Cardiac output monitoring: Technology and choice

The accurate quantification of cardiac output (CO) is given vital importance in modern medical practice, especially in high-risk surgical and critically ill patients. CO monitoring together with perioperative protocols to guide intravenous fluid therapy and inotropic support with the aim of improving CO and oxygen delivery has shown to improve perioperative outcomes in high-risk surgical patients. Understanding of the underlying principles of CO measuring devices helps in knowing the limitations of their use and allows more effective and safer utilization. At present, no single CO monitoring device can meet all the clinical requirements considering the limitations of diverse CO monitoring techniques. The evidence for the minimally invasive CO monitoring is conflicting; however, different CO monitoring devices may be used during the clinical course of patients as an integrated approach based on their invasiveness and the need for additional hemodynamic data. These devices add numerical trend information for anesthesiologists and intensivists to use in determining the most appropriate management of their patients and at present, do not completely prohibit but do increasingly limit the use of the pulmonary artery catheter.

Intraoperative myocardial ischemia during renal transplantation caused by anomalous origin of the right coronary artery.

Anomalous origin of the right coronary artery (AORCA) is a rare congenital anomaly with an incidence of 0.92% during routine cardiac catheterization. Its presence raises an important concern to the anaesthesiologist because it can lead on to myocardial ischaemia manifesting as either angina pectoris or myocardial infarction, or sudden death in young patients with minimal exertion, even in the absence of atherosclerosis. Patients with AORCA may be intolerant to stress and the high cardiac output condition owing to volume loading. Such a therapeutic manoeuvre may be desirable during renal transplantation to enable better perfusion of the renal graft immediately after grafting the kidney, in order to improve its function. Hence, haemodynamic goals in renal transplant recipient with AORCA can be contradictory during surgery, thereby rendering anaesthetic management challenging. We report a case of acute myocardial ischemia precipitated by fluid loading conditions in a patient with AORCA during renal transplant that was successfully treated with emergent intra-aortic balloon pump therapy intraoperatively. Judicious intraoperative fluid replacement is recommended, and volume overload must be avoided in AORCA patients undergoing surgery.