Anesthetic Considerations of Organ Procurement After Brain and Cardiac Death: A Narrative Review.

Organ donation procedures have become more frequent in the US as the need for transplants is increasing. Defining the anesthesiologist's role in organ donations after brain and cardiac death is important, as is understanding its ethics and practical physiologic and perioperative implications. Despite this, there are few papers specifically addressing the anesthetic management of organ donors. This review summarizes the preoperative, intraoperative, and postmortem considerations for the anesthesiologist involved in organ donation after either brain or cardiac death. A search of the published literature was performed using PubMed, Excerpta Medica dataBASE (EMBASE), and Google Scholar in March of 2022 for articles addressing anesthetic considerations of organ procurement surgeries after brain and cardiac death. This review demonstrates that anesthesiologists play a significant role in the organ procurement process. Their role in the perioperative management of the donor may affect the outcomes of organ transplantation. The gap between the number of organs harvested and the number of patients awaiting organ transplantation remains high despite continued efforts to increase the number of available organs. Perioperative management of organ donors aims at counteracting the associated unique physiologic derangements and targets optimization of oxygenation of the organs intended for procurement. Optimizing care after death can help ensure the viability of organs and the best outcomes for recipients. As organ donation after cardiac death (DCD) becomes more frequent in the US, anesthesiologists should be aware of the DCD classifications of donors and emerging novel perfusion techniques.

SAP BusinessObjects in Medical Informatics.

Electronic health record (EHR) generates a large amount of data filled with opportunities to enhance documentation compliance, quality improvement, and other metrics. Various software tools exist, but many clinicians are unaware of them. Our institution switched from a hybrid of paper and multiple small EHRs to one all-inclusive EHR system. We faced significant challenges beyond the typical new software deployment phase that affected our departmental regulatory compliance, quality measures, and research initiatives. We aimed to navigate these issues through the use of medical informatics. We used a multidimensional database software analysis tool called SAP BusinessObjects® (SAP SE. Released 2020. SAP BusinessObjects, Version 14.2.8.3671. Waldorf, Germany) to design automated queries for the patient database to generate various reports for our department. As a result, We improved our anesthesia documentation non-compliance from 13-17% of all cases to 4% within months. We have also used this tool to automatically generate various reports such as preoperative beta-blocker administrations, caseloads, case complications, procedure logs, and medication records. Even today many departments rely on manual checks for even the most basic documentation and quality metric compliance, which can be time consuming and costly. Using medical informatics tools is a highly efficient alternative. Fortunately, many software tools exist within most modern EHR packages, and most people can learn to use these tools productively.

Open tracheostomy for COVID-19-positive patients: A method to minimize aerosolization and reduce risk of exposure.

BACKGROUND: The COVID-19 virus is highly contagious, and thus there is a potential of infecting operating staff when operating on these patients. This case series describes a method of performing open tracheostomy for COVID-19 patients while minimizing potential aerosolization of the virus using typically available equipment and supplies. METHODS: This is a case series of 18 patients who were COVID-19-positive and underwent open tracheostomy in the operating room under a negative pressure plastic hood created using readily available equipment and supplies. Patients had to be intubated for at least 14 days, be convalescing from their cytokine storm, and deemed to survive for at least 14 more days. Other indications for tracheostomy were altered mental status, severe deconditioning, respiratory failure and failed extubation attempts. RESULTS: There were 14 men and 4 women with severe SARS-CoV2 infection requiring long-term intubation since March 23 or later. The mean age was 61.7 years, body mass index was 32.6, and the pretracheostomy ventilator day was 20.4 days. The indications for tracheostomy were altered mental status, severe deconditioning and continued respiratory with hypoxia. Failed extubation attempt rate was 16.7% and hemodialysis rate was 38.9%. All patients were hemodynamically stable, without any evidence of accelerating cytokine storm. To date there was one minor bleeding due to postoperative therapeutic anticoagulation. CONCLUSION: This report describes a method of performing open tracheostomy with minimal aerosolization using readily available equipment and supplies in most hospitals. LEVEL OF EVIDENCE: Therapeutic/care management, Level V.

Echocardiography derived three-dimensional printing of normal and abnormal mitral annuli.

