• At room temperature, anhydrous ammonia is a colorless, highly irritating gas with a pungent, suffocating odor. It is lighter than air and flammable, with difficulty, at high concentrations and temperatures. It is easily compressed and forms a clear, colorless liquid under pressure. Ammonia dissolves readily in water to form ammonium hydroxide - an alkaline solution. The concentration of aqueous ammonia solutions for household use is typically 5% to 10% (weight:volume), but solutions for commercial use may be 25% (weight:volume) or more, and are corrosive. Anhydrous ammonia is stored and shipped in pressurized containers, fitted with pressure-relief safety devices, and bears the label "Nonflammable Compressed Gas". Despite not meeting the Department of Transport definition of flammable, it should be treated as such.
• Anhydrous ammonia reacts with moisture in the mucous membranes to produce an alkaline solution (ammonium hydroxide). Exposure to ammonia gas or ammonium hydroxide can result in corrosive injury to the mucous membranes of the eyes, lungs, and gastrointestinal tract and to the skin due to the alkaline pH and the hygroscopic nature of ammonia.
• Responders should obtain assistance in identifying the chemical(s) from container shapes, placards, labels, shipping papers, and analytical tests. General information on these identification technicques is located in the Emergency Response Guidebook.
• Identification Tools - CHEMM-IST, WISER, Ammonia Chemical Properties
• Devices - (examples) - HazCat Industrial Chemical and Methamphetamine Identification Kit (Model KT1220 ) (solid and liquid), ChomAir Badges (vapor or gas), Safe Air Monitoring System (vapor or gas), Kitagawa Gas Detector Tubes (vapor), Sensidyne Gas Detection Tubes (vapor).
• A comprehensive source for the selection of chemical identification equipment is the Guide for the Selection of Chemical Detection Equipment for Emergency First Responders, Guide 100-06, January 2007, 3rd Edition published by the Department of Homeland Security.

Respiratory and Skin Protection: Positive-pressure-demand, self-contained breathing apparatus (SCBA) level A is recommended in response situations that involve exposure to potentially unsafe levels of ammonia liquid or vapor.

PPE required level B-C

Most likely B-C PPEs will be adequate. Levels As may be required if the hospital is close to the site of exposure and/or there is concern for vapor exposure (bring in HAZMAT for Level A PPEs).

Respiratory Protection: Positive-pressure, self-contained breathing apparatus (SCBA) is recommended in response situations that involve exposure to potentially unsafe levels of ammonia.

Skin Protection: Chemical-protective clothing is recommended because of the potential of inflammatory and corrosive effects.

• Level A - protective clothing is the highest level of protection. Level A includes a Self Contained Breathing Apparatus (SCBA) with a fully encapsulating vapor tight suit with gloves and booties attached to the suit (tanks last from 1/2 hour to 1 hour).
• Level B - requires the use of SCBA but has lesser skin protection. Level Bs are chemical resistant suits that are designed for splashes of liquids but not for gas or vapor hazards. A young soldier can last about 2 hours on a hot day with a external air hose.
• Level C is similar to B with the exception of the type of respiratory protection. The SCBA is replaced with an Air Purifying Respirator.
• Level D protective clothing is utilized when there are no respiratory hazard and no major skin hazard considerations. Level D for hospital personnel includes scrubs, safety glasses, shoe covers, and possibly a face shield.

Link to reference section for acute event PPE related safety information

Chemical casualty triage is based on walking feasibility, respiratory status, age, and additional conventional injuries. The triage officer must know the natural course of a given injury, the medical resources immediately available, the current and likely casualty flow, and the medical evacuation capabilities.

