Efficacies of fluid resuscitation as guided by lactate clearance rate and central venous oxygen saturation in patients with septic shock

Abstract

To estimate the efficacies of fluid resuscitations as guided by lactate clearance rate (LC) and central venous oxygen saturation (ScvO₂) in patients with septic shock. 100 patients diagnosed with septic shock from June 2012 to June 2014 in department of critical care medicine of sixteen hospitals were enrolled. They were randomly divided into two groups of study and control (each n = 50). After a diagnosis of sepsis shock, they were treated symptomatically timely and fluid resuscitation was started as early as possible according to the 2008 Guideline for Managing Sepsis & Septic Shock. Central venous pressure (CVP) ≥ 8 mmHg (1 mmHg = 0.133 kPa), mean arterial pressure (MAP) ≥ 65 mmHg, urine output ≥ 0.5 ml × kg⁻¹ × h⁻¹, ScvO₂≥ 70% and LC ≥ 10% (or lactate ≤ 2.0 mmol) served as target values for fluid resuscitation therapy in study group versus CVP ≥ 8 mmHg, MAP ≥ 65 mmHg, urine output ≥ 0.5 ml × kg⁻¹ × h⁻¹ and ScvO₂≥ 70% in control group. The general conditions and clinical characteristics, changes in CVP, MAP, urine output, ScvO₂, lactate level and/or LC before (0 hour) and every hour (1-6 h) after the start of fluid resuscitation and other related outcome indicators were recorded. No significant difference existed in general data. The 28-day mortality was 40% for study group versus 56% for control group. There was no significant inter-group difference (P > 0.05). The time of mechanical ventilation and length of intensive care unit (ICU) stay were lower in study group than those in control group [mechanical ventilation time (11.200 ± 17.069) vs (15.760 ± 14.215), P = 0.150; length of ICU stay (13.240 ± 17.127) vs (23.980 ± 18.298), P = 0.003]. The 28-day mortality was independently associated with LC and ScvO₂reaching target values for fluid resuscitation in study group (χ² = 10.930, P = 0.001) while the 28-day mortality was independently associated with ScvO₂reaching target value for fluid resuscitation in control group (χ² = 6.395, P = 0.011). Among all patients, the 28-day mortality was independently associated with ScvO₂reaching target value for fluid resuscitation (χ² = 14.530, P = 0.000), but not LC (χ² = 1.175, P = 0.278). A combination of LC and ScvO₂may serve an index in confirming the endpoint of fluid resuscitation for patients with septic shock. Fluid resuscitation therapy under the guidance of LC and ScvO₂is more accurate and reliable than the guidance of ScvO₂alone.