Menachem M. Weiner

The Use of Cerebral Oximetry as a Monitor of the Adequacy of Cerebral Perfusion in a Patient Undergoing Shoulder Surgery in the Beach Chair Position

Four cases of ischemic injury have been reported in patients undergoing orthopedic surgery in the upright position. We describe the use of cerebral oximetry as a monitor of the adequacy of cerebral perfusion in a 63‐year‐old woman who underwent arthroscopic rotator cuff surgery in a beach chair under general anesthesia. During positioning, a decrease in blood pressure was accompanied by a decrease in cerebral oxygen saturation (SctO2) and was treated with phenylephrine. When spontaneous ventilation resumed, an increase in end‐tidal carbon dioxide was accompanied by an increase in SctO2. Cerebral oximetry may prove useful as a guide monitor and manage nonsupine patients.

Methylene Blue is Associated With Poor Outcomes in Vasoplegic Shock

OBJECTIVES The purpose of this study was to investigate whether patients who received methylene blue as treatment for vasoplegia during cardiac surgery with cardiopulmonary bypass had decreased morbidity and mortality. DESIGN Retrospective analysis. SETTING Single tertiary care university hospital. PARTICIPANTS Adult patients who suffered from vasoplegia and underwent all types of cardiac surgery with cardiopulmonary bypass at this institution between 2007 and 2008. INTERVENTIONS With IRB approval, the authors reviewed the charts of the identified patients and divided them into 2 groups based on whether they had received methylene blue. Two hundred twenty-six patients were identified who met the inclusion criteria for the study. Fifty-seven of these patients had received methylene blue for vasoplegia. The authors collected data on preoperative and intraoperative variables as well as outcomes. MEASUREMENTS AND MAIN RESULTS The patients who received methylene blue had higher rates of in-hospital mortality, a compilation of morbidities, as well as renal failure and hyperbilirubinemia. A multiple logistic regression model demonstrated that receiving methylene blue was an independent predictor of in-hospital mortality (p value: 0.007, OR 4.26, 95% CI: 1.49-12.12), compilation of morbidities (p value: 0.001, OR 4.80, 95% CI: 1.85-12.43), and hyperbilirubinemia (p value:<0.001, OR 6.58, 95% CI: 2.91-14.89). Using propensity score matching, the association with morbidity was again seen but the association with mortality was not found. CONCLUSIONS The current study identified the use of methylene blue as treatment for vasoplegia to be independently associated with poor outcomes. While further studies are required, a thorough risk-benefit analysis should be applied before using methylene blue and, perhaps, it should be relegated to rescue use and not as first-line therapy.

Methylene Blue: Magic Bullet for Vasoplegia?

Methylene blue (MB) has received much attention in the perioperative and critical care literature because of its ability to antagonize the profound vasodilation seen in distributive (also referred to as vasodilatory or vasoplegic) shock states. This review will discuss the pharmacologic properties of MB and review the critical care, liver transplantation, and cardiac anesthesia literature with respect to the efficacy and safety of MB for the treatment of shock. Although improved blood pressure has consistently been demonstrated with the use of MB in small trials and case reports, better oxygen delivery or decreased mortality with MB use has not been demonstrated. Large randomized controlled trials are still necessary to identify the role of MB in hemodynamic resuscitation of the critically ill.

Comparison of expert and novice performance of a simulated transesophageal echocardiography examination.

Introduction Training in transesophageal echocardiography (TEE) requires a significant commitment of time and resources on behalf of the trainees and the instructors. Training opportunities may be limited in the busy clinical environment. Medical simulation has emerged as a complementary means by which to develop clinical skills. Transesophageal echocardiography simulators have been commercially available for several years, yet their ability to distinguish experts from novices has not been demonstrated. We used a standardized assessment tool to distinguish experts from novices using a commercially available TEE simulator. Methods Anesthesiologists certified in advanced perioperative TEE and anesthesiology resident physicians were recruited into the expert and novice cohorts, respectively. The cohorts were recruited from 2 academic medical centers. The novice cohort received a structured introduction to the basic TEE examination. Both cohorts then proceeded to perform a basic TEE examination involving normal cardiac anatomy, which was evaluated by blinded raters using a standardized assessment tool. Results The expert cohort consistently demonstrated the ability to obtain standard TEE imaging views in less time and more accurately than the novice cohort during the course of a simulated TEE examination. Conclusions A simulated transesophageal examination of normal cardiac anatomy in concert with a standardized assessment tool permits ample discrimination between expert and novice echocardiographers as defined for this investigation. Future research will examine in detail the role echocardiography simulators should play during echocardiography training including assessment of training level.