AIMS AND OBJECTIVES: The objective of this study was to assess the clinical feasibility of using echocardiographic data to generate three-dimensional models of normal and pathologic mitral valve annuli before and after repair procedures. MATERIALS AND METHODS: High-resolution transesophageal echocardiographic data from five patients was analyzed to delineate and track the mitral annulus (MA) using Tom Tec Image-Arena software. Coordinates representing the annulus were imported into Solidworks software for constructing solid models. These solid models were converted to stereolithographic (STL) file format and three-dimensionally printed by a commercially available Maker Bot Replicator 2 three-dimensional printer. Total time from image acquisition to printing was approximately 30 min. RESULTS: Models created were highly reflective of known geometry, shape and size of normal and pathologic mitral annuli. Post-repair models also closely resembled shapes of the rings they were implanted with. Compared to echocardiographic images of annuli seen on a computer screen, physical models were able to convey clinical information more comprehensively, making them helpful in appreciating pathology, as well as post-repair changes. CONCLUSIONS: Three-dimensional printing of the MA is possible and clinically feasible using routinely obtained echocardiographic images. Given the short turn-around time and the lack of need for additional imaging, a technique we describe here has the potential for rapid integration into clinical practice to assist with surgical education, planning and decision-making.

Impact of three-dimensional echocardiography on classification of the severity of aortic stenosis.

BACKGROUND: Owing to its elliptical shape, the left ventricle outflow tract (LVOT) area is underestimated by two-dimensional (2D) diameter-based calculations which assume a circular shape. This results in overestimation of aortic stenosis (AS) by the continuity equation. In cases of moderate to severe AS, this overestimation can affect intraoperative clinical decision making (expectant management versus replacement). The purpose of this intraoperative study was to compare the aortic valve area calculated by 2D diameter based and three-dimensional (3D) derived LVOT area via transesophageal echocardiography (TEE) and its impact on severity of AS. METHODS: The LVOT area was calculated using intraoperative 2D and 3D TEE data from patients undergoing aortic valve replacement (AVR) and coronary artery bypass graft (CABG) surgery using the 2D diameter (RADIUS), 3D planimetry (PLANE), and 3D biplane (π·x·y) measurement (ELLIPSE) methods. For each method, the LVOT area was used to determine the aortic valve area by the continuity equation and the severity of AS categorized as mild, moderate, or severe. RESULTS: A total of 66 patients completed the study. The RADIUS method (3.5 ± 0.9 cm(2)) underestimated LVOT area by 21% (p < 0.05) compared with the PLANE method (4.1 ± 0.1 cm(2)) and by 18% (p < 0.05) compared with the ELLIPSE method (4.0 ± 0.9 cm(2)). There was no significant difference between the two 3D methods, namely, PLANE and ELLIPSE. Seven AVR patients (18%) and 1 CABG surgery patient (6%) who had originally been classified as severe AS by the 2D method were reclassified as moderate AS by the 3D methods (p < 0.001). CONCLUSIONS: Three-dimensional echocardiography has the potential to impact surgical decision making in cases of moderate to severe AS.

Dynamic 3-dimensional echocardiographic assessment of mitral annular geometry in patients with functional mitral regurgitation.

BACKGROUND: Mitral valve (MV) annular dynamics have been well described in animal models of functional mitral regurgitation (FMR). Despite this, little if any data exist regarding the dynamic MV annular geometry in humans with FMR. In the current study we hypothesized that 3-dimensional (3D) echocardiography, in conjunction with commercially available software, could be used to quantify the dynamic changes in MV annular geometry associated with FMR. METHODS: Intraoperative 3D transesophageal echocardiographic data obtained from 34 patients with FMR and 15 controls undergoing cardiac operations were dynamically analyzed for differences in mitral annular geometry with TomTec 4D MV Assessment 2.0 software (TomTec Imaging Systems GmbH, Munich, Germany). RESULTS: In patients with FMR, the mean mitral annular area (14.6 cm(2) versus 9.6 cm(2)), circumference (14.1 cm versus 11.4 cm), anteroposterior (4.0 cm versus 3.0 cm) and anterolateral-posteromedial (4.3 cm versus 3.6 cm) diameters, tenting volume (6.2 mm(3) versus 3.5 mm(3)) and nonplanarity angle (NPA) (154 degrees ± 15 versus 136 degrees ± 11) were greater at all points during systole compared with controls (p < 0.01). Vertical mitral annular displacement (5.8 mm versus 8.3 mm) was reduced in FMR compared with controls (p < 0.01). CONCLUSIONS: There are significant differences in dynamic mitral annular geometry between patients with FMR and those without. We were able to analyze these changes in a clinically feasible fashion. Ready availability of this information has the potential to aid comprehensive quantification of mitral annular function and possibly assist in both clinical decision making and annuloplasty ring selection.

