Is Pyroglutamic Acid a Prognostic Factor Among Patients with Suspected Infection? A Prospective Cohort Study.

Pyroglutamic acid (PGA) is a compound that accumulates during oxidative stress and hence, elevated levels may be associated with poor prognosis in patients with infection or sepsis. To examine this hypothesis, patients presenting with acute infection were recruited in the emergency department and prospectively followed for 30 days. Sport urine samples were quantified for PGA. Outcomes were mortality and composite outcome of death or organ failure. Thirty two (32%) patients had qSOFA≥2. Median urine PGA was 22.9 (IQR 17.64, 33.53) µmol/mmol creatinine. Four patients demonstrated PGA values ≥ 63 µmol/mmol creatinine. Univariate analysis showed that PGA concentration ≥ 75th percentile (i.e. 33.53 µmol/mmol creatinine) was associated with higher rates of in-hospital mortality (p = 0.041) with similar trend for PGA ≥ 63 µmol/mmol creatinine (p = 0.04). However, multivariate analysis showed that PGA was not associated with worse outcomes, whereas heart rate was associated with both composite outcomes (HR 1.0, p = 0.008 and HR 1.02, p = 0.001 for composite outcome with 30 days and in-hospital mortality, respectively). Among low risk patients, high PGA levels were consistently associated with worse outcomes. In conclusion, urine PGA concentration was not associated with worse outcomes among septic patients. Nevertheless, future studies should evaluate this association in larger cohorts.

Intraoperative Hyperoxia Does Not Reduce Postoperative Pain: Subanalysis of an Alternating Cohort Trial.

BACKGROUND: Postoperative pain is common and promotes opioid use. Surgical wounds are hypoxic because normal perfusion is impaired. Local wound ischemia and acidosis promote incisional pain. Some evidence suggests that improving oxygen supply to surgical wounds might reduce pain. We therefore tested the hypothesis that supplemental (80% inspired) intraoperative oxygen reduces postoperative pain and opioid consumption. METHODS: We conducted a post hoc analysis of a large, single-center alternating cohort trial allocating surgical patients having general anesthesia for colorectal surgery to either 30% or 80% intraoperative oxygen concentration in 2-week blocks for a total of 39 months. Irrespective of allocation, patients were given sufficient oxygen to maintain saturation ≥95%. Patients who had regional anesthesia or nerve blocks were excluded. The primary outcome was pain and opioid consumption during the initial 2 postoperative hours, analyzed jointly. The secondary outcome was pain and opioid consumption over the subsequent 24 postoperative hours. Subgroup analyses of the primary outcome were conducted for open versus laparoscopic procedures and for patients with versus without chronic pain. RESULTS: A total of 4702 cases were eligible for analysis: 2415 were assigned to 80% oxygen and 2287 to 30% oxygen. The groups were well balanced on potential confounding factors. Average pain scores and opioid consumption were similar between the groups (mean difference in pain scores, -0.01 [97.5% CI, -0.16 to 0.14; P = .45], median difference in opioid consumption, 0.0 [97.5% CI, 0 to 0] mg morphine equivalents; P = .82). There were also no significant differences in the secondary outcome or subgroup analyses. CONCLUSIONS: Supplemental intraoperative oxygen does not reduce acute postoperative pain or reduce opioid consumption.

Association Between Mean Arterial Pressure and Acute Kidney Injury and a Composite of Myocardial Injury and Mortality in Postoperative Critically Ill Patients: A Retrospective Cohort Analysis.

OBJECTIVES: Hypotension thresholds that provoke renal injury, myocardial injury, and mortality in critical care patients remain unknown. We primarily sought to determine the relationship between hypotension and a composite of myocardial injury (troponin T ≥ 0.03 ng/mL without nonischemic cause) and death up to 7 postoperative days. Secondarily, we considered acute kidney injury (creatinine concentration ≥ 0.3 mg/dL or 1.5 times baseline). DESIGN: Retrospective cohort. SETTING: Surgical ICU at an academic medical center. PATIENTS: Two-thousand eight-hundred thirty-three postoperative patients admitted to the surgical ICU. INTERVENTIONS: A Cox proportional hazard survival model was used to assess the association between lowest mean arterial pressure on each intensive care day, considered as a time-varying covariate, and outcomes. In sensitivity analyses hypotension defined as pressures less than 80 mm Hg and 70 mm Hg were also considered. MEASUREMENTS AND MAIN RESULTS: There was a strong nonlinear (quadratic) association between the lowest mean arterial pressure and the primary outcome of myocardial injury after noncardiac surgery or mortality, with estimated risk increasing at lower pressures. The risk of myocardial injury after noncardiac surgery or mortality was an estimated 23% higher at the 25th percentile (78 mm Hg) of lowest mean arterial pressure compared with at the median of 87 mm Hg, with adjusted hazard ratio (95% CI) of 1.23 (1.12-1.355; p < 0.001). Overall results were generally similar in sensitivity analyses based on every hour of mean arterial pressure less than 80 mm Hg and any mean arterial pressure less than 70 mm Hg. Post hoc analyses showed that the relationship between ICU hypotension and outcomes depended on the amount of intraoperative hypotension. The risk of acute kidney injury increased over a range of minimum daily pressures from 110 mm Hg to 50 mm Hg, with an adjusted hazard ratio of 1.27 (95% CI, 1.18-1.37; p < 0.001). CONCLUSIONS: Increasing amounts of hypotension (defined by lowest mean arterial pressures per day) were strongly associated with myocardial injury, mortality, and renal injury in postoperative critical care patients.

Mild Perioperative Hypothermia and Myocardial Injury: A Retrospective Cohort Analysis.

BACKGROUND: We tested the primary hypothesis that final intraoperative esophageal temperature is associated with increased odds of a composite of in-hospital all-cause mortality and myocardial injury within 7 days after noncardiac surgery. Secondary exposures were time-weighted average intraoperative temperature and area <37°C threshold. METHODS: Myocardial injury was defined by postoperative fourth-generation troponin T ≥0.03 ng/mL apparently due to cardiac ischemia. Data were extracted for inpatients who had noncardiac surgery with general anesthesia at the Cleveland Clinic between 2012 and 2015. All had esophageal temperature monitoring and routine postoperative troponin monitoring. We estimated the confounder-adjusted association between final intraoperative esophageal temperature and the collapsed composite with multivariable logistic regression. We similarly estimated associations with time-weighted average intraoperative temperature and area <37°C. RESULTS: Two thousand two hundred ten patients were included. Nearly all final esophageal temperatures were 36°C-37°C. Ninety-seven patients (4.4%) had myocardial injury, and 7 (0.3%) died before discharge. Final intraoperative core temperature was not associated with the collapsed composite: odds ratio, 0.91 (95% confidence interval, 0.68-1.24) per 1°C decrease. Similarly, neither of the secondary exposures was associated with the composite outcome. CONCLUSIONS: We did not observe an association between mild perioperative hypothermia and mortality or myocardial injury in adults having noncardiac surgery. However, the range of final intraoperative temperatures was small and largely restricted to the normothermic range (36°C-37°C). Trials are needed to further assess the effect of temperature on myocardial injury.