Management of Medical Emergency-Anaphylaxis!

 MEDICAL EMERGENCY- ANAPHYLAXIS

Definition:

"Anaphylaxis is a systemic response to exposure to an allergen caused by rapid, IgE-mediatd release of histamine and other mediators from tissue mast cells and circulating basophils".

Symptoms:

• Symptoms usually occur within a few seconds or minutes of exposure but can be delayed or recur many hours after apparent resolution (exposure).

Causes:

1. Upper airway obstruction
2. Cardiovascular collapse

are the most common causes of death in anaphylaxis.

Treatment:

The treatment of anaphylaxis is directed towards its three Major Presentations:

1. Skin Manifestations: Angioedema, Urticaria
2. Respiratory distress: Wheezing, Stridor, Dyspnea from laryngeal edema, laryngospasm and bronchospasm
3. Hypotension

All specific treatment measures should be accompanied by basic resuscitative measures including clear airway, supplemented oxygen and IV access.

General Therapy and Skin Manifestations:

1. Epinephrine HCl, IM or SC, 0.3-0.5mg; may repeat q(every) 10-15 minutes. In children, 10microgram/kg up to 500 microgram/dose.

2. Diphenhydramine, IV or IM, 1-2mg/kg (up to 50mg) over 5-10 minutes.

3. Cimetidine, IV, 300mg over 5 minutes for urticaria or if hypotension does not respond to fluid replacement and pressors. In children, 3-5mg/kg IV.

4. Although controversial, corticosteroids such as Hydrocortisone phosphate or Succinate, IV, 200mg or Methylprednisolone, IV, 1-2mg/kg might reduce the risk of recurrent or prolonged anaphylaxis.

Respiratory Distress:

1. Assure adequate oxygenation with supplemented oxygen by mask titrated to an oxygen saturation above 90%.

2. In addition to the general therapy described above, add Albuterol, by nebulization, 2.5-5mg q 20 minutes. In children, 0.15mg/kg by nebulization q 20 minutes.

3. If response is inadequate after 3-4 doses of intermittent Albuterol, consider Albuterol, by continuous nebulization, 10-15mg/hr. In children, 0.5mg/kg/hr. by continuous nebulization.

Hypotension:

1. If response to the general therapy described above is inadequate, give NS or Lactated Ringers Injection, IV, 500-1000mL initially and continue at high flow rate. In children, 10-20mL/kg IV initially.

2. Epinephrine HCl, IV continuous infusion, 1 microgram/min, up to 10 microgram/min.

3. Dopamine HCl, IV, 2-5 microgram/kg/minute, titrate to desired effect.

4. Patients taking Beta-adrenergic Blockers may not respond adequately to epinephrine and Fluid replacement and can be adversely affected by unopposed Alpha-adrenergic stimulation from Epinephrine. Glucagon, IV, 5-10mg followed by 1-5mg/hr. by continuous infusion can increase myocardial contractility independent of Beta receptors.

Information notes:

*Salbutamol is also known as Albuterol (Beta2 adrenergic agonist).

Lactated Ringers solution also known as Sodium lactate solution. For replacing fluids and electrolytres.

Glucagon is a peptide hormone produced by Alpha cells of pancreas. It causes increased glucose and fatty acids in blood stream. Also considered as a Catabolic hormone