Case Study42 year old male presented to emergency department of St. Michaels Hospital, Toronto, Ontario complaining of pain and blisters on the index and middle fingers of his right hand. He indicated approximately 12 hours earlier, which cleaning the brick faade of a building, his had had been splashed with a cleaning solution that he suspected to contain hydrofluoric acid. He had immediately wiped his hand clean and rinse the site of contact for 10 minutes with water. He felt well until 4 hours after the incident he began to develop blisters and increasing pain.On examination, the worker was alert, but complained of throbbing pain in his right hand.HR: 100bpm; BP: 120/80mmHg. There were blisters and edema on the dorsal aspect of the right index and middle fingers. The fingers had a mottled appearance and were tender. He had decreased capillary refill, but had normal pulses and sensation. Electrolytes, calcium, and ECG were normal.HF is a chemical compound that contains fluorine, which is very reactive and poisonous. It can exist as a colorless gas or as a fuming liquid, or it can be dissolved in water to produce hydrofluoric acid. It is used to make refrigerants, herbicides, pharmaceuticals, high-octane gasoline, aluminum, plastics, electrical components, and fluorescent light bulbs. 60% of HF used in manufacturing is for processes to make refrigerants. It is also used for etching glass and metal.Content:> Brief Overview / Intro> Abstract / Case Study> Mechanism of Action> Clinical Effects> Treatment> ConclusionMonday, May 4th, 2015

Hydrofluoric Acid

Inhalation ExposureMove patient from toxic environment to fresh air and monitor for respiratory distress. Administer 100% humidified supplemental oxygen, perform endo-tracheal intubation and provide assisted ventilation as required.Administer inhald beta-2adrenergic agonist if bronchospasm develops Dermal ExposureImmediately wash all exposed areas with copious amounts of water or crystalloid solution for at least 30 minutes while removing all potentially contaminated clothing and jewelry. Massage calcium carbonate gel into the affect area until the pain has subsided for 15 minutes. References1. Facts About Hydrogen Fluoride (Hydrofluoric Acid). Centers for Disease Control and Prevention. http://www.bt.cdc.gov/agent/hydrofluoricacid/basics/facts.asp. April 22, 2013. Accessed April 13, 2015 2. Hydrofluoric Acid. In Micromedex 2.0. Greenwood Village (CO): Thompson Reuters. [updated 10/09/14; accessed04/15/11].http://www.micromedexsolutions.com/micromedex2/librarian/ND_T/evidencexpert/ND_PR/evidencexpert/CS/AABBCD/ND_AppProduct/evidencexpert/DUPLICATIONSHIELDSYNC/44CB44/ND_PG/evidencexpert/ND_B/evidencexpert/ND_P/evidencexpert/PFActionId/evidencexpert.IntermediateToFullDocumentLink/docId/118/contentSetId/51/title/HYDROFLUORIC%20ACID/servicesTitle/HYDROFLUORIC%20ACID 3. Why are fluoride ions in acidic environment as dangerous as hydrofluoric acid? Prevor. http://www.prevor.com/en/fluoride-ions-in-acidic-medium-corrosive-and-toxic-like-hydrofluoric-acid-a-danger-to-be-considered. Accessed April 13, 20154 . Qureshi R, House R, et al. Hydrofluoric acid burn: a case report. CJEM. 2002;4(4). http://www.cjem-online.ca/v4/n4/p292Accessed April 20. 2015ConclusionHydrofluoric Acid is a very toxic chemical to both adult and pediatric populations. Thus its use and storage at home and industrial settings must be strict to avoid any unnecessary harm. Eye ExposureIrrigate the eyes promptly with crystalloid solution (lactated ringers or normal saline).Calcium gluconate solution and benzethonium chloride have been suggested for treatment of eye exposure. Oral ExposureAttempt immediate administration of fluoride binding substance (milk, calcium carbonate tablets, milk of magnesia). Careful nasogastric suction or lavage (with calcium gluconate 10%) with small soft tube for patients with significant ingestions who present within 60 minutes of exposure and have not spontaneously vomited. Treatment OptionsHydrofluoric acid can be found in many domestic products including wheel cleaners and rust removers, containing approximately 3% HF. It is also the only etchant which attacks amorphous SiO2, quarts, or glasses at significant etch rate.

Mild to moderate toxicityDermal: can result in delayed, unlrelenting, severe pain without visible signs of injuryOcular: Muscosal irritationInhalation: mucosal irritation, dysp-nea, coughing, wheezingIngestion: GI irritation Highly electronegative fluoride ion penetrates tissues deeply and binds calcium leading to hypocalcemia (and hypomagnesemia), tissue burs and cell death. Poisoning is uncommon with mostly minor and moderate outcomes, but may be life-threatening. Toxicity usually occurs via dermal route but occasionally ocular, ingestion or inhalation. Severe poisoning most often occurs after ingestion, but may develop from a dermal exposure of a larger surface area and/or to a higher concentration product. Severe toxicityDermal: Tissue destruction or necrosisOcular: pain, conjunctival injection, corneal abrasion or ulceration, corneal opacification. Permanent visual deficits may occur in severe cases.Ingestion: significant GI burns, systemic poisoning with hypoca-lcemia, ventricular dysrrhythmias, hyperkalemia, hypomagnesmia, acid-osis, cardiac arrest.Inhalation: Dyspnea, bronchospasm, chemical pneumonitis, pulmonary edema, upper airway obstruction, chemical burns, respiratory failure. Clinical PresentationThere are several proposed toxicologic mechanisms:1. The fluoride ion inhibits many enzyme systems by binding to metal-containing enzymes and inactivating them. Enzyme systems affected include: acetylcholinesterase, adenyl cyclase, and sodium-potassium ATPase.2. HF passes easily though cell membranes by nonionic diffusion. The free fluoride ion forms complexes primarily with calcium and, to a lesser extent, magnesium. The complexes formed are insoluble and precipitate in tissues, resulting in pain and tissue destruction.3. Fluoride binds to potassium and magnesium ions leading to myocardial irritability and dysrrhythmias.gluconate drip was started at 250cc/hour, along with IV morphine. IV infusion was discontinued because of failure to relieve pain and a Bier Block was performed with some success. He was admitted to the plastic surgery service, and continuous calcium gluconate soaks were performed over the next 24 hours with resolution of discomfort in the hand. He was discharged with instructions to apply calcium gluconate gel and dressings to the right hand and to keep it splinted and elevated.Patient returned to the ED the next morning complaining of increasing pain. On inspection, his would appeared clean and improved from the day before. He was give 10 tablets of acetaminophen with codeine. When followed-up in 3 days, patient had improved and required no further treatment. Case Study ContinuedIn the Emergency Department:Patient received 0.7cc of calcium gluconate, administered intradermally at the sites of lesions with no pain relief, intramuscular tetanus toxoid, and acetaminophen with codeine for pain. He was seen by plastic surgery service who debrided the blisters and instituted hand soacks in 1% calcium gluconate, but severe pain persisted. 8 hours after arrival at ED, 5% IV calcium