A. Koster, C. Diehl, A. Dongas, T. Meyer-Jark, I. U. Lüth
Institute for Anesthesiology, Heart and Diabetes Center NRW, Bad Oeynhausen, Ruhr University of Bochum, Germany
[Applied Cardiopulmonary Pathophysiology 15: 213-219, 2011]
Although being a standard surgical procedure since decades, heart transplantation remains a challenge for the cardiac anesthetist as it requires a sophisticated monitoring and management of circulation, ventilation and homeostasis.
Right ventricular failure is the main contributor to early graft failure in heart transplantation. Particularly after prolonged ischemia and reperfusion injury, the donor heart often can not easily adapt to the increased pulmonary artery pressure and pulmonary vascular resistance of the recipient. Therefore, the special task of anesthesia for heart transplantation is to measure and calculate the actual pressures, resistance and transpulmonary gradient in the pulmonary artery bed of the recipient, initiate strategies to reduce pulmonary artery pressure and resistance and to augment right ventricular contractility.
After induction of anesthesia and placement of monitoring lines, a pulmonary artery catheter should be forwarded into the pulmonary artery and measurements performed. These data give important information in how far the patient will be at risk for an increased afterload of the right ventricle and concomitant right ventricular failure. Besides basic ventilation strategies to reduce pulmonary artery resistance such as hyperoxygenation and moderate hyperventilation are compulsory. Inhalation of selective pulmonary artery vasodilators such as nitric oxide or aerosolized prostaglandins should be initiated in case of an increased pulmonary artery pressure and resistance. Inotropic support of the right ventricle is achieved by a combination of beta-adrenergic drugs and phosphodiesterase-3 inhibitors. The effect of the therapy is monitored by measurement of cardiac output, left and right atrial filling pressures and pulmonary artery pressures and continuous monitoring of right and left ventricular function by online transesophageal echocardiography. If the left ventricular preload remains unsatisfactory during this therapy, a vasoconstrictor should be infused to achieve adequate systemic arterial (diastolic) pressures providing adequate coronary artery perfusion. If even these strategies fail to achieve adequate cardiac output the calcium channel sensitizer levosimendan and/or replacement of triiodthyronine (T3), which plasma levels are often decreased during longer periods of cardiopulmonary bypass, are additional pharmacological options. If pharmacological therapy remains unsatisfying to establish a stable circulatory condition, mechanical support must be established.
Severe hemorrhage is not a rare condition especially in patients with previous heart surgery and will be managed with replacement of coagulation factor concentrates and/or infusion of fresh frozen plasma and transfusion of platelet concentrates. Current monitoring assays such as the ROTEM device help to guide specific therapy. In case of uncontrollable hemorrhage infusion of recombinant coagulation factor VIIa is an ultimate option.
Key words: right heart failure, pulmonary artery hypertension, nitric oxide, iloprost, coagulation factor VIIa
Institute of Anesthesiology
Heart and Diabetes Center
32545 Bad Oeynhausen