• Diagnostic reasoning - applying DSM-5 criteria, building differentials
• Pharmacology - drug selection, dosing, side effects, drug interactions
• Psychotherapy - modality selection, therapeutic approaches
• Risk assessment - suicide/homicide risk, capacity evaluations
• Special populations - child/adolescent, geriatric, perinatal psychiatry
• Consult-liaison - medically complex patients, delirium, neuropsychiatry

• Internal medicine - cardiology, pulmonology, nephrology, GI, endocrinology, infectious disease, rheumatology, hematology/oncology
• Neurology - stroke, seizures, headache, movement disorders, dementia
• Emergency medicine - acute presentations, triage, resuscitation
• Surgery - pre/post-op management, acute abdomen, trauma
• Pediatrics - developmental, infectious, congenital conditions
• OB/GYN - pregnancy complications, gynecologic conditions
• Psychiatry - as discussed

Harpic (Strong Acid) Ingestion - Emergency Management

Understanding the Agent

Step 1 - Immediate Actions (First 0-30 minutes)

DO:

• Secure IV access - start IV fluids (NS or LR)
• Airway assessment - look for hoarseness, drooling, stridor, dysphonia. If any of these are present, intubate immediately (early, before edema progresses). Edema can worsen rapidly and make intubation impossible
• Oral dilution - give water or milk, up to ~500 mL, orally if the patient can swallow safely. This is only useful within the first few minutes - it has minimal benefit if delayed. Do NOT give if the patient cannot swallow safely
• Supplemental oxygen
• Cardiac monitoring and pulse oximetry
• Call Poison Control and get the product container if available

DO NOT:

• Do NOT induce vomiting - re-exposure of the esophagus to acid will cause additional burns
• Do NOT use activated charcoal - ineffective for acids, increases aspiration risk, and obscures endoscopic view
• Do NOT pass a nasogastric tube - can perforate damaged mucosa and cause further injury
• Do NOT attempt neutralization with bicarbonate or bases - causes exothermic reaction that worsens injury
• Do NOT give anything by mouth if the patient cannot swallow (vomiting, altered consciousness, stridor)

Step 2 - Investigations (Immediate)

Step 3 - Endoscopy (KEY DECISION)

• All patients with intentional ingestion should have upper endoscopy regardless of symptoms
• Patients with any symptoms (vomiting, odynophagia, chest/abdominal pain) require endoscopy
• Optimal timing: 12-24 hours after ingestion
  • Too early (< 6 hours): underestimates depth of injury
  • Too late (> 24 hours): wound softening increases perforation risk
• Do NOT scope if perforation is known or suspected on imaging

Zargar's Endoscopic Grading:

Step 4 - Specific Medical Management

• IV fluids - aggressive resuscitation for hypovolemia
• IV proton pump inhibitor (e.g., omeprazole/pantoprazole) - reduces further gastric acid production
• Analgesia - IV opioids if needed
• Corticosteroids - controversial; NOT routinely recommended. Consider dexamethasone 10 mg IV only if there is airway edema. Not shown to consistently prevent strictures; risk of infection and masking early signs of necrosis
• Prophylactic antibiotics - NOT indicated routinely
• Psychiatric evaluation - mandatory since this appears to be an intentional ingestion (2 cups is a large amount)

Step 5 - Disposition

Complications to Watch For

• Early (hours-days): Esophageal/gastric perforation, mediastinitis, peritonitis, airway necrosis (leading cause of early death)
• Late (weeks-months): Esophageal stricture (develops in 2-8 weeks in high-grade burns), gastric outlet obstruction (pyloric stricture)
• Long-term: 1000-fold increased risk of esophageal carcinoma (develops 40-50 years later)

Bottom Line for This Patient

1. Assess airway (act fast if any hoarseness/drooling)
2. IV access + fluids
3. Bloods including ABG, metabolic panel
4. CT chest and abdomen
5. GI/surgical team on standby
6. Plan endoscopy at 12-24 hours
7. Psychiatry consult (intentional ingestion)

• Rosen's Emergency Medicine, Chapter 143 | Schwartz's Principles of Surgery, 11th Ed.

