INTERVENTION CRITERIA
Medical assessment is recommended for: - Any concentration of hydrofluoric acid where calcium gluconate gel has not been given as a first aid procedure, even if asymptomatic - Any solutions of greater than 6% hydrofluoric acid, regardless if calcium gluconate gel has been administered - Any patient developing pain, erythema, or swelling at the exposure site at any time following the exposure to hydrofluoric acid |
Hospital assessment is recommended for: - Any hydrofluoric acid ingestion |
Hospital assessment is required for: - All eye exposures to hydrofluoric acid liquids - All symptomatic eye exposures to hydrofluoric acid vapors |
Medical assessment is recommended for: - Mild cough - Throat/nasal irritation |
The patient can be observed at home in the event of: Dermal exposures to: - Solutions of less than 6% hydrofluoric acid, involving very small areas of skin, but where the area has been decontaminated and calcium gluconate gel has been given as a first aid treatment Inhalation: - Where the exposure is via inhalation, serious symptoms are unlikely to develop and medical assessment is unlikely to be required However, if the following symptoms develop the patient should seek medical attention: Dermal: Pain Erythema Edema Inhalation: Mild cough Throat/nasal irritation Dyspnea or breathing difficulty Stridor Wheeze Tachypnea |
Medical assessment is recommended for: Dermal exposures to: - Any concentration of hydrofluoric acid where calcium gluconate gel has not been given as a first aid procedure - Any solutions of greater than 6% hydrofluoric acid Inhalation exposures with: - Any symptomatic exposure to hydrofluoric acid vapor |
Hospital admission is recommended for: Inhalation - Patients suffering: Dyspnea Breathing difficulty Tachypnea Stridor Wheeze Cyanosis Pulmonary signs Dermal Exposures to: - Solutions containing more than 6% hydrofluoric acid - Solutions of less than 6% hydrofluoric acid, if calcium gluconate has not been administered as a first aid procedure and can not be promptly administered - Any patient developing pain, erythema, or swelling at the exposure site, at any time following the exposure to hydrofluoric acid Ingestion - Any suspected or known hydrofluoric acid ingestion Ocular - Hospital assessment is required for all direct symptomatic eye exposures to hydrofluoric acid in liquid or vapor form - Observation by a reliable lay person without referral to a health care facility is appropriate for brief, asymptomatic exposures to airborne vapor or mists |
TREATMENT
TREATMENT SUMMARY
The personal protection and safety of the attending personnel must be considered at all times, during the treatment of patients exposed to hydrofluoric acid.
The treatment of all hydrofluoric acid exposures focuses on preventing systemic absorption, evaluating the degree of systemic toxicity and rapidly correcting electrolyte abnormalities. Following systemically toxic doses of hydrofluoric acid, the initial emergency stabilization involves monitoring for and correcting hypocalcemia, which may lead to severe hypotension, seizures or dysrhythmias, if left untreated. Blood pressure and ECG should also be closely monitored and IV access secured immediately.
Skin exposures should be decontaminated firstly with water and then treated with calcium gluconate gel. Although gastrointestinal decontamination is not recommended, patients should be given water, or preferably milk, to drink (no more than 1 to 2 cupfuls for an adult, 1/2 cupful for child), or calcium containing antacids. All ocular exposures are potentially severe and will require assessment by an ophthalmologist.
The mainstay of the supportive care focuses on the prevention and treatment of hypocalcemia. Monitor serum electrolyte levels (particularly calcium and magnesium) for evidence of hypocalcemia and hypomagnesemia. Patients should also be observed for symptoms secondary to the onset of hypocalcemia, i.e. hypotension, seizures or dysrhythmias. Administer IV calcium gluconate to replace calcium, if plasma levels are depleted or in the presence of secondary effects. Correct any hypomagnesemia and/or hyperkalemia using standard procedures. Hyperkalemia and metabolic acidosis may be severe enough to warrant urgent hemodialysis, if not responsive to standard treatment measures.
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EMERGENCY STABILIZATION
Initial emergency stabilization involves monitoring and correction of hypocalcemia, which if left untreated, may lead to severe hypotension, seizures or dysrhythmias. IV access should be secured immediately and cardiac function monitored closely. |
Ensure Adequate Cardiopulmonary Function |
Ensure the airway is protected if compromised (intubation may be necessary). |
Establish secure intravenous access in ingestions, inhalational exposures, and large dermal exposures (>3% body surface area).
