Latin American surgical outcomes study: study protocol for a multicentre international observational cohort study of patient outcomes after surgery in Latin American countries.

Background: Reported data suggest that 4.2 million deaths will occur within 30 days of surgery worldwide each year, half of which are in low- and middle-income countries. Postoperative complications are a leading cause of long-term morbidity and mortality. Patients who survive and leave the hospital after surgical complications regularly experience reductions in long-term survival and functional independence, resulting in increased costs. With a high volume of surgery performed, there is a growing perception of the substantial impact of even minor enhancements in perioperative care. The Latin American Surgical Outcomes Study (LASOS) is an international, multicentre, prospective cohort study of adults submitted to in-patient surgery in Latin America aiming to provide detailed data describing postoperative complications and surgical mortality. Methods: LASOS is a 7 day cohort study of adults undergoing surgery in Latin America. Details of preoperative risk factors, intraoperative care, and postoperative outcomes will be collected. The primary outcome will be in-hospital postoperative complications of any cause. Secondary outcomes include in-hospital all-cause mortality, duration of hospital stay after surgery, and admission to a critical care unit within 30 days after surgery during the index hospitalisation. Results: The LASOS results will be published in peer-reviewed journals, reported and presented at international meetings, and widely disseminated to patients and public in participating countries via mainstream and social media. Conclusions: The LASOS may augment our understanding of postoperative complications and surgial mortality in Latin America. Clinical trial registration: NCT05169164.

Opioids and premature biochemical recurrence of prostate cancer: a randomised prospective clinical trial.

BACKGROUND: Prostate cancer is one of the most prevalent neoplasms in male patients, and surgery is the main treatment. Opioids can have immune modulating effects, but their relation to cancer recurrence is unclear. We evaluated whether opioids used during prostatectomy can affect biochemical recurrence-free survival. METHODS: We randomised 146 patients with prostate cancer scheduled for prostatectomy into opioid-free anaesthesia or opioid-based anaesthesia groups. Baseline characteristics, perioperative data, and level of prostate-specific antigen every 6 months for 2 yr after surgery were recorded. Prostate-specific antigen >0.2 ng ml-1 was considered biochemical recurrence. A survival analysis compared time with biochemical recurrence between the groups, and a Cox regression was modelled to evaluate which variables affect biochemical recurrence-free survival. RESULTS: We observed 31 biochemical recurrence events: 17 in the opioid-free anaesthesia group and 14 in the opioid-based anaesthesia group. Biochemical recurrence-free survival was not statistically different between groups (P=0.54). Cox regression revealed that biochemical recurrence-free survival was shorter in cases of obesity (hazard ratio [HR] 1.63, confidence interval [CI] 0.16-3.10; p=0.03), high D'Amico risk (HR 1.58, CI 0.35-2.81; P=0.012), laparoscopic surgery (HR 1.6, CI 0.38-2.84; P=0.01), stage 3 tumour pathology (HR 1.60, CI 0.20-299) and N1 status (HR 1.34, CI 0.28-2.41), and positive surgical margins (HR 1.37, CI 0.50-2.24; P=0.002). The anaesthesia technique did not affect time to biochemical recurrence (HR -1.03, CI -2.65-0.49; P=0.18). CONCLUSIONS: Intraoperative opioid use did not modify biochemical recurrence rates and biochemical recurrence-free survival in patients with intermediate and high D'Amico risk prostate cancer undergoing radical prostatectomy. CLINICAL TRIAL REGISTRATION: NCT03212456.

S100B protein and neuron-specific enolase as predictors of postoperative cognitive dysfunction in aged dogs: a case-control study.

OBJECTIVE: Postoperative cognitive dysfunction (POCD) may be related to brain injury. S100B protein and neuron-specific enolase (NSE) have been investigated as potential biochemical markers of neural cell injury in animals and humans. This study aimed to investigate the association between POCD, brain injury and serum concentrations of S100B and NSE after periodontal surgery in aged dogs. STUDY DESIGN: Prospective observational animal study. ANIMALS: A total of 24 male and female dogs undergoing periodontal surgery. METHODS: Dogs were separated into two groups based on age: control group, 10 dogs ≤ 8 years and aged group, 14 dogs > 8 years. Cognitive function was measured preoperatively and on the seventh postoperative day using the Canine Cognitive Dysfunction Rating scale and the Age-Related Cognitive and Affective Disorders scale. S100B protein and NSE serum concentrations were measured before and immediately after the surgery. RESULTS: POCD was not observed after surgery in the present study. Serum concentrations of S100B and NSE were increased postoperatively in the control group but not in the aged group (p = 0.04 and 0.03, respectively). Preoperative S100B serum concentrations were significantly higher in the aged group (p = 0.01). CONCLUSIONS: There was no association between POCD and high concentrations of S100B and NSE in dogs. However, increased postoperative serum concentrations of S100B and NSE were found in the control group after surgery, an effect that may indicate neural damage. CLINICAL RELEVANCE: The results suggest that anesthesia and oral surgery are associated with higher postoperative serum concentrations of S100B and NSE in dogs ≤ 8 years old, which may indicate neural damage. Serum concentrations of S100B were elevated in aged dogs before anesthesia, a finding that might be related to chronic preoperative brain damage.

