Systemic inflammation and acute kidney injury after colorectal surgery.

BACKGROUND: In this retrospective review, the relative importance of systemic inflammation among other causes of acute kidney injury (AKI) was investigated in 1224 consecutive colorectal surgery patients. A potential benefit from reducing excessive postoperative inflammation on AKI might then be estimated. METHODS: AKI was determined using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. The entire population (mixed group), composed of patients with or without sepsis, and a subpopulation of patients without sepsis (aseptic group) were examined. Markers indicative of inflammation were procedure duration, the first postoperative white blood cell (POD # 1 WBC) for the mixed population, and the neutrophil-to-lymphocyte ratio (POD #1 NLR) for the aseptic population. Multivariable logistic regression was then performed using significant (P < 0.05) predictors. The importance of inflammation among independent predictors of AKI and AKI-related complications was then assessed. RESULTS: AKI occurred in 24.6% of the total population. For the mixed population, there was a link between inflammation (POD # 1 WBC) and AKI (P = 0.0001), on univariate regression. Medications with anti-inflammatory properties reduced AKI: ketorolac (P = 0.047) and steroids (P = 0.038). Similarly, in an aseptic population, inflammation (POD # 1 NLR) contributed significantly to AKI (P = 0.000). On multivariable analysis for the mixed and aseptic population, the POD #1 WBC and the POD #1 NLR were independently associated with AKI (P = 0.000, P = 0.022), as was procedure duration (P < 0.0001, P < 0.0001). Inflammation-related parameters were the most significant contributors to AKI. AKI correlated with complications: postoperative infections (P = 0.016), chronic renal insufficiency (CRI, P < 0.0001), non-infectious complications (P = 0.010), 30-day readmissions (P = 0.001), and length of stay (LOS, P < 0.0001). Inflammation, in patients with or without sepsis, was similarly a predictor of complications: postoperative infections (P = 0.002, P = 0.008), in-hospital complications (P = 0.000, P = 0.002), 30-day readmissions (P = 0.012, P = 0.371), and LOS (P < 0.0001, P = 0.006), respectively. CONCLUSIONS: Systemic inflammation is an important cause of AKI. Limiting early postsurgical inflammation has the potential to improve postoperative outcomes.

Treatment of Severe Hyperglycemia in Patients Without Diabetes After Colorectal Surgery.

Background: Several studies have suggested that intravenous insulin therapy for post-operative hyperglycemia improves outcomes after colorectal surgery. Despite the potential benefit, there is a reluctance to use this approach in patients without diabetes mellitus because of an unproven benefit and the potential for hypoglycemia. In this study, we examined whether sliding-scale insulin is sufficient to improve outcomes or if stricter glucose control is necessary. Patients and Methods: Of 1,064 consecutive colorectal surgery patients between August 2016 and December 2021, 478 patients without diabetes mellitus had an average of 6.4 ± 3.1 glucose samples taken within 48 hours after surgery. Sixty-six percent of patients with severe hyperglycemia (glucose ≥180 mg/dL) received sliding-scale insulin. Complication rates and effects of insulin were examined. Results: Severe hyperglycemia was associated with a higher total infection rate (p < 0.002), National Healthcare Safety Network-reported infections (NHSN; p < 0.026), total complications (p < 0.001), and length of stay (LOS; p < 0.000). Sliding-scale insulin did not lower the risk of infection or other complications. Hypoglycemia (glucose <70 mg/dL) occurred in 3.5% of patients, but was not related to insulin use, and was predictable with clinical variables: albumin (p < 0.032), operative duration (p < 0.012), and average post-operative glucose (p < 0.002; area under the curve [AUC], 0.86). Conclusions: Our data confirm that severe post-operative hyperglycemia in patients without diabetes mellitus after colorectal surgery is associated with complications. Sliding-scale insulin was safe but not effective. Treatment before severe hyperglycemia is reached, not after its occurrence, may be beneficial.

Postoperative Hyperglycemia in Patients with and without Diabetes After Major Joint Replacement: The Impact of an Enhanced Glucose Management Program.

BACKGROUND: Perioperative hyperglycemia can have an even more detrimental effect on postoperative outcomes in patients without diabetes than in patients with diabetes, but it has not been established if the treatment of patients without diabetes is safe and effective. We hypothesized that sliding-scale insulin for severe postoperative hyperglycemia (glucose ≥180 mg/dL) could lower mean postoperative glucose levels and minimize short-term complications in patients without diabetes undergoing major joint replacement. METHODS: In a prospective study group, 1,398 consecutive patients, with and without diabetes, undergoing joint replacement were monitored and treated for hyperglycemia and were compared with 886 historical, less frequently monitored controls. The primary outcome was the mean glucose level in patients with and without diabetes within 48 hours after the surgical procedure. Two secondary outcomes could be examined only in the prospective study group, which, by design, had much more frequent glucose sampling and insulin use than the historical controls. First, the contribution of comorbidities and procedural factors to postoperative hyperglycemia in patients without diabetes was assessed with multivariable linear regression. Second, the ability of insulin treatment to reduce complications in patients without diabetes who developed hyperglycemia was evaluated. RESULTS: In comparison with 886 historical controls, enhanced glucose management lowered the mean glucose (and standard deviation) from 129 ± 28 mg/dL to 123 ± 23 mg/dL for patients without diabetes (p = 0.041). Multivariable linear regression revealed factors that contributed to elevated mean glucose in patients without diabetes: preoperative fasting glucose (p < 0.001), perioperative steroid use (p < 0.001), general anesthesia (p < 0.001), procedure duration (p = 0.003), and transfusion (p 0.008). Of 968 patients without diabetes, 203 developed severe hyperglycemia. The recommended insulin coverage was given to 129 of these patients, and 74 patients did not receive it for various clinical reasons. Insulin treatment reduced the frequency of positive cultures from any site (p = 0.025) and a composite of positive cultures and readmissions (p = 0.006) in comparison with no insulin treatment. No patient without diabetes who received insulin experienced mild or severe hypoglycemia. CONCLUSIONS: Postoperative hyperglycemia is frequent in patients without diabetes after orthopaedic surgery, but an enhanced glucose management program can lower mean postoperative glucose levels. The treatment of hyperglycemia in patients without diabetes reduced short-term complications and was associated with minimal side effects. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.