• SALT Mass Casualty Triage - United States Government Recommendation
• START Adult Triage Algorithm
• JumpSTART Pediatric Triage Algorithm

• Check triage tag/card for any previous treatment or triage.
• Survey for evidence of associated traumatic/blast injuries.
• Observe for sweating, labored breathing, coughing/vomiting, secretions.
• Severe casualty triaged as immediate if assisted breathing is required.
• Blast injuries or other trauma, where there is question whether there is chemical exposure, victims must be tagged as immediate in most cases. Blast victim's evidence delayed effects such as ARDS, etc.
• Mild/moderate casualty: self/buddy aid, triaged as delayed or minimal and release is based on strict follow up and instructions.
• If there are chemical exposure situations which may cause delayed but serious signs and symptoms, then over-triage is considered appropriate to the proper facilities that can observe and manage any delayed onset symptoms.
• Expectant categories in multi-casualty events are those victims who have experienced a cardiac arrest, respiratory arrest, or continued seizures immediately. Resources should not be expended on these casualties if there are large numbers of casualties requiring care and transport with minimal or scant resources available.
• In a given category prioritize a child, pregnant woman over a non-pregnant adult.

The following exposed persons should be evaluated at a medical facility:

• Symptomatic patients complaining of persistent shortness of breath, severe cough, or chest tightness should be admitted to the hospital and observed until symptom-free. Pulmonary injury may progress for several hours.
• Those who have eye or skin burns that cover a large surface area.
• Those who have ingested ammonia.

Patient Release

• In a mass casualty situation, asymptomatic patients who are reliable historians and those who experienced only minor sensations of burning of the nose, throat, eyes, and respiratory tract (with perhaps a slight cough) may be released. In most instances, these patients will be free of symptoms in an hour or less. They should be advised to seek medical care promptly if symptoms develop or recur.
• If the treater feels that the patient has been exposed to a significant amount of ammonia, despite a relatively benign clinical appearance, if the incident involved a small number of patients, or the victims included young kids (especially infants or patients with special needs), they should be monitored in an ED "extended care" area for 6-12 hrs).

ABC/ALS Reminders - Initial stabilization - Evaluate and support the airway, breathing, and circulation. Intubate the trachea in cases of respiratory compromise (avoid blind nasotracheal intubation or use of an esophageal obturator). Use Bag Valve Mask (BVM) if unable to secure airway. Maintain adequate circulation. If trauma is suspected, maintain cervical immobilization manually and apply a decontaminable cervical collar and a backboard when feasible. Apply direct pressure to stop arterial bleeding, if present.

• Link to Basic and Advanced Life Support
• Link to Pediatric Basic and Advanced Life Support
• Link to Key Acute Care Adult Medications section
• Link to Key Acute Care Pediatric Medications section
• Link to Primary and Secondary Survey

• Inhalation of ammonia may cause nasopharyngeal and tracheal burns, bronchiolar and alveolar edema, and airway destruction resulting in respiratory distress or failure. Ammonia's odor threshold is sufficiently low to acutely provide adequate warning of its presence (odor threshold = 5 ppm; OSHA PEL = 50 ppm). However, ammonia causes olfactory fatigue or adaptation, making its presence difficult to detect when exposure is prolonged. Anhydrous ammonia is lighter than air and will therefore rise (will not settle in low-lying areas); however, vapors from liquefied gas are initially heavier than air and may spread along the ground.
• Skin/Eye Contact - the extent of injury produced by exposure to ammonia depends on the duration of the exposure and the concentration of the gas or liquid. Even low airborne concentrations (100 ppm) of ammonia may produce rapid eye and nose irritation. Higher concentrations may cause severe eye injury. Contact with concentrated ammonia solutions, such as some industrial cleaners (25%), may cause serious corrosive injury, including skin burns, permanent eye damage, or blindness. The full extent of damage to the eyes may not be clear until up to 1 week after the injury is sustained. Contact with liquefied ammonia can cause frostbite injury.
• Ingestion - ingestion of ammonium hydroxide, while uncommon, results in corrosive damage to the mouth, throat, and stomach. Ingestion of ammonia does not normally result in systemic poisoning.

Respiratory - the extent of injury produced by exposure to ammonia depends on the duration of the exposure, the concentration of the gas, and the depth of inhalation. Even fairly low airborne concentrations (50 ppm) of ammonia produce rapid onset of eye, nose, and throat irritation; coughing; and narrowing of the bronchi. More severe clinical signs include immediate narrowing of the throat and swelling, causing upper airway obstruction and accumulation of fluid in the lungs. This may result in low blood oxygen levels and an altered mental status. Mucosal burns to the tracheobronchial tree can also occur. Immediate onset of laryngospasm with respiratory arrest can occur.

