Yafen Liang

Effect of Preoperative Beta-Blocker Use on Outcomes Following Cardiac Surgery

Recent studies suggest that the use of preoperative β blockers in cardiac surgery may not provide improved mortality rates and may even contribute to negative clinical outcomes. We therefore assessed the role of β blockers on several outcomes after cardiac surgery (delirium, acute kidney injury [AKI], stroke, atrial fibrillation (AF), mortality, and hospital length of stay) in 4,076 patients who underwent elective coronary artery bypass grafting, coronary artery bypass grafting + valve, or valve cardiac surgery from November 1, 2009, to September 30, 2015, at Vanderbilt Medical Center. Clinical data from 2 prospectively collected datasets at our institution were reviewed: the Cardiac Surgery Perioperative Outcomes Database and the Society of Thoracic Surgeons Database. Preoperative β-blocker use was defined by Society of Thoracic Surgeons guidelines as patients receiving a β blocker within 24 hours preceding surgery. Of the included patients, 2,648 (65.0%) were administered a β blocker within 24 hours before surgery. Adjusting for possible confounders, preoperative β-blocker use was associated with increased odds of AKI stage 2 (odds ratio 1.96, 95% confidence interval 1.19 to 3.24, p <0.01). There was no evidence that β-blocker use had an independent association with postoperative delirium, AKI stages 1 and 3, stroke, AF, mortality, or prolonged length of stay. A secondary propensity score analysis did not show a marginal association between β-blocker use and any outcome. In conclusion, we did not find significant evidence that preoperative β-blocker use was associated with postoperative delirium, AF, AKI, stroke, or mortality.

Blood Gas Analyzer Accuracy of Glucose Measurements

Objective: To investigate the comparability of glucose levels measured with blood gas analyzers (BGAs) and by central laboratories (CLs). Material and Methods: Glucose measurements obtained between June 1, 2007, and March 1, 2016, at the Vanderbilt University Medical Center were reviewed. The agreement between CL and BGA results were assessed using Bland‐Altman, consensus error grid (CEG), and surveillance error grid (SEG) analyses. We further analyzed the BGAs’ performance against the US Food and Drug Administration (FDA) 2014 draft guidance and 2016 final guidance for blood glucose monitoring and the International Organization for Standardization (ISO) 15197:2013 standard. Results: We analyzed 2671 paired glucose measurements, including 50 pairs of hypoglycemic values (1.9%). Bland‐Altman analysis yielded a mean bias of −3.1 mg/dL, with 98.1% of paired values meeting the 95% limits of agreement. In the hypoglycemic range, the mean bias was −0.8 mg/dL, with 100% of paired values meeting the 95% limits of agreement. When using CEG analysis, 99.9% of the paired values fell within the no risk zone. Similar results were found using SEG analysis. For the FDA 2014 draft guidance, our data did not meet the target compliance rate. For the FDA 2016 final guidance, our data partially met the target compliance rate. For the ISO standard, our data met the target compliance rate. Conclusion: In this study, the agreement for glucose measurement between common BGAs and CL instruments met the ISO 2013 standard. However, BGA accuracy did not meet the stricter requirements of the FDA 2014 draft guidance or 2016 final guidance. Fortunately, plotting these results on either the CEG or the SEG revealed no results in either the great or extreme clinical risk zones.

Point-of-care Ultrasound Facilitated Detection of Femoral Occlusive Septic Emboli During Mitral Valve Surgery: A Case Report

Acute lower extremity ischemia from septic emboli is a surgical emergency. Timely diagnosis and management are critical to improve patient outcome. However, traditional diagnostic modalities such as intraoperative angiogram are time-consuming, require special equipment and personnel, and introduce contrast exposure for critically ill patients. There are limited reports of utilization of point-of-care ultrasound to detect peripheral septic emboli. We present a case where femoral occlusive septic emboli were identified by point-of-care ultrasound after mitral valve replacement. This facilitated early surgical embolectomy and limb salvage. We suggest that perioperative point-of-care ultrasonography should be used as a first-line screening test in patients with acute lower extremity ischemia.

A Near-Field Clutter Artifact Mimicking Pulmonary Thrombus During Transesophageal Echocardiography.

October 2016 • Volume 123 • Number 4 www.anesthesia-analgesia.org 831 A 23-year-old woman presented for pulmonary thrombectomy for chronic pulmonary embolism (PE). Her medical history included nonischemic dilated cardiomyopathy with left ventricular ejection fraction of 20%, endocarditis, right atrial thrombus, and endstage renal disease secondary to granulomatosis with polyangiitis. A preoperative computed tomography angiography showed an abrupt cutoff of the right pulmonary artery (RPA) without significant pulmonary arterial (PA) flow indicating an occlusive thrombus. The main and left PAs were patent without filling defects. The patient was brought to the operating room. General endotracheal anesthesia was induced after invasive arterial blood pressure monitoring was established. The transesophageal echocardiogram (TEE) showed moderately depressed left ventricular function with estimated ejection fraction of 35%. The right ventricle was dilated with mildly depressed systolic function and moderate tricuspid regurgitation. The midesophageal ascending aorta short-axis view demonstrated a thrombus in the RPA occluding the vessel (Figure 1) with a persistent filling defect when echo contrast was injected (Figure 2). However, an additional “mass” was observed occupying approximately two-thirds of the RPA. This semicircular mass was located adjacent to the echo transducer. It was initially considered to be part of the thrombus; however, when echo contrast was injected, it easily traversed the mass both before (Figure 2; Supplemental Digital Content, Video 1, http://links.lww. com/AA/B433) and after thrombectomy (Figures 3 and 4; Supplemental Digital Content, Video 2, http://links.lww. com/AA/B434); therefore, this was proven to be an artifact. Subsequently, a 4.5 × 4 × 3.1-cm large chronic clot was found to totally occlude the right main PA. The clot also extended to the right superior, middle, and lower PA. The clots were evacuated successfully, and the patient had an uneventful recovery.