Achal Dhir

Antifibrinolytics in cardiac surgery

Cardiac surgery exerts a significant strain on the blood bank services and is a model example in which a multi-modal blood-conservation strategy is recommended. Significant bleeding during cardiac surgery, enough to cause re-exploration and/or blood transfusion, increases morbidity and mortality. Hyper-fibrinolysis is one of the important contributors to increased bleeding. This knowledge has led to the use of anti-fibrinolytic agents especially in procedures performed under cardiopulmonary bypass. Nothing has been more controversial in recent times than the aprotinin controversy. Since the withdrawal of aprotinin from the world market, the choice of antifibrinolytic agents has been limited to lysine analogues either tranexamic acid (TA) or epsilon amino caproic acid (EACA). While proponents of aprotinin still argue against its non-availability. Health Canada has approved its use, albeit under very strict regulations. Antifibrinolytic agents are not without side effects and act like double-edged swords, the stronger the anti-fibrinolytic activity, the more serious the side effects. Aprotinin is the strongest in reducing blood loss, blood transfusion, and possibly, return to the operating room after cardiac surgery. EACA is the least effective, while TA is somewhere in between. Additionally, aprotinin has been implicated in increased mortality and maximum side effects. TA has been shown to increase seizure activity, whereas, EACA seems to have the least side effects. Apparently, these agents do not differentiate between pathological and physiological fibrinolysis and prevent all forms of fibrinolysis leading to possible thrombotic side effects. It would seem prudent to select the right agent knowing its risk-benefit profile for a given patient, under the given circumstances.

Anesthesia for Liver Transplantation

Orthotopic liver transplantation is the only definitive treatment for end-stage liver disease. More than 6000 procedures are performed in the United States annually with excellent survival rates. The shortage of donor organs leads to continued interest in techniques to enlarge the potential donor pool. Patients presenting for liver transplant suffer from important cardiovascular, respiratory, renal, neurological, and gastroenterological comorbidity. In the Western world, liver failure is increasingly caused by steatohepatitis, and transplant candidates are thus becoming older and more comorbid. The role of the transplant anesthesiologist is highly important in the preoperative assessment, intraoperative management, and postoperative care of these complex and sick patients. Appropriate investigation and management of comorbidities such as coronary artery disease and portopulmonary hypertension is controversial and differs between programs. The transplant procedure is a major surgery, and although massive transfusion is no longer commonplace, there is potential for significant hemodynamic instability, coagulopathy, and metabolic disturbance. Liver transplant surgery can be divided into the preanhepatic phase, the anhepatic phase, and the reperfusion phase, with important anesthetic considerations at each point.  An understanding of the surgical techniques used for vascular exclusion of the liver and the role of venovenous bypass is crucial for the anesthesiologist. Recent trends in perioperative care include the use of antifibrinolytic drugs and point-of-care coagulation tests, intraoperative renal replacement therapy, and “fast-track” extubation and postoperative care. Care of patients with fulminant hepatic failure or those receiving split-liver grafts requires special consideration.

Case report: Retroperitoneoscopic pheochromocytoma removal in an adult with Eisenmenger’s syndrome