Relationship among surgical volume, repair quality, and perioperative outcomes for repair of mitral insufficiency in a mitral valve reference center

OBJECTIVE Although it has been demonstrated that the repair rates and quality of the repair of mitral insufficiency are superior in mitral valve reference centers, it has not been studied whether an advantage exists for perioperative morbidity and mortality. We report 1 surgeons evolution over 7 years, specifically considering the changes in perioperative morbidity and mortality. METHODS We performed a retrospective review of 1054 patients who had undergone elective, day-of-surgery-admission mitral valve repair by a single surgeon (D.H.A.) at our institution from April 2005 to June 2012. The outcome variables studied were operative mortality (30-day or in-hospital mortality, if longer), length of stay, low cardiac output state after cardiopulmonary bypass, and major morbidity. RESULTS The overall operative mortality was 0.58%. Of the 1054 patients, 31% developed a low cardiac output state postoperatively and 6.52% experienced at least 1 of the composite morbidity events. Increased aortic crossclamp times were significantly and independently associated with a low cardiac output state, length of stay, and morbidity. When divided by service year, a statistically and clinically significant decrease was found in the aortic crossclamp time, despite an increase in the complexity of cases. The morbidity decreased concurrently with the decreases in crossclamp times. CONCLUSIONS As the number of mitral valve repairs performed each year by a single surgeon at a single institution increased, morbidity, including postoperative heart function and length of stay, decreased. This was demonstrated to occur in large part from a reduction in the aortic crossclamp times, despite an increase in the complexity of the procedures. This further demonstrates the value of reference centers for mitral valve surgery.

Intraoperative echocardiography for patients undergoing lung transplantation.

• Volume 118 • Number 4 www.anesthesia-analgesia.org 725 INDEX CASE A 34-year-old woman with end-stage lung disease secondary to cystic fibrosis is undergoing bilateral lung transplantation. After reperfusion of the left-transplanted lung, transesophageal echocardiography (TEE) assessment reveals a large (45 × 4 mm) echogenic mass arising from the left upper pulmonary vein (PV) extending into the left atrium (LA). Perioperative care of a patient undergoing lung transplantation can be challenging, given the patient’s limited cardiopulmonary reserve, and potential for hemodynamic and respiratory instability. Practice Guidelines from the American Society of Anesthesiologists and Society of Cardiovascular Anesthesiologists recommend TEE in the management of patients undergoing lung transplantation,1 particularly for assessment of hemodynamic instability and evaluation of pulmonary vasculature anastomoses.2,3 This Echo Didactics describes a focused examination for patients undergoing lung transplantation.

Influence of increased left ventricular myocardial mass on early and late mortality after cardiac surgery

BACKGROUND Increased left ventricular mass (LVM) is a well-recognized predictor of cardiovascular morbidity and mortality in epidemiological studies, but its impact on mortality after cardiac surgery is poorly defined. We hypothesized that patients with increased LVM index (LVMI) were more likely to have greater 30 day and 1 yr mortality. METHODS With IRB approval, intraoperative transoesophageal echocardiography images of 844 cardiac surgical patients were reviewed. LVMI was calculated using the American Society of Echocardiography recommended formula. Outcome variables studied were 30 day and 1 yr mortality. RESULTS Mortality within 30 days occurred in 28 patients (3.3%) and within 1 yr in 91 patients (10.8%). An almost linear relationship was found between increasing LVMI and the risk of mortality within 30 days of cardiac surgery. The odds ratio (OR) of dying within 30 days of surgery was 1.15 (95% confidence interval 1.01-1.31) per 20 g m(-2) increase in LVMI. This finding remained statistically significant in multivariate analysis controlling for the effects of age, weight, gender, surgery type, LV function, and functional status [OR=1.36 (1.11-1.66) per 20 g m(-2) increase]. Increased LVMI was not found to be a statistically significant predictor of 1 yr mortality. CONCLUSIONS Increased LVMI, but not LV systolic function as measured by the fractional area of contraction (FAC) was identified as a strong independent predictor of perioperative mortality after adult cardiac surgery. The relationship between LVMI and risk of 30 day mortality was nearly linear. Furthermore, decreased FAC, and not LVMI, was a strong independent predictor of 1 yr mortality.

