Chromium toxicity: Difference between revisions

Revision as of 01:49, 9 August 2018

Background

Blue white metal
Essential in glucose and fat metabolism
The predominant forms are trivalent (Cr³⁺) and hexavalent (Cr⁶⁺)
Cr⁶⁺ is a carcinogen
Uses
- Chrome platting
- Component of making stainless steel
- Used to make cement
- Welding
- Joint arthroplasty
- Coronary artery stents
- Tanned leather products

Toxicokinetics

Absorption
- Cr³⁺
  - Limited oral absorption with 98% recovered in feces
- Cr⁶⁺
  - Modestly absorbed
    - 10% orally
    - 50-85% inhalational
Distribution
- Cr⁶⁺ is rapidly converted to Cr³⁺ in the blood
- 50% total body burden is localized to the kidney and liver
  - With additional stores in bone marrow, lymph nodes, spleen, and testes
Elimination
- Urinary excretion of Cr³⁺ form
Cr⁶⁺
- Oxidative agent producing oxidative DNA damage
- Main cause of toxicity
Cr³⁺
- Rarely develops toxicity

Clinical Features

Acute
- Similar to corrosive metal ingestions
- GI hemorrhage
- Vomiting
- Bowel perforation
- Intravascular hemolysis with DIC
- Acute tubular necrosis and Renal failure
- Metabolic acidosis
- Hyperkalemia
- Acute lung injury
- Skin inflammation and ulcerations
  - Dermal chromic acid (H₂CrO₄) can lead to systemic toxicity with as little as 10% BSA
Chronic
- Most are occupational inhalation exposures
- Chrome holes
  - Nasal septal perforation
  - Skin ulcerations
- Chronic cough
- Dyspnea and bronchospasm
- Anaphylactoid-like reactions
- Pneumoconicosis
- Increase risk of lung cancer
  - Small cell lung cancer, however all types are associated with Cr⁶⁺ exposure
- Contact dermatitis and Type IV hypersensitivity reaction

Differential Diagnosis

Heavy metal toxicity

Evaluation

BMP
LFTs
CBC
CPK
EKG
If toxicity present add coagulation factors
Chromium levels
- Whole blood: 20-30 μg/L (380-580 nmol/L)
- Serum: 0.05-2.86 μg/L (1-56 nmol/L)
- Urine: < 1μg/g creatinine (<19.2 nmol/g creatinine)
  - Can reflect acute absorption of chromium over the past 1-2 days, however wide variation in metabolism and total body burden
- Baseline levels have varied over the past 50 years by 5000-fold, additionally it is difficult to establish standard reference range, use caution when interpreting these levels
- Phlebotomy needles and blood containers for storage contain chromium

Management

Decontamination
- Activated charcoal not indicated
- Consider NG lavage if Cr⁶⁺ ingestion and presenting within 1-2 hours without signs of vomiting
- Consider oral N-acetylcysteine
  - Shown to increases renal elimination of chromium in rats
Supportive care
Chelation
- Not effective in reducing chromium levels
Dialysis
- Not effective in those with normal renal function
- Consider in those on chronic dialysis

Disposition

Acute toxicity likely requires intensive care unit
Consult Toxicology or Poison Control Center

References

Bird, S. Chromium. In: Goldfrank's Toxicologic Emergencies. 9th Ed. New York: McGraw-Hill; 2011: 1243-1247

Authors:

@@ Line 13: / Line 13: @@
 **Tanned leather products
 ==Toxicokinetics==
+*Absorption
+**Cr<sup>3+</sup>
+***Limited oral absorption with 98% recovered in feces
+**Cr<sup>6+</sup>
+***Modestly absorbed
+****10% orally
+****50-85% inhalational
+*Distribution
+**Cr<sup>6+</sup> is rapidly converted to Cr<sup>3+</sup> in the blood
+**50% total body burden is localized to the kidney and liver
+***With additional stores in bone marrow, lymph nodes, spleen, and testes
+*Elimination
+**Urinary excretion of Cr<sup>3+</sup> form
+*Cr<sup>6+</sup>
+**Oxidative agent producing oxidative DNA damage
+**Main cause of toxicity
+*Cr<sup>3+</sup>
+**Rarely develops toxicity
 ==Clinical Features==
+*'''Acute'''
+**Similar to corrosive metal ingestions
+**GI hemorrhage
+**Vomiting
+**Bowel perforation
+**Intravascular hemolysis with [[DIC]]
+**[[Acute tubular necrosis]] and [[Renal failure]]
+**[[Metabolic acidosis]]
+**[[Hyperkalemia]]
+**[[Acute lung injury]]
+**Skin inflammation and ulcerations
+***Dermal chromic acid (H<sub>2</sub>CrO<sub>4</sub>) can lead to systemic toxicity with as little as 10% BSA
+*'''Chronic'''
+**Most are occupational inhalation exposures
+**Chrome holes
+***Nasal septal perforation
+***Skin ulcerations
+**Chronic cough
+**Dyspnea and bronchospasm
+**Anaphylactoid-like reactions
+**Pneumoconicosis
+**Increase risk of lung cancer
+***Small cell lung cancer, however all types are associated with Cr<sup>6+</sup> exposure
+**[[Contact dermatitis]] and [[Type IV hypersensitivity reaction]]
 ==Differential Diagnosis==
 ===[[Heavy metal]] toxicity===
@@ Line 47: / Line 87: @@
 *CPK
 *EKG
+*If toxicity present add coagulation factors
+*Chromium levels
+**Whole blood: 20-30 μg/L (380-580 nmol/L)
+**Serum: 0.05-2.86 μg/L (1-56 nmol/L)
+**Urine: < 1μg/g creatinine (<19.2 nmol/g creatinine)
+***Can reflect acute absorption of chromium over the past 1-2 days, however wide variation in metabolism and total body burden
+**Baseline levels have varied over the past 50 years by 5000-fold, additionally it is difficult to establish standard reference range, use caution when interpreting these levels
+**Phlebotomy needles and blood containers for storage contain chromium
 ==Management==
+*Decontamination
+**Activated charcoal not indicated
+**Consider NG lavage if Cr<sup>6+</sup> ingestion and presenting within 1-2 hours without signs of vomiting
+**Consider oral N-acetylcysteine
+***Shown to increases renal elimination of chromium in rats
+*Supportive care
+*Chelation
+**Not effective in reducing chromium levels
+*Dialysis
+**Not effective in those with normal renal function
+**Consider in those on chronic dialysis
 ==Disposition==
+*Acute toxicity likely requires intensive care unit
 *Consult Toxicology or Poison Control Center
 ==References==