Shock Syndromes II

Similar to other shock states, a relative arginine vasopressin deficiency develops in hemorrhagic

shock that is associated with catecholamine resistance, vasoplegia, and increased venous capacitance.

Supplemental vasopressin may be an adjunct to blood product resuscitation in hemorrhagic shock.

The AVERT-Shock trial was a single-center, randomized controlled trial investigating the

impact of low dose vasopressin (up to 0.04 units/min), compared to placebo, in adult trauma

patients who required at least 6 units of any blood product within 12 hours of injury. They

found that patients who received vasopressin required significantly less cumulative volume of

all blood products by around 1 L, and had a decreased incidence of deep vein thrombosis. No

difference was noted in other complications, such as acute respiratory distress syndrome, or

outcomes, including mortality.

ii.

Although this study challenges the traditional practice of avoiding vasopressors in a bleeding

trauma patient, confirmatory research is needed to determine if vasopressin significantly

improves morbidity and mortality.

In life-threatening hypotension, vasopressors may be recommended only after hypovolemia has

been corrected or when cardiac arrest is imminent.

End points of resuscitation

General recommendations include permissive hypotension, defined as SBP 80–90 mm Hg for

most patients, and urinary output greater than 30 mL/hour. Up to 85% of patients may be under-

resuscitated using SBP and urinary output as end points.

In patients with traumatic brain injury, permissive hypotension should be avoided. The 2016 Brain

Trauma Foundation guidelines recommend maintaining SBP at 110 mm Hg or greater for patients

15–49 years of age or older than 70 and at 100 mm Hg or greater in patients 50–69 years of age.

Patient Case

A 67-year-old man is accidentally shot in the buttocks while deer hunting with his friends. He is brought

to the ED immediately. While in transfer, the patient receives 500 mL of lactated Ringer solution. His vital

signs on admission to the ED are as follows: blood pressure 104/58 mm Hg, heart rate 108 beats/minute,

respiratory rate 22 breaths/minute, and temperature 95°F (35°C). On examination, he has 8/10 pain and

appears anxious. Which is best for resuscitation strategies?

hour and an SBP greater than 100 mm Hg.

output greater than 1 mL/kg/hour.

to normal mentation.

hour, an SBP greater than 80–90 mm Hg, and normal mentation.

Burn Resuscitation

Acute thermal injury triggers an inflammatory state that ultimately leads to third spacing of intravascular

fluid.

concomitant concern is to avoid over-administration of fluids, leading to abdominal or extremity

compartment syndrome, acute respiratory distress syndrome, and further third spacing.