J. Mauricio Del Rio

Nitro-oleic Acid, a Novel and Irreversible Inhibitor of Xanthine Oxidoreductase

Xanthine oxidoreductase (XOR) generates proinflammatory oxidants and secondary nitrating species, with inhibition of XOR proving beneficial in a variety of disorders. Electrophilic nitrated fatty acid derivatives, such as nitro-oleic acid (OA-NO2), display anti-inflammatory effects with pleiotropic properties. Nitro-oleic acid inhibits XOR activity in a concentration-dependent manner with an IC50 of 0.6 μm, limiting both purine oxidation and formation of superoxide \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \((\mathrm{O}_{2}^{{\bar{{\cdot}}}})\) \end{document}. Enzyme inhibition by OA-NO2 is not reversed by thiol reagents, including glutathione, β-mercaptoethanol, and dithiothreitol. Structure-function studies indicate that the carboxylic acid moiety, nitration at the 9 or 10 olefinic carbon, and unsaturation is required for XOR inhibition. Enzyme turnover and competitive reactivation studies reveal inhibition of electron transfer reactions at the molybdenum cofactor accounts for OA-NO2-induced inhibition. Importantly, OA-NO2 more potently inhibits cell-associated XOR-dependent \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{{\bar{{\cdot}}}}\) \end{document} production than does allopurinol. Combined, these data establish a novel role for OA-NO2 in the inhibition of XOR-derived oxidant formation.

Multinational Institutional Survey on Patterns of Intraoperative Transesophageal Echocardiography Use in Adult Cardiac Surgery

OBJECTIVES To assess institutional patterns of perioperative transesophageal echocardiography (TEE) usage. DESIGN The authors hypothesized that TEE is performed more frequently and comprehensively in academic centers, mainly by anesthesiologists, and barriers to performing TEE are due to inadequate resources. A survey was deployed to selected participants. Collated responses were assessed for demographic patterns in TEE practice, and 2-category comparisons were made with Chi-squared association tests. SETTING Web-based survey. PARTICIPANTS Practitioners in cardiovascular anesthesia/surgery in 200 institutions. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Surveys were completed by respondents representing 200 centers in 27 countries and 1,727 anesthesiologists with a mean annual institutional volume of 924 cases. Most centers were in the USA (53%) and were defined as academic (83%). Anesthesiologists performed (85%) and also read/reported TEEs (78%) in most centers. Three-dimensional TEE is performed routinely at 40% of centers. TEE is used routinely for valve surgery in 95% of institutions compared to 68% for coronary artery bypass graft surgery. Academic institutions assessed diastolic function more often than nonacademic centers (46% v 19%; p = 0.006). The most important reason cited for not using TEE in all cases was insufficient resource availability (47%). CONCLUSIONS These results suggest that TEE is performed more comprehensively in academic centers, mainly by anesthesiologists, and that lack of resources is a significant barrier to routine TEE usage. TEE is used more often for valve surgery than for coronary artery bypass graft surgery, and many centers use 3D TEE. This survey describes international TEE practice patterns and identifies limitations to universal adoption of TEE in cardiac surgery.

Long-term outcomes and management of the heart transplant recipient

Cardiac transplantation remains the gold standard in the treatment of advanced heart failure. With advances in immunosuppression, long-term outcomes continue to improve despite older and higher risk recipients. The median survival of the adult after heart transplantation is currently 10.7 years. While early graft failure and multiorgan system dysfunction are the most important causes of early mortality, malignancy, rejection, infection, and cardiac allograft vasculopathy contribute to late mortality. Chronic renal dysfunction is common after heart transplantation and occurs in up to 68% of patients by year 10, with 6.2% of patients requiring dialysis and 3.7% undergoing renal transplant. Functional outcomes after heart transplantation remain an area for improvement, with only 26% of patients working at 1-year post-transplantation, and are likely related to the high incidence of depression after cardiac transplantation. Areas of future research include understanding and managing primary graft dysfunction and reducing immunosuppression-related complications.

Pulmonary Dysfunction After Lung Transplantation: The Dilemma of Coexisting Mitral Regurgitation

A case of MR progression after single-lung transplant as a significant contributor to postoperative respiratory failure is reported. Pre-existing MR may progress due to the decompressive effects of lung transplantation on RV dimension and consequent alteration of MV geometry. This case highlights the importance of intraoperative TEE findings, especially pertaining to valvulopathies in the setting of lung transplantation. Postoperative surveillance of significant findings is imperative when any new symptoms are being investigated.

CASE 8—2015Paravertebral Catheter-Based Strategy for Primary Analgesia After Minimally Invasive Cardiac Surgery

