Douglas Shook

Perioperative Ultrasound Training in Anesthesiology: A Call to Action.

The purpose of this position paper is to define the scope of perioperative ultrasound (US), review the current status of US training practices during anesthesiology residency, and suggest the recommendations for current and future trainees on how to obtain perioperative US proficiency. We define per

Offsite anesthesiology in the cardiac catheterization lab.

Purpose of review The cardiac catheterization lab has concerns for both patient care and for safety. As the cardiac catheterization lab continues to evolve, the demand for anesthesia services will certainly increase. The role of the anesthesiologist in the cardiac catheterization lab must be defined in this changing environment. Recent findings Procedures in the cardiac catheterization lab are more complex, take longer, and involve higher acuity patients. Many of these cases require general anesthesia rather than sedation, and require management of unstable hemodynamics. Knowledge of echocardiography and fluoroscopy is beneficial. Anesthesiologists should be active in developing sedation and practice management guidelines. Radiation exposure and safety is an important concern. Summary The anesthesiologist is becoming an integral part of the cardiac catheterization lab team, and an important element in maintaining a high level of patient care with minimal complications in the evolving modern day cardiac catheterization lab.

Anesthesia in the cardiac catheterization laboratory and electrophysiology laboratory.

Procedures and interventions in the cardiac catheterization laboratory (CCL) and electrophysiology laboratory (EPL) are more complex and involve acutely ill patients. Safely caring for this growing patient population in the CCL and EPL is now a concern for all anesthesiologists and cardiologists. Anesthesiologists are uniquely trained to care for this complex patient population, allowing the cardiologist to focus on completing the interventional procedure successfully.

Three-dimensional versus two-dimensional echocardiographic assessment of functional mitral regurgitation proximal isovelocity surface area.

BACKGROUND:The geometric shape of the mitral regurgitation (MR) proximal isovelocity surface area (PISA) is conventionally assumed to be a hemisphere (HS). However, in functional MR, PISA is frequently neither an HS nor a hemiellipse (HE) but is often asymmetric and crescent shaped. We used 3-dimensional transesophageal echocardiographic (3D TEE), full-volume data sets to directly measure the PISA and subsequently compared calculated values of effective regurgitant orifice area (EROA) with conventional 2D TEE techniques. EROA calculations from all PISA measurements were finally compared with the cross-sectional area at the vena contracta, a well-validated reference measure of the functional MR orifice area. METHODS:Twenty-four cardiac surgical patients with functional MR, who underwent routine intraoperative TEE examinations with a 3D matrix array probe (X7-2t; IE33; Philips Healthcare, Inc., Andover, MA) were retrospectively evaluated for MR severity using quantitative 2D and 3D TEE-derived techniques. Conventional 2D TEE methods were used to estimate PISA assuming an HS shape and an HE shape. In addition, direct measurement of the 3D PISA was obtained (QLab, Philips Healthcare, Inc.) from corresponding full-volume, color-flow Doppler data sets. EROAs calculated from HS- and HE-PISA techniques were compared with the same values obtained from 3D TEE PISAs. EROAs obtained from all 3 PISA techniques were subsequently compared with vena contracta area. RESULTS:Three-dimensional PISA was significantly larger than both HS-PISA and HE-PISA (mean ± SD: 4.65 ± 2.03 cm2 vs 2.10 ± 1.58 cm2 and 2.75 ± 1.42 cm2; both P < 0.0001), respectively. HE-PISA was also larger than HS-PISA (P = 0.042). In addition, 3D EROA was larger than both HS- and HE-acquired EROAs (mean ± SD: 0.44 ± 0.21 vs 0.19 ± 0.12 cm2 and 0.26 ± 0.14; both P < 0.0001), respectively, while HE-EROA was larger than HS-EROA (P = 0.024). Vena contracta area correlated well with 3D EROA (Spearman r = 0.865), HS-EROA (Spearman r = 0.820; P < 0.001) and HE-EROA (Spearman r = 0.819). However, the difference between vena contracta area and 3D EROA was significantly less than the differences between vena contracta area and either 2D HS- or 2D HE-EROA (P < 0.0001). CONCLUSIONS:Quantitative assessment of functional MR severity by 3D TEE may be superior to 2D methods by permitting more direct measures of PISA. Two-dimensional TEE techniques for assessing functional MR severity that rely on an HS- or HE-PISA shape may underestimate the EROA due to geometric assumptions that do not account for asymmetry.