Rat Poison (Rodenticide) Poisoning - Complete Clinical Guide

TYPE 1: ANTICOAGULANT RODENTICIDES

Mechanism

• Inhibit Vitamin K epoxide reductase → block recycling of Vitamin K → depletion of clotting factors II, VII, IX, X (Vitamin K-dependent)
• 1st generation (warfarin): requires multiple doses to be lethal; half-life ~15 days
• 2nd generation / "superwarfarins" (brodifacoum, bromadiolone): single dose lethal; half-life 16-36 days; enterohepatic circulation prolongs effect for weeks to months

Clinical Features

Investigations

• PT/INR - key test; check at baseline and 48-72 hours post-ingestion
• PTT, CBC (platelet count, hemoglobin)
• Blood group and crossmatch if actively bleeding
• Serum brodifacoum/superwarfarin levels if available (guides duration of therapy)
• LFTs, renal function

Treatment / Prescription

Step 1 - Decontamination (only if early, within 1-2 hours)

• Activated charcoal 50 g orally (adults) - effective if given within 1-2 hours of ingestion
• Do NOT give empirically before PT/INR is checked - early Vitamin K1 masks the rise in INR and you may miss severity

Step 2 - Antidote: Vitamin K1 (Phytonadione)

Give ONLY when INR is elevated - not prophylactically

• Oral Vitamin K1 (Phytonadione): 10-50 mg orally, 2-4 times daily
• Children: 5-10 mg orally (0.4 mg/kg/dose), 2-4 times daily

• IV Vitamin K1: 10 mg slow IV infusion (over 30 min - risk of anaphylaxis with rapid IV push)
• PLUS Fresh Frozen Plasma (FFP) 15 mL/kg OR 4-Factor Prothrombin Complex Concentrate (4F-PCC / Kcentra) for immediate reversal

• Monitor PT/INR every 2-3 days during treatment
• Check PT/INR 2-3 days AFTER stopping Vitamin K1 - if elevated again, restart therapy
• Serum brodifacoum level < 10 ng/mL = safe to discontinue

CAUTION: Do NOT use Vitamin K3 (menadione) - ineffective for rodenticide poisoning. Must use Vitamin K1 (phytonadione) specifically.

TYPE 2: ALUMINUM PHOSPHIDE (AlP) / ZINC PHOSPHIDE

Mechanism

• On contact with moisture/gastric acid, releases phosphine gas (PH₃)
• Phosphine inhibits cytochrome c oxidase → blocks mitochondrial aerobic respiration → multi-organ failure
• Lethal dose: as little as 0.5-1 gram
• No specific antidote exists

Clinical Features (rapid onset - within 30 min to hours)

• GI: nausea, vomiting, abdominal pain, diarrhea, garlic-like odor on breath
• Cardiovascular: hypotension, refractory shock, arrhythmias (most common cause of death)
• Respiratory: pulmonary edema, ARDS
• CNS: headache, altered consciousness, seizures
• Metabolic: metabolic acidosis, hyperglycemia (poor prognostic sign)

Diagnosis

• Clinical history + garlic odor
• Silver nitrate test: gastric aspirate on silver nitrate paper turns black if phosphine present (bedside test)
• ABG (metabolic acidosis), ECG (arrhythmias), echo (cardiomyopathy)

Treatment / Prescription (Supportive - no antidote)

Immediate resuscitation:

• Secure airway, supplemental high-flow O₂
• IV access (central venous preferred)
• IV Normal Saline fluid resuscitation
• Continuous ECG + hemodynamic monitoring
• Baseline: ECG, ABG, blood glucose, electrolytes (Mg²⁺), CBC, LFT, RFT, echo