Dermal - dilute aqueous solutions (less than 5%) rarely cause serious burns but can be moderately irritating. Exposure to concentrated vapor or solution can cause pain, inflammation, blisters, necrosis and deep penetrating burns, especially on moist skin areas. Skin contact with compressed, liquid ammonia (which is stored at -28 °F) causes frostbite injury, and may also result in severe burns with deep ulcerations.

Ocular - ammonia has a greater tendency to penetrate and damage the eyes than does any other alkali. Even low concentrations of ammonia vapor (100 ppm) produce rapid onset of eye irritation. Contact with high concentrations of the gas, or with concentrated ammonium hydroxide, may cause swelling and sloughing of the surface cells of the eye, which may result in temporary or permanent blindness.

Gastrointestinal - nausea, vomiting, and abdominal pain are common symptoms following ingestion of ammonia. Ingestion of household ammonia (5-10%) has resulted in severe esophageal burns. Esophageal pain with swallowing, drooling and refusal of food suggest a more significant injury. Substernal chest pain, abdominal pain and rigidity suggest profound injury and potential perforation of the esophagus and/or stomach.

Link to Toxic Syndromes

Link to Primary and Secondary Survey

• Phosgene is distinguished by its smell in high concentrations and delayed onset of pulmonary edema.
• Riot agents cause an acute onset of burning sensation in the eyes and upper airway without progression of symptoms. Riot agents do not cause laryngospasm, except in hugh doses, and patients never develop symptoms of peripheral pulmonary edema.
• Nerve agents induce watery secretions as well as respiratory distress, but have a host of other symptoms, such as miosis, seizures, rapidity of onset, that can distinguish them from pulmonary agents.
• The respiratory toxicity of vesicants (i.e. mustard) is usually delayed but affects the central rather than the peripheral airway. Vesicant toxicity severe enough to cause dyspnea typically causes airway necrosis often with upper airway obstruction.
•  Link to Chemical Hazards Emergency Medical Management Intelligent Syndromes Tool (CHEMM-IST)

• Infants, toddlers, and young children do not have the motor skills to escape from the site of an incident.
• The vapors from liquefied gas are initially heavier than air and may spread along the ground high which is in the breathing zone of small children.
• Children exposed to ammonia are likely to experience increased severity of the same clinical effects seen in exposed adults.
• Exposure may be greater due to the higher number of respirations per minute in children.
• The smaller airway diameter, anatomic subglottic narrowing, omega shaped epiglottic structure, relatively large tongue size, less rigid ribs and trachea make them more vulnerable to nerve agent induces pathology i.e. stridor, bronchospasm, copious secretions.
• Vesicants and corrosives produce greater injury to children because of poor keratinization of their skin.
• Children, because of their relatively larger body surface area, lose heat quickly when showered. Consequently, decontamination may result in hypothermia unless heating lamps and other warming equipment are used.
• Having less fluid reserve increases the child's risk of rapid dehydration or shock after vomiting and diarrhea.
• Link to Primary and Secondary Survey

Antidotes - there are no specific antidotes for ammonia.

Supportive

Intubate the trachea in cases of coma or respiratory compromise. If not possible, perform cricothyroidotomy or place 14 gauge angiocatheter in crico-thyroid membrane (if equipped and trained to do so).

Link - placement of 14 gauge angiocatheter in cricothryroid membrane

Treat patients who have bronchospasm with aerosolized bronchodilators. The use of bronchial sensitizing agents in situations of multiple chemical exposures may pose additional risks. Consider the health of the myocardium before choosing which type of bronchodilator should be administered. Cardiac sensitizing agents may be appropriate; however, the use of cardiac sensitizing agents after exposure to certain chemicals may pose enhanced risk of cardiac arrhythmias (especially in the elderly). Ammonia poisoning is not known to pose additional risk during the use of bronchial or cardiac sensitizing agents.

Consider racemic epinephrine‡ aerosol for children who develop stridor. Dose 0.25-0.75 mL of 2.25% racemic epinephrine solution in 2.5 cc water, repeat every 20 minutes as needed, cautioning for myocardial variability.

