Medicine External Brain

Treatment Unstable  Synchronized cardioversion 150-200J Stable Rate control with metoprolol 5-10mg IV May also use diltiazem, verapamil Avoid in WPW (use procainamide) Amiodarone in HFrEF (<40% EF) 5mg/kg over 30 minutes + 1200mg over 24 hours Cardioversion Only if onset < 48 hours ago Otherwise need 3 weeks anticoagulation TEE May attempt pharmacologically with ibutilide   Notes Non-anticoagulated patients have 5% yearly embolic risk, 25% lifetime risk 10% yearly risk in DM2 or HF HR > 300 with wide QRS indicates pre-excitation syndrome like WPW

Treatment Second Degree (if symptomatic) Atropine  0.5mg every 5 minutes, max 3mg total Transcutaneous pacing  Always place pads in Mobitz II Pace if unresponsive to atropine Transvenous pacing if transcutaneous unsuccessful 0.2-20 mA Permanent Pacemaker Third Degree  Stable Apply transcutaneous pads Same treatment as Mobitz II Unstable Transcutaneous pacing until transvenous placement   Types of AV Block First Degree PR interval > 200ms   Second Degree type 1 (Mobitz I) PR intervals progressively lengthen before dropped beats   Second Degree type 2 (Mobitz II) Fixed PR intervals before dropped beats Third Degree (complete) Total dissociation between P waves and QRS

 Treatment Only treat if < 50bpm and evidence of hypoperfusion Transcutaneous cardiac pacing   Usually 50-100 mA, but may need up to 200mA Only Class I treatment for unstable patients Lorazepam (1-2mg IV) or morphine (2-4mg IV) for pain control Atropine 0.5mg push every 3-5 minutes, 3mg total max Epinephrine 2-10 micrograms/min IV Can also use dopamine Treat beta-blocker or CCB toxicity if present Glucagon 3-10mg IV over 1-2 minutes; then 1-5mg per hour           Causes Physiologic (vagal tone) Pharmacologic (CCBs, Beta-blockers, digoxin) Pathologic (Acute inferior MI, ICP, carotid sinus hypersensitivity, hypothyroid, sick sinus)   Notes Slow or low-dose administration of atropine can cause paradoxical bradycardia Atropine ineffective on heart-transplant patients  

Treatment  No treatment indicated usually 3 or more sequential PVCs should be managed as non-sustained Ventricular Tachycardia (VT) Notes Can be associated with hypoxia, drug effect (digoxin, sympathomimetics), electrolyte disturbances

Induction Agents Etomidate .3mg/kg  175lb man = 23mg Ketamine 1-2mg/kg 175lb man = 80-160mg Propofol .5-1.5mg/kg 175lb man = 40-120mg Causes hypotension Paralytic Agents Rocuronium 1-1.5mg/kg ideal body weight 175lb man = 80-120mg Onset 60 seconds Duration: 45-60 minutes Reversal by Sugammadex Immediate reversal dose: 16 mg/kg IV once  Succinylcholine 1-2mg/kg total body weight 175lb man = 80-160mg Onset 30-45 seconds Duration: ~15 minutes Side effects Hyperkalemia Faster O2 desat  

Prevention Acetazolamide 125 - 250mg BID Need to stay hydrated (diuretic) Dexamethasone 4mg q12h Treatment Descent (obviously)  at least 3000 feet Oxygen Nasal cannula unless HAPE also present -> then high flow Dexamethasone 10mg immediately then 4mg q6h  Notes One questionable-quality clinical trial found no benefit of 125mg BID acetazolamide, and recommended 250. More recent higher-powered trial found significant benefit of 125mg BID. Acetazolamide/Dexamethasone not directly studied as treatment for HACE -> studied in context of Acute Mountain Sickness (AMS)