Wednesday, April 28, 2010

Treatment anaphylaxis

Epinephrine
Epinephrine 1:1000, 0.01 mg/kg to a maximum of 0.5 mg, should be injected intramuscularly, without delay. This dose may be repeated at intervals of 5–15 minutes as necessary for controlling symptoms and maintaining blood pressure. 

Antihistamines
CPM an H1-blocker, 0.1 mg/kg IV q 6 hr.
Ranitidine, an H2-blocker, 1 mg/kg up to 50 mg intravenously
Cimetidine, an H2-blocker, 4 mg/kg IV q 8-12 hr
Fluids
Treatment of persistent hypotension despite epinephrine requires restoration of intravascular volume by fluid replacement, initially with a crystalloid solution, 20–30 mL/kg in the first hour.

Bronchodilators
Nebulized 2-agonists Salbutamol(Ventolin) (5mg/1ml)  dose 0.03-0.05 ml/kg/dose diluted in 2–3 mL saline

Corticosteroids
for prevent biphasic anaphylaxis. Intravenous methylprednisolone, 1 mg/kg, or hydrocortisone, 5 mg/kg, can be given every 6 hours.

Common Causes of Systemic Allergic and Pseudoallergic Reactions.






Common Causes of Systemic Allergic and Pseudoallergic Reactions.
Causes of anaphylaxis 
  Drugs
    Antibiotics
    Anesthetic agents
  Foods
    Peanuts, tree nuts, shellfish, and others
  Biologicals
    Latex
    Insulin
    Allergen extracts
    Antisera
    Blood products
    Enzymes
    Monoclonal antibodies (eg omalizumab)
  Insect venoms
Causes of anaphylactoid reactions 
  Radiocontrast media
  Aspirin and other nonsteroidal anti-inflammatory drugs
  Anesthetic agents

Anaphylaxis criteria

Anaphylaxis is highly likely when any one of the following three criteria are fulfilled:
   
1. Acute onset of an illness (minutes to several hours) with involvement of the skin, mucosal tissue, or both (eg, generalized hives, pruritus or flushing, swollen lips-tongue-uvula) and at least one of the following:
   
a. Respiratory compromise (eg, dyspnea, wheeze-bronchospasm, stridor, reduced peak expiratory flow, hypoxemia)

b. Reduced blood pressure or associated symptoms of end-organ dysfunction (eg, hypotonia [collapse], syncope, incontinence)
   
2. Two of more of the following that occur rapidly after exposure to a likely allergen for that patient (minutes to several hours):
   
a. Involvement of the skin-mucosal tissue (eg, generalized urticaria, itch-flush, swollen lips-tongue-uvula)

b. Respiratory compromise (eg, dyspnea, wheeze-bronchospasm, stridor, reduced PEFR, hypoxemia)

c. Reduced blood pressure or associated symptoms (eg, hypotonia [collapse], syncope, incontinence)

d. Persistent gastrointestinal symptoms (eg, crampy abdominal pain, vomiting)
   
3. Reduced blood pressure after exposure to a known allergen for that patient (minutes to several hours)
   
a. Infants and children: low systolic blood pressure (age specific) or greater than 30% decrease in systolic pressure

b. Low systolic blood pressure in children, defined as less than 70 mm Hg in those aged from 1 month to 1 year, less than (70 mm Hg + [2 x age]) in those 1–10 years of age, and less than 90 mm Hg in those 11–17 years

Saturday, April 3, 2010

Corrected calcium in hypoalbumin

Corrected calcium = serum calcium + 0.08 (40 - serum albumin)

Normal range: 9-10.5 mg/dL

Treatment of hypomagnesium

Medication

Oral replacement is appropriate for mild symptoms, while IV replacement is indicated for severe clinical effects.