6. Resp Med 2

• Diphenhydramine class

  Antihistamine, Histamine1 receptor blocker
• Diphenhydramine MOA


  Competitive antagonist H1 receptors - causes dryness of mucus membranes in Respiratory tract, GI smooth muscle, blood vessels

  
  

  Reverses extrapyramidal reactions
• Diphenhydramine Indications


  - Allergic reaction / Anaphylaxis

  - Extrapyramidal S/S from phenothiazines

  - Symptomatic dystonia

  - Vomiting
• Diphenhydramine Contraindications


  - Known sensitivity

  - Use w/ caution in acute asthma

  - Avoid while breast-feeding

  - Premature infants
• Diphenhydramine SE


  - Drowsiness

  - Sedation

  - Seizures

  - Thickened secretions causing asthma exacerbation

  - Anti-cholinergic effects

  - Paradoxical CNS excitation in children
• Diphenhydramine Adult Dose


  25-50 mg IM/IV/IO/PO (max 50mg)
• Diphenhydramine Ped Dose


  1mg/kg IV/IO slow push (max 50mg)
• Epinephrine Class


  Adrenergic sympathomimetic catecholamine
• Epinephrine MOA

  Direct-acting alpha and beta agonist

  -strong alpha effects: vasoconstriction

  -strong beta-1 effects: increased chronotropic and inotropic effects

  -Mod beta-2 effects: brochodilation

  
  

  Smooth muscle relaxation of stomach, intestines, bladder, and uterus
• Epinephrine Indications


  - Cardiac arrest

  - Anaphylaxis

  - Bradycardia

  - Severe refractory bronchconstriction / status asthmaticus

  - Croup/bronchiolitis/epiglottitis
• Epinephrine Contraindications


  - None in ER setting

  - Cardiac insufficiency

  - Relative contraindications: uncontrolled HTN, pulmonary edema, hypovolemic shock
• Epinephrine SE


  - Tachydysrhythmias

  - Palpitations

  - Anxiety / Restlessness

  - HA

  - N/V
• Epinephrine 1:1000 for Respiratory distress/wheezing/stridor


  5mg nebulized

  Adult/Ped
• Epinephrine 1:1000 for Status Asthmaticus + Anaphylaxis


  Adult: 0.3mg IM q5 min

  Ped: 0.15mg IM q5 min

  
  

  (q5-15 min for anaphylaxis)
• Epinephrine 1:10,000 for Cardiac Arrest


  Adult: 1mg IV/IO push q3-5 min

  Ped: 0.01 mg/kg IV/IO push q3-5 min, max 1mg
• Epinephrine 1:10,000 for Profound Bradycardia


  Adult: 0.02-0.2 mcg/min IV/IO infusion

  Ped: 0.01 mg/kg IV/IO q3-5 min, max single dose 10mcg
• Epinephrine 1:10,000 for status asthmaticus/circulatory collapse


  0.5 mcg/kg/min IV/IO infusion

  Adult + Ped
• Epinephrine 1:100,000 for BP support and profound bradycardia


  10-20 mcg push-dose IV/IO

  Adult only
• Magnesium Sulfate Class


  Electrolyte, cardiac antidysrhythmic
• Magnesium Sulfate MOA


  - Decreases ACh release at the motor NMJ, causes muscle relaxation

  - CNS depression -> anticonvulsant effects

  -Calcium antagonist -> smooth muscle relaxation [can cause bronchodilation after beta-agonists and anticholinergics have been given]

  -Slows rate of SA-node impulse formation and prolongs conduction time
• Magnesium Sulfate Indications


  - Eclamptic seizure during 3rd trimester or postpartum pt

  - Pregnancy induced HTN

  - Severe status asthmaticus or severe bronchospasm w/ impending respiratory failure

  - Cardiac arrest due to Torsades de pointes
• Magnesium Sulfate Contraindications


  - Known sensitivity

  - AV heart block
• Magnesium Sulfate SE

  - Drowsiness

  - CNS depression

  - Respiratory depression

  - Cardiac arrhythmia / AV heart block

  - Causes hypotension and bradycardia w/ rapid administration
• Magnesium Sulfate Adult Dose - Status asthmaticus


  1-2 gm in NS IV infused over 15-30 min
• Magnesium Sulfate Ped Dose - Status asthmaticus


  25-50 mg/kg IV/10 in NS IV infused over 15-30 min
• Magnesium Sulfate Dose - PIH/Eclampsia


  4gm in NS IV/IO infused over 20 min
• Magnesium Sulfate Adult Dose - Cardiac arrest due to Torsades de pointes


  1-2gm IV push
• Magnesium Sulfate Ped Dose - Cardiac arrest due to Torsades de pointes


  25-50 mg/kg IV/10