Pharmacology Flashcard 3

B. Rationale: Epinephrine and vasopressin are part of the asystole algorithm. Vasopressors are given as soon as IV/IO access is available. Epinephrine may be given every 3–5 minutes. Vasopressin may replace the first or second dose of epinephrine. Antiarrhythmics are not part of the asystole algorithm as there is an absence of rhythm. Atropine was removed from the asystole algorithm because it was determined unlikely to have any therapeutic benefit.

B. Rationale: Adding steroids, such as methylprednisolone, with epinephrine when treating patients with in-hospital cardiac arrest has shown improved survival rates in studies. It is thought that there is widespread systemic inflammation after cardiac arrest, and adding steroids can help patients when they have achieved a return of spontaneous circulation. There is no reported benefit of using steroids with epinephrine in out-of-hospital cardiac arrest.

A. Rationale: AV nodal blocking agents (e.g., beta-blockers, calcium channel blockers, digoxin, adenosine) should be avoided in patients with an irregular wide complex tachycardia. If the rhythm is pre-excited atrial fibrillation, these drugs may cause a paradoxical increase in the heart rate (ventricular response).

D. Rationale: Vasopressin is an anti-diuretic hormone that exerts its vasoconstrictive properties in the peripheral circulation while preserving patency of the cardiac, renal, and cerebral circulation.

D. Rationale: Amiodarone exerts its effect on the sodium, potassium, and calcium channels; it also blocks the α- and β-adrenergic receptors and thus has a negative inotropic effect.

D. Rationale: Research has shown that amiodarone is the first-line antiarrhythmic agent for cardiac arrest. It improves the rates of ROSC and survival to admission in patients with refractory VF/pulseless VT.

D. Rationale: All of these measures can help to speed drug delivery into central circulation. Drugs administered during CPR may not reach central circulation until several cycles of CPR have been completed.

A. Rationale: Epinephrine has been shown to increase ROSC but not survival from cardiac arrest. Studies have not supported vasopressin use over epinephrine in cardiac arrest. Vasopressin causes renal and coronary vasoconstriction. Epinephrine increases cerebral perfusion pressure during CPR.

B. Rationale: When used alone in patients with cardiac arrest, vasopressin and epinephrine are viable drugs to improve the chances of a return of spontaneous circulation. However, combining the two drugs brings no significant advantage compared to using epinephrine alone. Thus, in the interest of simplifying the adult cardiac arrest algorithm, vasopressin was removed.

B. Rationale: Morphine is indicated in the treatment of acute coronary syndromes. Its analgesic effect suppresses “neurohumoral activation, catecholamine release, and heightened myocardial oxygen demand.” It reduces the burden on myocytes by decreasing preload and systemic vascular resistance.