Patients who are comatose, hypotensive, or are having seizures or cardiac arrhythmias should be treated according to advanced life support (ALS) protocols.

• Link to Basic and Advanced Life Support
• Link to Pediatric Basic and Advanced Life Support
• Link to Key Acute Care Adult Medications section
• Link to Key Acute Care Pediatric Medications section
• Link to Primary and Secondary Survey

‡ Not FDA approved for this indication/Off-label use

If victims can walk, lead them out of the Hot/Warm Zones to the Decontamination Zone. Victims who are unable to walk may be removed on backboards or gurneys; if these are not available, carefully carry or drag victims to safety. Should there be a large number of casualties, and if decontamination resources permit, separate decontamination corridors should be established for ambulatory and non-ambulatory victims.

Consider appropriate management of chemically contaminated children, such as measures to reduce separation anxiety if a child is separated from a parent or other adult.

• Link to Management of the Deceased

Personnel should continue to wear the same level of protection as required in the Hot/Warm Zones.

Link to Hot/Warm Zones - Rescuer Protection.

If exposure levels are determined to be safe, decontamination may be conducted by personnel wearing a lower level of protection than that worn in the Hot/Warm Zones. However, do not attempt resuscitation without a barrier.

Speed is critical. If the victim is symptomatic, immediately institute emergency life support measures. Treatment should be given simultaneously with decontamination procedures. Quickly ensure that the victim has a patent airway and is ventilating well. Assist ventilation with a bag-valve-mask device equipped with a canister or air filter, if necessary (avoid blind nasotracheal intubation or use of an esophageal obturator). Maintain adequate circulation. Stabilize the cervical spine with a decontaminable collar and a backboard if trauma is suspected. Direct pressure should be applied to control heavy bleeding, if present.

• Link to Supportive Treatment in the Hot/Warm Zones
• Link to Basic and Advanced Life Support
• Link to Pediatric Basic and Advanced Life Support
• Link to Key Acute Care Adult Medications section
• Link to Key Acute Pediatric Medications section
• Link to Primary and Secondary Survey

Antidotes - there are no specific antidotes for ammonia.

Set up Considerations

• Use pictorial and written posted instructions for victims to self decon when able, use locale-appropriate multilingual signage.
• Double bag contaminated clothing etc. (place hearing aids, valuables in small bag). Place bag in container by showers.
• Victims who are able may assist with their own decontamination.
• Children and the elderly are at increased risk for hypothermia - provide warm showers, blankets.
• Privacy must be considered, if possible.
• The decontamination system should be designed for use in children of all ages, by parentless children, the non-ambulatory child, the child with special needs, and also allow families to stay together.
• Use step-by-step, child friendly instructions that explain to the children and parents what they need to do, why they are doing it, and what to expect.
• Take into consideration that infants when wet are slippery and will need a way to get them through the decontamination process - i.e. plastic buckets, car seats, stretchers...
• Designate a holding area and provide staff to support and supervise the children.
• Recommended age appropriate staffing ratios for untended children:
  • 1 adult to 4 infants
  • 1 adult to 10 preschool children
  • 1 adult to 20 school-age children

