Morning Report: Ammonia Toxicity

Dr. Waldman presents today’s Morning Report!

AMMONIA TOXICITY

Where can we find ammonia: glass cleaners, toilet bowel cleaners, metal polishes, floor strippers, wax removers, smelling salts, some refrigerants, explosives, pharmaceuticals, pesticides, textiles, leather, flame-retardants, plastics, pulp and paper, rubber, petroleum products, and cyanide

INHALATION INJURY:

Most common cause of injury
People who are capable of escaping their environment usually are not subject to severe exposures, because they flee upon detection of ammonia’s pungent odor
Signs/symptoms
- Rhinorrhea
- Scratchy throat
- Chest tightness
- Cough
- Dyspnea
- Eye irritation
Symptoms usually subside within 24-48 hours
Absence of symptoms following inhalational exposure to ammonia essentially rules out significant injury
Physical Exam
- HEENT: facial and oral burns and ulcerations
- RESP: Tachypnea, oxygen desaturation, stridor, drooling, cough, wheezing, rhonchi, and decreased air entry
- CNS: Loss of consciousness (if exposure is massive)
- Ocular: iritis, corneal edema, semi dilated fixed pupil (can eventually form cataracts)

TOPICAL INJURY: Burns

Gaseous ammonia mixes with water in eyes, skin, airways, forms ammonium (exothermic rxn)-> heat and chemical burns
Liquid ammonia freezes tissue on contact -> deep injuries
Physical Exam
- Mild skin burns -> yellow, soapy, soft in texture
- Severe skin burns -> black and leathery

INGESTION INJURY:

Ammonia ingestions in the home usually do not lead to significant damage; pH significantly higher in industrial strength products; however few case reports of injury with household products
Signs/Symptoms of ingestion:
- OP, epigastric and retrosternal pain
- Signs of perforated viscous (can occur up to 24-72 hrs after ingestion)
- Respiratory symptoms if aspiration PNA or pneumonitis

BLEACH + AMMONIA -> CHLORAMINE GAS:

Mild exposure: normal exam vs wheezing and decreased air entry
Moderate to severe exposure: dyspnea, pulmonary edema with secondary hypoxia, nausea, tracheobronchitis, toxic pneumonitis, intrapulmonary shunt, and/or pneumomediastinum

DIAGNOSIS:

Serum ammonia levels are of little value bc they do not correlate with clinical condition.
Labs: basic labs, co-ingestion labs, lactate
Eye: fluorescein staining, slit lamp exam, tonometry, conjunctival pH?
GI: advanced imaging for signs of perforation, endoscopy if significant ingestion
Pulmonary: PFTs, bronchoscopy if severe inhalation

MANAGEMENT:

Management is largely supportive
Decontaminate pt
Intubation
- When: resp distress, depressed MS, severe orofacial burns, stridor, hoarseness, burns identified on bronchoscopy or endoscopy
- How: consider procedural sedation rather than RSI (severe laryngeal edema)
- What: use large-size tubes to prevent plugging with sloughing mucosa
Burn management: irrigate copiously and frequently, apply silver sulfadiazine, tdap, BEWARE of aggressive fluid administration
Eyes: irrigate copiously, prompt optho consult
Ingestion: irrigate mouth with water or milk, do NOT induce emesis, prompt GI consult
Corticosteroids (very controversial)
- Increase mortality?
- May help with acute bronchospasm in pts with underlying RAD?
- May decrease airway edema?
- May decreased formation of esophageal strictures?