Shock

R57.9

DESCRIPTION

An acute syndrome that reflects the inability of the pulmonary and circulatory system to provide adequate perfusion, oxygen and nutrients to meet physiological and metabolic demands.

Compensation is achieved by increased pulse rate, and peripheral vascular constriction. The blood pressure is relatively well maintained but the patient still requires urgent resuscitation.

Shock can be further characterised:
- Hypovolaemic shock: loss of intravascular fluid, e.g. dehydration, haemorrhage or fluid shifts.
- Distributive shock: e.g. septicaemia and anaphylaxis.
- Cardiogenic shock: e.g. cardiac dysfunction.
- Dissociative shock: e.g. profound anaemia and carbon monoxide poisoning.
- Obstructive shock: e.g. pneumothorax and cardiac tamponade.
- Septic shock: many mechanisms are operative in septic shock.
- Neurogenic shock: e.g. spinal cord trauma.

Complications of shock include multi-organ dysfunction and/or failure.

DIAGNOSTIC CRITERIA

Evidence of compensated shock includes:

  • cold peripheries,
  • weak pulse pressure especially peripheral pulse weaker than central pulses,
  • prolonged capillary filling, i.e. > 3 seconds,
  • agitation/confusion/decreased level of consciousness,
  • skin pallor,
  • increased heart rate,
  • signs and symptoms of underlying conditions.

In uncompensated shock, falling BP and failure to act urgently will result in irreversible shock and death.

Facilities to start treatment of shock must be available at all health centres.

GENERAL AND SUPPORTIVE MEASURES

  • Follow the ABCD algorithm, see Triage .
  • Identify and treat the underlying cause.
  • Ensure good intravenous or intra-osseous access. In trauma, two large bore lines for access are important. See Intra-Osseous Infusion in Emergencies .
  • Perform relevant investigations.
  • Monitor:
    • vital signs and maintain within normal limits.
    • metabolic parameters and correct as needed.
    • urinary output – aim for at least 1 mL/kg/hour.

MEDICINE TREATMENT

To optimise oxygen delivery to the tissue, administer:

  • Oxygen, high flow, 15 L/minute via facemask with reservoir bag or 6–10 L/minute via head box.

If oxygen saturation < 92% or PaO2 < 80 mmHg consider need to intubate and continue respiratory support.

1.Hypovolaemic shock

Response to each step of management must be reviewed every 15 minutes. If after administration of a total of 40ml/kg of sodium chloride 0.9% fluid, shock has not resolved, consider other causes and the need for inotropes.

For fluid deficit (vs. blood loss):
IV fluids to correct the intravascular fluid deficit and improve circulation:

  • Sodium chloride 0.9%, IV, 20 mL/kg rapidly.
  • Review after each bolus to see if shock has resolved.

In children with severe malnutrition :

  • Sodium chloride 0.9%, IV, 10 mL/kg administered over 20 minutes.
  • Review after each bolus to see if shock has resolved.

With each re-assessment, if:

  • Shock has resolved (capillary filling time < 3 seconds, good pulse, normal blood pressure), do not repeat fluid bolus.
  • Shock is better but still present, repeat bolus (up to 40 mL/kg). After this further care should be in an ICU setting. Consider initiation of inotropes.
  • Monitor for persistence of shock, i.e.
  • Non-responding or decreasing BP.
  • Non-responding or increasing pulse rate/decreasing volume.
  • Non-responding or increasing capillary filling time.
  • Monitor for fluid or circulatory overload, i.e.
    • Increasing respiratory rate.
    • Increasing basal crepitations.
    • Increasing pulse rate.
    • Increasing liver size/tenderness.
    • Increasing JVP.

After circulatory stabilisation, continue with appropriate maintenance fluid.

For blood loss:

  • Packed red cells or whole blood, 5-10 mL/kg, repeat if required.

While awaiting blood products to arrive, proceed with volume resuscitation

2.Cardiogenic shock
Ideally children receiving treatment for cardiogenic shock should be in high care or ICU.

Inotropic support:
When perfusion is poor and blood pressure response is unsatisfactory, despite adequate fluid replacement.

  • Dobutamine, IV, 5–15 mcg/kg/minute.

Chronotropic/inotropic plus vascular tone support:
If tissue perfusion and blood pressure do not improve satisfactorily on adequate fluid volume replacement and inotropic support, consider:

  • Epinephrine (adrenaline), IV infusion, 0.01–1 mcg/kg/minute.

If poor ventricular contractility and increased afterload are considered as the primary problem, do not give epinephrine (adrenaline) but consider adding an afterload reducing agent to the dobutamine infusion but only with specialist advice.

3.Septic shock
Treatment for septic shock should be initiated urgently and then patients should preferably be transferred to an ICU.

Response to each step of management must be reviewed every 15 minutes.

IV fluids:

  • Sodium chloride 0.9%, IV, 10 mL/kg rapidly.
    • Review after each bolus to see if shock has resolved.

In children with severe malnutrition :

  • Sodium chloride 0.9%, IV, 10 mL/kg administered over 20 minutes.
    • Review after each bolus to see if shock has resolved.

With each reassessment, if:

  • Shock has not resolved after 40 ml/kg of sodium chloride 0.9% fluid, consider inotropes.
  • Shock has resolved (capillary filling time < 3 seconds, good pulse, normal blood pressure), do not repeat bolus. Proceed to other care.
  • Shock is better but still present, repeat bolus (up to 40 mL/kg). After this further care should be in an ICU setting.
  • Monitor for persistence of shock, i.e.:
    • Non-responding or decreasing BP.
    • Non-responding or increasing pulse rate/decreasing volume.
    • Non-responding or increasing capillary filling time.
  • Monitor for fluid or circulatory overload, i.e.:
    • Increasing respiratory rate.
    • Increasing basal crepitations.
    • Increasing pulse rate.
    • Increasing liver size/tenderness.
    • Increasing JVP.

Chronotropic/Inotropic plus vascular tone support
If tissue perfusion and blood pressure do not improve satisfactorily on adequate fluid volume replacement.
Titrate inotropes against the response, and add additional agent if poor response.

  • Epinephrine (adrenaline), IV infusion, 0.01–1 mcg/kg/minute.

If inadequate response:
ADD

  • Dobutamine, IV, 5–15 mcg/kg/minute.

Unresponsive septicaemic shock:

  • Hydrocortisone, IV, 1 mg /kg/dose, 6 hourly until shock has resolved.

Antibiotic therapy

Start antibiotics early.
Before initiating antibiotic therapy, take blood and urine specimens, if appropriate, for culture and sensitivity testing.
Reconsider antibiotic and/or antifungal therapy when culture and sensitivity results become available.

  • 3rd generation cephalosporins, e.g.:
  • Cefotaxime, IV, 75 mg/kg/dose, 8 hourly (neonates).

OR
Children > 1 month:

  • Ceftriaxone, IV, 50 mg/kg/dose, 12 hourly.

Caution

Patients must be resuscitated and stabilised before referral.