Page 67 - JSOM Summer 2022

Management severe sepsis demonstrated increased risk for morality with
aggressive fluid management. 17
Defined broadly as “the act of making something active or
vigorous again,” resuscitation in modern medicine refers to As far a type of fluid, there is emerging evidence supporting
the correction of all physiologic disorders in an acutely ill in- the usage of “balanced” crystalloids (e.g., PlasmaLyte or lac-
dividual. This may involve source control efforts for a patient tated Ringer’s), which relatively closer represent serum chem-
in septic shock, such as the drainage of an infectious intra-ab- istry, over saline solutions in sepsis and septic shock. There
18
dominal process, or blood product administration and hemor- is otherwise no compelling evidence supporting the use of one
rhage control in an actively bleeding trauma victim. crystalloid over another. Colloid solutions present mixed re-
sults in sepsis – hydroxyethyl starch (HES) and pentastarch
Resuscitation of shock victims must consider the etiology of are no longer used for resuscitation due to adverse effects. 19,20
shock. For instance, septic and nonhemorrhagic hypovolemic Multiple studies have found just equivalency of albumin to
shock patients benefit from initial crystalloid administration. crystalloid solutions, despite theoretic benefits. 21
However, this approach is harmful and even contraindicated in
most forms of cardiogenic shock secondary to decompensated For the hemorrhaging victim, a management strategy known as
heart failure, in which further volume (and thus preload) would damage control resuscitation (DCR) has emerged. The manage-
deteriorate cardiac output by way of the Frank-Startling mech- ment of hemorrhagic shock, including DCR and blood product
anism. In the situation of cardiogenic shock, preload reduc- resuscitation, is addressed separately in this supplement.
tion – and if there is impaired left ventricular systolic function
leading to reduced cardiac output – arterial vasoconstrictors
or inotropic agents would be the therapy of choice. The ideal Vasoactive Medications
fluid for resuscitation for an actively bleeding patient is whole Catecholamine agents, also known as sympathomimetics,
blood, followed by balanced blood components. Crystalloid form most available vasopressors. These agents exhibit phys-
resuscitation is a relative contraindication in hemorrhaging iologic action primarily through α -, β -, β -, and dopamine
trauma patients due to the worsening of the “lethal diamond”: (DA) receptors. α -Agonism results in vascular smooth muscle
1
2
1
1
hypothermia, dilutional coagulopathy, metabolic acidosis, and constriction. β -Receptors, present on myocardium, augment
hypocalcemia. Most forms of obstructive shock carry preload cardiac contractility (inotropy) and increase heart rate (chro-
1
10
dependence and thus IV volume replenishment is critical for notropy). Present in skeletal muscle, β -receptors improve per-
2
resuscitation beyond relieving the circulatory obstruction. All fusion via vasodilation. This list is by no means comprehensive
shock patients, regardless of etiology, should be maintained on of the breadth of physiologic function of adrenergic receptors
supplemental oxygen as to ensure peripheral oxygenation. in the human body.
Algorithmic approaches to the medical resuscitation of sepsis Vasoactive medications should be used without hesitation in
began to formulate in the late 1990s. A landmark resuscitation septic patients who fail initial resuscitation. Peripheral admin-
algorithm termed Early Goal Directed Therapy (EGDT) was istration of vasoactive medications is safe, however with high
introduced in 2001 by Rivers and colleagues. This strategy dose rates and or multiple vasopressors, central venous access
11
used 500mL crystalloid boluses, red blood cell transfusion, and is recommended. Critical care consultation is advised for all
22
vasoactive medication administration targeting central venous shock patients. Norepinephrine (Levophed) is the vasopressor
pressure (CVP), MAP, urine output (UO), and central venous agent of choice for septic shock. Epinephrine (Adrenalin) is a
oxygen saturation (ScVo ) within a 6-hour window. EGDT reasonable alternative in prehospital medicine due to its ver-
2
was found to decrease short-term mortality when compared satile clinical use and a similar physiological effect to norepi-
to standard of care resuscitation efforts at that time. Advance- nephrine. DA is no longer preferred as an initial agent in sepsis
ment in the understanding of resuscitation in septic shock oc- due to no advantage over norepinephrine, likely decreased
curred in the following years, as did confluence of practice. In survival, and a significant supraventricular arrhythmia rate.
23
2015, EGDT was then proven to carry no mortality benefit to Vasopressin is the only acceptable vasopressor in hemorrhagic
alternative or non-EGDT based strategies by a meta-analysis shock. It is also the preferred second-line agent in septic shock
of the ARISE, ProCESS, and ProMISe investigations. 12 and appears to have maximal impact when added during
mild to moderate norepinephrine drip rates. Phenylephrine
24
Controversies over the timing and amount of fluid have ex- (Neo-Synephrine) is a pure α -agonist and is preferred in cases
isted for decades. A 2017 review of mandated sepsis bundles of vasodilatory-predominant shock, such as neurogenic, or as
1
in the emergency department studying time-to-treatment a third-line pressor. There is no evidence that third- and fourth-
found no attributable mortality benefit for early versus late line vasopressor agents appreciably change clinical outcomes.
fluid administration. The attributable mortality reduction Dobutamine, an inotropic agent, affects cardiac contractility
13
of sepsis bundles appears to be overwhelmingly derived from and chronotropy, thereby augmenting cardiac output. Table 2
early empiric antibiotic administration and source control. provides vasoactive medications and their receptor affinity is
By convention and guideline, the recommended “dosage” of summarized below.
crystalloid administration is 30mL/kg. There is little evidence
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to support the administration of beyond 30mL/kg fluid for For the tactical or austere medic, field-expedient “push-dose”
resuscitation purposes. Variably defined large volume resusci- epinephrine can be created by the following process.
tations (typically in excess of 5L) have demonstrated tendency 1. Draw 1mL (1mg) of epinephrine 1:1,000 into an empty
toward harm, as have large net positive fluid balances. This syringe.
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has been shown even so far as a net positive fluid balance in 2. Now draw 9mL of normal saline into this syringe.
a hospital stay to be an independent predictor of mortality. 3. Waste 9mL of the admixture.
16
Furthermore, a 2011 analysis of sub-Saharan children with 4. Draw another 9mL of normal saline into your syringe.
Shock and Vasopressors | 65