Derivation and external validation of a prediction model for pneumococcal urinary antigen test positivity in patients with community-acquired pneumonia.

Objective: Derive and externally validate a prediction model for pneumococcal urinary antigen test (pUAT) positivity. Methods: Retrospective cohort study of adults admitted with community-acquired pneumonia (CAP) to 177 U.S. hospitals in the Premier Database (derivation and internal validation samples) or 12 Cleveland Clinic hospitals (external validation sample). We utilized multivariable logistic regression to predict pUAT positivity in the derivation dataset, followed by model performance evaluation in both validation datasets. Potential predictors included demographics, comorbidities, clinical findings, and markers of disease severity. Results: Of 198,130 Premier patients admitted with CAP, 27,970 (14.1%) underwent pUAT; 1962 (7.0%) tested positive. The strongest predictors of pUAT positivity were history of pneumococcal infection in the previous year (OR 6.99, 95% CI 4.27-11.46), severe CAP on admission (OR 1.76, 95% CI 1.56-1.98), substance abuse (OR 1.57, 95% CI 1.27-1.93), smoking (OR 1.23, 95% CI 1.09-1.39), and hyponatremia (OR 1.35, 95% CI 1.17-1.55). Negative predictors included IV antibiotic use in past year (OR 0.65, 95% CI 0.52-0.82), congestive heart failure (OR 0.72, 95% CI 0.63-0.83), obesity (OR 0.71, 95% CI 0.60-0.85), and admission from skilled nursing facility (OR 0.60, 95% CI 0.45-0.78). Model c-statistics were 0.60 and 0.67 in the internal and external validation cohorts, respectively. Compared to guideline-recommended testing of severe CAP patients, our model would have detected 23% more cases with 5% fewer tests. Conclusion: Readily available data can identify patients most likely to have a positive pUAT. Our model could be incorporated into automated clinical decision support to improve test efficiency and antimicrobial stewardship.

Challenges in cardiac risk assessment in bariatric surgery patients.

Bariatric surgery has serious associated medical comorbidity and procedure-related risks and is thus considered an intermediate- to high-risk noncardiac surgery. Most patients referred for bariatric surgery have a low or very low functional capacity, making cardiac risk assessment imperative. Stress echocardiography has a high negative predictive value and can avoid some of the table weight and torso diameter problems associated with myocardial perfusion imaging. Echocardiograph contrast agents improve the ability to identify endocardial borders and assess ventricular wall motion and may be used with stress and nonstress imaging protocols. Single photon emission computer tomography (SPECT) imaging with attenuation correction, combined supine and prone imaging, use of technetium isotope, and positron emission tomography (PET) imaging may all provide some advantage for myocardial perfusion imaging for the obese patient.

Challenges in pulmonary risk assessment and perioperative management in bariatric surgery patients.

Bariatric surgery has serious associated medical comorbidity and procedure-related risks and is, thus, considered an intermediate-to-high-risk non-cardiac surgery. Altered respiratory mechanics, obstructive sleep apnea (OSA), and less often, pulmonary hypertension and postoperative pulmonary embolism are the major contributors to poor pulmonary outcomes in obese patients. Attention to posture and positioning is critical in patients with OSA. Suspected OSA patients requiring intravenous narcotics should be kept in a monitored setting with frequent assessments and naloxone kept at the bedside. Use of reverse Tredelenburg position, preinduction, maintenance of positive end-expiratory pressure, and use of continuous positive airway pressure can help improve oxygenation in the perioperative period.

Perioperative management of the bariatric surgery patient: focus on cardiac and anesthesia considerations.

Obesity is a major public health problem in developed nations worldwide. Currently, the only treatment for severe obesity (BMI > or = 35 kg/m2 with comorbidity) that provides long-term weight loss is bariatric surgery. Restrictive, malabsorptive, and combination procedures have been developed. Each type of procedure has its merits and unique set of risks and complications. Weight loss after bariatric surgery is accompanied by predictable improvement or resolution of obesity-related comorbidities and improved quality of life and life expectancy. Candidates for bariatric surgery are often at high risk for complications because of obesity-related comorbidities. Therefore, careful patient selection for bariatric surgery, together with well-designed strategies for preventing and managing complications, are keys to success. Close monitoring for nutritional deficiencies and short- and long-term complications is required to completely assess outcomes of these procedures.