Multimodality Imaging of a Gerbode Defect

A 76-year-old woman with a history of aortic valve replacement was referred for echocardiography for routine postoperative evaluation. Transthoracic echocardiogram revealed evidence of an intracardiac shunt between the left ventricle (LV) and the right atrium (RA) (Figure 1A). Figure 1. Illustration of LV-RA shunt by ( A ) 2-dimensional transthoracic echocardgiography, ( B ) 2-dimensional transesophageal echocardiography, and ( C ) 3-dimensional transesophageal echocardiography. LV indicates left ventricle; RA, right atrium; RV, right ventricle; LA, left atrium; TV, tricuspid valve. A transesophageal echocardiogram confirmed the presence of an LV to RA shunt consistent with a Gerbode defect (Figure 1B and 1C). To …

Leaflet Thrombosis in Surgically Explanted or Post-Mortem TAVR Valves

Leaflet thrombosis is currently one of the greatest concerns related to transcatheter aortic valve replacement (TAVR). Symptomatic valve thrombosis is a rare occurrence, but reduced leaflet motion, diagnosed by computed tomography, seems to be a more common finding [(1)][1]. We screened our

Cardiac Resuscitation and Coagulation

1009 April 2014 C ARDIAC arrest occurs with an estimated annual incidence of 92 to 189 cases per 100,000 individuals and carries a poor prognosis despite advances in modern medicine.1 Even for patients in whom spontaneous circulation is restored, their subsequent hospital course is fraught with potential complications. Derangements in the coagulation and fibrinolytic systems frequently occur as a result of cardiac arrest and cardiopulmonary resuscitation (CPR). These changes play a significant role in the spectrum of conditions classified as “post–cardiac arrest syndrome.”2 In addition to the endogenous changes in blood coagulation after cardiac arrest, iatrogenic coagulopathies can be seen at various time points as ancillary effects of certain treatment options for these patients (fig. 1). In this article, we review the changes in the coagulation systems of patients experiencing cardiac arrest and CPR and further discuss coagulopathies potentially associated with hypothermia, thrombolysis, and extracorporeal membrane oxygenation (ECMO) therapy.

The Mechanism of Mitral Regurgitation Influences the Temporal Dynamics of the Vena Contracta Area as Measured with Color Flow Doppler.

BACKGROUND:In patients with mitral regurgitation (MR), the effective regurgitant orifice area can be estimated by measuring the vena contracta area (VCA). We hypothesize that the VCA has characteristic temporal dynamics related to the underlying mechanism of functional mitral regurgitation (FMR) versus degenerative mitral valve disease (DMVD). METHODS:VCA measurements obtained by planimetry of the proximal jet from 3D transesophageal echocardiographic (TEE) color flow Doppler data sets were acquired in 42 cardiac surgical patients, including 22 with FMR and 20 with DMVD. Serial VCAs were measured throughout systole for each patient to evaluate variation in the effective regurgitant orifice area. Tercile averages were compared within and between the FMR and DMVD groups using repeated measures analysis of variance. Pairwise tests were Bonferroni-corrected for the number of comparisons. RESULTS:Normalized average VCA values in patients with FMR revealed a biphasic pattern compared with a monophasic pattern in patients with DMVD. Among FMR patients, normalized average VCA values in early (1.10 ± 0.32 cm2) and late systole (1.11 ± 0.33 cm2) were similar but were both significantly greater compared with mid-systole (0.79 ± 0.22 cm2; P = 0.0144 and P = 0.0106, respectively). Among DMVD patients, normalized average VCA values in mid-systole (1.37 ± 0.15 cm2) were significantly greater than those in early (0.53 ± 0.14 cm2) and late systole (1.09 ± 0.18 cm2; P < 0.0001 for both). An analysis of normalized average VCAs also revealed significant differences between the FMR and the DMVD groups during early (1.10 ± 0.32 cm2 vs 0.53 ± 0.14 cm2) and mid-systole (0.79 ± 0.22 cm2 vs 1.37 ± 0.15 cm2; P < 0.0001 for both). CONCLUSIONS:VCA dynamics are governed by the mechanism of MR and are observed in FMR patients primarily as a biphasic temporal pattern compared with a monophasic temporal pattern in patients with DMVD.

