hydrofluoric acid
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Hydrofluoric Acid
Intensive Review Course in Clinical Toxicology 2007
Rama B. Rao
Hydrofluoric Acid (HF) Household
Glass etching Cleaning bricks and porcelain Rust removal
Industrial Leather tanning Electroplating Etching microchips
Hydrofluoric Acid pKa 3.5 Weak Acid Permeability coefficient 1.4 x 1024
cm/sec
Concentrations of HF Household (aqueous) 3-40% Industrial (aqueous) >70% Anhydrous HF 100%
Pathophysiology Deep penetration of tissues
Fluoride binding of divalent cations Calcium Magnesium
Alters Calcium dependent Potassium channels
Routes of Exposure
Dermal Inhalational Oral Ocular
HF Clinical Presentation: Local
Systemic
Systemic HF Hypocalcemia
Hypomagnesemia
Hyperkalemia
Prolonged QT Bleeding
Prolonged QT Torsades
ECG changes
Assessment: Systemic HF Vital signs Mental status ECG
Hyperkalemia Peaked T waves Progression to sine
waves QT prolongation Ventricular
dysrhythmias, ectopy
Laboratory Indicators Systemic HF
Acidemia Prolonged PT (or bleeding) Electrolytes: iCa2+, Mg2+, K+
Management Systemic HF Continuous ECG Monitoring 2+ large bore IVs, foley Laboratory:
Ca2+, Mg2+ , electrolytes, CBC Type and Screen PT/PTT ABG or VBG
Therapy Systemic HF Restore electrolyte homeostasis
Decontamination
Enhancement of urinary excretion F-
Treatment of dysrhythmias
Calcium Cardioprotective, restorative Dosing:
1 gm IV over 5 minutes Titrate to ECG effect May require grams Pediatrics:
20-60 mg/Kg Monitor concentrations
Calcium Preparations (10%) Calcium gluconate
0.465 mEq/mL Peripheral lines 60 mg/kg pediatric
Calcium chloride 1.36 mEq/mL Central line 20 mg/kg pediatric
Magnesium sulfate 20% Adults
20 ml (4 gm) over 20 minutes* Cautious/avoid in renal failure Observe vascular, neurological effects
Pediatrics 25-50 mg/kg/dose over 20 minutes
NaHCO3
Urinary alkalinization/Ion trapping F-
1-2 mEq/kg bolus Isotonic drip at 1.5 –2 x maintenance Serum pH 7.5-7.55
No potassium supplementation without absolute indication
Dysrhythmias Correct underlying derangements
In refractory cases: Amiodarone
In vitro Animal models with HF induced
hyperkalemia Human data lacking
HF Ingestions
HF Ingestions Readily absorbed
High fatality rate
Assume all ingestions are systemic exposures
HF Ingestions: Clinical Presentation Vomiting
Dysrhythmias
Rapid deterioration
Caustic injury minor
HF Decontamination Removal of gastric contents*
Careful NGT suction Use caution as provider
Delivery cations to GI tract Calcium carbonate Magnesium citrate
Inhalational HF Assume exposure with any dermal
exposure to the face Burning, stridor Dyspnea Bronchospasm Presume associated systemic and
ocular toxicity
Inhalational HF Airway management prn Screen for systemic, ocular toxicity Nebulization therapy
2.5 - 5 % Calcium gluconate (Dilution of a 10% solution) Limited data
Ocular HF Assume in inhalational
exposures Screen for additional
facial/systemic exposures Irrigation 1L LR Avoid calcium or
magnesium application*
Dermal HF Most common presentation Evaluate for systemic toxicity if:
Vital sign abnormalities Facial/neck exposures Alteration mental status High concentration solution Large body surface area
any concentration
Dermal HF Severe pain with few findings Onset pain often related to
concentrationConcentration of HF (%)
Symptoms onset
<20 May not occur for 12-18 hours
20-50 Within 1-8 hours>50 Immediate
Dermal HF
Dermal HF Irrigation with soap and water Topical calcium
Sterile water soluble lubricant 3.5 gm CaGluconate powder in 150 mL 25 mL of 10% CaGluconate in 75 mL Can consider
calcium carbonate Calcium chloride
Consider filling glove if hand exposure
Dermal HF Local intradermal injection calcium
0.5 mL/cm3 of 5% calcium gluconate Distal to injury Limited utility esp in digits
Dermal HF Intra-arterial
Calcium Hand injuries
Careful placement arterial line on AFFECTED side
Intra-Arterial Calcium 10 mL of 10%
Calcium gluconate in 40 mL D5W or NS
Infuse over 4 hours
Repeat prn Huisman LC, et al. Lancet. 2001;358:1510.
Dermal HF Digital blocks useful
Single digit/tip Delayed presentations No systemic toxicity
“Bier” blocks 25 mL of 2.5% CaGlu Limited utility: tourniquet
HF Summary Rapid screening for systemic toxicity
Intravascular Calcium administration: Gluconate unless central venous line
Adjunctive pain control
Acknowledgements Lewis Nelson Susi Vassallo NYCPCC
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