Permissive Hypotension Has No Deleterious Impact on Fluid Balance or Kidney Function

Abstract

OBJECTIVES: Mean arterial hypotension between 55 and 65 mm Hg could be tolerated safely in the absence of tissue hypoperfusion, but the consequences on fluid balance and kidney function remain unknown. DESIGN: During a 1-year period, we retrospectively collected data of consecutive septic patients admitted for sepsis with a mean arterial pressure (MAP) less than 65 mm Hg despite fluid resuscitation. SETTING: Medical 18-bed ICU in a tertiary teaching hospital. PATIENTS: Septic patients with a MAP less than 65 mm Hg despite initial resuscitation. INTERVENTIONS: In our ICU, MAP between 55 and 65 mm Hg was tolerated in the absence of peripheral hypoperfusion (permissive hypotension) or corrected using norepinephrine (septic shock group) when peripheral tissue hypoperfusion was present. MEASUREMENTS AND MAIN RESULTS: Ninety-four consecutive septic patients were included, 15 in the permissive hypotension group and 79 in the septic shock group. Median age was 66 years (57–77 yr) and 42% were women. The main sources of infection were respiratory (45%) and abdominal (18%). Severity was more important in septic shock group with higher Sequential Organ Failure Assessment score (7 [5–10] vs. 4 [1–6]; p < 0.0001), more frequent organ support therapy and ultimately higher mortality (38 vs. 0%; p < 0.01). The total volume of crystalloids infused before ICU admission was not different between groups (1930 ± 250 vs. 1850 ± 150 mL; p = 0.40). Within the 6 first hours of ICU stay, patients in the permissive hypotension group received less fluids (530 ± 170 vs. 1100 ± 110 mL; p = 0.03) and had higher urinary output (1.4 mL [0.88–2.34 mL] vs. 0.47 mL/kg/hr [0.08–1.25 mL/kg/hr]; p < 0.001). In addition, kidney injury evaluated using KDIGO score was lower in the permissive hypotension group at 48 hours (0 hr [0–1 hr] vs. 1 hr [0–2 hr]; p < 0.05). CONCLUSIONS: In septic patients without clinical peripheral hypoperfusion, mean arterial hypotension between 55 and 65 mm Hg could be tolerated safely without vasopressor infusion and was not associated with excessive fluid administration or kidney damage.