ABSTRACT
Patients recovering from cardiac surgery are typically monitored and treated for several hours to overnight in a traditional intensive care unit. Increasingly, some centers are using specialized recovery areas, post-anesthesia care units (PACU), or high-dependence nursing units as substitutes for the ICU. In many hospitals, what the ward is called is less important than the nurse-to-patient ratio. The nurse-topatient ratio for a fresh postoperative patient may well be greater than 1:1 if the patient is hemodynamically unstable, requiring an IABP or other assist device, or actively bleeding. A 1:1 nurse-to-patient ratio is reasonable for the first few hours of instability, and a 1:2 ratio is typically required for the first 6-24 h, depending on the type of anesthesia utilized and rapidity of extubation. Once the patient meets the criteria in Table 20.5, less nursing attention will be needed, and the patient can typically be moved to a lower-dependence area. The risks of premature ICU discharge include respiratory compromise, particularly aspiration as a result of residual sedation and/or neurologic changes, and unrecognized renal or metabolic problems, plus continued bleeding. Cardiac arrhythmias are more difficult to predict, and may not occur until the third or fourth postoperative day, so continued electrocardiographic monitoring is appropriate after ICU discharge. ICU readmission rates are typically in the 5-9% range, and are most often precipitated by pulmonary and cardiac complica-
Neurologic and psychological
Able to protect airway (adequate gag reflex; or tracheostomized)
Able to signal distress (verbal or using call button)
Cardiac
Stable MAP=70 without pressor support
Adequate perfusion (Cl =2.2; warm extremities; satisfactory urine output)
No inotropic support other than low-dose dopamine (=3 µg kg-1 min-1)
Heart rhythm: sinus with few or no PVCs; or atrial fibrillation with controlled rate
Not pacer dependent (unless suitable junctional-ventricular escape rate)
Respiratory
Maintaining pH >7.35 and PCO 2 within 8 mmHg of baseline value
Oxygen saturation =92% on nasal cannula or simple mask (<50% F iO2)
Coughing well and clearing secretions; suctioned twice per shift or less
No pneumothorax, large effusions, or pulmonary edema on CXR
Renal or metabolic
Urine output at least 0.5 cm3 kg-1 h-1
Weight within 5 kg of preoperative value
Renal function (creatinine) near baseline (or known problem followed by consultant)
Serum potassium =3.5 mequiv
Blood glucose adequately controlled
Hematologic
Hematocrit =6%
Chest tube output <50 cm 3 h-1
Clotting parameters within normal range unless deliberately anticoagulated
Infectious
tions; less often by infection, gastrointestinal bleeding, or neurologic events.
