Hemodynamic goals vary depending on the patient’s history, the operation, and institutional practice (see Chapter 20); typical values for the early postoperative period are listed in Table 17-1. Hypovolemia and modest vasodilatation are common during the early postoperative period, and a fluid challenge may be required. The doses of any vasoactive drugs should be confirmed. Vasoactive and inotropic drugs may be titrated to the patient’s hemodynamic state (mean arterial pressure, cardiac output) or, in patients with impaired ventricular function, they may be maintained at a constant level for a set period (e.g., until extubation or overnight).

Table 17-1 Standard Hemodynamic Goals During the Early Postoperative Period

MAP	65-90 mmHg
CVP	8-12 mmHg
PAWP (or PAD)	10-14 mmHg
Cardiac index	>2.2-2.6 l/min/m²
S_VO₂ (or S_SVCO₂)	>60%-70%

CVP, central venous pressure; MAP, mean arterial pressure; PAWP, pulmonary artery wedge pressure; S_SVCO₂, superior vena cava oxygen saturation; S_VO₂, mixed venous oxygen saturation; PAD, pulmonary artery diastolic pressure

Respiratory System

The adequacy of ventilation is assessed by: (1) auscultating the patient’s chest to ensure that air entry is equal and that the breath sounds are normal; (2) reviewing the oxygen saturation (S_pO₂) and blood gas results; and (3) checking the ventilator settings. The endotracheal tube should be inspected to ensure that it is properly secured and at an appropriate distance from the teeth and gums (21 to 23 cm for women, 22 to 24 cm for men). Changes in the initial ventilator settings are commonly required, depending on the blood gas results. The presence of coarse breath sounds or high airway pressures suggests the need for endotracheal suctioning. Discontinuation of mechanical ventilation can usually proceed according to standard protocol.

Bleeding and Fluids

All surgical sites should be inspected for bleeding and hematoma formation. If a radial artery graft has been used, the donor forearm should be elevated and the perfusion to the hand assessed. Chest drains should be inspected for blood and the presence of bubbling. A transfusion threshold should be determined. The results of any coagulation tests should be reviewed and a decision regarding the need for blood component therapy made. Maintenance and resuscitation fluids should be prescribed, usually according to protocol.

Renal System and Electrolytes

Following cardiopulmonary bypass (CPB), patients are typically polyuric. The absence of polyuria may indicate a blocked or kinked urinary catheter. If this is suspected, the catheter should be flushed with 50 ml of sterile water. Polyuria is not usual after off-pump coronary artery bypass (OPCAB) surgery. Red staining of the urine indicates either elevated free plasma hemoglobin or urinary tract bleeding, both of which are common in postoperative cardiac surgery patients. Coagulation tests and a measure of the plasma-free hemoglobin concentration should be obtained. Potassium and, possibly, magnesium supplementation should be prescribed.

Other

Pupil size and reactivity should be noted and the patient’s level of sedation documented. Core temperature should be measured, and the patient should be rewarmed to 36.5°C using a forced-air warming device, taking care not to cause hyperthermia (i.e., maximum ≤37°C). All lines and tubes should be inspected. Routine postoperative drugs should be prescribed.

Chest Radiograph

The chest radiograph should be reviewed to check the positions of all lines and tubes, to assess the presence of any pulmonary pathology (atelectasis, pulmonary edema, pneumothorax, fluid collection), and to rule out abnormalities of the cardiac silhouette indicative of mediastinal bleeding, pericardial fluid, or ventricular dysfunction.

Medical Rounds

The patient should be reviewed every 2 to 4 hours by the medical team, or more frequently if indicated. The treatment plan should be updated according to the patient’s progress. On the morning of POD-1, a multidisciplinary ward round should be performed and should include input from all members of the healthcare team: doctors, physician’s assistant, nurse, physical therapist, dietitian, and pharmacist. The suitability of the patient for discharge to the surgical ward should be assessed at that time.

Bedside Care

The bedside care of the patient is primarily the responsibility of the patient’s nurse. The nurse is responsible for monitoring and documenting the patient’s clinical condition, facilitating progress, and detecting and intervening in potential problems. In a well-run ICU with clear practice guidelines, the great majority of patient care is carried out by the bedside nurse according to protocol.

