Rokyta Richard, Matejovic Martin, Krouzecky Ales, Opatrny Karel, Ruzicka Jiri, Novak Ivan
ICU, Department of Internal Medicine I, School of Medicine, Charles University, Plzen, Czech Republic.
Nephrol Dial Transplant. 2004 Mar;19(3):623-30. doi: 10.1093/ndt/gfg615.
A number of haemodialysis studies have demonstrated beneficial effects of cooler dialysates on global haemodynamics in chronic dialysis patients. However, the effects of continuous venovenous haemofiltration (CVVH)-induced cooling on regional perfusion and energy metabolism in critically ill septic patients have not been well defined.
Nine septic mechanically ventilated patients (age 40-69 years) were investigated during CVVH (ultrafiltration 30-35 ml/kg/h). Baseline data (=WARM 1) were collected when core temperature (Tc) was >37.5 degrees C; the second data set (=COLD) was obtained after 120 min of 'cooling'; and a third set (=WARM 2) was obtained after 120 min of 'rewarming'. During 'warming' (WARM 1 and 2, respectively), both substitution fluids (SFs) and 'returned' blood (RB) were warmed (37 degrees C), whereas during 'cooling', the SFs were at 20 degrees C and RB was not warmed. We measured hepatic venous (HV) haemoglobin oxygen saturation (ShvO(2)), blood gases, lactate and pyruvate. Gastric mucosal PCO(2) (PgmCO(2)) was measured by air tonometry and the gastric mucosal - arterial PCO(2) difference (PCO(2) gap) was calculated. Haemodynamic monitoring was performed with arterial and pulmonary arterial thermodilution catheters.
Tcs were significantly altered [WARM 1, 37.9 degrees C (37.6, 38.3); COLD, 36.8 degrees C (36.3, 37.1); WARM 2, 37.5 degrees C (37.0, 38.0); P<0.001; data are median, 25th and 75th percentiles, respectively]. Systemic vascular resistance significantly increased during cooling. As a result, mean arterial pressure increased. Cooling was associated with significant decreases in heart rate, cardiac output, systemic oxygen delivery and consumption. ShvO(2) did not change [WARM 1, 51.0% (44.0, 59.5); COLD, 49.0% (42.0, 58.0); WARM 2, 51.0% (46.0, 57.0); P = NS]. The splanchnic oxygen extraction ratio, the HV lactate to pyruvate ratio, HV acid base status and PCO(2) gap remained unchanged.
Mild core cooling induced by CVVH may not affect hepatosplanchnic oxygen and energy balance in septic critically ill patients, even though it affects global haemodynamics.
多项血液透析研究已证明，较凉的透析液对慢性透析患者的整体血流动力学具有有益作用。然而，连续性静脉-静脉血液滤过（CVVH）诱导的低温对重症脓毒症患者局部灌注和能量代谢的影响尚未明确。
对9例接受机械通气的脓毒症患者（年龄40 - 69岁）在进行CVVH（超滤率30 - 35 ml/kg/h）期间进行研究。当核心体温（Tc）>37.5℃时收集基线数据（=WARM 1）；在“降温”120分钟后获取第二组数据（=COLD）；在“复温”120分钟后获取第三组数据（=WARM 2）。在“升温”期间（分别为WARM 1和WARM 2），置换液（SFs）和“回输”血液（RB）均加热至（37℃），而在“降温”期间，SFs为20℃且RB未加热。我们测量了肝静脉（HV）血红蛋白氧饱和度（ShvO₂）、血气、乳酸和丙酮酸。通过空气张力测定法测量胃黏膜PCO₂（PgmCO₂）并计算胃黏膜 - 动脉PCO₂差值（PCO₂差值）。使用动脉和肺动脉热稀释导管进行血流动力学监测。
Tc有显著变化[WARM 1，37.9℃（37.6，38.3）；COLD，36.8℃（36.3，37.1）；WARM 2，37.5℃（37.0，38.0）；P<0.001；数据分别为中位数、第25和第75百分位数]。降温期间全身血管阻力显著增加。结果，平均动脉压升高。降温与心率、心输出量、全身氧输送和消耗的显著降低相关。ShvO₂未变化[WARM 1，51.0%（44.0，59.5）；COLD，49.0%（42.0，58.0）；WARM 2，51.0%（46.0，57.0）；P = 无显著性差异]。内脏氧摄取率、HV乳酸与丙酮酸比值、HV酸碱状态和PCO₂差值保持不变。
CVVH诱导的轻度核心体温降低可能不会影响脓毒症重症患者的肝内脏氧和能量平衡，尽管它会影响整体血流动力学。
