Shock, Sepsis & Multisystem · Topic 3 of 14

Hypovolemic & Hemorrhagic Shock

Shock & resuscitation · hypovolemic shock

Hypovolemic & Hemorrhagic Shock

Lost volume, low output. In hemorrhage: stop the bleeding, transfuse 1:1:1, accept SBP 80–90 mmHg until control, and give tranexamic acid within 3 hours.

Key numbers

ATLS hemorrhage classes by percent blood lostClass IV > 40% loss

Permissive hypotension: SBP 80–90 until controlSBP 80–90 mmHg

Transfuse plasma, platelets, red cells 1:1:11:1:1

Tranexamic acid within 3 hours of injuryTXA 1 g ≤ 3 h

Shock index ≥ 0.9–1.0 flags transfusion needSI ≥ 0.9–1.0

01 · DoPermissive hypotension: SBP 80–90 until control

Until major bleeding is stopped, use restricted-volume resuscitation to SBP 80–90 mmHg (MAP about 50–60) — not with traumatic brain injury, where MAP ≥ 80 mmHg is kept in severe TBI (GCS ≤ 8).

02 · DoTransfuse plasma, platelets, red cells 1:1:1

In severe hemorrhagic shock transfuse early with plasma, platelets and red cells in about a 1:1:1 ratio (or whole blood) rather than more crystalloid, limiting dilutional and consumptive coagulopathy.

03 · GiveTranexamic acid within 3 hours of injury

Give tranexamic acid as soon as possible, and within 3 hours of injury, to the bleeding trauma patient: 1 g IV over 10 minutes, then 1 g infused over 8 hours.

Presentation

What you'll see

Narrowed pulse pressure precedes hypotensionEarly hemorrhage is compensated: tachycardia, narrowed pulse pressure, cool skin and delayed capillary refill appear before blood pressure falls, so a normal BP does not exclude major blood loss.

Diagnosis & monitoring

Work-up

ATLS hemorrhage classes by percent blood lost must knowATLS classes by blood volume lost: I < 15%, II 15–30%, III 31–40%, IV > 40%. Blood pressure usually holds until class III; class IV needs a massive transfusion protocol.

Shock index ≥ 0.9–1.0 flags transfusion needShock index = heart rate ÷ systolic BP (normal 0.5–0.7); with pulse pressure it grades hypovolemia — SI ≥ 0.9–1.0 is associated with massive transfusion and need for intervention.

Track lactate and base deficit seriallyMeasure lactate (or base deficit if lactate is unavailable) early and repeatedly to estimate blood loss and hypoperfusion; a normal first hemoglobin can mask early bleeding, so repeat it.

Monitor coagulation and ionized calcium earlyMonitor coagulation early and repeatedly (PT/INR, fibrinogen, platelets or viscoelastic testing) and keep ionized calcium in the normal range (1.1–1.3 mmol/L) with calcium chloride, especially during massive transfusion.

Do right now

In this order

First moves

Hemorrhage control comes before volume

→

Transfuse plasma, platelets, red cells 1:1:11:1:1

→

Tranexamic acid within 3 hours of injuryTXA 1 g ≤ 3 h

→

Permissive hypotension: SBP 80–90 until controlSBP 80–90 mmHg

Why each step

Hemorrhage control comes before volumeControl bleeding first — direct compression, a tourniquet for extremity hemorrhage, a pelvic binder, and immediate surgery or angioembolization; volume replacement accompanies rather than precedes hemostasis.

Transfuse plasma, platelets, red cells 1:1:1In severe hemorrhagic shock transfuse early with plasma, platelets and red cells in about a 1:1:1 ratio (or whole blood) rather than more crystalloid, limiting dilutional and consumptive coagulopathy.

Tranexamic acid within 3 hours of injuryGive tranexamic acid as soon as possible, and within 3 hours of injury, to the bleeding trauma patient: 1 g IV over 10 minutes, then 1 g infused over 8 hours.

Permissive hypotension: SBP 80–90 until controlUntil major bleeding is stopped, use restricted-volume resuscitation to SBP 80–90 mmHg (MAP about 50–60) — not with traumatic brain injury, where MAP ≥ 80 mmHg is kept in severe TBI (GCS ≤ 8).

Management

Orders

Limit crystalloid; switch to blood earlyIn hemorrhage give limited crystalloid (adults about 1 L, or 5–10 mL/kg red cells, then reassess); prefer balanced crystalloid, but 0.9% saline with severe head injury, and restrict colloids.

Fluid-loss shock: rapid isotonic crystalloid, reassessNonhemorrhagic hypovolemic shock (vomiting, diarrhea, burns, diuretics, osmotic diuresis, capillary leak) is treated with isotonic crystalloid — 1 L rapidly in adults, then reassess and repeat.

Norepinephrine only if volume misses the targetIf restricted volume replacement does not reach the target pressure, add norepinephrine to fluids (dobutamine for myocardial dysfunction); vasopressors never substitute for hemorrhage control.

Find the source: FAST, then CT if stableFind the source with point-of-care ultrasound (FAST) and, if stable enough, contrast whole-body CT; think also of GI bleeding, ruptured AAA and ruptured ectopic pregnancy (pregnancy test).

Damage control surgery when coagulopathic or acidoticChoose damage control surgery for hemorrhagic shock with ongoing bleeding, coagulopathy, hypothermia, acidosis or inaccessible major injuries; prevent heat loss and rewarm actively.

More detail

Reference

Show 4 reference facts

Once red cells are needed, the European guideline targets hemoglobin 7–9 g/dL; Merck suggests about 9 g/dL after bleeding control and about 10 g/dL with active coronary or cerebrovascular disease.

Large-bore peripheral catheters suffice for most resuscitation (1 L crystalloid in 10–15 minutes); an 8.5 French central line with a pressure infuser gives a unit of red cells in under 5 minutes.

Recombinant factor VIIa is not first-line; consider it off-label only when major bleeding and coagulopathy persist despite all other measures.

Intubate without delay for airway obstruction, GCS ≤ 8, hypoventilation or hypoxemia; avoid hypoxemia and aim for normoventilation.

Pearl

Stop the bleeding, give blood instead of saline, accept a lower pressure until control, and give TXA within 3 hours.

Sources · Rossaint R et al. The European guideline on management of major bleeding and coagulopathy following trauma: sixth edition. Crit Care 2023;27:80 (includes ATLS 10th-edition hemorrhage classes) · Merck Manual Professional — Shock (reviewed Jun 2026) · Merck Manual Professional — Intravenous Fluid Resuscitation (2026) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).