Echocardiographic evaluation of mitral inflow hemodynamics after asymmetric double-orifice repair.

BACKGROUND:A comprehensive transesophageal echocardiographic (TEE) examination is essential for the evaluation of a mitral valve (MV) repair. The edge-to-edge MV repair (i.e., Alfieri stitch) can pose a unique challenge in assessing iatrogenic mitral stenosis, especially when an asymmetric double-orifice is created. The reliability of the simplified Bernoulli equation for evaluating transvalvular pressure gradients across an asymmetric Alfieri MV repair remains controversial. We sought to evaluate the reliability of this principle further by comparing TEE-acquired pressure gradients across each orifice in patients undergoing asymmetric, double-orifice repair. METHODS:Routinely collected intraoperative, 2-dimensional and 3-dimensional TEE datasets acquired from 15 patients undergoing double-orifice MV repair were retrospectively reviewed and analyzed. Planimetered anterior lateral (AL) and posterior medial (PM) orifice areas were acquired from 3-dimensional TEE full volume datasets, by cropping the image to develop a short-axis view at the narrowest diastolic orifice cross-sectional area at the MV leaflet tips. Transmitral Doppler flow velocity values were measured through the AL and PM orifices. Peak and mean pressure gradients were calculated from the simplified Bernoulli equation at both orifices and were compared to each respective orifice for each patient. RESULTS:The mean difference between the AL and PM orifice areas for each patient was statistically significant (0.72 ± 0.40 cm2, P < 0.0001). The mean differences between the AL and PM parameters were also significant for peak velocity: 0.15 m/s, SD: 0.08, P < 0.0001; peak pressure gradients: 1.76 mm Hg, SD: 1.42, P < 0.0001; and mean pressure gradient: 1.04 mm Hg, SD: 0.93, P < 0.0001. CONCLUSIONS:The echocardiographic assessment of MV dysfunction after an Alfieri repair is important. Although the differences that we demonstrated between orifice areas and maximum velocities across the asymmetric orifices after a double-orifice MV repair are statistically significant, the corresponding difference in mean transorifice pressure gradient is not clinically relevant. Thus, either orifice can be interrogated with Doppler echocardiography for the determination of pressure gradients after double-orifice MV repair.

Identifying variability in mental models within and between disciplines caring for the cardiac surgical patient

BACKGROUND: The cardiac operating room is a complex environment requiring efficient and effective communication between multiple disciplines. The objectives of this study were to identify and rank critical time points during the perioperative care of cardiac surgical patients, and to assess variability in responses, as a correlate of a shared mental model, regarding the importance of these time points between and within disciplines. METHODS: Using Delphi technique methodology, panelists from 3 institutions were tasked with developing a list of critical time points, which were subsequently assigned to pause point (PP) categories. Panelists then rated these PPs on a 100-point visual analog scale. Descriptive statistics were expressed as percentages, medians, and interquartile ranges (IQRs). We defined low response variability between panelists as an IQR ⩽ 20, moderate response variability as an IQR > 20 and ⩽ 40, and high response variability as an IQR > 40. RESULTS: Panelists identified a total of 12 PPs. The PPs identified by the highest number of panelists were (1) before surgical incision, (2) before aortic cannulation, (3) before cardiopulmonary bypass (CPB) initiation, (4) before CPB separation, and (5) at time of transfer of care from operating room (OR) to intensive care unit (ICU) staff. There was low variability among panelists’ ratings of the PP “before surgical incision,” moderate response variability for the PPs “before separation from CPB,” “before transfer from OR table to bed,” and “at time of transfer of care from OR to ICU staff,” and high response variability for the remaining 8 PPs. In addition, the perceived importance of each of these PPs varies between disciplines and between institutions. CONCLUSIONS: Cardiac surgical providers recognize distinct critical time points during cardiac surgery. However, there is a high degree of variability within and between disciplines as to the importance of these times, suggesting an absence of a shared mental model among disciplines caring for cardiac surgical patients during the perioperative period. A lack of a shared mental model could be one of the factors contributing to preventable errors in cardiac operating rooms.