Miller P R, Meredith J W, Chang M C
Department of General Surgery, The Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina 27157, USA.
J Trauma. 1998 Jan;44(1):107-13. doi: 10.1097/00005373-199801000-00013.
To evaluate the effects of maintaining increased levels of preload on cardiopulmonary function and visceral perfusion during resuscitation.
Randomized, prospective study of 39 consecutive trauma patients with a low right ventricular ejection fraction (<40%) admitted to a university Level I trauma center during a 10-month period. Patients were randomized to one of two groups: increased preload (PL), or normal preload with inotropes (INO). The PL group received fluid administration to maintain a target right ventricular end-diastolic volume index (RVEDVI) > or = 120 mL/m2 during resuscitation. The INO group had inotropes added according to a prospectively determined protocol and was maintained at a RVEDVI of 90 to 100 mL/m2. Systemic perfusion was assessed using oxygen transport and acid-base parameters, and pulmonary function was evaluated with PaO2/FiO2 ratio, dynamic compliance, ventilator days, and incidence of adult respiratory distress syndrome. Gut perfusion was assessed by measuring gastric intramucosal pH (pHi). Data are expressed as means +/- SD.
The mean RVEDVI was significantly higher in the PL group (n = 19) than in the INO group (n = 20) during resuscitation (119+/-18 vs. 103+/-22 mL/m2, p = 0.01). There was no difference in oxygen delivery, mixed venous oxygen saturation, lactate, PaO2/FiO2 ratio, dynamic compliance, or ventilator days between the groups. The incidence of adult respiratory distress syndrome was not significantly different (PL 31% vs. INO 50%, p > 0.1). In the patients who had pHi measured sequentially during resuscitation (PL = 13, INO = 17), the final pHi was significantly higher in the PL group (7.31+/-0.1 vs. 7.16+/-0.2, p = 0.03).
Patients resuscitated at higher levels of preload have significantly better visceral perfusion than those resuscitated at normal preload with addition of inotropes. This higher preload does not adversely affect pulmonary function.
评估复苏期间维持较高前负荷水平对心肺功能和内脏灌注的影响。
对一所大学一级创伤中心在10个月期间收治的39例右心室射血分数较低（<40%）的连续创伤患者进行随机、前瞻性研究。患者被随机分为两组之一：增加前负荷（PL）组，或使用血管活性药物的正常前负荷（INO）组。PL组在复苏期间接受液体输注以维持目标右心室舒张末期容积指数（RVEDVI）≥120 mL/m²。INO组根据预先确定的方案添加血管活性药物，并维持RVEDVI在90至100 mL/m²。使用氧输送和酸碱参数评估全身灌注，并用PaO₂/FiO₂比值、动态顺应性、机械通气天数和成人呼吸窘迫综合征的发生率评估肺功能。通过测量胃黏膜内pH值（pHi）评估肠道灌注。数据以均值±标准差表示。
复苏期间，PL组（n = 19）的平均RVEDVI显著高于INO组（n = 20）（119±18 vs. 103±22 mL/m²，p = 0.01）。两组之间的氧输送、混合静脉血氧饱和度、乳酸、PaO₂/FiO₂比值、动态顺应性或机械通气天数无差异。成人呼吸窘迫综合征的发生率无显著差异（PL组为31%，INO组为50%，p>0.1）。在复苏期间序贯测量pHi的患者中（PL组 = 13例，INO组 = 17例），PL组的最终pHi显著更高（7.31±0.1 vs. 7.16±0.2，p = 0.03）。
与使用血管活性药物的正常前负荷复苏的患者相比，较高前负荷水平复苏的患者内脏灌注明显更好。这种较高的前负荷对肺功能没有不利影响。
