Shock: Types, Signs and First Actions

Medical-Surgical · Cardiovascular·Updated 2026-10-27

What it is

Shock is inadequate tissue perfusion that leaves cells without enough oxygen, forcing anaerobic metabolism and lactic acidosis. The four types are hypovolemic (volume loss), cardiogenic (pump failure), distributive (septic, anaphylactic, neurogenic vasodilation) and obstructive (tamponade, tension pneumothorax, massive pulmonary embolism). Compensation through the sympathetic nervous system and RAAS raises heart rate, constricts skin vessels and cuts urine output, so these signs appear before hypotension.

What the NCLEX focuses on

Early signs: restlessness or anxiety, tachycardia, tachypnea, cool clammy skin, delayed capillary refill; hypotension is a late sign.
Falling urine output is the best bedside indicator of renal perfusion.
Hypovolemic shock: isotonic crystalloid (0.9% sodium chloride or lactated Ringer's) and blood for hemorrhage.
Cardiogenic shock: crackles, JVD and low output; fluids are given cautiously, with inotropes such as dobutamine.
Neurogenic shock (spinal injury at T6 or above): hypotension with bradycardia and warm, dry skin.
Septic shock: vasopressors needed to keep MAP 65 mm Hg or higher and lactate above 2 mmol/L despite adequate fluids; cultures before antibiotics, norepinephrine first-line.
Anaphylactic shock: IM epinephrine first; antihistamines and corticosteroids are adjuncts.

Priority nursing actions

Maintain airway and breathing; give oxygen and keep the client supine unless dyspneic.
Insert two large-bore IV catheters (or IO access) and give prescribed isotonic fluids.
Treat the cause: control bleeding, give IM epinephrine, or draw cultures and give antibiotics.
Start prescribed vasopressors after adequate fluids to reach the MAP goal.
Monitor MAP, heart rate, level of consciousness, hourly urine output and lactate.

Numbers to know

Value	Target	Why it matters
Mean arterial pressure	65 mm Hg or higher	Minimum for organ perfusion
Urine output	At least 0.5 mL/kg/hr	Lower output means poor renal perfusion
Lactate	Below 2 mmol/L (18 mg/dL)	Rising lactate shows anaerobic metabolism
Sepsis fluid bolus	30 mL/kg crystalloid within 3 hours	For hypotension or lactate 4 mmol/L or higher
Antibiotics in septic shock	Within 1 hour of recognition	Each delay raises mortality
Epinephrine IM (adult, anaphylaxis)	0.3 to 0.5 mg of 1 mg/mL, anterolateral thigh	Reverses vasodilation and bronchospasm

Common exam traps

Choosing Trendelenburg position: wrong because it impairs ventilation and gives no lasting rise in blood pressure.
Choosing to wait for hypotension before acting: wrong because restlessness, tachycardia and cool skin already signal shock.
Choosing dextrose-containing or hypotonic fluids for rapid resuscitation: wrong because they leave the vascular space.
Choosing a large fluid bolus for cardiogenic shock with crackles: wrong because it worsens pulmonary edema.
Choosing an antihistamine first for anaphylaxis: wrong because only epinephrine reverses airway edema and hypotension.

What to teach

A client with anaphylaxis history carries two epinephrine auto-injectors, uses one at the first sign of a reaction, then calls 911.
After discharge for sepsis, report fever, confusion, fast breathing or reduced urine output at once.

Try 2 NCLEX-style questions on this topic

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Question 1 · QID 36BAB31D

A client arrives after a high-speed motor-vehicle collision. Which new finding requires the nurse’s most immediate follow-up?

Select the best answer.

A. Urine output averaging 32 mL/hr
B. Cool, pale, clammy skin with increasing restlessness
C. Increasing pain and swelling around a fractured wrist with intact distal pulses
D. Oxygen saturation of 92% on room air with mild tachypnea

Question 2 · QID B1DF7C27

A client has had severe vomiting and diarrhea for 3 days. Assessment findings include:

Finding	Value
Heart rate	124/min
Blood pressure	82/48 mm Hg
Skin	Cool
Capillary refill	Delayed
Urine output	15 mL/hr

Which prescribed IV fluid should the nurse administer first for rapid volume resuscitation?

Select the best answer.

A. 0.9% sodium chloride
B. Lactated Ringer's solution with 5% dextrose
C. 0.45% sodium chloride with 20 mEq/L potassium chloride
D. 5% albumin

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Sources

Harding MM, Kwong J, Hagler D, Reinisch C. Lewis's Medical-Surgical Nursing: Assessment and Management of Clinical Problems. 12th ed. Elsevier; 2023; Chapter: Shock, Sepsis, and Multiple Organ Dysfunction Syndrome.
Evans L, Rhodes A, Alhazzani W, et al. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2021. Crit Care Med. 2021;49(11):e1063-e1143.

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