01Approach to the Critical Patient/attcp54

Immediate priorities

›Immediate stabilization

›Airway patency and aspiration risk

›If vomiting and reduced consciousness then airway protection

›Breathing and oxygenation

›Oxygen for hypoxemia

›Circulation and perfusion

›Large bore IV access times 2

›Continuous cardiac monitoring

›Defibrillator pads in place

›Rapid 12 lead ECG

›Repeat ECG after any rhythm change

›Point of care glucose

›Hypoglycemia correction

›High risk features

›Ventricular tachycardia or ventricular fibrillation

›Urgent digoxin specific Fab

›High grade AV block

›Urgent digoxin specific Fab

›Hemodynamic instability

›Urgent digoxin specific Fab

›Hyperkalemia in suspected cardiac glycoside poisoning

›Urgent digoxin specific Fab

›Team activation

›Poison centre or medical toxicology consult early

›Early antidote coordination and dosing strategy

›Cardiology consult for unstable conduction disease

›Temporary pacing planning

02History/hx59

Exposure characterization

›Exposure details

›Digoxin formulation

›Tablet dose in mg

›Capsule dose in mg

›Liquid dose and concentration

›Timing

›Time of last therapeutic dose

›Time of suspected overdose

›Intent

›Medication error

›Drug interaction

›Renal function decline

›Ingestion of plants or toxins

›Co exposures

›AV nodal blockers

›Beta blocker

›Non dihydropyridine calcium channel blocker

›Antiarrhythmics

›Amiodarone

›Quinidine

›Propafenone

›Antibiotics and antifungals

›Macrolide

›Azole

›Diuretics and electrolytes

›Loop diuretic

›Thiazide diuretic

03Physical Exam/exam34

Core exam domains

›Hemodynamic status

›Bradycardia

›Perfusion signs

›Hypotension

›Shock index trend

›Irregular rhythm

›Variable pulse deficit

›Neurologic status

›Mental status

›Confusion

›Agitation

›Reduced level of consciousness

›Pupils

›Alternate causes of delirium

›Volume status

›Dehydration signs

›Dry mucosa

›Orthostasis

›Heart failure signs

›Pulmonary edema

›Peripheral edema

›GI findings

›Ongoing emesis

›Aspiration risk

›Abdominal tenderness

›Alternate diagnosis consideration

04Differential Diagnosis/ddx25

Life threatening mimics

›Bradyarrhythmia and shock differential

›Beta blocker toxicity ICD-10 T44.7X1A

›Hypoglycemia and bronchospasm clues

›Calcium channel blocker toxicity ICD-10 T46.1X1A

›Hyperglycemia clue

›Hyperkalemia due to renal failure ICD-10 E87.5

›Severe metabolic acidosis clue

›Sick sinus syndrome ICD-10 I49.5

›History of pauses

›Inferior myocardial infarction ICD-10 I21.19

›ST elevation in inferior leads

›Ventricular ectopy differential

›Acute coronary syndrome ICD-10 I24.9

›Troponin and ischemic ECG changes

›Polymorphic VT due to long QT ICD-10 I47.2

›QT prolongation drivers

›Sympathomimetic toxicity ICD-10 T43.601A

›Hypertension and agitation

Non cardiac contributors

›Altered mental status differential

›Sepsis ICD-10 A41.9

›Fever and hypotension

›Medication toxicity other than digoxin

›Sedative hypnotic effect

›Hypoxia

›Respiratory failure

05Laboratory Tests/lt40

Immediate labs

›Initial laboratory panel

›Basic metabolic panel

›Potassium for severity and Fab indication

›Creatinine for clearance prediction

›Bicarbonate for acid base status

›Magnesium

›Hypomagnesemia correction target

›Calcium

›Baseline value for hyperkalemia algorithms

›Venous blood gas

›pH for arrhythmia risk

›Lactate for shock severity

›Glucose

›Co ingestion screen

›Cardiac injury labs

›Troponin

›Concurrent ischemia consideration

›BNP or NT proBNP

›Heart failure assessment

Digoxin level interpretation

›Serum digoxin concentration

›Timing considerations

›Levels within 6 hours after acute ingestion may not reflect tissue distribution

›Level for dosing calculations ideally after 6 hours

›Chronic toxicity caveats

›Serum level may be within therapeutic range with clinical toxicity

›Post Fab caveats

06Diagnostic Tests/dt39

Scoring Systems

›Severity and antidote criteria

›Life threatening toxicity indicators

›Ventricular tachycardia or ventricular fibrillation

›Asystole or pulseless electrical activity with suspected glycoside poisoning

›Symptomatic bradycardia with high grade AV block

›Hypotension or shock attributed to digoxin effect

›Hyperkalemia in suspected acute cardiac glycoside poisoning

›Antidote dosing calculation pathways

›If ingested dose known

›Vials equals digoxin dose ingested in mg times 0.8

›Each vial binds 0.5 mg digoxin equivalent

›If serum concentration and weight available

›Formula option A US package insert vials equals serum digoxin ng/mL times weight kg divided by 100

