Evidence Supporting Fast Track Cardiac Recovery

There are several randomized trials and a meta-analysis of randomized trials that have addressed the question of safety of FTCA.³ None of the trials was able to demonstrate differences in outcomes between the fast track group and the conventional anesthesia group, but meta-analysis of the randomized trials demonstrated a reduction in the duration of intubation by 8 hours (Fig. 26-1) and the ICU length of stay by 5 hours in favor of the fast track group. However, the length of hospital stay was not statistically different.

Figure 26-1 Forrest plot showing the weighted mean difference in extubation times. The overall effect was an 8.1-hour reduction in extubation times. FTCA = fast track cardiac anesthesia; TCA = traditional cardiac anesthesia.

One concern with FTCA is the potential for an increase in the incidence of adverse events, notably awareness. Awareness in patients undergoing FTCA was systematically investigated and the reported incidence of explicit intraoperative awareness was 0.3%. This is comparable to the reported incidence during conventional cardiac surgery. This suggests that FTCA does not increase the incidence of awareness compared with conventional cardiac surgery.

FTCA appears safe in comparison to conventional high-dose narcotic anesthesia. It reduces the duration of ventilation and ICU length of stay considerably without increasing the incidence of awareness or other adverse events. It also appears effective at reducing costs and resource utilization. As such, it is the standard of care in many cardiac centers. The usual practice at many institutions is to treat all patients as fast track candidates with the goal of allowing early tracheal extubation for every patient. However, if complications occur that would prevent early tracheal extubation, then the management strategy is modified accordingly. It has been demonstrated that the risk factors for delayed tracheal extubation (>10 hours) are increased age, female gender, postoperative use of intra-aortic balloon pump (IABP), inotropes, bleeding, and atrial arrhythmia. The risk factors for prolonged ICU length of stay (>48 hours) are those of delayed tracheal extubation plus preoperative MI and postoperative renal insufficiency. Care should be taken to avoid excess bleeding (antifibrinolytics) and to treat arrhythmias either prophylactically or on occurrence (β-blockers, amiodarone).

Postcardiac Surgical Recovery Models

The failure of many randomized FTCA trials to show reductions in resource utilization likely stems from the traditional ICU models used by these centers during the study period. Even when trials were combined in a meta-analysis, the ICU length of stay was reduced only by 5 hours despite patients being extubated a mean of 8 hours earlier.³ Typically, patients who are extubated within the first 24 hours of ICU admission are transferred to the ward on postoperative day 1 in the morning or early afternoon. This allows the following daytime cardiac cases to have available ICU beds but prevents patient transfers during night-time hours. Two models have been proposed to deal with this issue: the parallel model and the integrated model. In the parallel model, patients are admitted directly to a CRA, where they are monitored with 1:1 nursing care until tracheal extubation. Following this, the level of care is reduced to reflect reduced nursing requirements with ratios of 1:2 or 1:3. Any patients requiring overnight ventilation are transferred to the ICU for continuation of care. The primary drawback with the parallel model is the physical separation of the CRA and ICU, which leads to two separate units and thus does not eliminate the requirement to transfer patients. The integrated model overcomes these limitations because all patients are admitted to the same physical area, but postoperative management such as nursing-to-patient ratio is variable based on patient requirements. Because nursing care accounts for 45% to 50% of ICU costs, reducing the nursing requirements where possible creates the greatest saving. Other cost savings from reductions in arterial blood gases measurement, use of sedative drugs, and ventilator maintenance are small. The goal is a postoperative unit that allows variable levels of monitoring and care based on patient need. Furthermore, FTCA has been demonstrated to be a safe and cost-effective practice that decreases resource utilization after patient discharge from the index hospitalization up to 1-year follow-up.⁴

INITIAL MANAGEMENT OF FAST TRACK CARDIAC ANESTHESIA PATIENTS: THE FIRST 24 HOURS

On arrival in the CRA, initial management of cardiac patients consists of ensuring an efficient transfer of care from operating room staff to CRA staff while at the same time maintaining stable patient vital signs. The anesthesiologist should relay important clinical parameters to the CRA team. To accomplish this, many centers have devised hand-off sheets to aid in the transfer of care. The patient’s temperature should be recorded, and, if it is low, active rewarming measures should be initiated with the goal of rewarming the patient to 36.5°C. Shivering may be treated with low intravenous doses of meperidine (12.5 to 25 mg). Hyperthermia, however, is common within the first 24 hours after cardiac surgery and may be associated with an increase in neurocognitive dysfunction, possibly as a result of hyperthermia exacerbating cardiopulmonary bypass (CPB)−induced neurologic injury (Box 26-2).