Gastric Decontamination:

• Gastric lavage with KMnO₄ (potassium permanganate) solution - oxidizes phosphine, reduces absorption
• Alternatively: coconut oil or liquid paraffin lavage - oil-based solutions trap phosphine and reduce absorption (supported by 2024 meta-analyses)
• Activated charcoal - limited evidence but may be used
• Do NOT induce vomiting - increases inhalation risk of phosphine gas

Cardiovascular support:

• For hypotension: Norepinephrine (preferred) or Phenylephrine
• Avoid dopamine/dobutamine (pro-arrhythmic)
• Have defibrillator and temporary pacemaker ready at bedside
• Antiarrhythmics as needed

Metabolic correction:

• IV Sodium Bicarbonate for metabolic acidosis (aggressive correction protocol shown to improve outcomes - 30% vs 55% mortality)
• Treat hyperglycemia (insulin infusion if needed)
• Correct hypomagnesemia (IV Magnesium sulfate)

Other supportive:

• Dexamethasone - if adrenal insufficiency suspected
• N-acetylcysteine - antioxidant; used in some centers (evidence mostly animal studies)
• Hemodialysis - for renal failure, severe acidosis, or fluid overload (phosphine not effectively removed, but helps metabolic derangements)
• Psychiatric consult for intentional ingestions

Poor prognostic factors:

• Metabolic acidosis on admission
• Shock at presentation
• Hyperglycemia
• Arrhythmias

TYPE 3: YELLOW PHOSPHORUS / RATOL PASTE

Mechanism

• Direct hepatotoxin + nephrotoxin
• "Three-stage poisoning":
  • Stage 1 (0-24h): GI symptoms - nausea, vomiting, abdominal pain, garlic odor, glowing stool in dark
  • Stage 2 (24-72h): Apparent recovery ("latent phase") - patient seems better
  • Stage 3 (72h+): Fulminant hepatic failure, jaundice, coagulopathy, renal failure, encephalopathy

Treatment

• NO antidote
• Gastric lavage with KMnO₄ (1:5000 solution) - oxidizes yellow phosphorus
• Avoid fats and oils in diet (increases absorption)
• Supportive care for liver failure: FFP, lactulose, NAC
• Monitor LFTs, PT/INR, renal function daily
• Liver transplant may be required in fulminant failure

TYPE 4: BROMETHALIN

Mechanism

• Uncouples oxidative phosphorylation in CNS mitochondria → cerebral edema

Clinical Features

• Low dose: hind limb weakness, tremors, ataxia
• High dose: severe tremors, seizures, cerebral edema, coma
• Onset delayed 24-96 hours

Treatment

• NO antidote
• Activated charcoal early (within 1-2 hours, or multiple dose if large ingestion)
• Supportive: IV Mannitol or hypertonic saline for cerebral edema
• Anticonvulsants (benzodiazepines) for seizures
• ICU monitoring

TYPE 5: STRYCHNINE

Mechanism

• Blocks glycine receptors in spinal cord → uncontrolled motor excitation

Clinical Features

• Onset 15-30 minutes
• Opisthotonus (arched back), risus sardonicus (fixed smile), violent muscle spasms
• Triggered by noise, light, touch
• Death from respiratory muscle spasm/exhaustion

Treatment

• Benzodiazepines (Diazepam 5-10 mg IV) - first line to control spasms
• If refractory: propofol infusion or neuromuscular blockade + intubation
• Quiet, dark room - minimize stimulation
• Activated charcoal if ingestion within 1-2 hours and airway is protected
• Supportive: correct acidosis, monitor for rhabdomyolysis (CK, renal function)

Quick Comparison Table

• Always identify the specific agent - treatment is completely different
• AlP/ZnP is the deadliest with highest mortality in South Asian populations
• Superwarfarin (brodifacoum) requires months of Vitamin K1 - do not stop early
• Psychiatric evaluation is mandatory in all intentional ingestions