›Formula option B EU SmPC vials equals serum digoxin ng/mL times weight kg divided by 200

›Poison centre guidance for local standardization

›Evidence levels

›Digoxin Fab administration for life threatening poisoning Class I

›Temporary pacing while awaiting Fab effect Class IIa

›Lidocaine or phenytoin for ventricular dysrhythmias while awaiting Fab effect Class IIb

MRI

›MRI use cases

›Neurologic deficit not explained by toxicity

›Stroke evaluation

›Contraindications consideration

›Unstable patient and monitoring limitations

CT

›CT use cases

07Disposition/dispo26

Level of care decisions

›ICU indications

›Digoxin specific Fab administration

›Rebound toxicity monitoring

›Ventricular dysrhythmia

›Antiarrhythmic infusion requirement

›High grade AV block

›Pacing requirement

›Significant hyperkalemia

›Serial potassium and ECG monitoring

›Hemodynamic instability

›Vasopressor requirement

›Telemetry admission indications

›Symptomatic toxicity without ICU criteria

›Persistent GI symptoms

›Mild conduction abnormalities

›Electrolyte derangements requiring IV replacement

›Hypokalemia or hypomagnesemia

Discharge considerations

›Discharge criteria for mild cases

›Normal vital signs and stable rhythm

›No high grade AV block

›Symptoms resolved

›No ongoing vomiting

›Electrolytes normalized

›Potassium and magnesium stable

›Clear medication plan

›Digoxin held and follow up arranged

08Treatment/t110

Antidote and definitive therapy

›Digoxin specific immune Fab

›Indications

›Ventricular tachycardia or ventricular fibrillation

›Class I

›Symptomatic bradycardia with high grade AV block

›Class I

›Cardiac arrest attributed to cardiac glycoside poisoning

›Class I

›Hyperkalemia with suspected acute cardiac glycoside poisoning

›Class I

›Dosing by known ingestion

›Vials equals digoxin dose ingested in mg times 0.8

›Tablet bioavailability assumption 0.8

›Full neutralization option vials equals total body load mg divided by 0.5

›Each vial binds 0.5 mg digoxin equivalent

›Dosing by serum level and weight

›Formula option A US package insert

›Vials equals serum digoxin ng/mL times weight kg divided by 100

›Formula option B EU SmPC

›Vials equals serum digoxin ng/mL times weight kg divided by 200

›Conversion support

›Digoxin nmol/L times 0.781 equals digoxin ng/mL

›Administration

›Initiate infusion over at least 30 minutes if stable

›Slower rate if infusion reaction

›If cardiac arrest then bolus dosing strategy per local protocol

›Repeat dose after 15 to 30 minutes if inadequate response

›Adverse effects and monitoring

›Anaphylaxis and infusion reaction readiness

›Epinephrine and airway equipment available

›Worsening heart failure due to loss of inotropy

›Diuresis and oxygen support as needed

›Hypokalemia after reversal

›Frequent potassium monitoring

Supportive care and decontamination

›Decontamination for acute ingestion

›Activated charcoal single dose

›1 g/kg PO or NG

›Typical adult dose 50 g

›Airway protection prerequisite

›Activated charcoal multiple dose

›Consider for massive ingestion or prolonged absorption

›0.5 g/kg every 4 hours

›Ileus and aspiration risk monitoring

›Fluids

›Isotonic crystalloid for dehydration

›Cautious in heart failure

›Electrolyte correction

›Potassium repletion in hypokalemia

›Slow IV replacement with telemetry

›Avoid overcorrection in chronic toxicity

›Magnesium sulfate for hypomagnesemia

›2 g IV over 10 to 20 minutes

›Repeat dosing to upper normal range

Bradyarrhythmia management while awaiting Fab

›Atropine

›Initiate 1 mg IV

›Repeat every 3 to 5 minutes

›Maximum 3 mg

›Limited efficacy in infranodal block

›Early pacing planning

›Transcutaneous pacing

›If unstable bradycardia refractory to atropine

›Analgesia and sedation if time allows

›Transvenous pacing

›If persistent high grade AV block with instability

›Cardiology support

Ventricular dysrhythmia management while awaiting Fab

›Lidocaine

›Initiate 1 to 1.5 mg/kg IV bolus

›Repeat 0.5 to 0.75 mg/kg every 5 to 10 minutes

›Maximum 3 mg/kg

›Infusion

›Initiate 1 to 4 mg per minute

›Phenytoin

›Initiate 15 mg/kg IV

›Maximum infusion rate 50 mg per minute

›Hypotension monitoring

›Electrical therapy caveats

›Synchronized cardioversion for unstable VT

›Use lowest effective energy

›Fab prioritized when available

›Defibrillation for VF or pulseless VT

›Standard ACLS energy

