Intraoperative hypotension affects postoperative acute kidney injury depending on the invasiveness of abdominal surgery: A retrospective cohort study

Intraoperative hypotension (IOH) or highly invasive surgery adversely affects postoperative clinical outcomes. It is, however, unclear whether IOH affects postoperative acute kidney injury (AKI) depending on the invasiveness of abdominal surgery. We speculated that IOH in highly invasive abdominal surgery is a significant risk factor for postoperative AKI. We retrospectively reviewed the data of 448 patients who underwent abdominal surgery. Patients were divided into 3 groups: highly (such as pancreaticoduodenectomy and hepatectomy), moderately (open abdominal surgery), and minimally (laparoscopic surgery) invasive surgeries. The association between the time-weighted average (TWA) of mean arterial pressure (MAP) values (≤60 and ≤ 55 mm Hg) and AKI occurrences in each group was assessed. Postoperative AKI occurred after highly, moderately, and minimally invasive surgeries in 33 of 222 (14.9%), 14 of 110 (12.7%), and 12 of 116 (10.3%) cases, respectively (P = .526). The median [interquartile range] of TWA-MAP ≤ 60 mm Hg, as an IOH parameter, was 0.94 [0.33-2.08] mm Hg in highly, 0.54 [0.16-1.46] mm Hg in moderately, and 0.14 [0.03-0.57] mm Hg in minimally invasive surgeries (P < 0001). In addition, there was a significant association between TWA-MAP and AKI in highly invasive surgery, unlike in moderately and minimally invasive surgery, with adjusted odds ratios (95% confidence interval) for TWA-MAP ≤ 60 and ≤ 55 mm Hg associated with AKI of 1.23 [1.00-1.52] (P = .049) and 1.55 [1.02-2.36] (P = .041), respectively. Intraoperative MAP ≤ 60 mm Hg in highly invasive abdominal surgery is associated with postoperative AKI, compared to moderately and minimally invasive surgeries. Additionally, low MAP thresholds in highly invasive surgery increase postoperative AKI risk.