Cardiogenic shock (c)is caused by decreased cardiac output producing
inadequate tissue perfusion. Anaphylactic shock (d)is a severe systemic
hypersensitivity reaction resulting in hypotension and airway compromise.
Septic shock (e)is a clinical syndrome of hypoperfusion, hypotension, or
multiorgan dysfunction caused by infection.
205.The answer is d.(Tintinalli, p 194.) Atropineis the initial treatment
of choice for patients in second-degree, Mobitz I AV block. The majority of
patients respond to atropine without further treatment. Mobitz I is com-
monly seen with acute inferior MI, digoxin toxicity, myocarditis, and after
cardiac surgery.
Observation alone (a) is appropriate for stable patients. However, this
patient is hypotensive and needs more aggressive management. Transcuta-
neous (eg, electrical pads are placed externally, most commonly on the ante-
rior chest wall) (b) or transvenous (eg, pacing wires are threaded into the
right ventricle [RV] through a central vein) pacing (c) is an appropriate
treatment and should be attempted if atropine is unsuccessful. Finally, if all
else fails, epinephrine (e) or dopamine drips can be started. These treat-
ments should be applied judiciously as the resulting increased HR may
worsen patients with active ischemia as the etiology for their bradycardia.
Furthermore, patients with acute inferior wall MI may have right ventricu-
lar failure and may be hypotensive because of decreased preload, not brady-
cardia. IV fluids would be the therapy of choice in patients with inferior MI.
206.The answer is b.(Tintinalli, pp 189-191.)This patient had a run of
torsades de pointes,an atypical VT where the QRS axis swings from pos-
itive to negative within a single ECG lead. This dysrhythmia is frequently
seen in patients with significant heart disease who have a prolonged QT
interval. There are many possible causes of prolonged QT; however, com-
mon etiologies include drugs (eg, antidysrhythmics, psychotropics), elec-
trolyte abnormalities, and coronary heart disease. This patient was likely
on a phenothiazine for her schizophrenia leading to prolonged QT syndrome
and an episode of torsades de pointes. Administration of magnesium sulfate
has been shown to decrease runs of torsades.
Observation alone (a),is not adequate. Conventional VT treatments,
such as lidocaine (c)are often ineffective. Procainamide can actually further
prolong the QT interval. If magnesium is unsuccessful, the next strategy
involves increasing the HR from 90 to 120 beats per minute and thereby
reducing the QT interval and preventing recurrence of torsades de pointes.
Shock and Resuscitation Answers 229