Publications

OBJECTIVE: The present study aimed to validate the utility of bedside cardiac ultrasound to identify patients for the risk of postoperative atrial fibrillation (POAF).

DESIGN: A prospective cohort study of consecutive patients.

SETTING: Single-center tertiary referral center.

PARTICIPANTS: After Institutional Review Board consent, 169 patients undergoing elective cardiac surgery were enrolled in the study.

INTERVENTIONS: A preoperative transthoracic echocardiographic interrogation assessing diastolic function was performed. Measurements were assessed offline with experienced echocardiographers blinded to clinical outcomes.

MEASUREMENTS AND MAIN RESULTS: The primary outcome was POAF during the first 72 hours after surgery. A total of 169 patients completed the study, 44 of whom (26.0%) developed POAF, and 39 (25.2%) had diastolic dysfunction. Patients with POAF had a higher rate of postoperative heart failure, reintubation within 24 hours of surgery, and length of stay (p = 0.002, 0.01, and 0.0006, respectively). Predictors significant for POAF included increasing age, left atrial volume indexed to body surface area (LAVI), and diastolic dysfunction (p = 0.02, 0.0001, and 0.001, respectively). Multivariate spline regressions demonstrated a nonlinear correlation between increasing LAVI and risk of POAF.

CONCLUSION: Left atrial volume can be assessed efficiently preoperatively to provide superior risk stratification over clinical factors and diastolic parameters alone for the prediction of POAF. Furthermore, the present study demonstrated that the cutoffs of chamber quantification currently used do not appropriately capture the increased risk of POAF. Thus, LAVI provides a simple measure to identify patients who are in need of targeted prophylaxis for POAF.

OBJECTIVES: Echocardiographic assessment of right ventricular (RV) function is based largely on visual estimation of tricuspid annulus and motion of the free wall. Regional strain analysis has provided an objective measure of myocardial performance assessment, but is limited in use by vendor-specific software. The study was designed to investigate statistical correlation between RV region-specific strain and echocardiographic parameters of RV function using a vendor-neutral RV-specific strain assessment program.

DESIGN: This is a retrospective study.

SETTING: Tertiary hospital.

PARTICIPANTS: One hundred seven patients undergoing coronary artery bypass graft, valve repair or replacement, or a combination of procedures.

INTERVENTION: None.

MEASUREMENTS AND MAIN RESULTS: One hundred seven patients underwent comprehensive echocardiographic of RV function intraoperatively. Off-line analysis of global, longitudinal, and septal strain was performed using a vendor-neutral software. The 2 values were compared statistically. All pairs demonstrated strong statistical significance; the strongest relationships were between (1) RV fractional area change (FAC) (%)-RV longitudinal strain (r2 = 0.83, p < 0.001), and (2) tricuspid annular plane systolic excursion (mm)-lateral S' velocity (cm/s) (r2 = 0.80, p < 0.001). The weakest correlations were (1) RV FAC (%)-lateral S' velocity (cm/s) (r2 = 0.37, p < 0.001), and (2) lateral S' velocity (cm/s)-RV longitudinal strain (r2 = 0.40, p < 0.001).

CONCLUSION: RV function can be assessed objectively by strain analyses across different platforms using the artificial intelligence-based vendor-neutral strain analysis software. There is a statistically significant correlation between strain values and conventional 2-dimensional echocardiographic parameters of RV function.

Diastolic dysfunction (DD) is a common condition that is increasingly encountered in patients undergoing both cardiac and noncardiac surgery as the age profile of our patient population increases and the noninvasive diagnosis of DD becomes more accessible. There is a growing body of evidence demonstrating the significance of DD and adverse perioperative outcomes, and thus, it is becoming imperative for anesthesiologists to have an understanding of the pathophysiology, diagnosis, and management of patients with DD. Current guidelines are based on transthoracic echocardiogram (TTE) measurements in patients who are spontaneously breathing and in a euvolemic state and, consequently, not applicable to the perioperative period. In this review article, we discuss the grading of DD as well as introduce a practical approach to the diagnosis and management of patients with DD during the perioperative period.

Simulator-based workflow training in echocardiography appears to be gravely lacking. Workflow, or the technical and logistical steps taken to safely and efficiently execute an ultrasound procedure, is an aspect of echocardiography nearly equivalent in importance to performing the procedure itself. A knowledge gap in workflow presently exists between trainees and senior staff; this knowledge gap stems from the fact that workflow education usually is obtained "on the job" through extended repetition. Indeed, the designers of current echocardiographic simulators have gone leaps and bounds to simulate echocardiographic procedures, but none presently allows for workflow training. In this review, the authors describe a proficiency-based educational model for echocardiography, specifically highlighting transesophageal echocardiography, and briefly discuss its design. In addition, the review describes a simulator that when used in combination with formal didactics could provide echocardiographic workflow training.

Spinal drain placement to prevent spinal cord ischemia during thoracic aorta surgery is a necessary yet complex undertaking in patients with coagulopathies. Thromboelastography (TEG) can be used as a point-of-care management tool to monitor coagulation status before drain placement and removal. We present 2 cases: a case of a patient with factor VII deficiency and a case of a patient with thrombocytopenia for whom TEG was an important procedural adjunct during coagulopathy reversal. TEG parameters are also discussed to encourage more frequent TEG use as an adjunct during these complex cases.

OBJECTIVE: Due to its circular shape, the area of the proximal left ventricular tract (PLVOT) adjacent to aortic valve can be derived from a single linear diameter. This is also the location of flow acceleration (FA) during systole, and pulse wave Doppler (PWD) sample volume in the PLVOT can lead to overestimation of velocity (V1) and the aortic valve area (AVA). Therefore, it is recommended to derive V1 from a region of laminar flow in the elliptical shaped distal LVOT (away from the annulus). Besides being inconsistent with the assumptions of continuity equation (CE), spatial difference in the location of flow and area measurement can result in inaccurate AVA calculation. We evaluated the impact of FA in the PLVOT on the accuracy of AVA by continuity equation (CE) in patients with aortic stenosis (AS).

METHODS: CE-based AVA calculations were performed in patients with AS once with PWD-derived velocity time integral (VTI) in the distal LVOT (VTILVOT) and then in the PLVOT to obtain a FA velocity profile (FA-VTILVOT) for each patient. A paired sample t-test (P < 0.05) was conducted to compare the impact of FA-VTILVOT and VTILVOT on the calculation of AVA.

RESULT: There were 46 patients in the study. There was a 30.3% increase in the peak FA-VTILVOT as compared to the peak VTILVOT and AVA obtained by FA-VTILVOT was 29.1% higher than obtained by VTILVOT.

CONCLUSION: Accuracy of AVA can be significantly impacted by FA in the PLVOT. LVOT area should be measured with 3D imaging in the distal LVOT.

Analgesia for many open thoracic and abdominal procedures has traditionally been accomplished through neuraxial techniques or paravertebral blocks. Erector spinae plane (ESP) blocks purport effective analgesia over a similar anatomical distribution with a more favorable side effect profile and complication rate than epidurals. However, the extent of clinical applicability for ESP blocks has yet to be elucidated. In this case series, we demonstrate the efficacy of ESP blocks for 3 distinct etiologies of acute pain: planned perioperative analgesia, rescue postoperative analgesia, and traumatic pain.