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Pharmacy & Acute Care University
Pharmacy & Acute Care University
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General Approach and Management of Poisoned Patients

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  1. Module 1: Introduction
  2. Module 2 : Initial Evaluation and Stabilization
  3. Module 3 - Diagnostic Testing
  4. Module 4 - Gastrointestinal Decontamination
  5. Module 5 - Enhanced Elimination and Extracorporeal Therapies
  6. Module 6 - Antidotes and Specific Treatments
  7. Module 7 - Disposition and Follow-Up
  8. Module 8: Case Studies
  9. Module 9 - Summary and Additional Resources
  10. Module 10: Approach to the Toxic Patient Feedback

Quizzes

Participants 396

  • Allison Clemens
  • April
  • ababaabhay
  • achoi2392
  • adhoward1
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Learning Objectives:

  1. Interpret acid-base and electrolyte abnormalities to identify the toxin or class of toxins 
  2. Understand the appropriate use and limitations of urine toxicology screens
  3. Decide which quantitative blood levels will aid diagnosis and guide management
  4. Order other laboratory tests and imaging strategically based on clinical findings
  5. Integrate poison control center consultations into the diagnostic approach

Acid-Base and Electrolytes:

– Check arterial or venous blood gases early to assess pH and carbon dioxide levels.

– An elevated anion gap metabolic acidosis suggests:

  • Toxic alcohols (methanol, ethylene glycol)
  • Diabetic ketoacidosis 
  • Uremia
  • Lactic acidosis
  • Salicylate poisoning

– A high osmolal gap indicates the presence of low molecular weight toxins like methanol and ethanol.

– Calculate the osmolal gap using: Measured osmolality – [2 x Na+] + [glucose/18] + [BUN/2.8].

– A normal gap does not rule out toxic alcohol ingestion. Use freezing point depression osmometry which detects methanol.

– An increased anion gap with a normal osmolal gap suggests diabetic or alcoholic ketoacidosis. 

– A non-gap metabolic acidosis points to ingestions of acids/alkalis, renal tubular acidosis, or uremia.

– Evaluate electrolytes for derangements pointing to specific toxins:

  • Hyperchloremic metabolic acidosis – hydrochloric acid, aspirin
  • Hypokalemia – barium, laxatives, licorice 
  • Hyperkalemia – potassium salts, succinylcholine
  • Hypocalcemia – fluoride, oxalates, ethylene glycol

Urine Drug Testing:

  • Urine toxicology screens have limited utility for acute management decisions.
  • Immunoassays test qualitatively for common drugs of abuse and have high false positives/negatives. 
  • Comprehensive GC-MS testing takes too long to impact acute care and is expensive.
  • Routine urine drug testing is not recommended in most alert, asymptomatic overdose patients.
  • Screens may be considered for severe or persistent CNS/respiratory depression.
  • Always specify which drugs are included and which require separate testing.
  • Never rely on urine tests alone – correlate with clinical presentation.
  • Check urine fluorescence under Wood’s lamp for quinine or fluorescein.

Quantitative Blood Levels:

– Order measured levels for toxins with known therapeutic/toxic ranges:

  •   Acetaminophen
  •   Salicylates
  •   Lithium
  •   Valproic acid
  •   Carbamazepine
  •   Digoxin
  •   Theophylline
  •   Ethylene glycol (draw prompt EG level if ingestion suspected)

– Levels can guide need for antidotes and extracorporeal removal therapies.

– Draw ethanol levels if alcoholic ketoacidosis is suspected.

– Consider iron, mercury, and heavy metal levels based on clinical context.

– Send serum β-HCG in women of childbearing age.

Other Laboratory Tests:

– Obtain liver enzymes (AST, ALT, bilirubin) to assess for hepatotoxicity.

– Check serum creatinine, BUN to evaluate for kidney injury, acidosis.

– Order creatine kinase for suspected rhabdomyolysis.

– Send troponin, BNP for myocardial injury from cardiotoxins.

– Assess CBC, PT/INR to diagnose hemorrhagic disorders. 

– Check serum lipase if opioid or anticholinergic ingestion.

– Draw lactate and venous blood gas for occult hypoperfusion.

Diagnostic Imaging:

– Obtain CXR if respiratory distress is present to evaluate for aspiration, pulmonary edema.

– Order CT head for mental status changes to rule out intracranial pathology.

– Consider abdominal CT if bowel obstruction or body packing is suspected.

– Obtain flat plate abdomen or KUB to identify radiopaque foreign material.

Poison Control Center Consultation: 

– Early call to poison control center or clinical toxicologist speeds optimal diagnosis and treatment.

– Information provided includes identifying agent, estimating risk, gauging expected toxicity.

– Guidance given on need for laboratory tests, decontamination, antidotes, and disposition.

– Help with differential diagnosis when multiple ingested agents suspected.

– Follow-up calls allow discussion of clinical course and response to management.

In summary, smart test ordering, integration of poison expertise, and vigilant monitoring are essential for guiding the management of the poisoned patient. We will next review various decontamination techniques.