Renal Angina Is a Sensitive, but Nonspecific Identifier of Postcardiac Surgery Acute Kidney Injury.

OBJECTIVES: Acute kidney injury (AKI) is a common complication of cardiac surgery, and early detection is difficult. This study was performed to determine the sensitivity, specificity, positive predictive value, negative predictive value, and statistical performance of renal angina (RA) as an early predictor of AKI in an adult cardiac surgical patient population. DESIGN: Retrospective, nonrandomized, observational study. SETTING: A single, university-affiliated, quaternary medical center. PARTICIPANTS: The study comprised 324 consecutive patients undergoing coronary artery bypass grafting or cardiac valvular surgery from February 1 through July 30, 2014. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred-seven patients at moderate or high risk of developing postoperative renal injury were identified, 82 of whom met criteria for RA. The occurrence of RA was found to have an 80.9% sensitivity and 30.8% specificity for the prediction of AKI using Acute Kidney Injury Network criteria and 89.3% sensitivity and 27.8% specificity when paired with the Risk, Injury, Failure, Loss, End Stage Renal Disease criteria. A receiver operating characteristic area under the curve analysis revealed a nonsignificant predictive ability of 55.8% (95% confidence interval 0.47-0.65) when RA was paired with Acute Kidney Injury Network criteria; however, the receiver operating characteristic area under the curve was significant when paired with Risk, Injury, Failure, Loss, End Stage Renal Disease criteria, with a predictive ability of 0.586 (0.509-0.662). CONCLUSIONS: RA is a sensitive, but nonspecific, predictor of postcardiac surgery AKI, with clinical utility most suited as a screening tool.

Effect of positive end-expiratory pressure on blood loss during retropubic and robot-assisted laparoscopic radical prostatectomy.

OBJECTIVES: To study the effect of end-expiratory pressure used during anesthesia on blood loss during radical prostatectomy. METHODS: We evaluated 247 patients who underwent either radical retropubic prostatectomy or robot-assisted laparoscopic prostatectomy at a single institution from 2008 to 2013 by one of four surgeons. Patient characteristics were compared using t-tests, rank sum or χ(2) -tests as appropriate. The association between positive end-expiratory pressure and estimated blood loss was tested using linear regression. RESULTS: Patients were classified into high (≥4 cmH2 O) and low (≤1 cmH2 O) positive-end expiratory pressure groups. Estimated blood loss in radical retropubic prostatectomy was higher in the high positive end-expiratory pressure group (1000 mL vs 800 mL, P = 0.042). Estimated blood loss in robot-assisted laparoscopic prostatectomy was lower in the high positive end-expiratory pressure group (150 mL vs 250 mL, P = 0.015). After adjusting for other factors known to influence blood loss, a 5-cmH2 O increase in positive end-expiratory pressure was associated with a 34.9% increase in estimated blood loss (P = 0.030) for radical retropubic prostatectomy, and a 33.0% decrease for robot-assisted laparoscopic prostatectomy (P = 0.038). CONCLUSIONS: In radical retropubic prostatectomy, high positive end-expiratory pressure was associated with higher estimated blood loss, and the benefits of positive end-expiratory pressure should be weighed against the risk of increased estimated blood loss. In robot-assisted laparoscopic prostatectomy, high positive end-expiratory pressure was associated with lower estimated blood loss, and might have more than just pulmonary benefits.

Regional variation in prosthesis choice for aortic valve replacement in older patients.

BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate regional practice patterns regarding aortic valve replacement (AVR) by comparing bioprosthetic versus mechanical valve usage in patients aged > or = 65 years, and to determine whether the choice of valve type for AVR in these patients varied by geographic region. METHODS: The details were acquired of all mechanical and bioprosthetic AVRs performed in patients aged > or = 65 years between 1999 and 2006, as contained in the Florida State Inpatient Database. By using a small area analysis, the patients' zip codes were aggregated into hospital referral regions based on where they were most likely to receive AVR. The regional rates of both mechanical and bioprosthetic AVR were then determined. RESULTS: Of 23,925 AVRs performed during this period, 15,368 involved a bioprosthetic aortic valve and 8,557 a mechanical aortic valve. Statewide, 64% of AVRs in these patients involved a bioprosthesis. Regional rates of mechanical AVRs varied widely, from 10% to 81%. CONCLUSION: Substantial regional differences were identified in practice patterns for AVR in patients aged > or = 65 years. This suggested that provider preference, in addition to patient pathology, would often determine the type of valve implanted.

Geography or pathology? Regional variation in atrial septal defect closure rates and techniques.

BACKGROUND: Since the introduction of percutaneous closure in the United States, rates of secundum atrial septal defect and patent foramen ovale closures have increased substantially. Whether or not closure rates are uniform or vary due to differences in regional practice patterns is unknown. We sought to investigate this by comparing regional rates of closure across Florida. METHODS: We identified all atrial septal defect closures from 2001 to 2006 in the Florida State Inpatient Database. Using small area analysis, zip codes were assigned to Hospital Referral Regions based on where patients were most likely to go for closure. We obtained population-normalised rates of overall, percutaneous, and surgical closure. RESULTS: Of 1830 atrial septal defect and patent foramen ovale closures from 2001 to 2006, 751 were surgical and 1004 were percutaneous. The statewide closure rate was 1.91 per 100,000 people per year; regional rates varied 3.8-fold from 0.78 to 2.94 per 100,000 people per year. Percutaneous rates varied sevenfold from 0.25 to 1.75 per 100,000 people per year, while surgical rates varied 2.71-fold from 0.53 to 1.44 per 100,000 people per year. CONCLUSIONS: Despite a consistent prevalence of atrial septal defects, and patent foramens ovale, rates of repair vary across regions, suggesting that closure is driven by provider practice patterns rather than patient pathology. Efforts should be directed towards increasing consensus regarding the appropriate, evidence-based indications for closure so as to avoid the costs and potential negative sequelae of over- or undertreatment.