Nicholas W. Markin

The Safety of Transesophageal Echocardiography in Patients Undergoing Orthotopic Liver Transplantation

OBJECTIVE To evaluate the safety of transesophageal echocardiography for the evaluation and intraoperative monitoring of patients during orthotopic liver transplantation. DESIGN Retrospective observational study. SETTING Tertiary care, university teaching hospital. PARTICIPANTS Patients (n = 116) who underwent intraoperative transesophageal echocardiography during liver transplantation. INTERVENTIONS Intraoperative transesophageal echocardiography during liver transplantation. MEASUREMENTS AND MAIN RESULTS The authors evaluated the safety of intraoperative transesophageal echocardiography in patients undergoing liver transplantation through a retrospective chart review. Complications associated with transesophageal echocardiography use were divided into minor and major complications. Out of 116 patients who underwent intraoperative transesophageal echocardiography, there was one minor and one major complication. The major complication rate was 0.86% (1/116) and the overall complication rate was 1.7% (2/116). There was no statistically significant correlation between pre-transplant sclerotherapy for treatment of varices and intraoperative transesophageal echocardiography-related gastrointestinal bleeding. Although the reported complication rate is higher than what has been quoted in the cardiac literature, intraoperative transesophageal echocardiography during liver transplantation has a low complication rate. CONCLUSIONS Intraoperative transesophageal echocardiography is a relatively safe method of monitoring cardiac performance in liver transplant patients.

Transesophageal Speckle-Tracking Echocardiography Improves Right Ventricular Systolic Function Assessment in the Perioperative Setting

Background: Perioperative evaluation of right ventricular (RV) systolic function is important to follow intraoperative changes, but it is often not possible to assess with transthoracic echocardiographic (TTE) imaging, because of surgical field constraints. Echocardiographic RV quantification is most commonly performed using tricuspid annular plane systolic excursion (TAPSE), but it is not clear whether this method works with transesophageal echocardiographic (TEE) imaging. This study was performed to evaluate the relationship between TTE and TEE TAPSE distances measured with M‐mode imaging and in comparison with speckle‐tracking TTE and TEE measurements. Methods: Prospective observational TTE and TEE imaging was performed during elective cardiac surgical procedures in 100 subjects. Speckle‐tracking echocardiographic TAPSE distances were determined and compared with the TTE M‐mode TAPSE standard. Both an experienced and an inexperienced user of the speckle‐tracking echocardiographic software evaluated the images, to enable interobserver assessment in 84 subjects. Results: The comparison between TTE M‐mode TAPSE and TEE M‐mode TAPSE demonstrated significant variability, with a Spearman correlation of 0.5 and a mean variance in measurement of 6.5 mm. There was equivalence within data pairs and correlations between TTE M‐mode TAPSE and both speckle‐tracking TTE and speckle‐tracking TEE TAPSE, with Spearman correlations of 0.65 and 0.65, respectively. The average variance in measurement was 0.6 mm for speckle‐tracking TTE TAPSE and 1.5 mm for speckle‐tracking TEE TAPSE. Conclusions: Using TTE M‐mode TAPSE as a control, TEE M‐mode TAPSE results are not accurate and should not be used clinically to evaluate RV systolic function. The relationship between speckle‐tracking echocardiographic TAPSE and TTE M‐mode TAPSE suggests that in the perioperative setting, speckle‐tracking TEE TAPSE might be used to quantitatively evaluate RV systolic function in the absence of TTE imaging. HighlightsTTE M‐mode TAPSE and TEE M‐mode TAPSE do not agree, and TEE M‐mode TAPSE should not be used to quantify RV systolic function.Speckle‐tracking echocardiography allows accurate TAPSE measurements for TTE and TEE imaging compared with TTE M‐mode TAPSE.Speckle‐tracking TEE TAPSE could be used to quantify RV systolic function in the perioperative setting when standard TTE methods are not possible.

The use of virtual training to support insertion of advanced technology at remote military locations.

