Evaluation of the value of early use of norepinephrine infusion in the improvement of renal function in patients with severe sepsis with early renal impairment using cystatin C, a sensitive renal marker

Abstract

Introduction Acute renal failure occurs in ∼23% of patients with severe sepsis. The combination of acute renal failure and severe sepsis may carry a mortality of up to 70%. Several studies have demonstrated that serum cystatin C level is a better marker of glomerular filtration rate (GFR) compared with serum creatinine, particularly for individuals with small-to-moderate decreases in GFR. To maintain organ perfusion in sepsis, a mean arterial pressure of 65 mmHg should be maintained with fluid therapy and vasopressors. Marked delays in initiation are associated with increase in mortality risk in patients with septic shock. Patients and methods Sixty patients enrolled in the study proved to have severe sepsis with early renal impairment. Patients were randomly allocated into one of two groups (30 patients each): the norepinephrine infusion group (the N group) and the control group (the C group). The N group received norepinephrine infusion + conventional treatment for severe sepsis, whereas the C group was treated with conventional treatment for severe sepsis according to the latest Surviving Sepsis Campaign. For each patient, the following data were collected: age, body weight, hemodynamic changes, urine output, renal function as detected from levels of the sensitive renal marker cystatin C and from serum creatinine levels, blood urea nitrogen, and estimated GFR (eGFR). Results There was a statistically significant increase in blood pressure and urine output in the N group at 10 min and 2 h, respectively, after norepinephrine infusion and on comparing subsequent measures with baseline values (T0) and also when compared with corresponding values in the C group. In addition, patients in the N group showed a statistically signifi cant decrease in serum cystatin C levels and an increase in eGFR based on cystatin C levels after 2 h of norepinephrine infusion, compared with baseline values and values in the C group, denoting marked improvement in GFR. Serum creatinine levels, blood urea nitrogen levels, and eGFR based on serum creatinine levels showed no significant difference in either group whether compared with baseline of the same group or when comparing both groups together. Conclusion The results this study demonstrate that early continuous infusion of norepinephrine at 0.5–1 μg/ kg/min may have a renoprotective role in septic patients with early renal impairment detected by levels of the sensitive renal marker cystatin C.