Anaphylaxis/anaphylactic shock

T78.2 + (Y34.99/Y57.9/Y14.99)

DESCRIPTION

An acute, potentially life-threatening hypersensitivity reaction.

The reaction usually starts within seconds to minutes after administration of, or exposure to a substance to which the individual has been sensitised.

Clinical manifestations range from mild urticaria and angioedema to upper airway obstruction, bronchospasm, hypotension, shock and death.

The reaction can be short-lived, protracted or biphasic, i.e. acute with recurrence several hours later.

Immediate reactions are usually the most severe and/or life threatening.

GENERAL MEASURES

Administer adrenaline (epinephrine) immediately (see below)

Cardiopulmonary resuscitation, if required.

Maintain an open airway. Intubate, if necessary.

Monitor all vital parameters (including pulse and blood pressure) closely.

Reassure and comfort the patient.

Patient counselling to prevent recurrence.

An alert bracelet should be worn at all times.

MEDICINE TREATMENT

  • Adrenaline (epinephrine) 1:1000, 0.5 mL, IM, immediately into anterolateral thigh.
    • Repeat dose every 5 minutes, as required.

In cases of persistent hypotension or where multiple repeat doses are required:

  • Adrenaline (epinephrine), IV infusion, start at 0.05 mcg/kg/minute titrated according to the response.
    • Dilute 10 mg i.e. 10 ampoules of adrenaline 1:1 000 in 1 L sodium chloride 0.9%.
    • Infuse according to weight and clinical response.
    • Infusion rate: mL/hour:
Weight in kg
mcg/kg/minute 50 60 70 80 90 100 110
0.05 15 18 21 24 27 30 33
0.1 30 36 42 48 54 60 66
0.2 60 72 84 96 108 120 132
0.3 90 108 126 144 162 180 198
0.4 120 144 168 192 216 240 264
0.5 150 180 210 240 270 300 330
0.6 180 216 252 288 324 360 396
0.7 210 252 294 336 378 420 462
0.8 240 288 336 384 432 480 528
0.9 270 324 378 432 486 540 594
1 300 360 420 480 540 600 660

LoEIII

AND

  • Hydrocortisone, IV/IM, 200 mg, immediately as a single dose.

AND

Intravenous fluids

Establish an intravenous line:

  • Sodium chloride 0.9%, IV.

LoEI [13]

If bronchospasm:

  • Oxygen if saturation <94%.

LoEI [14]

AND

  • Salbutamol, nebulisation, 5 mg.
    • Nebulise continuously (refill the nebuliser reservoir every 20 minutes) at a flow rate of 6–8 L/minute

LoEIII [15]

AND

  • Ipratropium bromide, nebulisation 0.5 mg, added to salbutamol solution.

LoEIII [16]

If urticaria and/or itch present:

  • Antihistamine, e.g.:
  • Promethazine, IV 25–50 mg as a single dose.

OR

  • Cetirizine, oral, 10 mg as a single dose.

LoEIII [17]