Shock Syndromes II

Hypovolemic shock is a result of reduced intravascular volume (i.e., reduced preload), which, in turn,

reduces stroke volume and cardiac output (CO), leading to inadequate tissue perfusion. Hypovolemic

shock accounts for around 16% of all cases of shock requiring vasoactive medications.

exsanguination is estimated to be the direct cause of around 50,000 deaths from trauma in the United

States (Table 1).

Responsible for up to 30%–40% of trauma-related mortality

Leading cause of death in patients younger than 45; thus, burden to society is even larger

Although commonly associated with trauma, hypovolemic shock can also occur in other clinical

scenarios (e.g., heat stroke, acute gastrointestinal [GI] bleeding, surgical, obstetrics, pharmacologic

toxicity, burns, pancreatitis, loss of extracellular fluid).

A study examined the impact of race and insurance status on trauma mortality rates among patients

18–64 years of age with an Injury Severity Score of 9 or higher caused by blunt or penetrating trauma,

using data from the National Trauma Data Bank from 2001 to 2005. Specifically, the study aimed to

determine whether race and insurance status independently predicted outcome disparities after trauma.

The crude mortality rates were 5.7%, 8.2%, and 9.1% for the White, African American, and Hispanic

groups, respectively (p<0.005). Crude mortality by insurance status was statistically lower for patients

with insurance (4.4%) than for patients without insurance (8.6%) (p<0.005). The study also found that

African American and Hispanic patients with insurance had higher mortality rates than White patients

with insurance, and this effect worsened for patients without insurance across groups.

According to the Cause of Hemorrhage

Cause of Hemorrhage

Death from

Hemorrhage

(%)a

U.S. Cases

Global Cases

No. of

Deaths/yr

Years of

Life Lost

No. of

Deaths/yr

Years of

Life Lost

Trauma

49,440

1,931,786

1,481,700

74,568,000

Abdominal aortic

aneurysm

65,273

191,700

2,881,760

Peptic ulcer disease

38,597

141,000

3,903,600

Maternal disorder

69,690

4,298,240

aEstimates of deaths from hemorrhage as a percentage of all deaths from the given diagnosis.

Modified from: Cannon JW. Hemorrhagic shock. N Engl J Med 2018;378:370-9.

Hypovolemic shock can be categorized as hemorrhagic and nonhemorrhagic:

Whole blood loss (hemorrhagic): Whole blood loss can be external or internal.

External hemorrhage: Trauma, surgical procedures, or penetrating injuries resulting in visible

blood loss

ii.

Internal hemorrhage: Blood loss into body compartments or cavities (eg, retroperitoneal space,

chest cavity, or limb hematomas) that may not be immediately apparent