Washing Instructions

• If there will be significant delay to decontamination, have the victims rinse off with water exposed skin surfaces and disrobe (disposable clothing kits should be available).
• Remove all clothing (at least down to their undergarments) and place the clothing in a labeled durable 6-mil polyethylene bag (removal of clothing, at least to the undergarment level will reduce victim's contamination by 85%).
• If clothes have been exposed to contamination, then care must be taken when undressing to avoid transferring chemical agents to the skin - i.e. any clothing that has to be pulled over your head should be cut off instead of being pulled over your head.
• If exposure to liquid agent is suspected, cut and remove all clothing and wash skin immediately with soap and water.
• If exposure to vapor only is certain, remove outer clothing and wash exposed skin with soap and water.
• Cover all open wounds with plastic wrap prior to performing head-to-toe decontamination (particular attention should be made to open wounds because ammonia is readily absorbed through abraded skin).
• Flush the exposed skin and hair with plain water for 2 to 3 minutes then wash twice with mild soap. Rinse thoroughly with water. Be careful not to break the patient/victim's skin during the decontamination process.
• Flush exposed or irritated eyes with plain water or saline for at least 15 minutes by tilting the head to the side, pulling eyelids apart with fingers, and pouring water slowly into eyes. Remove contact lenses if easily removable without additional trauma to the eye. If a corrosive material is suspected or if pain or injury is evident, continue irrigation while transferring the victim to the Support Zone.
• Do not irrigate eyes that have sustained frostbite injury.
• Scraping with a wooden stick, i.e. a tongue depressor or popsicle stick, can remove bulk agent.
• Caution - many people shower as they do it at home rather than conducting a rapid decontamination of their bodies. Too aggressive scrubbing can lead to further damage to skin and open wounds.
• Utilizing large amounts of water by itself is very effective (limit pressure in infants).
• If water supplies are limited, and showers are not available, an alternative form of decontamination is to use absorbent powders such as flour, talcum powder, or Fuller's earth.
• Certification of decontamination is accomplished by the following: processing through the decontamination facility; utilization of a device designed for confirmation of successful decontamination, such as a Draeger Gas Detector that detects ammonia gas.
  A comprehensive source for the selection of chemical identification equipment is the Guide for the Selection of Chemical Detection Equipment for Emergency First Responders, Guide 100-06, January 2007, 3rd Edition published by the Department of Homeland Security.
• If still contaminated, repeat shower procedure.
• Victims should be kept warm and quiet; any activity subsequent to exposure may increase the likelihood of death.

Decontamination of First Responder:

• Begin washing PPE of the first responder using soap and water solution and a soft brush. Always move in a downward motion (from head to toe). Make sure to get into all areas, especially folds in the clothing. Wash and rinse (using cold or warm water) until the contaminant is thoroughly removed.
• Remove PPE by rolling downward (from head to toe) and avoid pulling PPE off over the head. Remove the SCBA after other PPE has been removed.
• Place all PPE in labeled durable 6-mil polyethylene bags.

Decontamination of Infants and Children

• Video: Decontamination of Infants and Children (HHS/AHRQ, Children's Hospital Boston) (Watch video)
  • Decontamination of Children (HHS/AHRQ) provides a step-by-step decontamination demonstration in real time, and trains clinicians about the nuances of treating infants and children, who require special attention during decontamination.

Wound Management

• Link to Wound Management

References

• Medical Management of Chemical Casualties Handbook, 2nd edition, September, 1995
• Braue EH, Boardman CH. Decontamination of Chemical Casualties
• Jagminas L. CBRNE - Chemical Decontamination (eMedicine)

Following decontamination the patient should be reassessed; noting changes in triage category (if any), the need for or the modification of supportive therapy (See ABC reminders/Advanced Treatment) .

ABC Reminders

Quickly access airway patency. If trauma is suspected, maintain cervical immobilization manually and apply a cervical collar and a backboard when feasible. Ensure adequate respiration and pulse. Document oxygen saturation. Place on a cardiac monitor.

Link to Primary and Secondary Survey

If the patient is symptomatic, immediately institute emergency life support measures.

Clinical Signs and Symptoms - Link to clinical signs and symptoms

Inhalation Exposure

• The diagnosis of acute ammonia toxicity is primarily clinical, based on symptoms of irritation and breathing difficulty. However, laboratory testing is useful for monitoring the patient and evaluating complications.
• If cough or difficulty in breathing develops, evaluate for hypoxia, respiratory tract irritation, bronchitis, pneumonitis and pulmonary edema. Chest radiography and pulse oximetry (and/or ABG measurements) are recommended if significant inhalation exposure is suspected.
• ECG monitoring should be provided for patients with significant ammonia exposure.
• Inhalation of higher concentrations can very rapidly lead to respiratory distress. This can occur almost immediately with initial symptoms of stridor, followed shortly by wheezing, rales, hemoptysis, and subsequent pulmonary edema (including Acute Lung Injury or Acute Respiratory Distress Syndrome). Immediate onset of laryngospasm with respiratory arrest can occur.
• Acute Lung Injury (ALI), Acute Respiratory Distress Syndrome (ARDS)
  • ALI/ARDs is a process of nonhydrostatic pulmonary edema with resultant arterial hypoxemia associated with a variety of causative etiologies (including severe ammonia toxicity). Left atrial hypertension should be excluded.
  • The standard definition of ALI identifies those patients as having bilateral pulmonary infiltrates and arterial hypoxemia using the concentration of arterial oxygen in the blood divided by the inspired fraction of oxygen (i.e. a PaO2 ratio of less than 300). If the patient's Pa02/Fi02 is less than 200, then a diagnosis of ARDS can be made.
  • Link to Overview Literature for diagnosis and management of ALI and ARDS