Neuraxial Anesthesia and Timing of Heparin Administration in Patients Undergoing Surgery for Congenital Heart Disease Using Cardiopulmonary Bypass

OBJECTIVE The goal of this review was to add to the existing literature documenting the safety of performing neuraxial techniques in patients who are subsequently fully heparinized, with particular emphasis on the timing of heparin administration. This will help improve risk estimation and possibly lead to a more widespread use of neuraxial anesthesia in patients undergoing cardiac surgery. DESIGN Retrospective chart review. SETTING Single tertiary-care university hospital. PARTICIPANTS All patients undergoing surgery for congenital heart diseases during a 5-year period. INTERVENTIONS The medical records of all patients undergoing surgery for congenital heart diseases during a 5-year period were reviewed for any complications related to the use of neuraxial anesthesia. Furthermore, the interval from neuraxial anesthesia to heparinization for cardiopulmonary bypass was examined. RESULTS In total, 714 patients were identified who had neuraxial anesthesia administered before full heparinization for cardiopulmonary bypass. No cases of symptomatic spinal or epidural hematomas occurred. Further analysis showed that the interval from neuraxial anesthesia to full heparinization was <1 hour in 466 patients. CONCLUSIONS No complications related to neuraxial anesthesia were found in a series of 714 patients undergoing surgery for congenital heart disease using cardiopulmonary bypass, including 466 patients in whom the interval from neuraxial anesthesia to full heparinization was <1 hour.

Increased Left Ventricular Myocardial Mass Is Associated With Arrhythmias After Cardiac Surgery

OBJECTIVES The purpose of this study was to investigate whether patients with an elevated left ventricular mass index undergoing cardiac surgery were more likely to experience postoperative atrial and ventricular arrhythmias. DESIGN A retrospective analysis. SETTING A single tertiary care university hospital. PARTICIPANTS One thousand consecutive patients undergoing all types of adult cardiac surgery. INTERVENTIONS With institutional review board approval, intraoperative transesophageal echocardiographic images were reviewed by a single reviewer. The left ventricular mass index was calculated using the American Society of Echocardiography-recommended formula. Medical charts were reviewed for the occurrence and type of clinically significant postoperative arrhythmias. MEASUREMENTS AND RESULTS Of the patients who had an elevated left ventricular mass index, 47.6% (225/473) developed clinically significant postoperative arrhythmias compared with 38.3% (142/371) of patients with a normal left ventricular mass index (odds ratio [OR] = 1.46; 95% confidence interval [CI], 1.11-1.93; p = 0.007). In the multivariate analysis, this finding remained statistically significant, controlling for the effects of age, weight, sex, surgery type, left ventricular function, functional status, left atrial dimensions, and a history of atrial fibrillation (OR = 1.40; 95% CI, 1.03-1.90 per 100-g/m(2) increase in the left ventricular mass index). An increased left ventricular mass index was also an independent predictor of the separate or combined occurrence of atrial or ventricular arrhythmias. CONCLUSIONS An elevated left ventricular mass index was a strong independent predictor of clinically significant postoperative atrial and ventricular arrhythmias after adult cardiac surgery. Although prospective validation is required, targeting patients for arrhythmia prophylaxis therapy may be justified in patients with a left ventricular mass index >188 g/m(2).

Case Scenario: Cesarean Section Complicated by Rheumatic Mitral Stenosis

C ARDIAC disease in pregnancy remains an important etiology of maternal and fetal morbidity and mortality. Estimates of the incidence of cardiac disease in pregnant patients in developed countries range from 0.2 to 3%. Although the incidence of rheumatic heart disease (RHD) has decreased in developed countries, it still accounts for most of the cardiac disease–related maternal mortality in developing countries—as well as in immigrants to the United States from these nations. Mitral stenosis is the most commonly acquired valve lesion encountered in pregnant women and is almost invariably caused by RHD. Pregnancy and the peripartum period represent a physiologic burden that may worsen symptoms in even moderate degrees of cardiac disease. Consequently, many women are first diagnosed with cardiac disease during pregnancy. The need to provide labor analgesia or anesthesia for a Cesarean section to a woman with cardiac disease is not infrequent and can be challenging. In this case scenario, we discuss the peripartum management of a patient with severe mitral valve disease.