Acute Care Medicine - Bites and Toxicology Flashcards
Discuss the risk factors for bite wounds and most common bacteria
Risks - deeps wounds: puncture or involve bone/joint - crush injury - wounds >12hrs without treatment - wounds over poorly vascularized area - cat or human bites Bacteria - Pasteurella found in dog and cat mouth - Eikenella corrodens in human mouth - Oral anaerobes and skin pathogens
Discuss the wound care and closure for bite wounds
Wound Care
- explore to remove foreign bodies
- wash with anti-septic
- pressure irrigation
- debride necrotic or devascularized tissue
Wound Closure Criteria
- low risk for infection
- bite <12hrs
- bite involving vascularized tissue
- dog bites
- closure usually done for wounds for cosmesis
- require prophylactic antibiotics
Wound Closure Not
- infected
- high risk for infection
- bite >12hrs
- bites involving poorly vascularized tissue
- human and cat bites
- puncture wounds
- bites involving crush injury
- immune compromisedDiscuss antibiotics for wounds
Infected Wounds - Pip-Tazo 4.5g IV Q8H - Ceftriazone 1g IV Q24H and Flagyl 500mg IV Q8H - Meropenem 1g Q8H - can change once have culture High Risk Infection - Amox-clav 500mg PO TID for 3-5d
Discuss rabies prophylaxis
High Risk Features - mammal appears unwell, wild or stray - high risk mammal (bat, racoon, skunk, fox, coyote, bobcat, woodchuck) - geographical area with high prevalance - dog, cat, or ferret that is either unavailable for 10-day quarantine or have symptoms of rabies Post-Exposure Prophylaxis - includes rabies immunoglobulin - rabies vaccine IM on day 0,3,7,14
Discuss the ABCDDEFG of toxicology
Airway
- ensure patent airway
Breathing
- Provide oxygen if hypoxic
Circulation
- cardiac monitoring or ECG
- IV fluids for all
DONT (universal antidotes)
- Dextrose IV for hypoglycemia
- most toxins lead to hypoglycemia so require bedside blood glucose
- O2
- Naloxone 0.4mg IM for suspected opioid or respiratory depression
- Thiamine for alcoholic
Decontamination
- water irrigation for toxins on skin
- GI decontamination can do activate charcoal if within 1-2hrs of ingestion
- whole bowel irrigation
Elimination
- dialysis for aspirin, digoxin and toxic alcohol
Focused Therapy
- specific antidote
Get Toxicology HelpDiscuss the anion gap and osmal gap calculations
Anion Gap
- Na - (Cl + HCO3) = 12 (normal)
Osmol Gap
- Expected osmolality: 2xNa + Blood glucose + BUN
- osmol gap <10 normal, >10 abnormal
- Raised due to alcohol, ethylene glycol, methanol, mannitol, DKA
Discuss the investigations for toxicology
- Electrolytes
- Creatinine, BUN
- blood glucose
- serum osmolality
- Serum specific drugs (acetaminophen, aspirin, digoxin, anti-epileptics, toxic alcohol)
- Blood gas for metabolic acidosis (low pH, pCO2 and compensatory low HCO3
- ECG
- Tox screen
Discuss the differential for metabolic acidosis
MUDPULESCT - Methanol, metformin - Uremia - Diabetic Ketoacidosis - Paraldehyde - Iron, isoniazid - Lactate - Ethylene glycol - Salicylates - CO, cyanide - Toluene Increased Ion Gap (>12) and Increased Osmol Gap (>10) - toxic alcohol
Discuss the toxidrome for Opioids
Vitals - Bradycardia - Hypotension - Respiratory depression and hypoxia Presentation - Decreased LOC - miosis (constricted pupils) Management - Naloxone 0.4mg IM - IV fluids
Discuss the toxidrome for Anticholinergics
- TCA, antihistamines (benadryl, Gravol) Vitals - tachycardia - Hypertension - Hyperthermia Presentation - Confusion, agitated - mydriasis - dry mouth - dry skin - urinary retention - constipation Management - supportive with cooling, IV fluids, benzodiazepine - antidote for TCA - NaHCO3 IV for prolonged QTc
Discuss the toxic dose and diagnosis of acetaminophen overdose
Dose
- 150mg/kg
Diagnosis
- based on the Rumack-Matthew nomogram and acetaminophen level at least 4hrs post-ingestion
- if above can proceed to treatment as risk of hepatic toxicity
Discuss the presentation of acetaminophen overdose
Stage 1 - Day 1 - Non-specific nausea and vomiting Stage 2 - Day 1-3 - Hepatitis (RUQ pain, elevated AST/ALT) - pancreatitis - acute renal failure Stage 3 - Day 4-5 - Liver failure (jaundice, coagulopathy, hypoglycemia, encephalopathy) - renal failure - multi-organ failure Stage 4 - Day 5-10 - eventual recovery in liver function
Discuss the treatment of acetaminophen overdose
- If within 1hr then charcoal for GI decontamination
- if taken above toxic dose then automatic treatment with N-acetylcysteine
- Cannot give after 8hrs
- replenish store of glutathione which continues to detoxify NAPQI
Discuss the toxidrome for aspirin
Dose - >300mg/kg Presentation - Neurologic: tinnitus, confusion, seizure - GI: n/v leading to hypovolemia - Resp: hyperventilation due to metabolic acidosis Investigation - serum ASA - blood gas Management - IV fluids - urine alkinalization by IV NaHCO3 to get urine to pH >7.5 to facilitate clearance - hemodialysis
Discuss the toxidrome for toxic alcohol
Pathophysiology
- methanol form formic acid and ethylene glycol form oxalic acid which lead to metabolic acidosis
Presentation
- Formic acid: altered mental status, ataxia, seizure, decreased visual acuity
- Oxalic acid: renal failure
Investigation
- serum osmalality raised by methanol and ethylene glycol
- blood gas
- serum toxic alcohol level
Management
- antidote: ethanol IV or fomepizole
- block alcohol dehydrogenase to prevent conversion into toxic metabolites
- hemodialysis
