In decades past, the otherwise healthy patient for coronary bypass surgery was the “ideal” patient for cardiac surgery/anesthesia teams*. Such patients often presented with one- or two-vessel coronary artery disease in need of surgical revascularization. Perhaps the patient had suffered a myocardial infarction but, overwhelmingly, ventricular function tended to be preserved. Free from both systolic and diastolic ventricular dysfunction, such patients tolerated anesthesia induction, maintenance, and emergence easily. Often these patients were relatively young, in their forties, fifties, and sixties and lacked other organ system diseases. Time on cardiopulmonary bypass tended to be short because the patients often required only one or two vessel revascularizations.
Today, patients presenting for coronary artery surgery are anything but “routine.” Frequently they will have already undergone numerous percutaneous coronary interventions (PCIs) prior to being referred for surgery. Many patients will have had a history of recurrent small myocardial infarctions, anginal episodes, and catheterizations. Over time, myocardial damage accrues, leaving some patients with systolic and diastolic ventricular dysfunction. Other patients are referred for coronary bypass surgery because they have complex coronary artery lesions not readily amenable to PCI (e.g., patients with high SYNTAX scores—see Chapter 1) or they have concurrent valvular heart disease.
Although few of today’s patients for coronary revascularization are “easy” to manage, review of the anesthesia management for this particular surgical procedure provides an overview of the anesthesia maneuvers necessary in the management of almost all adult cardiac surgeries. In other words, the skills and techniques applied in managing the “routine” coronary artery bypass graft (CABG) surgery also apply when managing anesthesia for more complex procedures.
*Warning: There is no such thing as routine cardiac anesthesia.
IMMEDIATE PREOPERATIVE ASSESSMENT AND ANTIBIOTIC PROPHYLAXIS
Increasingly, patients are admitted to the hospital for elective CABG on the day of surgery. In that instance, the anesthesiologist may have very few moments to meet and to assess the patient for cardiac surgery. Most institutions operating a same-day admission cardiac surgery program will have arranged for the patient to be evaluated in a preoperative anesthesia clinic well before the day of surgery. If that is the case, the anesthesiologist reviews the evaluative work completed in the outpatient clinic. Still, it is critically important that the anesthesiologist completes an immediate assessment prior to preparing the patient for surgery.
Patients should be questioned regarding any change in their overall health since their preoperative evaluation. They are asked if they are currently experiencing any dyspnea or anginal pain. Patients should be monitored at this time with electrocardiogram, pulse oximeter, and automatic blood pressure cuff. Supplemental oxygen should be provided.
Most patients will have continued their medications, including beta-blockers, on the morning of surgery as instructed. Angiotensin converting enzyme inhibitors can lead to perioperative hypotension, and many patients will have been instructed to discontinue these medications. However, there may be outcome benefits in continuing ACE therapy perioperatively. ...