En face view of the mitral valve: definition and acquisition.

A 3-dimensional echocardiographic view of the mitral valve, called the "en face" or "surgical view," presents a view of the mitral valve similar to that seen by the surgeon from a left atrial perspective. Although the anatomical landmarks of this view are well defined, no comprehensive echocardiographic definition has been presented. After reviewing the literature, we provide a definition of the left atrial and left ventricular en face views of the mitral valve. Techniques used to acquire this view are also discussed.

Echocardiographic anatomy of the mitral valve: a critical appraisal of 2-dimensional imaging protocols with a 3-dimensional perspective.

OBJECTIVE: To highlight the limitations of traditional 2-dimensional (2D) echocardiographic mitral valve (MV) examination methodologies, which do not account for patient-specific transesophageal echocardiographic (TEE) probe adjustments made during an actual clinical perioperative TEE examination. DESIGN: Institutional quality-improvement project. SETTING: Tertiary care hospital. PARTICIPANTS: Attending anesthesiologists certified by the National Board of Echocardiography. INTERVENTION: Using the technique of multiplanar reformatting with 3-dimensional (3D) data, ambiguous 2D images of the MV were generated, which resembled standard midesophageal 2D views. Based on the 3D image, the MV scallops visualized in each 2D image were recognized exactly by the position of the scan plane. Twenty-three such 2D MV images were created in a presentation from the 3D datasets. Anesthesia staff members (n = 13) were invited to view the presentation based on the 2D images only and asked to identify the MV scallops. Their responses were scored as correct or incorrect based on the 3D image. METHODS AND MAIN RESULTS: The overall accuracy was 30.4% in identifying the MV scallops. The transcommissural view was identified correctly >90% of the time. The accuracy of the identification of A1, A3, P1, and P3 scallops was <50%. The accuracy of the identification of A2P2 scallops was ≥50%. CONCLUSION: In the absence of information on TEE probe adjustments performed to acquire a specific MV image, it is possible to misidentify the scallops.

Changes in mitral annular geometry after aortic valve replacement: a three-dimensional transesophageal echocardiographic study.

BACKGROUND AND AIM OF THE STUDY: Intraoperative real-time three-dimensional transesophageal echocardiography (RT-3D TEE) was used to examine the geometric changes that occur in the mitral annulus immediately after aortic valve replacement (AVR). METHODS: A total of 35 patients undergoing elective surgical AVR under cardiopulmonary bypass was enrolled in the study. Intraoperative RT-3D TEE was used prospectively to acquire volumetric echocardiographic datasets immediately before and after AVR. The 3D echocardiographic data were analyzed offline using TomTec Mitral Valve Assessment software to assess changes in specific mitral annular geometric parameters. RESULTS: Datasets were successfully acquired and analyzed for all patients. A significant reduction was noted in the mitral annular area (-16.3%, p < 0.001), circumference (-8.9%, p < 0.001) and the anteroposterior (-6.3%, p = 0.019) and anterolateral-posteromedial (-10.5%, p < 0.001) diameters. A greater reduction was noted in the anterior annulus length compared to the posterior annulus length (10.5% versus 6.2%, p < 0.05) after AVR. No significant change was seen in the non-planarity angle, coaptation depth, and closure line length. During the period of data acquisition before and after AVR, no significant change was noted in the central venous pressure or left ventricular end-diastolic diameter. CONCLUSION: The mitral annulus undergoes significant geometric changes immediately after AVR. Notably, a 16.3% reduction was observed in the mitral annular area. The anterior annulus underwent a greater reduction in length compared to the posterior annulus, which suggested the existence of a mechanical compression by the prosthetic valve.

Mitral annular nonplanarity: correlation between annular height/commissural width ratio and the nonplanarity angle.

