Shock

Last updated: September 2023

Shock is a condition of widespread reduced tissue perfusion and inadequate oxygen delivery. Prolonged shock can result in cellular dysfunction and irreversible organ failure. Mortality is high without early diagnosis and treatment.

Clinical features

Shock should be suspected in patients with:

• Sign(s) of hypotension: weak pulse, low or declining blood pressure (BP) a Citation a. Hypotension is based on systolic blood pressure (SBP) in adults: SBP < 90 mmHg or decrease in SBP ≥ 40 mmHg from baseline or mean arterial pressure MAP < 65 mmHg. Shock is often accompanied by hypotension but may also occur with normal or elevated BP. , narrow pulse pressure
• Acute onset of signs of tissue hypoperfusion:
  • Skin: pallor, mottled skin, sweating, cold extremities or lower limb temperature gradient b Citation b. Run the back of the hand from the toe to the knee. A notable temperature change from the cold foot to the warm knee is a positive temperature gradient, indicating distal hypoperfusion. , capillary refill time (CRT) ≥ 3 seconds
  • Lungs: tachypnea, dyspnoea
  • Heart: tachycardia, which often occurs before BP decreases
  • Kidney: oliguria (urine output < 0.5 to 1 ml/kg/hour) or anuria
  • Brain: thirst, anxiety, agitation, confusional state, apathy, altered mental status

Management

• Attend to the patient immediately even if the type of shock is not known. Call for help. Move to critical care unit if possible.
• Assess and manage A (airway), B (breathing), and C (circulation) according to Basic Life Support (see below). If anaphylaxis is suspected, immediately go to specific management.  
• Take a rapid history to try to determine underlying cause.
• Monitor:
  • urine output hourly (insert a urinary catheter)
  • HR, RR, BP, temperature, CRT, SpO₂, and level of consciousness
• Perform the following tests:
  • haemoglobin and blood glucose level
  • malaria rapid diagnostic test in endemic area: see Malaria, Chapter 6
  • blood culture (if available) and blood group
• In children, administer ceftriaxone IV e Citation e. For IV administration of ceftriaxone, dissolve only in water for injection. : one dose of 80 mg/kg. Reassess need for further antibiotic treatment according to underlying cause.
• Treat pain: see Pain, Chapter 1.

Primary objective of shock management is to restore adequate tissue perfusion, demonstrated by:

• Returning vital signs, CRT, SpO₂, mental status, etc. to normal.
• Maintaining mean arterial pressure (MAP) f Citation f. MAP = diastolic BP (DBP) + 1/3 (SBP-DBP). A patient with BP 90/60 has a MAP = 60 + 1/3 (90-60) = 70. > 65 mmHg in adults (or higher if patient has pre-existing hypertension).
• Maintaining urine output > 0.5 to 1 ml/kg/hour.

After initial management:

• Take a more detailed history.
• Perform a comprehensive physical examination.
• In case of dehydration: see Dehydration, Chapter 1.
• In case of blunt thoracic or abdominal trauma, perform POCUS g Citation g. POCUS should only be performed and interpreted by trained clinicians. : (e)FAST exam to evaluate for pneumothorax or free fluid in pleural, pericardial and/or peritoneal spaces. Refer to surgeon as required.

On-going care:

• Re-evaluate patient’s condition and response to treatment every 10 minutes until patient is stable.
• Perform a second comprehensive physical examination.
• Initiate nutritional support adapted to patient's needs as soon as possible and reassess regularly. Patients have high protein and energy requirements. Enteral route is preferred. 

Basic Life Support

1) Manage airways and breathing

• Lay the patient on their back. However:
  • if spinal trauma is suspected, do not move the patient;
  • in case of anaphylaxis, the patient may prefer a sitting position.
• In case of altered mental status:
  • be prepared with mask and bag if needed for ventilation;
  • remove any airway obstruction (e.g. secretions, foreign body);
  • open airway: stand at head of bed, place one hand on the forehead and gently tilt the head back. Simultaneously, place the fingertips of the other hand under the chin and lift the chin. If suspicion of spinal trauma, do not move the neck. Instead, place heels of both hands on patient’s parietal areas, and use index and middle fingers of both hands to push the angle of mandible anteriorly (jaw thrust)
  • if needed, insert an oropharyngeal airway.
• Auscultate lungs to assess ventilation.
• Administer 10 to 15 litres/minute of oxygen with mask to maintain SpO₂ > 94%.
• If SpO₂ remains ≤ 94% with oxygen, see If resources allow.