Effective training in advanced medical technologies is essential for military healthcare providers to support the far forward battlefield. The use of modern video communication technologies and novel medical devices can be utilized for meeting this challenge. This study demonstrates the combined use of video conferencing equipment and videolaryngoscopy in the virtual training of a novice in videolaryngoscopy, nasal intubation and airway foreign body removal.

Paradoxical air embolus during endoscopic retrograde cholangiopancreatography: an uncommon fatal complication.

Air embolism during endoscopic retrograde cholangiopancreatography is a rare but potentially fatal complication. A 66-year-old man underwent endoscopic retrograde cholangiopancreatography and remained stable until the end of the procedure, when he was found to have mottling on his right side and became hypoxic and unresponsive. Transesophageal echocardiography showed air within the left ventricle, consistent with systemic air embolism. Mortality resulted from significant cardiac and cerebral ischemia. The literature suggests that capnography is helpful in early diagnosis of air embolus, but it could not be used in this case because the patients trachea was not intubated.

Intraoperative transesophageal echocardiography diagnosis of rare source of right ventricular failure after heart transplant.

A 44-year-old male born with d-transposition of the great arteries underwent a Mustard atrial switch procedure after birth (Fig. 1) and eventually developed failure of the morphologic right ventricle (RV). He was admitted for New York Heart Association Class IV heart failure symptoms requiring continuous inotropic therapy and an intraaortic balloon pump to reduce the work of his systemic ventricle, the RV. Heart transplantation was performed, restoring the patient to normal anatomy. Failure of the allograft RV was diagnosed on postoperative day 1 using transthoracic echocardiography (Video 1A and B, see Supplemental Digital Content 1, http://links.lww.com/ AA/A406). No improvement was subsequently seen and he was scheduled for RV assist device (RVAD) placement on postoperative day 10. General anesthesia was induced and transesophageal echocardiography (TEE) was performed showing a dilated RV with depressed systolic function (Video 2A, see Supplemental Digital Content 2, http://links.lww.com/AA/A407). A narrowing of the pulmonary artery (PA) anastomosis, diameter of 1.14 cm, was seen approximately 2.5 cm above the pulmonic valve (Fig. 2A) (Video 2B, http://links.lww. com/AA/A407). Evaluation with 2-dimensional (2D) and color-flow Doppler (CFD) of the anastomosis was performed and showed flow acceleration at the anastomosis and turbulence distal to the narrowed region (Video 2C, http://links.lww.com/AA/A407). Continuous-wave Doppler showed a maximum velocity of 343 cm/second across this narrowing, representing a peak gradient of 47 mm Hg (Fig. 3A). This anastomosis was revised during cardiopulmonary bypass (CPB) secondary to these findings and as planned, a Thoratec PVAD (Thoratec Corporation, Pleasanton, CA) pulsatile ventricular assist device (VAD) for the RV was implanted. Post-CPB imaging showed improved PA internal diameter and decreased peak gradient to 12 mm Hg with the RVAD flow paused (Fig. 3B). The pulsatile RVAD was used until RV function improved and removal of the device occurred 17 days later. DISCUSSION This patient underwent the Mustard procedure for correction of d-transposition of the great arteries, which directs systemic venous blood through the left atrium, left ventricle, and into the PA and directs pulmonary venous blood through the right atrium, the morphologic RV and into the aorta (Fig. 1B). Over time, the Mustard procedure can lead to dysfunction of the morphologic RV because it lacks sufficient contractile reserve and atrioventricular valve function to generate systemic pressures long-term. For many individuals with either congenital or acquired forms of heart disease that result in decreased cardiac function, cardiac transplantation is the final treatment option for those who cannot recover with other therapies. RV failure continues to have significant morbidity for patients undergoing cardiac transplantation, especially those with high pulmonary vascular resistance preoperatively. RV failure after transplantation has been caused by preexisting pulmonary hypertension, poor RV myocardial protection, air embolism, or rare anatomic/anastomotic complications. Such causes of postoperative RV dysfunction secondary to outflow tract obstruction have been reported after anastomotic stricture after lung transplantation and kinking of the PA after heart transplantation. Pretransplant heart catheterization on our patient demonstrated PA pressures of 40/25 mm Hg (mean 35 mm Hg) and pulmonary vascular resistance of 2.56 Woods units, which was appropriate to attempt cardiac transplantation. Postoperative treatment with a VAD has been used after heart transplantation and for individuals with heart failure after acute myocardial infarction. VAD therapy allows recovery of ventricular function over time and eventual removal of the device, as it occurred in this patient. Examination after the RVAD was paused demonstrated improved RV function and normal tricuspid annulus plane systolic excursion before RVAD extraction on posttransplant day 27. Regarding the intraoperative findings, a normal diameter of the PA at the level of the stricture is 1.5 to 2.1 cm and normal flow through the PA and pulmonic valve should be 100 cm/second. Because the diameter of stricture on 2D imaging was 1.14 cm, it was a smaller than expected diameter for the PA. A focused evaluation using 2D echo in 2 orthogonal planes, midesophageal ascending aorta shortaxis view and midesophageal ascending aorta long-axis view, was important for confirmation that a stenotic area was present and not artifact. Manipulation of the TEE probe depth in these 2 views allowed visualization of the PA in long-axis and short-axis, respectively, though visualization of the PA with these views is not always available. The use of CFD to demonstrate flow acceleration at the From the Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE.