OBJECTIVE: To compare two methods of mitral annular nonplanarity: the mathematically calculated annular height-to-commissural width ratio (AHCWR) and the echocardiographically derived nonplanarity angle. DESIGN: Prospective. SETTING: Tertiary care university hospital. INTERVENTIONS: Three-dimensional transesophageal echocardiography. PARTICIPANTS: Patients undergoing mitral valve surgery. MEASUREMENTS AND MAIN RESULTS: Using 3-dimensional transesophageal echocardiography, volumetric datasets were acquired from 22 patients undergoing mitral valve surgery. The intraoperative nonplanarity angle was calculated with Mitral Valve Assessment software (Tomtec GmbH, Munich, Germany). Furthermore, the datasets acquired during 3-dimensional transesophageal echocardiography were exported to Matlab software (MathWorks, Natick, MA), which was used to calculate the AHCWR. The nonplanarity angle was seen to correlate favorably with the AHCWR (r = 0.70). CONCLUSIONS: A favorable correlation was found between the nonplanarity angle and the AHCWR. This suggests that the nonplanarity angle can be used to assess mitral annular nonplanarity in a clinically feasible fashion.

Monitoring the variation in myocardial function with the Doppler-derived myocardial performance index during aortic cross-clamping.

OBJECTIVES: To investigate the effects of acute elevation in afterload on global (systolic and diastolic) myocardial function by performing serial intraoperative transesophageal echocardiograms during and after cross-clamp application on patients undergoing elective abdominal aortic aneurysm (AAA) surgery. DESIGN: A prospective observational study. SETTING: A tertiary care university hospital. PARTICIPANTS: Patients undergoing elective AAA repair under general anesthesia (GA). INTERVENTION: The use of perioperative transesophageal echocardiography to calculate a tissue Doppler-derived myocardial performance index (MPI) during different stages of the surgery. MEASUREMENT AND RESULTS: Twenty consecutive patients scheduled for suprarenal AAA repair under GA were included in the study. Perioperative transesophageal echocardiography was performed after the induction of GA. MPI was calculated with Doppler tissue imaging as the sum of isovolumetric contraction and relaxation times divided by the ejection time before cross-clamping of the aorta and then 2, 10, and 20 minutes after cross-clamp application. A final MPI was measured after unclamping of the aorta. As compared with baseline, cross-clamp application initially worsened MPI within 2 minutes and then MPI improved to baseline after 10 minutes of cross-clamp application. The MPI improved significantly after unclamping of the aorta. CONCLUSIONS: The authors observed a temporal variation in global myocardial function after the application of a cross-clamp in the suprarenal position. There was transient deterioration of global myocardial function (the prolongation of MPI) 2 minutes after cross-clamp application, which improved within 10 minutes. Myocardial function returned to baseline after unclamping the aorta.

Anterior myocardial infarction with dynamic left ventricular outflow tract obstruction.

We present the case of a 78-year-old woman who presented with acute anterior myocardial infraction. An intraoperative transesophageal echocardiogram revealed an akinetic apex with hyperkinesis of the basal segments causing systolic anterior motion of the mitral valve. The patient was immediately placed on cardiopulmonary bypass. Her postoperative course was uneventful. We present transesophageal and transthoracic echocardiographic videos showing this unique complication and describing the challenge of managing a patient who required opposing therapies.

Influence of low tidal volume ventilation on time to extubation in cardiac surgical patients.

BACKGROUND: Low tidal volumes have been associated with improved outcomes in patients with established acute lung injury. The role of low tidal volume ventilation in patients without lung injury is still unresolved. We hypothesized that such a strategy in patients undergoing elective surgery would reduce ventilator-associated lung injury and that this improvement would lead to a shortened time to extubation METHODS: A single-center randomized controlled trial was undertaken in 149 patients undergoing elective cardiac surgery. Ventilation with 6 versus 10 ml/kg tidal volume was compared. Ventilator settings were applied immediately after anesthesia induction and continued throughout surgery and the subsequent intensive care unit stay. The primary endpoint of the study was time to extubation. Secondary endpoints included the proportion of patients extubated at 6 h and indices of lung mechanics and gas exchange as well as patient clinical outcomes. RESULTS: Median ventilation time was not significantly different in the low tidal volume group; a median (interquartile range) of 450 (264-1,044) min was achieved compared with 643 (417-1,032) min in the control group (P = 0.10). However, a higher proportion of patients in the low tidal volume group was free of any ventilation at 6 h: 37.3% compared with 20.3% in the control group (P = 0.02). In addition, fewer patients in the low tidal volume group required reintubation (1.3 vs. 9.5%; P = 0.03). CONCLUSIONS: Although reduction of tidal volume in mechanically ventilated patients undergoing elective cardiac surgery did not significantly shorten time to extubation, several improvements were observed in secondary outcomes. When these data are combined with a lack of observed complications, a strategy of reduced tidal volume could still be beneficial in this patient population.

