Medications

If the patient with ACS begins to develop shock and is unable to protect his/her airway, then you might have to perform endotracheal intubation (Refer to Airway Management CPG). The following considerations should be made regarding induction and post-intubation sedation medications:41

1. Ketamine should be avoided in patients with acute MI or heart failure due to increased myocardial oxygen consumption and negative inotropic effects.
2. Etomidate is recommended for induction of anesthesia given its neutral effects on hemodynamics.
3. Propofol should be used with caution in induction, given its ability to cause acute hypotension. It is generally safe for maintenance of anesthesia, however, caution should be used in patients with severe cardiac disease as propofol has also been shown to exacerbate cardiac dysfunction through its negative inotropic effects.
4. Versed/Fentanyl is acceptable for induction/maintenance of anesthesia.

Ventilator Settings

High intrathoracic pressures affect the right and left ventricles differently. High intrathoracic pressures impair right ventricular filling, yet reduces left ventricular afterload. In a patient’s post-MI that require mechanical ventilation, minimization of intrathoracic pressures for a patient with inferior/right ventricular infarction is essential to maintain cardiac output. PEEP and tidal volume should be minimized as much as possible.