Increased HR is best achieved by placing a transvenous pacemaker (d); this
technique is sometimes called overdrive pacing. During the time it takes for
transvenous pacemaker placement, unstable patients can be started on iso-
proterenol (e), a β-adrenergic receptor agonist to medically increase the HR.
207.The answer is e.(Tintinalli, p 229.)This patient has significant hypoten-
sion and tachycardia with mental status changes and needs type O, Rh-positive
bloodnow. His hypovolemic shockis most likely caused by a brisk upper
GI bleeding,secondary to variceal bleeding. While his blood is being processed
in the laboratory, including type and cross, complete blood count, chemistry
panel, liver function tests, and coagulation profile, a nasogastric tube should be
placed and octreotide administered. A gastroenterologist and surgeon should
also be consulted. Type O, Rh-negative blood is reserved for women in their
childbearing years to prevent potential Rh sensitization.
Isotonic crystalloid (b), such as 0.9% normal saline, should run con-
currently with the packed RBC transfusion, but will not replace the oxygen-
carrying capacity of lost RBC. Hypertonic sodium chloride (a)is unlikely
to be helpful in an acute GI bleed. There is not enough time to wait for
cross-matched (c)or type-specific blood (d).
208.The answer is b.(Tintinalli, pp 228-231.)Crystalloids,such as
normal saline (0.9% sodium chloride)orlactated ringersare the pre-
ferred resuscitation fluid in the United States. The patient is currently stable;
however, he is tachycardic and has suffered an injury with the potential for
significant morbidity. The FAST examination will help illustrate the extent
of this patient’s injury. In the meantime, the patient should be started on iso-
tonic crystalloid solution. There is currently no convincing evidence that
either solution—normal saline or Ringers lactate—is superior to the other.
Hypertonic saline (a)helps prevent the extravascular fluid shift seen
with isotonic crystalloids, but is volume limited owing to the risk of hyper-
natremia. Furthermore, clinical studies have not shown clear evidence of
improved outcome using hypertonic saline. Colloid solutions (c), such as
albumin, FFP, and dextran solutions have larger protein components and
would therefore be expected to remain in the intravascular space. However,
this is a theoretical benefit, as numerous studies have not shown improved
outcome using colloid solutions. Blood (d and e)is the best resuscitation
fluid. Cross-matched blood is preferred over type-specific blood, if time is
available to perform the cross-match. In this case, the patient has only mini-
mal tachycardia. He can receive crystalloid first with continuous monitoring
230 Emergency Medicine