2) Maintain circulation

• Control bleeding:
  • apply direct manual pressure and/or compression/haemostatic dressing to the wound;
  • in case of massive life-threatening bleeding from an extremity (e.g. leg) not controlled by direct pressure: apply a windlass tourniquet h Citation h. The patient should receive surgery within 1 hour of the application of a windlass tourniquet. After 1 hour, there is a risk of ischaemic injury of the limb. If surgery is not possible and the tourniquet is required to save the patient’s life, it should be left in place. Any tourniquet that has been applied for more than 6 hours should be left in place until arrival at a facility capable of providing definitive surgical care. [5] Citation 5. Richey SL. Tourniquets for the control of traumatic hemorrhage: a review of the literature. World J Emerg Surg. 2007;2:28. Published 2007 Oct 24.  
    https://doi.org/10.1186/1749-7922-2-28 .
• Insert 2 peripheral IV lines (catheters 20-22G in children and 14-18G in adults) or an intraosseous (IO) needle.
• Administer Ringer lactate (RL) i Citation i. Crystalloids should be used. Colloids (e.g. modified fluid gelatin, albumin) are not recommended. , glucose 5%-Ringer lactate (G5%-RL) j Citation j. Remove 50 ml of RL from a 500 ml RL bottle or bag, then add 50 ml of 50% glucose to the remaining 450 ml of RL to obtain 500 ml of 5% glucose-RL solution. , and/or blood, following specific management described below. Reassess before giving additional fluid therapy. Monitor for fluid overload k Citation k. In case of fluid overload: sit the patient up, reduce the infusion rate to a minimum and administer furosemide IV (0.5 mg/kg in children; 40 mg in adults). Monitor the patient closely over 30 minutes and assess for underlying cardiorespiratory or renal disease. Once the patient is stabilised, reassess the necessity of continuing IV fluids. If IV fluids are still required, re-start at half the previous infusion rate and monitor closely. , especially in patients at risk, e.g. severely malnourished children; patients with severe malaria, heart disease, severe anaemia; older patients.  
• Maintain normal body temperature.
• If unable to maintain BP, see If resources allow.

Anaphylaxis

• Remove exposure to causal agent.
• Administer epinephrine (adrenaline) IM into the mid-anterolateral thigh. Use undiluted solution and a 1 ml syringe graduated in 0.01 ml [6] Citation 6. Emergency treatment of anaphylaxis. Guidelines for healthcare providers. Rescuscitation Council UK. Updated 2021 [Accessed May 31 2023].
  https://www.resus.org.uk/sites/default/files/2021-05/Emergency%20Treatment%20of%20Anaphylaxis%20May%202021_0.pdf :
  • Children under 6 months: 0.1 to 0.15 ml
  • Children 6 months to 5 years: 0.15 ml
  • Children 6 to 12 years: 0.3 ml
  • Children over 12 years l Citation l. If small or prepubertal children, administer 0.3 ml of epinephrine. and adults: 0.5 ml

Repeat after 5 minutes if no or poor clinical improvement (up to a total of 3 IM injections). 

• Monitor HR, BP, CRT and clinical response.
• In case of stridor, administer nebulized epinephrine: 0.5 mg/kg/dose (max. 5 mg) in 5 ml of 0.9% sodium chloride over 10 to 15 minutes
• If SpO₂ is < 94%, ventilate with bag mask.
• Administer a bolus of RL:
  • Children: 10 ml/kg as quickly as possible
  • Adults: 500 ml as quickly as possible

Repeat bolus once if signs of poor perfusion persist after 15 minutes.

• If shock persists after 3 IM injections of epinephrine, in particular if unable to maintain BP, see If ressources allow.
• After initial treatment with epinephrine and IV fluids, some patients (e.g. patients requiring continuing treatment after 2 doses of epinephrine IM or patients with ongoing asthma or shock) may benefit from a short course of corticosteroid therapy. When the patient is stable, prednisolone PO : 1 to 2 mg/kg (max. 50 mg) once daily in the morning for 3 to 5 days. Use an IV corticosteroid only if the patient cannot take oral treatment.

Septic shock

Cardiogenic shock

• Administer RL with extreme caution and monitor closely for signs of fluid overload:
  • Adults: 100 to 250 ml over 30 minutes
  • Subsequent fluid administration should be based on thorough patient assessment, including urinary output, mental status and SpO₂.
• Vasopressors are often required to maintain BP, see If resources allow.
• In case of acute heart failure, see Heart failure in adults, Chapter 12.
• Arrhythmias should be managed according to Advanced Life Support techniques as appropriate and where available.

Hypovolemic non-haemorrhagic shock

• Administer RL:
  • Children under 1 year: 30 ml/kg over 1 hour then 70 ml/kg over 5 hours
  • Children/adolescents 1 to 14 years: 30 ml/kg over 30 minutes then 70 ml/kg over 2.5 hours
  • Adolescents 15 years and over and adults: 250 to 500 ml as quickly as possible (to be repeated once if required) then adjusted to patient’s condition, providing up to 70 ml/kg over 2.5 hours

Hypovolaemic haemorrhagic shock

In order to prevent the “lethal trauma triad” of hypothermia, acidosis and coagulopathy:

• Determine blood group and if needed transfuse, as quickly as possible:
  • Children under 20 kg: 20 ml/kg of whole blood
  • Children 20 kg and over and adults: an adult unit of whole blood

Repeat if needed.

• If blood is not immediately available, administer a bolus of RL with caution (i.e. minimize the use of RL) while waiting for blood:
  • Children: 20 ml/kg as quickly as possible
  • Adults: 250 to 500 ml as quickly as possible

When blood is available, stop RL and administer blood only.

• Warm the patient (blankets, warm room, warm IV fluids).
• In case of trauma presenting within 3 hours, administer tranexamic acid slow IV (over 10 minutes):
  • Children: 15 mg/kg (max. 1 g)
  • Adults: 1 g

Then immediately start a second dose, administered by IV infusion over 8 hours.

• In case of postpartum haemorrhage, refer to the guide Essential obstetric and newborn care, MSF.
• Refer to surgery if needed.

Obstructive shock

The management described up to this point will provide only temporary stabilization. Treat the cause or refer for aetiological treatment:

• Pulmonary embolism: anticoagulation +/- thrombolysis.
• Tension pneumothorax: needle decompression/finger thoracostomy, followed by insertion of chest tube.
• Cardiac tamponade: pericardial tap.