CuraRN

Hypovolemic Shock

Student study notes from paramedic coursework (2023 to 2024), not medical advice. Verify clinical values against current references and your local protocols.

EMS etiologies

Setting: ER

Hypovolemic shock occurs when there is insufficient blood volume or extracellular fluid in the body to maintain adequate organ perfusion. This condition can be caused by severe dehydration or blood loss. The body’s inability to maintain normal blood flow leads to organ dysfunction, potentially progressing to multiple organ failure if left untreated. Hypovolemic shock is a medical emergency that requires immediate intervention.

Causes of Hypovolemic Shock

1. Blood Loss (Hemorrhagic Shock):
   • Trauma (blunt or penetrating) is the most common cause of hemorrhagic shock.
   • Internal - gastrointestinal (GI) bleeding, ectopic pregnancy, post-surgical bleeding, splenic rupture, and ruptured aortic aneurysms.
   • Blood loss can occur both externally and internally (e.g., chest, abdomen, retroperitoneum, or thighs).
2. Fluid Loss (Non-Hemorrhagic Hypovolemia):
   • Gastrointestinal losses from vomiting, diarrhea, or external drainage (e.g., from a stoma).
   • Renal losses from excessive diuresis, as seen with certain medications or conditions like hyperglycemia.
   • Skin fluid losses due to burns, excessive sweating, or skin damage.
   • Third-spacing, where fluid is sequestered in areas like the intestines or in response to conditions like pancreatitis or vascular issues.

Clinical Presentation:

Patients with hypovolemic shock may exhibit:

• Tachycardia (fast heart rate)
• Hypotension (low blood pressure)
• Cold, clammy skin
• Decreased urine output
• Confusion or altered mental status due to reduced brain perfusion
• Pallor and cyanosis from vasoconstriction and poor oxygenation

Severe cases may involve acidosis, hypothermia, and coagulopathy (clotting dysfunction), known as the “lethal triad” in trauma-related shock.

Treatment Modalities:

Immediate treatment for hypovolemic shock focuses on:

• Restoring fluid volume through rapid intravenous fluid or blood transfusion.
• Identifying and stopping the source of blood or fluid loss.
• Monitoring and managing complications, such as acidosis and coagulopathy.

In trauma-related cases, damage control resuscitation focuses on permissive hypotension, hemostatic resuscitation, and damage control surgery to minimize further bleeding and prevent complications.