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Severe hypotension, seizures or dysrhythmias indicate severe hypocalcemia. Whilst it is preferable to document reduced serum ionized calcium, in the presence of these effects intravenous calcium is warranted even without serum test results.  |
Blood pressure ECG Serum ionized calcium Serum electrolytes including: Magnesium Potassium Sodium |
DECONTAMINATION
The personal protection and safety of the attending personnel must be considered at all times during the treatment of patients. Gastrointestinal decontamination is not recommended following ingestion. Following dermal and/or ocular exposures the initial decontamination procedure is rapid and thorough irrigation with water. Dermal exposures should then be treated with a calcium gluconate gel or solution. All eye exposures require a standard eye examination and referral to an ophthalmologist for additional assessment. |
Ensure the patient has been given a small amount of fluid to drink (1 to 2 cupfuls for an adult, 1/4 to 1/2 cupful for a young child), however, be aware large amounts of fluid may increase the risk of vomiting, with attendant risks from re-exposure of the esophagus to the corrosive substance. Decontamination is not recommended. Activated charcoal is not indicated as it does not adequately adsorb this substance and will impair visibility if endoscopy is required. Nasogastric aspiration, gastric lavage, and whole bowel irrigation are contraindicated. No benefit has been demonstrated from these procedures, and there is significant risk of perforation during gastric intubation. Emesis is contraindicated due to both risks of re-exposure of the esophagus to the corrosive substance and/or aspiration, and the increased intraluminal pressure produced by emesis. |
Irrigate Skin Immediately |
Remove contaminated clothing or jewellery. Flush the affected area with water as soon as possible. Continue to irrigate until all of the contaminant is removed. Further treatment will then be required to address signs and symptoms. |
Apply Calcium Gluconate Gel |
A 2.5% calcium gluconate gel massage should be performed. Continue massaging into the burned skin for a minimum of 30 minutes and for as long as the pain persists. For digital exposures place the gel in a latex glove and put this on the affected hand. If no gel is available, mix calcium gluconate (10 mL of 10%) with KY jelly (10 g) and apply, or use a calcium or magnesium solution for soaking the affected area. Sometimes pain persists for up to four hours.
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All blisters should be removed and the underlying tissues cleaned. The blister fluid is generally contaminated and it is contraindicated to leave the blisters intact. Removal of nails SHOULD BE AVOIDED if periungual or ungual tissues are involved. Pain at these sites will usually respond well to either intra-arterial or regional intravenous calcium therapy. Any excision of affected tissue should be avoided.
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Immediate copious irrigation with water or normal saline for at least 30 minutes is required. Application of ice packs during any transportation to medical facilities has been suggested. Examination with fluorescein and slit-lamp to assess the injury is recommended for all exposures. The patient should always be referred to an ophthalmologist. Further injury may be reduced with application of a 1% solution of calcium gluconate in saline. This is used to wash the eye for a further 5 to 10 minutes (after the initial immediate irrigation), and thereafter as drops every 2 to 3 hours for 48 to 72 hours, or as long as clinically indicated. |
Remove the patient from the exposure. If respiratory symptoms such as shortness of breath are present, administer oxygen and provide additional support if necessary. |
SIGNS AND SYMPTOMS
The onset and severity of symptoms is concentration dependent. Hydrofluoric acid is moderately corrosive by ingestion, inhalation, skin and eye exposure, and can cause systemic toxicity via all routes. Unlike more corrosive acids, it may not cause immediate localized pain and tissue damage when individuals are exposed to concentrations less than 50%. Local symptoms may be delayed and should be monitored for following exposures to low concentration formulations. Systemic symptoms of hypocalcemia, hypomagnesemia, hyperkalemia, pulmonary edema, metabolic acidosis, ventricular dysrhythmias and death may occur following ingestion or large dermal exposures. |
Onset/Duration of Symptoms |
The onset and severity of symptoms may vary depending on the concentration and the route of exposure. Following exposure to low concentration formulations localized symptoms may be delayed, while onset of local and systemic symptoms may be rapid following high concentration exposures. Pain may be delayed and may not be proportional to the size of the visible injury. This may result in delayed triage or medical diagnosis on presentation to hospital. Without appropriate treatment, burns can continue to increase in surface area for 4 to 7 days.
Hydrofluoric acid primarily produces tissue damage by the dissociation of fluoride ions into the tissues. This is a relatively slow process, compared to the corrosive action of other acids. Hypocalcemia, hypomagnesemia and acidosis may occur within 1 to 2 hours following large dermal exposures or ingestions of hydrofluoric acid.
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Hydrofluoric acid is moderately corrosive by ingestion, inhalation, skin and eye exposure. Systemic toxicity can occur from all routes of exposure, but is most likely following ingestions or significant dermal exposures to concentrated formulations.
Following any exposure to hydrofluoric acid systemic toxicity is possible and may be delayed; a cautious approach must be applied in all cases.
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Following an exposure to hydrofluoric acid, mild symptoms are associated with local effects, while moderate or severe symptoms are an indication of systemic toxicity or an exposure to a concentrated formulation. | Mild Hydrofluoric Acid Toxicity | Moderate Hydrofluoric Acid Toxicity | Severe Hydrofluoric Acid Toxicity | Edema Pain Erythema | Blanching Blistering Ulceration Vomiting Necrosis | Decalcification of the bone Cardiac dysrhythmias Metabolic acidosis Hypocalcemia Hepatic damage Cardiac arrest Death |
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CHRONIC EFFECTS
Chronic ingestion or inhalation can lead to fluorosis.
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Weight loss Malaise Nausea Diarrhea Constipation Anemia Leukopenia Weakness Discoloration of teeth Osteosclerosis
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Do Not Archive. This document is current on day of issue,
NZ: 18.May.2012 |
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