Non-Pharmacologic Treatment

• Administer 100% humidified supplemental oxygen, perform endotracheal intubation and provide assisted ventilation as required.
• Positioning - 60-70% of patients with ARDS will have improvement in oxygenation in the prone position.
• Maintain adequate ventilation and oxygenation with frequent monitoring of arterial blood gases and/or pulse oximetry. If a high FIO2 is required to maintain adequate oxygenation, mechanical ventilation and positive-end-expiratory pressure (PEEP) may be required; ventilation with small tidal volumes (6 milliliters/kilogram) is preferred if ARDS develops.
• To minimize barotraumas and other complications, use the lowest amount of PEEP possible while maintaining adequate oxygenation.
• Link - Approaches in the management of acute respiratory failure in children
• Use of smaller tidal volumes (6 milliliters/kilogram) and lower plateau pressures (30 cm water or less) has been associated with decreased mortality and more rapid weaning from mechanical ventilation in patients with ARDS (Brower et al, 2000). Despite the lack of a specific pharmacologic treatment, lung protective ventilation has reduced the mortality of ALI from 40% in 2000 to 25% in 2006.

Drug Therapy for Inhalation Exposure‡*

Animal experiments and anecdotal human experience suggests that inhaled beta-adrenergic agonists, aminophylline, corticosteroids, terbutaline, other beta2 agonists, N-acetyl cysteine and ibuprofen may be effective in treating ammonia-induced pulmonary edema. Optimal doses of these agents have not been established (off label usage)‡*

• Inhaled beta adrenergic agonists if bronchospasm develops - Consider racemic epinephrine aerosol for children who develop stridor. Dose 0.25-0.75 mL of 2.25% racemic epinephrine solution in 2.5 cc water, repeat every 20 minutes as needed, cautioning for myocardial variability. Consider the health of the myocardium before choosing which type of bronchodilator should be administered. Cardiac sensitizing agents may be appropriate; however, the use of cardiac sensitizing agents after exposure to certain chemicals may pose enhanced risk of cardiac arrhythmias (especially in the elderly). Ammonia poisoning is not known to pose additional risk from such drug therapies. The use of bronchial sensitizing agents in situations of multiple chemical exposures may pose additional risks.
• IV Aminophylline is a second line agent that might be helpful - 5-6 milligram/kilogram loading dose followed by 1 milligram/kilogram every 8 to 12 hours to maintain a serum level of 10 to 20 micrograms/milliliter.
• Methylprednisolone - children 2 mg/kg loading then 2 mg/kg divided Q6h, adults 250 mg Q6H, steroids are likely of most utility in patients with latent or overt reactive airway disease.
• Beta2 adrenergic agonists such as terbutaline, isoetharine at conventional doses.
• N-acetylcysteine - up to 10 milliliters of a 20% solution aerosolized.
• Ibuprofen 800 milligrams (15 mg/kg in children) every 8 to 12 hours for at least one dose.
• Antibiotics are indicated only when there is evidence of infection. More than 60% of ARDS patients experience a (nosocomial) pulmonary infection.