Purpose: Patients with uncorrected or palliated, complex congenital heart lesions requiring surgery can benefit from laparoscopic techniques, but retroperitoneal insufflation may render them hemodynamically unstable. Alterations in cardiopulmonary physiology during retroperitoneal insufflation have been studied, yet there are no cases detailing this approach in patients with congenital heart lesions. We present a case of a pheochromocytoma removal via retroperitoneoscopy in a patient with a palliated, complex heart lesion.Clinical features: A 28-yr-old woman was admitted for removal of a pheochromocytoma through retroperitoneoscopy. The main feature of her heart disease was a complete atrioventricular canal defect. She eventually developed Eisenmenger’s syndrome and became chronically cyanotic. Retroperitoneal insufflation with CO2 gas did not change hemodynamic variables. Significant increases in peak airway pressures were encountered, possibly due to the distending effects of insufflation, or due to increasing the minute ventilation to reduce exogenous CO2. Arterial CO2 remained stable, but a significant increase between end-tidal and arterial levels became apparent with insufflation. Tumour manipulation led to systemic (and possibly pulmonary) hypertension, which exacerbated ventricular dysfunction. This condition resulted in atrioventricular valve regurgitation, as seen on transesophageal echocardiography, and diminished pulmonary blood flow with subsequent desaturation. These changes resolved with antihypertensive medications. The patient’s trachea was extubated four hours postoperatively, and she recovered uneventfully.Conclusion: Patients with altered cardiopulmonary physiology may tolerate retroperitoneoscopic insufflation with relative hemodynamic stability. Appropriate use of short-acting, vasoactive drugs and aggressive monitoring of PaCO2 and hemodynamic variables is required.RésuméObjectif: Les patients ayant des lésions cardiaques congénitales complexes non corrigées ou palliées nécessitant une chirurgie peuvent profiter de techniques laparoscopiques; toutefois, un rétropneumopéritoine peut rendre leur hémodynamie instable. Les modifications de la physiologie cardiopulmonaire pendant un rétropneumopéritoine ont été étudiées, mais il n’existe aucun cas décrivant cette approche chez des patients souffrant d’anomalies cardiaques congénitales. Nous présentons un cas d’ablation de phéochromocytome par rétropéritonéoscopie chez un patient ayant une anomalie cardiaque congénitale complexe palliée.Éléments cliniques: Une femme de 28 ans a été admise pour une ablation de phéochromocytome par rétropéritonéoscopie. Une déficience totale de son canal atrio-ventriculaire constituait l’élément principal de sa maladie cardiaque. Elle a finalement développé un syndrome d’Eisenmenger et est devenue chroniquement cyanotique. Un rétropneumopéritoine avec du gaz CO2 n’a pas modifié les variables hémodynamiques. Des augmentations significatives dans les pics de pression ventilatoire ont été observées, possiblement provoquées par les effets distensifs de l’insufflation ou par l’augmentation de la ventilation minute pour réduire le CO2 exogène. Le CO2 artériel est resté stable, mais une augmentation significative entre les niveaux télé-expiratoire et artériel est apparue lors de l’insufflation. La manipulation tumorale a provoqué une hypertension systémique (et possiblement pulmonaire), ce qui a exacerbé la dysfonction ventriculaire. La conséquence de cette condition a été une régurgitation des valves atrio-ventriculaires, telle qu’observées par échocardiographie transoesophagienne, et un débit sanguin pulmonaire réduit avec une désaturation subséquente. Ces modifications ont pu être contrées avec des médicaments anti-hypertenseurs. La trachée de la patiente a été extubée quatre heures après l’opération, et elle s’est rétablie normalement.Conclusion: Les patients présentant une physiologie cardiopulmonaire altérée pourraient tolérer un rétropneumopéritoine et maintenir une hémodynamie relativement stable. L’utilisation adéquate de médicaments vasoactifs à action courte et une surveillance agressive de la PaCO2 et des variables hémodynamiques sont nécessaires.

Giant Cystic Pheochromocytoma Containing High Concentrations of Catecholamines and Metanephrines

