Interaction Effects of Acute Kidney Injury, Acute Respiratory Failure, and Sepsis on 30-Day Postoperative Mortality in Patients Undergoing High-Risk Intraabdominal General Surgical Procedures

• Published in: Anesthesia and analgesia Vol. 121; no. 6; pp. 1536 - 1546
• Main Authors: Kim, Minjae, Brady, Joanne E, Li, Guohua
• Format: Journal Article
• Language: English
• Published: United States International Anesthesia Research Society 01.12.2015
• Subjects: Acute Disease; Acute Kidney Injury - mortality; Acute Kidney Injury - surgery; Adult; Aged; Aged, 80 and over; Cohort Studies; Female; Humans; Male; Middle Aged; Mortality - trends; Postoperative Complications - etiology; Postoperative Complications - mortality; Respiratory Insufficiency - mortality; Respiratory Insufficiency - surgery; Retrospective Studies; Risk Factors; Sepsis - mortality; Sepsis - surgery; Surgical Procedures, Operative - adverse effects
• ISSN: 0003-2999; 1526-7598
• DOI: 10.1213/ANE.0000000000000915

BACKGROUND:Acute kidney injury (AKI), acute respiratory failure, and sepsis are distinct but related pathophysiologic processes. We hypothesized that these 3 processes may interact to synergistically increase the risk of short-term perioperative mortality in patients undergoing high-risk intraabdominal general surgery procedures. METHODS:We performed a retrospective, observational cohort study of data (2005–2011) from the American College of Surgeons-National Surgical Quality Improvement Program, a high-quality surgical outcomes data set. High-risk procedures were those with a risk of AKI, acute respiratory failure, or sepsis greater than the average risk in all intraabdominal general surgery procedures. The effects of AKI, acute respiratory failure, and sepsis on 30-day mortality were assessed using a Cox proportional hazards model. Additive interactions were assessed with the relative excess risk due to interaction. RESULTS:Of 217,994 patients, AKI, acute respiratory failure, and sepsis developed in 1.3%, 3.7%, and 6.8%, respectively. The 30-day mortality risk with sepsis, acute respiratory failure, and AKI were 11.4%, 24.1%, and 25.1%, respectively, compared with 0.85% without these complications. The adjusted hazard ratios and 95% confidence intervals for a single complication (versus no complication) on mortality were 7.24 (6.46–8.11), 10.8 (8.56–13.6), and 14.2 (12.8–15.7) for sepsis, AKI, and acute respiratory failure, respectively. For 2 complications, the adjusted hazard ratios were 30.8 (28.0–33.9), 42.6 (34.3–52.9), and 65.2 (53.9–78.8) for acute respiratory failure/sepsis, AKI/sepsis, and acute respiratory failure/AKI, respectively. Finally, the adjusted hazard ratio for all 3 complications was 105 (92.8–118). Positive additive interactions, indicating synergism, were found for each combination of 2 complications. The relative excess risk due to interaction for all 3 complications was not statistically significant. CONCLUSIONS:In high-risk general surgery patients, the development of AKI, acute respiratory failure, or sepsis is independently associated with an increase in 30-day mortality. In addition, the development of 2 complications shows significant positive additive interactions to further increase the risk of mortality. Our findings suggest that interactions between these 3 perioperative complications increase the risk of mortality more than would be expected by the independent effects of each complication alone.