ORT-ACCESS MINIMALLY INVASIVE cardiac surgery (PACS) has potential advantages when compared with traditional sternotomy techniques. These include smaller surgical incision, reduced trauma and blood loss, and shorter length of hospital stay. 1,2 Typically, PACS procedures are performed through a right anterior minithoracotomy or hemisternotomy, and postoperative pain commonly is managed primarily using intravenous analgesics, usually with an on-demand opioid or opioid-based patient-controlled analgesia (PCA). When an opioid is chosen as the primary strategy, particularly an intravenous PCA, benefits include ease of use, availability, and improved patient satisfaction, compared with on-demand pain treatment. Common adverse effects to opioidbased strategies include respiratory depression, delirium, and gastrointestinal dysfunction, which substantially can inhibit postoperative recovery and potentially cause harm to the aging and comorbid population that represents many cardiac surgery patients. In addition, minithoracotomy incisions used during PACS procedures also involve an increased risk of chronic pain, which is not prevented or reduced by an opioid-only strategy. 2–4 Analgesic strategies that reduce opioid consumption and improve long-term outcome after PACS, including regional or neuraxial anesthetic techniques, are desirable to reduce this complication and improve outcomes from PACS procedures. For thoracic surgery patients, regional analgesia delivered through thoracic paravertebral (PV) or epidural catheters provides high-quality analgesia for post-thoracotomy pain and is associated with reduced overall complication rates relative to parenteral opioids. 5–14 Published studies indicate that thoracic PV and epidural-based analgesia delivery of continuous local anesthetic infusions are approximately of equal value for pain control, but PV catheters are associated with fewer side effects, including hypotension. 15–17 The advantages of regional techniques involving the neuraxis always must be contrasted against their associated risk of epidural hematoma, particularly related to anticoagulation used during cardiopulmonary bypass (CPB). To avoid the risk of epidural hematoma, an alternate approach to neuraxial regional analgesia includes PV catheter placement. Although the usefulness of PV catheters have been confirmed for post-lung resection thoracotomy analgesia, their value for PACS patients is unclear. Here, the clinical course of 3 cardiac surgery patients undergoing PACS with PV catheters inserted for primary analgesia is described. These examples are reviewed in the context of existing literature and also serve to highlight the challenges of postoperative analgesia for PACS patients.

Noteworthy Literature Published in 2017 for Thoracic Transplantation Anesthesiologists

Thoracic organ transplantation constitutes a significant proportion of all transplant procedures. Thoracic solid organ transplantation continues to be a burgeoning field of research. This article presents a review of remarkable literature published in 2017 regarding perioperative issues pertinent to the thoracic transplant anesthesiologists.

Right Ventricular Function in Left Heart Disease: Relevance to the Mitral Valve

Right ventricular (RV) function is an independent prognostic factor for short- and long-term outcomes in cardiac surgical patients. Patients with mitral valve (MV) disease are at increased risk of RV dysfunction before and after MV operations. Yet RV function is not part of criteria for decision making or risk stratification in this setting. The role of MV disease in the development of pulmonary hypertension (PHTN) and the ultimate impact of PHTN on RV function have been well described. Nonetheless, there are other mechanisms by which MV disease and MV surgery affect RV performance. Research suggests that PHTN may not be the most important determinant of RV dysfunction. Both RV dysfunction and PHTN have independent prognostic significance. This review explores the unique anatomic and functional features of the RV and the pathophysiologic and prognostic implications of RV dysfunction in patients with MV disease in the perioperative period.

Postoperative Critical Care of Lung Transplant Patients

Lung transplantation is the treatment of choice for patients with end-stage lung disease. Such interventions have had a more widespread use due to advances in the understanding of the pathophysiology of this patient population and the immunologic mechanisms involved with rejection and immunosuppressive therapy. There have also been substantial surgical technical advancements as well as development of new pharmacologic agents during the last 30 years. Due to such improvements, lung transplant recipients have now a better survival rate. The role of the multidisciplinary critical care team is paramount in the successful implementation of lung transplantation and in preventing and minimizing morbidity and mortality in this highly complex patient population. In particular, it is important for the critical care professional to have a comprehensive knowledge of the unique complications and issues present in multiple organ systems that can affect the lung transplant recipient patient during the immediate postoperative period.

Multimodal Evaluation of Aortic Regurgitation After Mitral and Tricuspid Valve Repairs.

August 2015 • Volume 121 • Number 2 www.anesthesia-analgesia.org 319 A 66-year-old man underwent mitral valve (MV) repair (annuloplasty and single neochord placement), tricuspid valve (TV) ring annuloplasty, and a modified Cox-maze procedure through a minimally invasive right thoracotomy approach. Preprocedural intraoperative transesophageal echocardiography (TEE) revealed severe mitral regurgitation with flail P2 segment and moderate tricuspid regurgitation with annular dilation. There was mild central aortic regurgitation (AR) graded by vena contracta (VC) measurement. After uneventful surgical repair and separation from cardiopulmonary bypass (CPB), TEE showed no evidence of stenosis or significant regurgitation in the repaired MV or TV. However, there was a second AR jet in addition to the previous central regurgitation. By 2-dimensional color-flow Doppler, the new AR jet was at or near the noncoronary cusp (NCC) and left coronary cusp commissure (Fig. 1; Supplemental Digital Content, Video 1, http://links. lww.com/AA/B122). Analysis of 3-dimensional (3D) full-volume and 3D color full-volume data sets revealed a possible NCC perforation (Fig. 2; Supplemental Digital Content, Video 2, http://links.lww.com/AA/B123). The AR was graded as moderate by the pressure half-time (PHT) method (PHT = 470 milliseconds) using continuouswave Doppler of the central AR jet in the deep transgastric view. The risks and benefits of surgical AR correction were weighed: repair or replacement may have required a partial or full sternotomy for surgical access and CPB reinitiation. The team elected for conservative management with close follow-up. The patient was tracheally extubated on the day of surgery and discharged home on postoperative day 6. Transthoracic echocardiography at 3-month follow-up revealed trace mitral regurgitation, trace tricuspid regurgitation, and moderate-to-severe AR (PHT 475 milliseconds).