Rippe Cirugia Cardiaca

Management of the Postoperative Cardiac Surgical Patient
Catherine Dudick
Alan Lisbon
The management of the postoperative cardiac surgical patient is a dynamic process that requires modern intensive care unit (ICU) technology and sharp clinical skills. The approach must be done in a methodical way with the goal of reestablishing cardiac performance and adequate systemic perfusion. Earlydetection of acute complications has a significant impact on morbidity and mortality. The postoperative care of cardiac surgical patients is best handled using a systematic approach [1,2].
Monitoring
The restoration and maintenance of physiologic homeostasis without further injury to the heart and other organs represent the most important goal in the care of the postoperative cardiac surgical patientand requires proper patient monitoring. An arterial cannula, usually in the radial artery, permits easy access to blood for various laboratory tests (see Chapter 3) and provides the ability to measure systemic blood pressure continuously, mean arterial pressure (MAP) being the value of most interest. As the systemic pulse travels from the aorta, the systolic pressure rises and the diastolicpressure falls, causing a variation of the measured blood pressure from site to site. The MAP is the least dependent on site or technique of measurement and the least affected by measurement damping; it also determines tissue blood flow via autoregulation [3].
At least one lead of the surface electrocardiogram also should be displayed, with several leads being monitored for ST-segment changes. Pulseoximetry allows assessment of oxygen saturation and reduces the need for arterial blood gases. The end-tidal carbon dioxide monitor may provide useful physiologic information about the adequacy of ventilation, and it also provides an additional alarm to signal ventilator malfunction or disconnection.
A triple-lumen pulmonary artery catheter (PAC) inserted via an internal jugular vein permitsmeasurement of the right atrial, pulmonary artery, and pulmonary artery occlusion (PAOP) pressures and the determination of cardiac output (CO) and mixed venous saturation. Newer pulmonary artery catheters with an oximeter probe at the distal end allow continuous monitoring of mixed venous oxygen saturation and cardiac index. However, based on multiple randomized, controlled clinical trials in a varietyof settings, the routine use of pulmonary artery catheterization does not lead to improved clinical outcomes [4,5,6,7,8,9]. Although the PAC-Man trial, an open randomized trial involving 65 UK ICUs and over 1,000 patients, demonstrated no clear benefit or harm in using a PAC [4], the use of a PAC carries attendant risks such as infection, pulmonary artery rupture, and arrhythmia.
Thetransesophageal Doppler (TED) monitor is an emerging diagnostic tool both in the operating room and the ICU. It allows real-time evaluation of intracardiac blood flow, anatomy, and function. Being a volumetric index, in some instances it may be superior to invasive monitoring [10], particularly in the setting of valvular disease or respiratory disease when pressure-based readings may not accurately reflectvolume status. In both cardiac and noncardiac patient populations, several studies demonstrated that TEE provided unexpected information that significantly altered the therapeutic plan, even in patients with an indwelling PAC [10,11].
Initial Assessment
A brief but systematic physical examination of the patient is mandatory on arrival in the ICU. Inspection of the skin and extremities may revealintraoperative injuries, infiltration or disconnection of intravenous (IV) infusions, absence of pulses, signs of drug or transfusion reactions, or evidence of hypoperfusion. Auscultation of the chest may reveal unilateral absence of breath sounds due to malposition of the endotracheal tube or pneumothorax. Auscultation of the heart should document heart sounds, prosthetic valve sounds, and the...