <0.05）诱导全身血管阻力轻微增加（995 +/-117对1088 +/-160达因秒/厘米（5），p <.05）和氧提取率（28 +/-2%对30 +/-2%，p <.05）。标准化粘膜内Pco（2）降低（50 +/-4 vs. 44 +/-3 μ g，p <.05），pHi升高（7.33 +/-0.03 vs. 7.36 +/-0.02; p <0.05），但Delta Pco（2）没有变化。在这一小群稳定患者中，Paco（2）的中度急性变化对整体血流动力学有显著影响，但通过Delta Pco（2）评估的内脏灌注没有变化。在这些情况下，使用pHi来评价胃灌注似乎不可靠。
Objective: To describe global hemodynamics and splanchnic perfusion changes in response to acute modifications in Paco(2), in hemodynamically stable patients.Design: Prospective, randomized crossover study.Setting: Medical-surgical intensive care unit at a community hospital (400,000 inhabitants).Patients: Ten critically ill patients who were sedated, paralyzed, and mechanically ventilated.Interventions: Hypercapnia and hypocapnia were obtained by increasing and reducing instrumental deadspace in random order. After each intervention, patients returned to the basal condition. Each period lasted 80 min: 20 min to achieve stable Paco(2) and 60 min for tonometer equilibration. In each period, global hemodynamic variables and tonometric data were collected. The periods were compared using analysis of variance.Measurements and Main Results: Acute hypercapnia (Paco(2) from 40 +/- 3 to 52 +/- 3 torr, p < .05) increased cardiac index (3.43 +/- 0.37 vs. 3.97 +/- 0.43 mL/min/m(2), p < .05), heart rate (95 +/- 6 vs. 105 +/- 3 heats/min, p < .05), and mean pulmonary artery pressure(21 +/- 1 vs. 24 +/- 1 mm Hg, p < .05) and reduced systemic vascular resistance (992 +/- 98 vs. 813 +/- 93 dyne.sec/cm(5), p < .05) and oxygen extraction ratio (27 +/- 3% vs. 22 +/- 2%, p < .05). Standardized intramucosal Pco(2) increased from 49 +/- 2 to 61 +/- 3 torr (p < .05) with an associated decrease in calculated intramucosal pH ([pHi] 7.35 +/- 0.03 vs. 7.25 +/- 0.02, p < .05), but the gastro-arterial Pco(2) gradient (Delta Pco(2) did not change. Acute hypocapnia (Paco(2) from 41 +/- 3 to 34 +/- 3 torr, p < .05; pH 7.41 +/- 0.01 to 7.47 +/- 0.02, p < .05) induced slight increments in systemic vascular resistance (995 +/- 117 vs. 1088 +/- 160 dyne sec/cm(5), p < .05) and oxygen extraction ratio (28 +/- 2% vs. 30 +/- 2%, p < .05). Standardized intramucosal Pco(2) decreased (50 +/- 4 vs. 44 +/- 3 torr, p < .05), pHi increased (7.33 +/- 0.03 vs. 7.36 +/- 0.02; p < .05), but Delta Pco(2) did not change.Conclusions: In this small group of stable patients, moderate acute variations in Paco(2), had a significant effect on global hemodynamics, but splanchnic perfusion, assessed by Delta Pco(2), did not change. In these conditions, the use of pHi to evaluate gastric perfusion appears unreliable.