A detailed record of the patient’s clinical state is recorded in the 24-hour chart. Hemodynamic and respiratory status, fluid balance (including chest drainage), and drug infusions are recorded every half hour. Blood gases, potassium, and glucose are obtained every 2 hours initially while the patient is ventilated, and every 4 hours thereafter. If a PAC is in situ, cardiac index, S_VO₂, and PAWP are recorded every 2 hours, at least initially. The patient’s neurologic status (pupil size and reactivity, depth of sedation) is recorded every 2 to 4 hours. If a radial graft has been used or an intraaortic balloon pump is in situ, perfusion to the affected limb should be documented every 1 to 2 hours. Immobile patients should be turned every 4 to 6 hours, varying among supine and left and right lateral tilt positions to avoid the formation of pressure areas. However, for the many patients who are ventilated for only a few hours, this is not necessary. Prior to stopping sedation, a patient is usually sponge-washed to remove any dried blood or surgical antiseptic from the skin. Once the patient is extubated, pain and sedation scores and nausea are assessed on a regular basis (see Chapter 4).

At the start of each nursing shift, a detailed handover of the patient’s status and progress takes place, and a nursing care plan is formulated. Once per nursing shift, a multisystem assessment of the patient and associated devices is performed. This includes examining the patient, checking the ventilator settings and alarms, zeroing and leveling the transducers, checking all drug infusions, checking the monitors’ alarm settings, and checking that the suction tubing and drains are all connected and working correctly. For a patient who is paced, the pacing mode, thresholds, and sensitivities are assessed. The presence and function of emergency equipment, such as a manual resuscitator, oxygen tubing, oral airway, and mask, are confirmed.

On the morning following surgery, a 12-lead electrocardiogram (ECG) and a full set of blood tests (urea and creatinine, electrolytes, blood gas, hepatic function, CK-MB, troponin, and complete blood count) are obtained. Once the chest drains are removed, a repeat chest radiograph is performed.

MANAGEMENT OF SPECIFIC ISSUES

Drugs Given at Admission

Most units have a standard protocol for the drugs that are prescribed on admission. They may include electrolytes, sedatives and analgesics, antiemetics, antipla telet drugs, and prophylaxis for atrial fibrillation. Additional medications are also indicated for specific cardiac procedures, such as CABG surgery and valve surgery. The routine drugs used at our institution are shown in Table 17-2. Individual practice varies widely.

Table 17-2 Examples of Routine Drugs

Sedation and Analgesia
Propofol	100-300 mg/hr titrated to effect
Morphine	IV: 1-2 mg as required; PO: 10-20 mg of a short-acting formulation as required + 10-20 mg of a long-acting formulation twice daily for 3 days
Acetaminophen	1 g PO or PR 6 hourly
Antiemetics
Ondansetron	4 mg 6 hourly PO or IV as required
Prochlorperazine	12.5-25 mg 8 hourly PO or PR as required
Dexamethasone	8 mg daily IV as required
Atrial Fibrillation Prophylaxis
Amiodarone	400 mg PO 3 times daily for 2 days beginning on the first postoperative day; thereafter 200 mg twice daily for 1 week
Other Drugs
Potassium chloride	10-20 mmol IV slowly to maintain K⁺ 4.5-5 mmol/l
Furosemide	20-40 mg IV daily starting on POD-1 and continuing until back to preoperative weight

Note: these are the drugs used at the authors’ institution. Additional drugs are given for specific cardiac operations.

IV, intravenous; PO, per os; POD, postoperative day; PR, per rectum.

Electrolytes

Following CPB, renal potassium losses are typically high, which can cause hypokalemia and precipitate arrhythmias. Aggressive potassium supplementation is commonly required in the first few hours following surgery, aiming for a serum concentration of 4.5 to 5 mmol/l. Hypocalcemia and hypomagnesemia are also common during the early postoperative period. Calcium typically normalizes over a period of hours without the need for supplementation. Magnesium supplementation should be considered in patients with marked hypomagnesemia (>0.8 mmol/l), preoperative diuretic use, or an unstable rhythm. Magnesium sulfate may form part of routine prophylaxis against atrial fibrillation.

Analgesic Medications

In intubated patients, analgesia may be provided by intermittent intravenous administration of an opioid such as morphine combined with intravenous or rectal acetaminophen (see Chapter 4). Once the patient is extubated and awake, intravenous opioid therapy may be given by means of a patient-controlled analgesia system in combination with oral or rectal acetaminophen. Nonsteroidal antiinflammatory drugs may be used in patients who are without contraindications but are best avoided until postoperative renal function is known.