Predictors and their prognostic value for no ROSC and mortality after a non-cardiac surgery intraoperative cardiac arrest: a retrospective cohort study.

Data on predictors of intraoperative cardiac arrest (ICA) outcomes are scarce in the literature. This study analysed predictors of poor outcome and their prognostic value after an ICA. Clinical and laboratory data before and 24 hours (h) after ICA were analysed as predictors for no return of spontaneous circulation (ROSC) and 24 h and 1-year mortality. Receiver operating characteristic curves for each predictor and sensitivity, specificity, positive and negative likelihood ratios, and post-test probability were calculated. A total of 167,574 anaesthetic procedures were performed, including 158 cases of ICAs. Based on the predictors for no ROSC, a threshold of 13 minutes of ICA yielded the highest area under curve (AUC) (0.867[0.80-0.93]), with a sensitivity and specificity of 78.4% [69.6-86.3%] and 89.3% [80.4-96.4%], respectively. For the 1-year mortality, the GCS without the verbal component 24 h after an ICA had the highest AUC (0.616 [0.792-0.956]), with a sensitivity of 79.3% [65.5-93.1%] and specificity of 86.1 [74.4-95.4]. ICA duration and GCS 24 h after the event had the best prognostic value for no ROSC and 1-year mortality. For 24 h mortality, no predictors had prognostic value.

Predictors of major complications after elective abdominal surgery in cancer patients.

BACKGROUND: Patients undergoing abdominal surgery for solid tumours frequently develop major postoperative complications, which negatively affect quality of life, costs of care and survival. Few studies have identified the determinants of perioperative complications in this group. METHODS: We performed a prospective observational study including all patients (age > 18) undergoing abdominal surgery for cancer at a single institution between June 2011 and August 2013. Patients undergoing emergency surgery, palliative procedures, or participating in other studies were excluded. Primary outcome was a composite of 30-day all-cause mortality and infectious, cardiovascular, respiratory, neurologic, renal and surgical complications. Univariate and multiple logistic regression analyses were performed to identify predictive factors for major perioperative adverse events. RESULTS: Of a total 308 included patients, 106 (34.4%) developed a major complication during the 30-day follow-up period. Independent predictors of postoperative major complications were: age (odds ratio [OR] 1.03 [95% CI 1.01-1.06], p = 0.012 per year), ASA (American Society of Anesthesiologists) physical status greater than or equal to 3 (OR 2.61 [95% CI 1.33-5.17], p = 0.003), a preoperative haemoglobin level lower than 12 g/dL (OR 2.13 [95% CI 1.21-4.07], p = 0.014), intraoperative use of colloids (OR 1.89, [95% CI 1.03-4.07], p = 0.047), total amount of intravenous fluids (OR 1.22 [95% CI 0.98-1.59], p = 0.106 per litre), intraoperative blood losses greater than 500 mL (2.07 [95% CI 1.00-4.31], p = 0.043), and hypotension needing vasopressor support (OR 4.68 [95% CI 1.55-27.72], p = 0.004). The model had good discrimination with the area under the ROC curve being 0.80 (95% CI 0.75-0.84, p < 0.001). CONCLUSIONS: Our findings suggest that a perioperative strategy aimed at reducing perioperative complications in cancer surgery should include treatment of preoperative anaemia and an optimal fluid strategy, avoiding fluid overload and intraoperative use of colloids.

S100B protein and neuron-specific enolase as predictors of cognitive dysfunction after coronary artery bypass graft surgery: A prospective observational study.

BACKGROUND: Postoperative cognitive dysfunction (POCD) may be related to the systemic inflammatory response and an increase in serum markers of brain injury such as S100B protein and neuron-specific enolase (NSE). OBJECTIVE: The study aims to evaluate the association between POCD and serum levels of S100B and NSE after coronary artery bypass grafting surgery (CABG). DESIGN: Prospective observational study. SETTING: Single university teaching hospital. PATIENTS: We investigated 88 patients undergoing CABG. MAIN OUTCOMES MEASURES: Cognitive function was measured preoperatively, and at the 21st and 180th postoperative days (i.e. 6 months after surgery). S100B protein and NSE serum levels were evaluated preoperatively, after induction of anaesthesia, at the end of surgery and at 6 and 24 h after surgery. RESULTS: The incidence of POCD was 26.1% at 21 days after surgery and 22.7% at 6 months after surgery. Increased serum levels of S100B protein and NSE were observed postoperatively and may indicate brain damage. CONCLUSION: Although serum levels of S100B protein and NSE are both significantly increased postoperatively, our findings indicate that serum levels of S100B protein may be more accurate than NSE in the detection of POCD after CABG. TRIAL REGISTRATION: NCT01550159.

Ultrasound-guided percutaneous dilational tracheostomy versus bronchoscopy-guided percutaneous dilational tracheostomy in critically ill patients (TRACHUS): a randomized noninferiority controlled trial.

