Bradycardia. R. Ian RossFrye, M.D.

Transcription

1 Bradycardia R. Ian RossFrye, M.D.

2 Bradycardia Bradycardic patients DIE: Drugs Ischemia / Infarction Electrolytes Pearl: BB & CCB minimally responsive to atropine Clonidine & Digoxin responsive to atropine Drugs - BCCD: Beta blockers Calcium channel blockers / Clonidine Digoxin Electrolytes: Hyperkalemia Pearl: If a patient shows up with in one hour of a known CCB ingestion: Intubate Charcoal Gastric lavage

3 Bradycardia - Management Initial Management: A, B, C s Maintain the airway Assist breathing as necessary, O2 Cardiac monitor & EKG IV access Pacing pads Accucheck Check pupils Unstable Vital Signs? Bradycardia: HR < 60 Hypotension: SBP < 100 AMS Chest pain Acute heart failure Stable Vital Signs? ST s looking saggy? Consider Digoxin Toxicity EKG Hyperglycemia? Consider CCB Poisoning CCB inhibit pancreatic insulin secretion Consider hyperkalemia DKA Myosis? Consider clonidine poisioning Tx with Naloxone Peaked T, Loss of P, Wide QRS, Sine wave? Consider hyperkalemia Back to Initial Management

4 Bradycardia - Management Unstable Vital Signs: 1) Atropine 0.5 mg q 3 min Max 3 mg 2a) Glucagon + Calcium + More Atropine 2b) Digoxin immune Fab If atropine ineffective: Transcutaneous pacing or Dopaime infusion 2-10mcg/kg/min or Epinephrine infusion 2-10 mcg/min 3) Insulin + Glucose 4a) Your patient is dying, they ve definitely OD d on a β-blocker or Ca-Blocker & cardiac arrest is here or coming soon: Lipid Resuscitation Therapy Methylene Blue 4b) Your TCP isn t picking up & you re filling their body with every drug you can find Transvenous Pacing Back to Initial Management

5 Bradycardia, Unstable - Management, β-block & Ca-Block Glucagon Give early in the course of disease Dosing: Initial bolus 50mcg / Kg over 1-2 min Average 70 Kg patient - 3.5mg Can repeat, stack, or increase dose of boluses as needed Follow with 2mg-10mg / hr gtt Titrate to Adequate HR & BP Give with zofran to avoid vomiting Mechanism: Activation of camp Heart Inotropy & Chronotropy Liver Gluconeogenesis Back to Unstable Vital Signs

6 Bradycardia, Unstable - Management, β-block & Ca-Block Calcium: Calcium Chloride: 3x the available calcium than Calcium Gluconate Requires a central line Dosing: 1-2 g IV infused over min Repeat every 20 minutes prn up to 5 doses Calcium Gluconate: Safe in peripheral IV s Dosing: 60 mg/kg IV over 5 minutes q10-20 minutes Not to exceed 3-4 g/dose Max 3-4 doses Back to Unstable Vital Signs

7 Bradycardia, Unstable - Management, β-block & Ca-Block Insulin: Dosing: 1 U / Kg body weight bolus Average 70 Kg patient - 70 Units Followed by: 1U / Kg / hr gtt 0.5g / kg / hr dextrose gtt q15min accu-checks Titrate dextrose gtt to mg / dl Monitor serum K. K will be driven into the cells, so serum K will fall, but at the conclusion of therapy, will rise again. Supplement carefully - hypokalemia to 3.0 mmol/l ok Mechanism: CCB inhibit pancreatic insulin secretion - supplementation Allows glucose utilization in heart cells Myocardial contractility & vasomotor tone Lactate uptake Back to Unstable Vital Signs

8 Bradycardia, Unstable - Management, β-block & Ca-Block Lipid Resuscitation Therapy: Dosing: 1.5 ml/kg bolus of 20% Intralipid 0.25 ml/kg/min Repeat the bolus in PEA or Asystole Repeat bolus if initial response & then redevelops hemodynamic instability Mechanism: Possibly lipid sink Methylene Blue: Dosing: 1 mg/kg bolus over 10 min Follow with 1 mg/kg/hr gtt Mechanism: Nitric oxide scavenging Inhibition of smooth muscle relaxation Back to Unstable Vital Signs

9 Bradycardia - Management, Digoxin Labs: Potassium & magnesium K > 5.5 meq/l 100% mortality Dig Level Treatment: If unknown amount ingested: 10 vials of Fab Repeat as necessary PVC s? Give 2g MgS)4 If known amount ingested: # of vials = (amount ingested [mg] x 0.8) 0.5 Followed by 10 vials of Fab if not responding Fab: A single vile of digoxin immune Fab binds 0.5mg of digoxin Back to Unstable Vital Signs

10 Bradycardia - Management, Hyperkalemia Insulin Dosing: 10 Units IV + 1 Amp D50 Mechanism: Drives potassium into the cells Calcium Dosing: Calcium Chloride: 0.5-1g IV over 5-10 minutes Calcium Gluconate: 1.5-3g IV over 2-5 minutes Mechanism: Stabilizes the cardiac membrane electrically Back to Hyperkalemia

11 Bradycardia - Management, Hyperkalemia Albuterol: Dosing: 10-20mg nebulized over 10 minutes Mechanism: Activates NaK ATPase Bicarbonate: If there is associated metabolic acidosis Dosing: 50 meq (1 amp) IV over 5 minutes Dialysis: Once you have the patient stabilized Back to Hyperkalemia

12 Bradycardia, Stable - Disposition Immediate release formulations: If asymptomatic 8 hours after ingestion, can discharge safely Sotalol requires 12 hours of monitoring Sustained release formulations: Monitor for 24 hours post ingestion Back to Initial Management

13 Bradycardia - Appendix Hyperkalemia, Peaked T waves: T waves QRS complex height Back to Bradycardia - Initial Management

14 Bradycardia - Appendix Digoxin effect: Sagging / Slurred ST segments Back to Bradycardia - Initial Management

15 Bradycardia - Appendix Transcutaneous Pacing: 1) Apply pacing pads 2) If conscious - sedate with Ketamine 3) Start in Demand Mode, if not capturing put into Fixed Mode. 4) Just because you see a QRS complex does not mean that its capturing. Check the pulse & keep turning up the juice until you feel a pulse Back to Bradycardia - Unstable Vital Signs

16 Bradycardia - Resources Aggarwal N, Kupfer Y, Seneviratne C, Tessler S. Methylene blue reverses recalcitrant shock in β-blocker and calcium channel blocker overdose. BMJ Case Reports: 2013, published online. Engebresten K, Kaczmarek K, Morgan J, Holger J. High-dose Insulin Therapy in Beta-Blocker and Calcium channel-blocker Poisoning. Clin Tox: 2011, Levin R, Degrange A, Bruno G, Del Mazo C, Taborda D, Griotti J, Boullon F. Methylene Blue Reduces Mortality and Morbidity in Vasoplegic Patients After Cardiac Surgery. Ann Throac Surg: 2004, Wesley P, Tomislav J. Emergency Department Management of Calcium- Channel Blocker, Beta Blocker, and Digoxin Toxicity. Emergency Medicine Practice, EB Medicine: February 2014, Vol 16, Num 2. Tomassoni A, Sanders S, Marcolini E. Emergency Department Treatment of Beta Blocker and Calcium Channel Blocker Poisoning. EM Critical Care, EB Medicine: May/June 2014; Vol 4, Num 3. Back to Bradycardia