Evaluation of the value of dexmedetomidine infusion in the improvement of renal function in preeclamptic patient with early renal impairment using cystatin C, a sensitive renal marker

Abstract

Background Preeclampsia is characterized by the development of hypertension and proteinuria after 20 weeks of gestation. Altered renal function is an essential component of its pathophysiology. Serum cystatin C level is a better marker of glomerular fi ltration rate (GFR) than serum creatinine particularly for individuals with small to moderate decreases in GFR. Dexmedetomidine has great α2 selectivity and low placental transfer with anxiolytic, anesthetic, hypnotic, and analgesic properties. α2-Adrenoceptor activation produces renal-protective effects including inhibition of renin release, increased GFR, and increased secretion of sodium and water. Patients and methods The study included 60 American Society of Anesthesiology II –III patients, 19–40 years of age, proved to have mild preeclampsia with early renal impairment. They were randomly divided into two groups. The dexmedetomidine infusion group (Dexa group) that included 30 patients who received dexmedetomidine infusion (n = 30), whereas the control group (Cont group) (n = 30) were treated by conventional treatment according to the Obstetric ICU Protocol of Ain-Shams University Hospitals. For each patient, the following data were collected: age, gestational age, body weight, height, hemodynamic changes, fetal heart rate, urine output, and renal function as detected by sensitive renal marker cystatin C and also by serum creatinine, blood urea nitrogen (BUN), and then estimation of GFR. Results There was statistically significant decrease in blood pressures (systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure) in the Dexa group 10 min after dexmedetomidine infusion and after comparing subsequent measures to baseline value (T0) and also when compared with corresponding values in the Cont group. In addition, the Dexa group showed statistically significant increase in urine output 2 h after dexmedetomidine infusion in comparison with the baseline values and with the Cont group, denoting improvement in urine output. Patients in the Dexa group showed a statistically significant decrease in serum cystatin C and increase in estimated glomerular filtration rate (eGFR) based on cystatin C after 2 h of sympathetic block by epidural activation in comparison with baseline value and when compared with the Cont group, denoting marked improvement in GFR. Measurement of urine protein/creatinine ratio, serum creatinine, BUN, and eGFR based on serum creatinine showed no significant difference in both groups whether comparing to baseline of the same group or comparing both groups together. Conclusion Continuous infusion of dexmedetomidine 0.4 mcg/kg/h showed marked benefi t improving renal function and better control of blood pressure in preeclamptic patients with early renal impairment detected by sensitive renal marker cystatin C.