PURPOSE: Percutaneous dilational tracheostomy (PDT) is routinely performed in the intensive care unit with bronchoscopy guidance. Recently, ultrasound has emerged as a potentially useful tool to assist PDT and reduce procedure-related complications. METHODS: An open-label, parallel, non-inferiority randomized controlled trial was conducted comparing an ultrasound-guided PDT with a bronchoscopy-guided PDT in mechanically ventilated critically ill patients. The primary outcome was procedure failure, defined as a composite end-point of conversion to a surgical tracheostomy, unplanned associated use of bronchoscopy or ultrasound during PDT, or the occurrence of a major complication. RESULTS: A total of 4965 patients were assessed for eligibility. Of these, 171 patients were eligible and 118 underwent the procedure, with 60 patients randomly assigned to the ultrasound group and 58 patients to the bronchoscopy group. Procedure failure occurred in one (1.7%) patient in the ultrasound group and one (1.7%) patient in the bronchoscopy group, with no absolute risk difference between the groups (90% confidence interval, -5.57 to 5.85), in the "as treated" analysis, not including the prespecified margin of 6% for noninferiority. No other patient had any major complication in either group. Procedure-related minor complications occurred in 20 (33.3%) patients in the ultrasound group and in 12 (20.7%) patients in the bronchoscopy group (P = 0.122). The median procedure length was 11 [7-19] vs. 13 [8-20] min (P = 0.468), respectively, and the clinical outcomes were also not different between the groups. CONCLUSIONS: Ultrasound-guided PDT is noninferior to bronchoscopy-guided PDT in mechanically ventilated critically ill patients.

Outcomes of patients with trauma and intraoperative cardiac arrest.

BACKGROUND: Although the occurrence of intraoperative cardiac arrest is rare, it is a severe adverse event with a high mortality rate. Trauma patients have additional causes for intraoperative arrest, and we hypothesised that the survival of trauma patients who experienced intraoperative cardiac arrest would be worse than nontrauma patients who experienced intraoperative cardiac arrest. OBJECTIVES: The aim of the present study was to compare the outcomes of trauma and nontrauma patients after intraoperative cardiac arrest. METHODS: In a tertiary university hospital and trauma centre, the intraoperative cardiac arrest cases were evaluated from January 2007 to December 2009, excluding patients submitted to cardiac surgery. Data were prospectively collected using the Utstein-style. Outcomes among the patients with trauma were compared to the patients without trauma. RESULTS: We collected data from 81 consecutive intraoperative cardiac arrest cases: 32 with trauma and 49 without trauma. Patients in the trauma group were younger than the patients in the nontrauma group (44±23 vs. 63±17, p<0.001). Hypovolaemia (63% vs. 35%, p=0.022) and metabolic/hydroelectrolytic disturbances (41% vs. 2%, p<0.001) were more likely to cause the cardiac arrest in the trauma group. The first documented arrest rhythm did not differ between the groups, and pulseless electrical activity was the most prevalent rhythm (66% vs. 53%, p=0.698). The return of spontaneous circulation (47% vs. 63%, p=0.146) and survival to discharge with favourable neurological outcome (16% vs. 14%, p=0.869) did not differ between the two groups. CONCLUSIONS: The outcomes did not differ between patients with trauma and nontrauma intraoperative cardiac arrest.

Potassium in hemorrhagic shock: a potential marker of tissue hypoxia.

BACKGROUND: This study was designed to evaluate serum potassium level variation in a porcine model of hemorrhagic shock (HS). METHODS: Eight pigs were studied in a controlled hemorrhage model of HS. Blood withdrawal began at a 50 mL/min to 70 mL/min rate, adjusted to reach a mean arterial pressure (MAP) level of 60 mm Hg in 10 minutes. When MAP reached 60 mm Hg, the blood withdrawal rate was adjusted to maintain a MAP decrease rate of 10 mm Hg every 2 minutes to 4 minutes. Arterial and mixed venous blood samples were collected at MAP levels of 60 mm Hg, 50 mm Hg, 40 mm Hg, 30 mm Hg, 20 mm Hg, and 10 mm Hg and analyzed for oxygen saturation, Po2, Pco2, potassium, lactate, bicarbonate, hemoglobin, pH, and standard base excess. RESULTS: Significant increase in serum potassium occurred early in all animals. The rate of rise in serum potassium and its levels accompanied the hemodynamic deterioration. Hyperkalemia (K >5 mmol/L) incidence was 12.5% at 60 mm Hg and 50 mm Hg, 62.5% at 40 mm Hg, 87.5% at 30 mm Hg, and 100% at 20 mm Hg. Strong correlations were found between potassium levels and lactate (R = 0.82), SvO2 (R = 0.87), DeltapH (R = 0.83), and DeltaPco2 (R = 0.82). CONCLUSIONS: Serum potassium increase accompanies the onset of HS. The rise in serum potassium was directly related to the hemodynamic deterioration of HS and strongly correlated with markers of tissue hypoxia.