Shock

Clinical definition and danger

Shock is an acute failure of tissue perfusion. Oxygen delivery becomes inadequate for cellular needs, and delayed correction can lead to irreversible organ injury and death.

Do not wait for hypotension before acting. Children, young adults, pregnant patients, and previously healthy adults may maintain blood pressure until shock is advanced.

The first clinical task is to recognise poor perfusion, support airway and breathing, restore circulation when appropriate, and treat the cause in parallel.

Clinical features

Suspect shock in any severely ill patient with hypotension or signs of acute tissue hypoperfusion. In children, treat shock when a critically ill child has a cold lower-limb temperature gradient, capillary refill time of 3 seconds or more, weak radial pulse, or severe tachycardia.

• Circulation: weak pulse, low or falling blood pressure, narrow pulse pressure, delayed capillary refill, cold extremities, mottled skin, pallor, sweating, or a cold-to-warm temperature gradient from foot toward knee.
• Respiratory system: tachypnoea, dyspnoea, low oxygen saturation, or respiratory fatigue.
• Heart: tachycardia often precedes hypotension; bradycardia or arrhythmia may occur in specific causes.
• Kidneys: oliguria, no urine output, or falling urine output below about 0.5 to 1 ml/kg/hour.
• Brain: thirst, anxiety, agitation, confusion, apathy, drowsiness, or reduced level of consciousness.

Classify the likely type of shock

• Mixed shock is common. Sepsis with dehydration, trauma with tension pneumothorax, or anaphylaxis with bronchospasm may need more than one pathway at the same time.
• If the diagnosis is uncertain, continue resuscitation and reassessment while searching for reversible causes.

Immediate management

• Attend immediately, call for senior help, and move the patient to an emergency or critical-care area when possible.
• Use an ABC approach: protect airway, assess breathing, support oxygenation, restore circulation, and treat the cause at the same time.
• If anaphylaxis is suspected, give IM epinephrine immediately and remove the trigger if possible.
• Take a focused rapid history: onset, fever or infection source, allergy exposure, medicines, trauma, bleeding, diarrhoea/vomiting, burns, chest pain, pregnancy, surgery, immobilisation, heart disease, immunodeficiency, and recent antibiotics or admission.
• Insert two peripheral IV lines if possible, using an intraosseous route when IV access cannot be obtained quickly in a critically ill patient.
• Check haemoglobin and blood glucose early. In malaria-endemic settings, test for malaria when relevant. Send blood culture and blood group/crossmatch when available, but do not delay emergency treatment.
• Treat pain, hypoglycaemia, hypothermia, and severe anaemia when present.

Monitoring targets

The practical target is restored perfusion. Reassess repeatedly because the same treatment can be lifesaving in one shock type and harmful in another.

• Monitor pulse, respiratory rate, blood pressure, temperature, capillary refill, oxygen saturation, mental status, skin temperature, urine output, and response to each intervention.
• Insert a urinary catheter when appropriate and record hourly urine output.
• In adults, aim for adequate mental status, improving perfusion, oxygen saturation above 94% when possible, mean arterial pressure above 65 mmHg unless a higher target is clinically required, and urine output above about 0.5 to 1 ml/kg/hour.
• Reassess at least every 10 minutes while unstable. Review for ongoing bleeding, fluid overload, resistant infection, missed obstruction, cardiogenic shock, hypoglycaemia, severe anaemia, or worsening respiratory failure.

Airway and breathing support

• Position the patient supine unless spinal injury is suspected or the patient with anaphylaxis is more comfortable sitting upright.
• For altered consciousness, clear secretions or foreign material, open the airway with head tilt and chin lift, or use jaw thrust if spinal trauma is possible.
• Use an oropharyngeal airway when indicated and available.
• Auscultate the chest and assess ventilation. Give high-flow oxygen by mask when available, commonly 10 to 15 litres/minute, targeting oxygen saturation above 94%.
• If oxygen saturation remains low or breathing fails, provide bag-mask ventilation and escalate to non-invasive or invasive ventilation where resources and trained staff are available.
• Complete airway obstruction requires immediate advanced airway management, including intubation or emergency front-of-neck access where trained care is available.