Ingestion Exposure

• Induced emesis and gastric lavage are contraindicated to avoid further exposure of the esophagus. Neutralization agents are contraindicated as it is thought an exothermic reaction will occur.
• Blind passage of a NG tube is contraindicated unless cleared by a gastroenterologist.
• Lateral neck and chest x-rays should be performed if there is any underlying suspicion of perforation.
• Prior to intubation for esophagoscopy, assessment of laryngotracheal injury should be performed.
• Esophagoscopy should be carried out on all patients with suspected caustic ingestion (at approximately 48 hours post event) to delineate the extent of esophageal injury.
  • At 48 hours post ingestion enough time has passed such that effects of the injury have demarcated itself so that appropriate grading of severity can be reliably predicted.
  • Esophagoscopy allows for the insertion of a NG tube under vision. The NG tube, in addition to providing a mechanism for enteral feedings, assists in maintaining the patency of the esophageal lumen.
• The use of anti-reflux therapy, antibiotics and steroids are the other arms of management.
  • The routine use of anti-reflux therapy is recommended to prevent secondary reflux-associated injury (typically proton pump inhibitors for a total of 6 weeks).
  • There is evidence suggesting a lower rate of stricture formation with antibiotic usage. However, some investigators suggest that antibiotics promote the influx of gram negative organisms without decreasing stricture formation rates as well as potentially masking serious bacterial infections. A routine antibiotic regime includes the use of third generation cephalosporins for 48 hours and if oral intake is tolerated change over to clindamycin for six weeks duration.
  • The additive role of steroids is controversial. While multiple studies demonstrate that steroids are able to modify the inflammatory response at the site of injury, multiple trials and reviews have shown little or no measurable benefit from varying doses of steroids in their ability to reduce the rate of stricture formation. Grade 2 injuries are where steroids are felt to be the most beneficial in preventing stricture formation. Many clinicians justify their use when simultaneously treating upper airway edema/laryngeal injury and esophageal injury. One therapeutic approach is to initially utilize dexamethasone for the 48 hours prior to the esophagoscopy with transition to oral equivalent dosing and continuance of therapy for one more weeks duration.
• In spite of therapy, stricture formation occurs in 10% of esophageal caustic burns. Half of grade two burns have long term strictures.
• The management of esophageal strictures is endoluminal first and, should that fail, then esophageal replacement surgery is utilized.

Fluids

• Crystalloid solutions must be administered cautiously, AVOIDING a net positive fluid balance. Monitor fluid status through a central line or Swan Ganz(R) catheter.
• Diuretics may be needed to avoid a net positive fluid balance but are almost always contraindicated. Pulmonary edema due to ammonia inhalation is not hypervolemic in origin; patients tend to be hypovolemic and hypotensive. Dopamine may be required for treatment of hypotension, bradycardia, or renal failure.

Eye Exposure

• Ammonia exposed eyes should be irrigated for at least 15 minutes or until the pH of the conjunctival fluid has returned to normal. Test visual acuity and examine the eyes for corneal damage and treat appropriately. Immediately consult an ophthalmologist for patients who have corneal injuries. Patients who have corneal injury should be re-examined within 24 hours.

Dermal Exposure

• If ammonia gas or solution was in contact with the skin, chemical burns may result; treat as thermal burns.
• Frostbite has not been commonly reported but is a potential risk.
• Re-warming
  • Do not institute re-warming unless complete re-warming can be assured; re-freezing thawed tissue increases tissue damage. Place affected area in a water bath with a temperature of 40 to 42 degrees Celsius for 15 to 30 minutes until thawing is complete. The bath should be large enough to permit complete immersion of the injured part, avoiding contact with the sides of the bath. A whirlpool bath would be ideal. Some authors suggest that an antibacterial (hexachlorophene or povidone-iodine) be added to the bath water (Murphy et al, 2000).
  • Correct systemic hypothermia.
  • Re-warming may be associated with increasing pain, requiring narcotic analgesics.

