A 70 year old male with a past medical history coronary artery disease, heart failure with reduced ejection fraction, and severe aortic stenosis presents via EMS for shortness of breath. History is limited due to acute respiratory distress while patient is on CPAP. Vital signs are: BP 88/60, HR 120, T 36.7, RR 30, SpO2 90% on PEEP 8 and FiO2 100%. On exam, he is in severe respiratory distress with accessory muscle usage and speaks in 2 word phrases. There is a prominent systolic ejection murmur over the right second intercostal space. Rales are heard at the lung bases bilaterally, and there is 4+ pitting edema of the lower extremities. EKG shows sinus tachycardia. Which of the following is the preferred resuscitation strategy to optimize hemodynamics prior to intubation?
A: bolus 1 liter isotonic fluids
B: epinephrine infusion
C: norepinephrine infusion
D: phenylephrine infusion
E: push dose epinephrine prior to induction
Answer: phenylephrine infusion
This patient is presenting in acute hypoxic respiratory failure likely secondary to pulmonary edema related to acute on chronic heart failure. Patients with severe aortic stenosis are preload dependent to maintain coronary and systemic perfusion. Thus, typical management with positive airway pressure and nitrates should be used cautiously. In hypotensive patients with aortic stenosis, phenylephrine is the vasopressor of choice due to its pure alpha-1 agonist effects to increase diastolic blood pressure and coronary perfusion. Reflex bradycardia is also beneficial to allow for more diastolic filling time. Inotropes such as epinephrine are not recommended due to tachycardia and increased myocardial oxygen demand. Norepinephrine is a reasonable alternative but not the preferred agent. Fluid administration is likely to worsen this patient’s hemodynamics and respiratory status by volume overload.
References:
Goertz AW, Lindner KH, Schutz W, Schirmer U, Beyer M, Georgieff M. Influence of phenylephrine bolus administration on left ventricular filling dynamics in patients with coronary artery disease and patients with valvular aortic stenosis. Anesthesiology. 1994;81(1):49-58.
