creation date: 2026-09-01 16:36
tags: Pathologies
Hypovolemic Shock
Background
Definitions
Shock is defined as a life-threatening condition of circulatory failure. It is a state of cellular tissue hypoxia due to inadequate oxygen delivery for the metabolic demands.
The effects of shock are initially reversible but can deteriorate to an irreversible state with multiorgan failure and death.
Four types of shock are recognized, of which multifactorial shock is possible. The specifics of each type are described in their respective pages:
- Distributive (66% – 62% septic shock, 4% other)
- Cardiogenic (16%)
- Hypovolemic (16%)
- Obstructive (2%)
The general approach to undifferentiated shock is described separately. This articles describes specific findings and treatment of this type of shock.
Etiology
Hypovolemia results from a loss of intravascular fluid causing decreased preload and stroke volume, thus decreased cardiac output.
Hemorrhagic
- Shock due to a reduction in intravascular volume from blood loss
- Can be due to blunt or penetrating trauma, upper, and lower GI bleed (in order of prevalence).
- Less common causes include intra- and postoperative bleeding, ruptured aneurysm, and more
Non-hemorrhagic
- Loss of fluid other than blood
- Could be from GI (eg. diarrhea, vomitting), skin loss (eg. burns), renal loss (eg. salt-wasting nephropathies), or third space losses into extravascular space or body cavities
Risk Factors
- Trauma
- GI problems (eg. ulcer, bleed)
- Surgery
- Ectopic pregnancy
- Burst aneurysm
Clinical Presentation
Signs & Symptoms
Vitals:
- Tachycardia (may be normal on beta blocker)
- Hypotension
- Tachypnea (unless severe shock)
- SpO2 usually normal (unless severe)
- Decreased pulse pressure
Presents with characteristic reduced preload with suspected/known cause:
- Reduced skin turgor
- Dry mucous membranes
- Collapsible IVC on imaging
- Low CVP (<8 mmHg)
- Orthostatic hypotension
- Pallor
- Flattened JVP
- Sequelae of chronic liver disease
Findings may vary additionally based on hemorrhagic or nonhemorrhagic etiology.
History & Physical Exam
Diagnosis
Criteria
Shock is a clinical diagnosis.