Wound Care

• Digits should be separated by sterile absorbent cotton; no constrictive dressings should be used. Protective dressings should be changed twice per day.
• Perform daily hydrotherapy for 30 to 45 minutes in warm water 40 degrees Celsius. This helps debride devitalized tissue and maintain range of motion.
• The injured extremities should be elevated and should not be allowed to bear weight.
• Prophylactic antibiotics are recommended by some authors.
• Clear blisters should be debrided but hemorrhagic blisters left intact.
• Further surgical debridement should be delayed until mummification demarcation has occurred (60 to 90 days). Spontaneous amputation may occur.
• Analgesics may be required during the re-warming phase; however, patients with severe pain should be evaluated for vasospasm. Arteriography and noninvasive vascular techniques (e.g., Doppler ultrasound, digital plethysmography, isotope scanning), have been useful in evaluating the extent of vasospasm after thawing.
• Tetanus prophylaxis as indicated.
• Topical aloe vera may decrease tissue destruction and should be applied every 6 hours.
• Ibuprofen is a thromboxane inhibitor and may help reduce tissue loss. Adult dose of 200 milligrams every 12 hours is recommended.
• Adjunct pharmacological agents (heparin, vasodilators, prostacyclins, prostaglandin synthetase inhibitors, thrombolytics, and dextran) are controversial and not routinely recommended.

‡ Not FDA approved for this indication/Off-label use

* Pregnancy Categories: Refer to DailyMed regarding Pregnancy Categories and additional pregnancy-related information.

Antidotes and Other Treatments

• There is no specific antidote for ammonia poisoning. Although administration of corticosteroids to limit esophageal scarring is recommended by some toxicologists, this treatment is unproven and may be harmful in patients who have perforation or serious infection.
• Hemodialysis is not effective.

The diagnosis of acute ammonia toxicity is primarily clinical, based on respiratory difficulties and irritation. However, laboratory testing is useful for monitoring the patient and evaluating complications.

Routine laboratory studies for all exposed patients include:

• CBC, glucose, and electrolyte determinations.
• Patients who have respiratory complaints may require pulse oximetry (and/or ABG measurements) and chest radiography.
• No specific biomarker for ammonia exposure exists.
• Link to Basic and Advanced Life Support

Patient Release/Follow-up

• Persons who have been exposed only to ammonia gas and are currently asymptomatic are not likely to develop complications.
• Delayed Effects - residual bronchoconstriction, bronchiectasis and small airway disease may occur, and chronic obstructive pulmonary disease can develop. Patients exposed by inhalation who are initially symptomatic should be observed carefully and reexamined periodically. Pulmonary function tests should be repeated on an annual basis.
• Patients who have corneal injuries should be reexamined in 24 hours.
• Link to Surveillance for Possible Chemical Emergencies
• Link to Management of the Deceased

Follow-up Instructions

• Call your doctor or the Emergency Department if you develop any unusual signs or symptoms within the next 24 hours, especially:
  • coughing
  • difficulty breathing or shortness of breath
  • wheezing or high-pitched voice
  • chest pain or tightness
  • increased pain or a discharge from exposed eyes
  • increased redness or pain or a pus-like discharge in the area of a skin burn
  • stomach pain or vomiting
• No follow-up appointment is necessary unless you develop any of the symptoms listed above.
• Call for an appointment with Dr. _____________ in the practice of ___________________.
  When you call for your appointment, please say that you were treated in the Emergency Department at ____________ Hospital by _______________ and were advised to be seen again in ______ days.
• Return to the Emergency Department/Clinic on __________ (date) at ____________ AM/PM for a follow-up examination.
• Do not perform vigorous physical activities for 1 to 2 days.
• You may resume everyday activities including driving and operating machinery.
• Do not return to work for _______ days.
• You may return to work on a limited basis. See instructions below.
• Avoid exposure to cigarette smoke for 72 hours; smoke may worsen the condition of your lungs.
• Avoid drinking alcoholic beverages for at least 24 hours; alcohol may worsen injury to your stomach or have other effects.
• Avoid taking the following medications: ________________________________
• You may continue taking the following medication(s) that your doctor(s) prescribed for you:
  _________________________________________________________________
  _________________________________________________________________
  _________________________________________________________________
  
• Other instructions:
  _________________________________________________________________
  _________________________________________________________________
  _________________________________________________________________
  
  

• Provide the Emergency Department with the name and the number of your primary care physician so that the ED can send him or her a record of your emergency department visit.
  
  
• You or your physician can get more information on the chemical by contacting: ____________________________ or ____________________________, or by checking out the following Internet Web sites: ________________________; ___________________________.

Signature of patient    _____________________________________ Date _____________

Signature of physician _____________________________________ Date _____________

Adapted from Medical Management Guidelines for Ammonia (ATSDR/CDC)

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