Giant saphenous vein graft pseudoaneurysm causing tricuspid valve stenosis.

We present the case of a 72-year-old male who was diagnosed with a saphenous vein graft pseudoaneurysm, detected on routine chest echocardiogram 13 years after undergoing coronary artery bypass graft surgery. Intraoperative transesophageal echocardiography revealed the pseudoaneurysm to be causing functional tricuspid stenosis, which was relieved after surgical excision of the mass.

Utility of a transesophageal echocardiographic simulator as a teaching tool.

OBJECTIVE: This study was designed to test the hypothesis that simulator-based transesophageal echocardiographic training was a more effective method of training anesthesia residents with no prior experience in echocardiography as compared with conventional methods of training (books, articles, and web-based resources). STUDY DESIGN: A prospective randomized study. SETTING: An academic medical center (teaching hospital). PARTICIPANTS: The participants consisted of first-year anesthesia residents. INTERVENTION: The study design was composed of 2 groups: a control group (group 1, conventional group) and a study group (group 2, simulator group). The residents belonging to group 2 (simulator group) received a 90-minute simulator-based teaching session moderated by a faculty experienced in transesophageal echocardiography. Residents belonging to group 1 (conventional group) were asked to review the guidelines of the comprehensive intraoperative transesophageal echocardiographic examination published by the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. They also were encouraged to use other learning resources (eg, textbooks, electronic media, and web-based resources) to understand the underlying concepts of echocardiography. Written pre- and post-test was administered to both groups. MEASUREMENTS AND MAIN RESULTS: The groups were compared for the pretest scores by the nonparametric Mann-Whitney U test. Pre- and post-test scores were compared with a Wilcoxon paired test in the individual groups. The results showed a statistically significant difference between the scores of the 2 groups with better scores in the simulation group in the post-training test. CONCLUSION: The simulator-based teaching model for transesophageal echocardiography is a better method of teaching the basic concepts of transesophageal echocardiography like anatomic correlation, structure identification, and image acquisition.

Changes in mitral valve annular geometry after repair: saddle-shaped versus flat annuloplasty rings.

BACKGROUND: Saddle-shaped annuloplasty rings are being increasingly used during mitral valve (MV) repair to conform the mitral annulus to a more nonplanar shape and possibly reduce leaflet stress. In this study utilizing three-dimensional transesophageal echocardiography we compared the effects of rigid flat rings with those of the saddle rings on the mitral annular geometry. Specifically we measured the changes in nonplanarity angle (NPA) before and after MV repair. METHODS: Geometric analysis on 38 patients undergoing MV repair for myxomatous and ischemic mitral regurgitation with full flat rings (n = 18) and saddle rings (n = 18) were performed. The acquired three-dimensional volumetric data were analyzed utilizing the "Image Arena" software (TomTec GmBH, Munich, Germany). Specifically, the degree of change in the NPA was calculated and compared before and after repair for both types of rings. RESULTS: Both types of annuloplasty rings resulted in significant changes in the geometric structure of the MV after repair. However, saddle rings lead to a decrease in the NPA (7% for ischemic and 8% for myxomatous MV repairs) (ie, made the annulus more nonplanar), whereas flat rings increased the NPA (7.9% for ischemic and 11.8% for myxomatous MV repairs) (ie, made the annulus less nonplanar); p value 0.001 or less. CONCLUSIONS: Implantation of saddle-shaped rings during MV repair surgery is associated with augmentation of the nonplanar shape of the mitral annulus (ie, decreases NPA). This favorable change in the mitral annular geometry could possibly confer a structural advantage to MV repairs with the saddle rings.