›Avoided or caution agents

›Amiodarone

›Can increase digoxin levels and worsen toxicity

›Procainamide

›Hypotension and conduction worsening concern

›Quinidine

›Potent digoxin level increase

Hyperkalemia in suspected cardiac glycoside poisoning

›Antidote first strategy

›Digoxin specific Fab as definitive therapy

›Potassium reduction expected after reversal

›Temporizing measures

›Insulin regular 10 units IV

›Dextrose 25 g IV if glucose less than 11 mmol/L

›Glucose monitoring every 30 to 60 minutes

›Nebulized albuterol 10 to 20 mg

›Tachycardia monitoring

›Sodium bicarbonate 50 mmol IV

›Consider if metabolic acidosis

›Calcium salts

›Controversial historical avoidance

›If immediately life threatening ECG instability and Fab not immediately available then consider calcium with toxicology guidance

›Potassium removal

›Loop diuretic if adequate renal function

›Volume status monitoring

›Potassium binders

›Delayed onset

›Dialysis

›For refractory hyperkalemia due to renal failure

›Digoxin removal limited

09Special Populations/sp27

Pregnancy

›Pregnancy considerations

›Maternal stabilization priority

›Continuous fetal monitoring if viable gestation and stable maternal status

›Digoxin specific Fab use

›Use for maternal life threatening toxicity

›Placental transfer considerations and specialist input

›Hyperkalemia management

›Same physiologic principles with obstetric coordination

Geriatric

›Older adult considerations

›Chronic toxicity predominance

›Nonspecific symptoms and delirium

›Renal clearance reduction

›Lower threshold for Fab in instability

›Polypharmacy interaction burden

›Medication reconciliation emphasis

›Higher pacing risk

›Early cardiology involvement

Pediatrics

›Pediatric considerations

›Weight based dosing for all therapies

›Activated charcoal 1 g/kg

›Digoxin specific Fab dosing

›Use calculated vial fraction strategies when very small doses required

›Dilution to 1 mg/mL approach for small volume administration

›Plant ingestion risk

›Oleander and foxglove exposure suspicion

10Background/b37

Epidemiology

›Epidemiology

›Narrow therapeutic index drug exposure

›Toxicity risk increases with renal impairment and drug interactions

›Chronic toxicity more common than acute overdose

›Older adults and heart failure populations

›Non pharmaceutical glycoside exposures

›Oleander and foxglove

›Bufo toad venom

Pathophysiology

›Mechanism

›Na K ATPase inhibition

›Increased intracellular sodium

›Increased intracellular calcium via Na Ca exchange

›Increased vagal tone

›AV nodal conduction slowing

›Arrhythmogenesis

›Increased automaticity

›Triggered activity

›Electrolyte interactions

›Hypokalemia increases binding and toxicity

›Higher arrhythmia risk

›Hyperkalemia in acute overdose

›Marker of severe Na K ATPase blockade

›Hypomagnesemia potentiates dysrhythmias

›Replacement reduces ectopy risk

Therapeutic Considerations

›Digoxin specific Fab rationale

11Patient Discharge Instructions/pdi19

copy discharge instructions

›Discharge instructions

›Digoxin hold plan

›Do not restart unless explicitly instructed

›Medication list review

›Avoid new interacting medications unless prescriber aware

›Hydration guidance

›Maintain oral fluids if not restricted for heart failure

›Follow up plan

›Primary prescriber within 24 to 72 hours

›Lab recheck plan for potassium and creatinine

›Return to emergency care immediately

›Fainting or near fainting

›Chest pain

›New shortness of breath

›Persistent vomiting

›New confusion

›Palpitations

›Slow heart rate symptoms

›Severe weakness

12References/r12

Key sources

›Clinical guidelines and consensus

›American Heart Association focused update on poisoning related cardiac arrest and life threatening toxicity 2023

›Digoxin specific Fab recommended for life threatening cardiac glycoside poisoning

›DIGIFab EU SmPC June 2024

›Dosing options including vials equals serum digoxin ng/mL times weight kg divided by 200

›Conversion digoxin nmol/L times 0.781 equals digoxin ng/mL

›DIGIFAB FDA package insert

›Chronic toxicity dosing vials equals serum digoxin ng/mL times weight kg divided by 100

›Acute ingestion dosing based on total body load and 0.8 tablet bioavailability

›Evidence based summaries

›NCBI StatPearls Digoxin immune Fab updated 2024

›Indications and monitoring considerations

Evidence & Review

Evidence & Review