A 27-yr-old woman, known with neurofibromatosis type 1 and generalized anxiety disorder, presented with headaches, episodic palpitations, and pallor. Atenolol, started for hypertension by her family doctor, triggered a hypertensive crisis (226/126 mm Hg). Twentyfour-hour urine analysis demonstrated elevated excretion of metanephrine [65.7 ( 1.52; upper limit of reference range) mol/d] and normetanephrine [59.27 ( 1.95) mol/d], and to a lesser extent norepinephrine [2806 ( 569) nmol/d] and epinephrine [1222 ( 149) nmol/d]. Abdominal computed tomography (CT) scan showed a large solid and cystic lesion involving the right adrenal gland (Fig. 1A). 131-I methyliodobenzylguanidine scan showed a right adrenal tumor with prominent peripheral uptake and large central defect (Fig. 1B). After medical preparation with 3 wk of phenoxybenzamine (up to 90 mg/d), propranolol, and preoperative saline loading, the patient appeared clinically adequately blocked. However, anesthetic induction (fentanyl, propofol, lidocaine, and rocuronium) caused a hypertensive crisis (280/170 mm Hg) and prevented surgery. Phenoxybenzamine dosage was increased to 60 mg three times a day, and nifedipine SR 30 mg was added. Intravenous phenylephrine (1 mg) did not affect intraarterial blood pressure, indicating adequate -blockade. The next day, during open adrenalectomy, brittle blood pressure was noted until completion of tumor dissection. A sample of the liquefied tumor center was obtained (Fig. 2). Compared with plasma reference values (1), the cystic fluid contained extremely high concentrations of norepinephrine [65,967 ( 3.4) nmol/liter], epinephrine [51,000 ( 0.8) nmol/liter], dopamine [791.5 ( 0.21) nmol/liter], metanephrine [1,150 ( 0.3) nmol/liter], and normeta-

Aortic dissection: To be or not to be?

Patients with acute aortic dissection present with such varied symptoms that diagnosis becomes difficult. Various imaging techniques like computed tomography angiography (CTA), magnetic resonance imaging and ultrasonography are used to diagnose this entity, but they too have their limitations. We present a case, which was falsely diagnosed as acute aortic dissection by CTA, which resulted in patient undergoing sternotomy.

Anemia and Patient Blood Management in Cardiac Surgery—Literature Review and Current Evidence

The prevalence of anemia is high in patients undergoing cardiac surgery. There is enough evidence that the presence of anemia increases perioperative mortality and morbidity both in noncardiac and cardiac surgery. Anemia is an independent risk factor for increased blood transfusion, length of stay, morbidity, and poor outcomes. It is prudent to delay elective surgery to enhance erythropoiesis preoperatively. There is a synergistic interaction between anemia and blood transfusion in cardiac surgery resulting in worse outcomes that are greater than simply the additive effects of both conditions. Although blood transfusions save lives, the indiscriminate use of transfusions is without any strong supporting evidence. The current literature is not clear on the benefits of a restrictive transfusion strategy during adult cardiac surgery. Observational studies and/or trials in noncardiac surgery should not be used as guidelines to make transfusion decisions for patients undergoing cardiac surgery. Guidelines for cardiac surgery patients should be developed only from the trials performed within this population. One’s decision to transfuse should not be based solely on a single hemoglobin level. Because of the risks

Anesthesia for Cardiac Ablation

As the complexity and duration of cardiac ablation procedures increase, there is a growing demand for anesthesiologist involvement in the electrophysiology suites for sedation and anesthesia provision, hemodynamic and neuromonitoring, and procedural guidance through transesophageal echocardiography. To deliver high-quality perioperative care, it is important that the anesthesiologist is intimately familiar with the evolving techniques and technologies, the anesthetic options and ventilation strategies, and the anticipated postprocedural complications.

Cardiac Arrest After the Removal of a Central Venous Catheter

1. Leyvi G, Bello R, Wasnick J, et al: Assessment of cerebral oxygen balance during deep hypothermic circulatory arrest by continuous jugular bulb venous saturation and near-infrared spectroscopy. J Cardiothorac Vasc Anesth 20:826-833, 2006 2. Baraka A, Naufal M, El-Khatib M: Correlation between cerebral and mixed venous oxygen saturation during moderate versus tepid hypothermic hemodiluted cardiopulmonary bypass. J Cardiothorac Vasc Anesth 20:819-825, 2006 3. Nawfal M, El-Khatib MF, Taha S, et al: Effect of alpha-stat versus pH-stat strategies on cerebral oximetry during moderate hypothermic cardiopulmonary bypass. Eur J Anaesth 7:1-5, 2006 4. Laussen P: Optimal blood gas management during deep hypothermic paediatric cardiac surgery: Alpha-stat is easy, but pH-stat may be preferable. Paediatr Anaesth 12:199-204, 2002