Ammonia Toxicity - Etiology, Signs, Symptoms, Diagnosis and Treatment

Introduction:

Ammonia is an anhydrous colorless, irritating gas with a pungent and suffocating odor. It is a flammable and toxic gas. It can be easily compressed and converted into colorless liquid under pressure. Ammonia is hygroscopic and can readily be dissolved in water and forms ammonium hydroxide-an alkaline solution. Excessive exposure to ammonia can lead to health hazards and results in ammonia toxicity. Ammonia is a naturally occurring by-product in the human body by metabolic reactions. It is also detected in the human gut by the various enzyme activities of the bacteria.

What Are the Uses of Ammonia?

Ammonia levels in the blood can be used to test different disorders and may help in diagnosis and monitoring conditions that cause high ammonia levels.

Hepatic Encephalopathy - It is a condition that happens when the liver is damaged to completely metabolize ammonia. In this disorder, ammonia can accumulate in the blood and travel to the brain. It can result in confusion, disorientation, and life-threatening conditions like a coma.

Reye Syndrome - It is a serious fatal condition that affects the liver and brain. It mostly affects children and teenagers suffering from viral infectious diseases such as chicken pox or the flu and who have taken aspirin to treat their illnesses. The etiology of Reye syndrome is unknown. But because of the risk, children and teens should not be taken for granted.

Urea Cycle Disorders - It is a rare genetic defect that affects the body's ability to change ammonia into urea.The test may also be used to monitor the effectiveness of treatment for liver disease or kidney failure.

What Are the Routes of Exposure to Ammonia?

Inhalation - Inhaling ammonia can result in the following problems -

• Nasopharyngeal and tracheal chemical burns.

• Upper airway obstruction.

• Bronchiolar or alveolar edema and narrowing.

• Laryngospasm.

• Respiratory failure.

• Hypoxia

• Cough

Skin contact -

• Household cleaners and industrial cleaners may consist of ammonia which can lead to skin irritation and burning.

• Skin chemical burns.

• Blistering, pain.

• Necrosis.

• Contact with compressed liquid ammonia can cause frostbite injury and deep ulcerating burns.

Eye contact

• If a person comes in contact with high concentrations of the gas ammonium hydroxide can lead to permanent vision loss.

Ingestion

• Corrosive damage and chemical burns to the oropharynx, esophagus, and stomach.

• Nausea.

• Vomiting.

• Chest pain.

• Abdominal pain.

What Is the Physiopathology of Ammonia Toxicity?

Ammonia reacts directly when it comes in contact with moisture in the skin, eyes, oral cavity, respiratory tract, and particularly mucous surfaces to form the very caustic ammonium hydroxide. Ammonium hydroxide can result in the necrosis of tissues through the elimination of the cell membrane lipids (saponification), leading to cellular destruction. As cell proteins break down, water is extracted, resulting in inflammatory reactions that can cause serious damage to the human body.

What Is the Etiology of Ammonia Toxicity?

Ammonia toxicity is mainly caused by excessive exposure to ammonia gas. The following are the reasons causing ammonia poisoning or toxicity.

• Gas leaks from the industries, storage, or transportation of ammonia. People working in such spaces are at high risk for inhalation and skin exposure.

• Application of ammonia-containing fertilizers in the soil leads to high levels of ammonia in the air. Hence, the farmers who rely on ammonia-based fertilizers are at an increased risk for inhalational exposure.

• Household and industrial cleaners contain 5 percent to 25 percent of ammonia in them. Hence families, especially children of such households, are at higher risk for accidental or intentional exposure.

• Ammonia is produced by decaying manure. Therefore, the farmers working in animal confinement areas are at a higher risk for inhalational exposure.

What Are the Signs and Symptoms Associated With Ammonia Toxicity?

Ammonia toxicity can affect many body parts and follow the signs and symptoms associated with ammonia toxicity.

• Cough.

• Chest pain (severe).

• Chest tightness.

• Difficulty breathing.

• Rapid breathing.

• Wheezing.

• Fever.

• Tearing and burning of eyes.

• Temporary blindness.

• Throat pain (severe).

• Mouth pain.

• Lip swelling.

• Rapid pulse.

• Collapse and shock.

• Confusion.

• Difficulty walking.

• Dizziness.

• Lack of coordination.

• Restlessness.

• Stupor (altered level of consciousness).

• Bluish-colored lips and fingernails.

• Severe stomach pain.

• Vomiting.

What Is the Investigation for the Diagnosis of Ammonia Toxicity?

The following are the investigations performed for the diagnosis of ammonia toxicity.

• A complete blood count is done to detect the presence of ammonia in the blood.

• Blood urea nitrogen (BUN) and creatinine.

• Serum lactic acid levels.

• Kidney function tests.

• Serum electrolytes.

• Prothrombin time (PT), international normalized ratio (INR).

• Blood type and cross-matching.

• Urine output monitoring.

In patients with suspected respiratory injury:

• Pulse oximetry.

• Cardiac monitoring.

• Serial blood gasses.

• Chest X-ray is done to detect respiratory distress in ammonia toxicity.

• Pulmonary function tests (PFTs).

• Bronchoscopy in suspected severe acute inhalation.

• Ventilation-perfusion (V/Q) scan.

In patients with suspected ingestion:

• Endoscopy.

• Ultrasound Sonography.

In patients with exposure to the eye following tests are performed to determine the effect of ammonia on the eyes, as ammonia toxicity can result in eye irritation.

• Slit-lamp examination with fluorescein staining.

• Tonometry.

• Conjunctival pH measurement.

How Is Ammonia Exposure Treated?

There is no specific treatment or antidote for ammonia poisoning, but ammonia's effects can be curable, and most of the reported cases have shown a good prognosis. Immediately remove the contact of ammonia from the skin and eyes with a wash of clear water. Treatment consists of supportive measures and symptomatic treatment, which can include the administration of humidified oxygen, indication of bronchodilators, and managing the airway. Ingested ammonia can be diluted with milk or water.

Conclusion:

Ammonia is a very common chemical present in the day to day life. The possibility of excessive ammonia exposure is very high. People using hair dye to color their hair also have ammonia in it. Therefore it is very important to know and understand the adverse effects of ammonia and its toxicity which affects well-being. If a person experiences any above-mentioned signs and symptoms should consult their doctor for help.