Is a Pulmonary Artery Catheter Needed If You Have Transesophageal Echocardiography in a Routine Coronary Artery Bypass G
Since the proliferation of intraoperative transesophageal echocardiography (TEE), many anesthesiologists have questioned the need for pulmonary artery catheters (PACs), particularly in routine coronary artery bypass grafting (CABG) surgeries. Utilization
- PDF / 95,720 Bytes
- 4 Pages / 595.276 x 790.866 pts Page_size
- 29 Downloads / 178 Views
20
Christopher Y. Tanaka and John Hui
Case The new anesthesiologist at the hospital, Dr. Pro, is assigned to relieve Dr. Con for the evening from a coronary artery bypass grafting (CABG) surgery. As Dr. Pro enters the room, he sees the case is well underway but not yet on cardiopulmonary bypass (CPB). Dr. Con, obviously anxious to leave, quickly begins to give sign out, “Pretty routine CABG: 67-year-old guy, 3-vessel disease, normal ejection fraction, normal valves, otherwise healthy, easy intubation…” Dr. Pro scans the monitor and furrows his eyebrows and asks, “Where’s the pulmonary artery catheter (PAC)? Where I trained, we put a PAC in all of our cardiac cases.” Dr. Con replies, “So, at this hospital, we only place PACs in patients with specific issues such as poor ventricular function or valvular abnormalities. We should be fine with the central venous catheter (CVC) and transesophageal echocardiography (TEE)” [1].
Question Is a pulmonary artery catheter needed if you have TEE in a routine CABG? PRO: Of course, every CABG should have a PAC. Let’s review how much useful information you can get from a PAC. First, you get direct measurements of the pulmonary artery pressures (PAP). Second, by wedging the PAC, you can measure the pulmonary capillary wedge pressure C.Y. Tanaka (&) J. Hui Department of Anesthesiology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 East 210th Street, Bronx, NY 10467, USA e-mail: ctanaka@montefiore.org J. Hui e-mail: [email protected]
(PCWP). Third, you can measure cardiac output (CO) using thermodilution. From these numbers, you can calculate multiple parameters: systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), stroke volume, etc. Finally, you can draw a mixed venous oxygen saturation (SvO2) to calculate cardiac output using Fick’s equation to assess adequacy of oxygen delivery [2]. CON: Yes, we can get a lot of numbers from a PAC, but some of them have potential issues. Accurate measurement of PCWP assumes the catheter tip is in West lung zone 3 [3], and positive pressure ventilation can cause overestimation of left ventricular end diastolic pressure [4]. Thermodilution is inaccurate if performed incorrectly or if there is significant tricuspid or pulmonic regurgitation. TEE can estimate all of the same numbers a PAC gives you, except SvO2 [2]. For instance, systolic PAP is easily estimated using Doppler measurements of tricuspid regurgitation. You can easily calculate SVR, PVR, CO, and PCWP. You can also assess valvular function, diastolic function, wall motion, and ejection fraction. PRO: You make it sounds like I am trying to argue that a PAC is better than TEE. The PAC should be a complement to TEE. A CABG patient is at high risk of many catastrophic events that are accompanied by acute increases in PAP, including left ventricular dysfunction, mitral regurgitation, and pulmonary arterial vasoconstriction [5]. The PAC’s strength is that it continuously displays PAPs and can aid in rapid diagnosis of these complications. Detecting acut
Data Loading...
