Optimal blood pressure decreases acute kidney injury after gastrointestinal surgery in elderly hypertensive patients: A randomized study: Optimal blood pressure reduces acute kidney injury.

STUDY OBJECTIVE: To determine the appropriate mean arterial pressure (MAP) control level for elderly patients with hypertension during the perioperative period.

DESIGN: A prospective, randomized study.

SETTING: Three teaching hospitals in China.

PATIENTS: Six hundred seventy-eight elderly patients with chronic hypertension undergoing major gastrointestinal surgery.

INTERVENTIONS: Patients were randomly allocated to three groups and the target MAP level was strictly controlled to one of three levels: level I (65-79mmHg), level II (80-95mmHg), or level III (96-110mmHg).

MEASUREMENTS: The primary outcome was acute kidney injury (AKI) (50% or 0.3mg·dL-1 increase in creatinine level) during the first 7 postoperative days. The secondary outcomes were perioperative adverse complications. Moreover, vasoactive agents were observed during surgery.

MAIN RESULTS: The overall incidence of postoperative AKI was 10.9% (71/648). AKI occurred significantly less often in patients with level II MAP control (6.3%;13/206) than in patients with level I (13.5%; 31/230) and level III (12.9%; 27/210) (P<0.001) MAP control. Level II was associated with lower incidences of hospital-acquired pneumonia (6.7%; 14/206; P=0.014) and admission to the intensive care unit (ICU) (4.4%; 9/206; P=0.015) and with shorter length of stay in the ICU (P=0.025) when compared with level I and level III. Use of norepinephrine, phenylephrine, and nitroglycerin was significantly higher for patients with level III MAP control than for patients with level I and level II MAP control (P=0.001).

CONCLUSIONS: For elderly hypertensive patients, controlling intraoperative MAP levels to 80 to 95mmHg can reduce postoperative AKI after major abdominal surgery.