Transesophageal Echocardiogram-Guided Stent Placement in Superior Vena Cava Syndrome Secondary to Granulomatous Lung Disease: A Case Series and Literature Review

Obstruction of the superior vena cava (SVC) is an uncommon, but potentially life-threatening condition due to likely development of edema in the head and neck and potential respiratory compromise. Less than half of those affected by SVC syndrome survive more than a year. Obstruction can be from neoplasms or secondary to benign disease. Treatment for most cases of symptomatic SVC syndrome involves placement of a stent to relieve the stenosis. Serious complications such as stent migration, pulmonary embolism, and cardiac tamponade can occur in 5% to 10% of cases, and inadequate imaging of the SVC–atrial junction by fluoroscopy contributes to these problems. The overlapping contrast in the atrium makes it difficult to precisely place the distal end of the stent, potentially allowing for embolization of the stent to occur. We present a case series of 3 patients wherein transesophageal echocardiography was used for guidance of stent placement in the SVC and significantly aided in placement.

Heart Failure With Preserved Ejection Fraction: A Perioperative Review

HEART FAILURE (HF) with preserved ejection fraction (HFpEF) presents significant challenges for anesthesiologists. Nearly 50% of patients presenting with HF have HFpEF, defined as having clinical HF with a left ventricular ejection fraction (LVEF) 450% and abnormal left ventricular diastolic dysfunction (LVDD). Even though HFpEF is a strong predictor of negative postoperative outcomes, it often is difficult to diagnose and the management strategies are unclear. Although there have been specific articles published with regard to the echocardiography descriptors, diagnosis, and relationship of LVDD with HF, the authors believed it was timely to present a review article for clinicians on the subject of perioperative HFpEF. This article reviews what is known about the pathogenesis, diagnosis, management options, and implications of HFpEF in the perioperative arena.

The Implementation of a Preoperative Transthoracic Echocardiography Consult Service by Anesthesiologists

We describe a preoperative transthoracic echocardiography consult service led by anesthesiologists. The implementation process and the patient cohort are described. Preoperative transthoracic echocardiographic examinations were mostly performed in patients undergoing intermediate- or high-risk noncardiac surgery and in patients with a higher calculated mortality risk. All transthoracic echocardiographic examinations were interpreted by anesthesiologists.

Virtual intubation training at a remote military site

To provide medical support to the far forward battlefield, training in advanced medical technologies is essential for military healthcare providers. To meet this challenge, the use of modern video communication technologies and novel medical devices can be implemented. This study demonstrates the combined use of modern video conferencing technology and video laryngoscopy equipment in the virtual laryngoscopy training of deployed military medical personnel.