Comparison of the effect of fluid resuscitation as guided either by lactate clearance rate or by central venous oxygen saturation in patients with sepsis

Abstract

To compare the efficacy of fluid resuscitation as guided by lactate clearance rate (LCR) and central venous oxygen saturation (ScvO2) in patients with sepsis. A prospective randomized control study was conducted. Fifty patients diagnosed with severe sepsis or septic shock from January 2011 to February 2012 in department of critical care medicine of Fourth Hospital of Hebei Medical University were enrolled in the study. The patients were randomly divided into two groups according to the sequence (each n=25): ScvO2 group and LCR group. After ICU admission, the patients were treated symptomatically timely, and fluid resuscitation was started as early as possible according to Surviving Sepsis Campaign guidance for management of severe sepsis and septic shock 2008. Central venous pressure (CVP)≥8 mm Hg (1 mm Hg=0.133 kPa), mean arterial pressure (MAP)≥65 mm Hg and ScvO2≥0.70 served as goal values to accomplish the fluid resuscitation therapy in ScvO2 group, while CVP≥8 mm Hg, MAP≥65 mm Hg, LCR≥10% served as goal value to accomplish the fluid resuscitation therapy in LCR group. The general condition and clinical characteristics on arrival in ICU, changes in CVP, MAP, ScvO2, lactate level and/or LCR before (0 hour) and 3, 6, 72 hours after the start of fluid resuscitation and the other related conditions during the therapy were recorded. There was no significant difference in general data or clinical characteristics before the start of therapy, occurrence of organ dysfunction, or treatment measures during different time periods after start of fluid resuscitation. Compared with the condition immediately before fluid resuscitation, at 3 hours after start of fluid resuscitation, CVP were improved in LCR and ScvO2 groups (8.58±1.17 mm Hg vs. 6.33±1.21 mm Hg, 9.08±2.43 mm Hg vs. 5.33±0.98 mm Hg, both P<0.05); at 6 hours after start of fluid resuscitation, heart rate (HR) and respiratory rate (RR) were lowered in LCR and ScvO2 groups (HR: 96±18 bpm vs. 127±13 bpm, 98±13 bpm vs. 116±19 bpm, RR: 23±3 times/min vs. 33±9 times/min, 24±5 times/min vs. 35±6 times/min, all P<0.05), oxygenation index (PaO2/FiO2) was increased in LCR and ScvO2 groups (179±41 mm Hg vs. 86±21 mm Hg, 202±33 mm Hg vs. 95±17 mm Hg, both P<0.05), and there was no significant difference in MAP in both groups. There was no significant difference in all indexes between two groups. In LCR group, 3 hours after start of fluid resuscitation, lactate level was significantly decreased (2.81±0.18 mmol/L vs. 3.43±1.31 mmol/L, P<0.05). Compared with the value 3 hours after start of fluid resuscitation, LCR was significantly improved at 6 hours and 72 hours after start of fluid resuscitation in LCR group [(42.69±8.75)%, (48.87±9.69)% vs. (20.32±4.58)%, both P<0.05]. Compared with that immediately before fluid resuscitation, ScvO2 was significant improved in ScvO2 group at 3 hours after start of fluid resuscitation (0.65±0.04 vs. 0.53±0.06, P<0.05). There was no significant difference in success rate of fluid resuscitation comparing that of 6 hours and that of 72 hours [6 hours: 72% (18/25) vs. 64% (16/25), χ(2)=0.368, P=0.762; 72 hours: 88% (22/25) vs. 88% (22/25) ,χ(2)=0.000, P=1.000], length of ICU stay (8±3 days vs. 10±4 days, t=0.533, P=0.874), length of hospital stay (29±11 days vs. 35±16 days, t=0.692, P=0.531), improvement rate [84% (21/25) vs. 76%(19/25), χ(2)=0.500, P=0.480] or 28-day mortality [20% (5/25) vs. 28% (7/25), χ(2)=0.439, P=0.742] between LCR and ScvO2 groups. Both LCR and ScvO2 can be taken as the index in confirming the endpoint of fluid resuscitation for patients with severe sepsis and septic shock. Fluid resuscitation therapy under the guidance of LCR is accurate and reliable in patients with severe sepsis and septic shock.