重症肺炎需机械通气患者的液体负平衡

目的 分析重症肺炎需机械通气患者液体平衡的原因、特点，以便更好地指导治疗并帮助判断预后。方法对入选64例重症肺炎需要机械通气的患者进行前瞻性研究。按7d内液体平衡程度将患者分为负平衡组和正平衡组，把基础疾病、年龄≥65岁、APACHEII≥20和血肌酐≥2．0mg／dl等作为影响因素进行比较，比较两组临床肺部感染评分（CPIS）、血清降钙素原（PCT）、抗生素治疗有效率、2周内撤机成功率及预后。结果 负平衡组和正平衡组的生存率分别为77．78％（28／36）、21．42％（6／28），两者之间的差异有统计学意义（χ^2=20．08，P〈0．05）。负平衡组恶性肿瘤、近期激素治疗、年龄≥65岁、APACHEII≥20、抗生素治疗有效数、2周内撤机成功数与正平衡组比较，差异均有统计学意义（χ^2分别=4．53、4．30、4．13、6．02，P均〈0．05）。CPIS比较：负平衡组D1、D3、D5、D7的CPIS分别为7．49±1．13、5．97±1．00、5．21±1．60、3．89±1．53，正平衡组D1、D3、D5、D7的CPIS分别为7．61±1.10、7．67±0．86、7．87±1．40、7．90±1．52；两组比较，差异有统计学意义（F=176．49，P〈0．05）。PCT比较：负平衡组D1、D3、D5、D7的PCT≥2ng／ml例数分别为32、12、5、4，正平衡组D1、D3、D5、D7的PCT≥2ng／ml例数分别为25、23、22、20，两组比较，差异有统计学意义（χ^2=17．77，P〈0．05）。结论 1周内液体负平衡的出现提示感染得到有效控制，可能是良好预后的预测指标之一；持续的液体正平衡提示感染持续存在，预后不良。

Fluid balance in mechanical ventilated patients with severe pneumonia

Objective To investigate the mechanism and manifestations of fluid balance in mechanical ventilated patients with severe pneumonia. Methods Patients were observed continuously in a perspective study. 64 invasive ventilated patients with severe pneumonia were enrolled, divided to two groups according to the fluid balance during seven days. A number of demographic and physiologic variables were extracted from the medical records. Past medical history, age. admission APACHEII and serum creatinine were analyzed as influencing factors. We monitored the fluid balance and studied the relationship between fluid balance and CPIS, PCT, adequate antibiotic therapy, successful weaning from ventilation and outcome. Results 28 of 36 patients who achieved a negative fluid balance during the first 7 days of treatment survived,only 6 of 28 patients who failed to achieve a negative fluid balance survived（χ^2=20.08,P〈0.05）. Significant differences were found in the numbers of malignant tumor, prior glucocorticoid treatment, adequate antibiotic therapy and weaning from ventilation between the two groups （χ^2=4.53,4.30,4.13,6.02,P〈0.05）. CPIS of negative fluid balance group was respectively 7.49± 1.13, 5.97±1.00, 5.21 ±1.60, 3.89±1.53 on D1, D3, D5, D7 , and that of positive fluid balance group was respectively 7.61±1.10, 7.67±0.86, 7.87±1.40, 7.90±1.52. Significant difference was found in CPIS in the two groups（ F=176.49, P〈0.05）. Numbers of PCT〉2ng/ml of negative fluid balance group was respectively 32, 12, 5, 4 on DI, D3, D5, D7 , and that of positive fluid balance group was respectively 25, 23, 22, 20. Significant difference was found in numbers of PCT〉2ng/ml in the two groups （χ^2=17.77,P〈0.05）. Conclusions The negative fluidbalance achieved in the first 7 days of treatment suggests effective control of sepsis, and probably portends a good prognosis in invasive ventilated patients with severe pneumonia.