Circulation, bleeding control, and fluids

• Control external bleeding with direct pressure and a compression or haemostatic dressing. For life-threatening limb bleeding not controlled by pressure, apply a windlass tourniquet and arrange definitive surgical control urgently.
• Use crystalloids rather than colloids. Ringer lactate is commonly preferred; 0.9% sodium chloride is an alternative in many settings.
• Record all infused volumes and all fluid losses. Reassess before every additional bolus.
• Watch closely for fluid overload, especially in severe acute malnutrition, severe malaria, heart disease, severe anaemia, renal disease, older adults, and patients already showing pulmonary oedema.
• If fluid overload develops, sit the patient up, reduce IV fluids to the minimum, reassess lungs and perfusion, and use furosemide only when clinically indicated and monitored.

Anaphylactic shock treatment

Anaphylaxis is a clinical diagnosis. Treat immediately when acute allergic features are associated with respiratory compromise, hypotension, collapse, severe gastrointestinal symptoms, or laryngeal involvement.

• Remove the trigger when possible. Monitor heart rate, blood pressure, capillary refill, breathing, oxygen saturation, and clinical response.
• For stridor, nebulised epinephrine may be used where available and monitored; for persistent hypoxia, ventilate with bag and mask.
• Give Ringer lactate bolus if poor perfusion persists: 10 ml/kg rapidly in children or 500 ml rapidly in adults, repeating once after reassessment when needed.
• If shock persists after 3 IM epinephrine doses, manage in a critical-care setting with vasoactive infusion if resources allow.
• After epinephrine and fluids, selected patients with ongoing asthma, shock, or need for repeated epinephrine may benefit from a short corticosteroid course once stable; oral prednisolone is preferred when the patient can swallow.

Septic shock treatment

Look for the source of infection and obtain cultures when this does not delay treatment. Antibiotics should start rapidly, guided by likely focus, severity, allergy history, pregnancy status, local resistance, and recent healthcare exposure.

• In children with shock, give ceftriaxone IV as an early empiric dose while reassessing the cause and ongoing antibiotic need.
• If cultures identify an organism, narrow or adapt therapy. If improving after 24 to 48 hours, switch to oral therapy when clinically appropriate, except when the infection focus requires prolonged IV treatment.
• If there is no improvement after 48 to 96 hours, reassess for resistant pathogens, wrong source, abscess, catheter infection, obstruction, immunodeficiency, or recent hospital/antibiotic exposure.
• Control the source: remove infected catheters, drain abscesses, irrigate and debride traumatic wounds, relieve obstruction, and refer for surgery where needed.

Cardiogenic shock treatment

• Avoid aggressive fluid loading. If fluids are needed, give small cautious Ringer lactate boluses, such as 100 to 250 ml over 30 minutes in adults, and reassess lungs, oxygenation, mental status, urine output, and perfusion.
• Look for acute heart failure, myocardial ischaemia, arrhythmia, valvular disease, myocarditis, and cardiotoxic medicines or toxins.
• Vasopressors or inotropes are often required when hypotension persists, but they need critical-care monitoring and controlled infusion.
• Treat arrhythmias using advanced life-support protocols where trained staff and equipment are available.

Hypovolaemic non-haemorrhagic shock treatment

• Treat the cause of fluid loss, such as diarrhoea, vomiting, intestinal obstruction, burns, heat illness, or poor intake.
• Start oral rehydration as soon as the patient can drink safely when diarrhoea or vomiting is the cause.
• Monitor for electrolyte disturbance, abdominal distension, ongoing losses, urine output, and recurrence of shock.

