WHAT IS THE APPROPRIATE TI-ERAPY TO MAINTAIN CARDIAC OUTPUT AS PULMONARY VASCULAR RESISTANCE INCREASES?

The right ventricle in sepsis

Right ventricular dysfunction is common in sepsis and septic shock because of decreased myocardial contractility and elevated pulmonary vascular resistance despite a concomitant decrease in systemic vascular resistance. The mainstay of treatment for acute right heart failure includes treating the underlying cause of sepsis and reversing circulatory shock to maintain tissue perfusion and oxygen delivery. Decreasing pulmonary vascular resistance with selective pulmonary vasodilators is a reasonable approach to improving cardiac output in septic patients with right ventricular dysfunction. Treatment for right ventricular dysfunction in the setting of sepsis should concentrate on fluid repletion, monitoring for signs of RV overload, and correction of reversible causes of elevated pulmonary vascular resistance, such as hypoxia, acidosis, and lung hyperinflation.

Anesthesia for bilateral lung transplantation without cardiopulmonary bypass: initial experience and review of intraoperative problems

Bilateral lung transplantation (BLT) is a recently described procedure based on two sequential single-lung transplantations (SLT), which are performed by a transverse sternobithoracotomy. It does not require either cardiac arrest or routine use of cardiopulmonary bypass (CPB). The intraoperative management of 10 patients suffering from end-stage pulmonary disease is reported. Implantation of the first graft is quite similar to a SLT. Problems encountered during this procedure (ie, hypoxemia, hypercapnia, or low cardiac output) were due to restricted pulmonary and cardiac reserve. Preoperative and intraoperative assessment of the recipient's respiratory and cardiac status was, therefore, of prime importance. Mild preoperative pulmonary hypertension, well-preserved right ventricular function, and removal of the less well-perfused lung limited these difficulties; no patient required partial CPB at this stage. During the second lung implantation, gas exchange was provided by the first grafted lung. Measurements of pulmonary vascular resistance (PVR), venous admixture (Qva/Qt), and dead space (VD/VT) assessed with the arterial-to-end-tidal CO2 difference were used to confirm the adequacy of perfusion and V/Q matching. In one patient, partial CPB was instituted because of surgical difficulty related to inadequate size matching of the lungs. In the other patients, first graft function was satisfactory and the second graft was implanted without CPB. With chest closure, PVR returned to nearly normal values (range, 57-293, mean 167 dynes.s.cm-5) and Qva/Qt increased (range, 3 to 36, mean 20%). This limited series demonstrates that CPB is optional during this procedure. Good selection of recipients and donors, good lung preservation methods, and a short duration of cold ischemia are essential to success.