Hypovolaemic haemorrhagic shock treatment

• Stop bleeding and arrange definitive surgical or obstetric care immediately when needed.
• Determine blood group and transfuse as soon as indicated and available. When blood is available, prioritise blood rather than repeated crystalloid boluses.
• If blood is not immediately available, give cautious Ringer lactate while waiting: about 20 ml/kg rapidly in children or 250 to 500 ml rapidly in adults, then reassess.
• Prevent the trauma triad of hypothermia, acidosis, and coagulopathy by warming the patient, warming IV fluids where possible, limiting unnecessary crystalloids, controlling bleeding, and moving quickly to surgery when required.
• For traumatic bleeding presenting within 3 hours, give tranexamic acid slow IV over 10 minutes when not contraindicated: children 15 mg/kg up to 1 g; adults 1 g, followed immediately by a second dose over 8 hours according to protocol.
• For postpartum haemorrhage, follow the obstetric emergency protocol and refer to essential obstetric and newborn care guidance.

Obstructive shock treatment

• Resuscitation provides only temporary stabilisation. Definitive treatment of the obstruction is required.
• Suspected pulmonary embolism may need anticoagulation and, in selected severe cases, thrombolysis according to available expertise and contraindications.
• Tension pneumothorax requires immediate decompression followed by chest tube insertion.
• Cardiac tamponade requires urgent pericardial drainage by trained staff.
• Use point-of-care ultrasound such as eFAST for blunt thoracic or abdominal trauma only when trained clinicians can perform and interpret it; do not delay lifesaving procedures for imaging when the diagnosis is clinically obvious.

Vasopressors and advanced resources

Use vasoactive infusions only when there is close monitoring, appropriate vascular access, controlled delivery with syringe or infusion pump when possible, trained staff, and frequent review. Peripheral infusion requires a large proximal peripheral line and close inspection for extravasation.

• Account for all carrier fluid when calculating fluid balance.
• Measure and correct potassium, magnesium, calcium, phosphate, and other abnormalities when resources allow.
• Order further investigations such as imaging or laboratory testing based on the suspected cause and the patient's stability.

Complications to prevent and detect

• Organ failure: acute kidney injury, altered mental status, respiratory failure, liver injury, myocardial dysfunction, coagulopathy, or lactic acidosis.
• Treatment complications: fluid overload, pulmonary oedema, extravasation of vasoactive infusions, arrhythmia, hypoglycaemia, electrolyte derangement, antibiotic toxicity, and transfusion reactions.
• Sepsis complications: abscess, necrotising infection, resistant organism, meningitis, pneumonia progression, catheter-related infection, and septic embolic phenomena.
• Haemorrhage complications: recurrent bleeding, hypothermia, acidosis, coagulopathy, compartment ischaemia after tourniquet use, and delayed definitive surgery.

Prevention and system measures

• Prevent septic shock through vaccination, early infection treatment, safe surgery, clean wound care, catheter hygiene, hand hygiene, and antimicrobial stewardship.
• Prevent anaphylaxis recurrence by documenting the trigger, avoiding re-exposure, educating the patient, and ensuring emergency action planning where feasible.
• Prevent hypovolaemic shock by early ORS use in diarrhoea, rapid management of vomiting, safe water and sanitation, nutrition support, and early referral for severe dehydration.
• Prevent haemorrhagic shock through trauma prevention, rapid bleeding control training, safe obstetric care, early recognition of postpartum haemorrhage, and reliable referral pathways.
• Emergency units should keep shock medicines, fluids, oxygen, glucose testing, blood-grouping access, monitoring tools, and transfer pathways ready before the emergency happens.

Referral and handover

• Refer urgently when shock persists, oxygen need is high, airway support is required, surgery or obstetric care is needed, vasoactive infusion is required, blood transfusion is needed but unavailable, or diagnosis remains uncertain after initial stabilisation.
• Handover should include onset, likely shock type, vital signs trend, mental status, urine output, capillary refill, oxygen support, fluids and blood given, medicines and times, glucose and haemoglobin values, cultures/tests sent, suspected source, and response to treatment.
• During transfer, continue oxygen if available, maintain warmth, secure lines, monitor consciousness and breathing, and send a trained escort when possible.