Test Category: Specialist Biochemistry
Investigation Name:Bromide
Alias or Abbreviation:Br
Accreditation:Extension to scope
Intro:
Bromide salts were previously widely used as sedatives and anti-epileptics. Newer drugs have now replaced most bromide therapy; however, bromide salts are still used to treat refractory seizures in children.Chronic bromide toxicity, also referred to as “bromism”, may arise due to long-term ingestion of bromide salts. Bromism impairs neuronal transmission leading to neurological and psychiatric disturbances such as delirium, hallucinations, tremor and in severe cases, coma.
Other manifestations include anorexia, constipation and skin rashes. Acute toxicity, although very rare, has been reported to cause nausea and vomiting, as well as significant nephrotoxicity and ototoxicity. The risk of toxicity of bromide, can be difficult to predict due to considerable individual variation in the threshold for toxicity. Toxicity may be apparent at concentrations well below the therapeutic range (occasionally as low as 5 mmol/L). Immediate action must be taken to prevent further increase in individuals with serum concentrations in excess of 35 mmol/L.
Alkyl bromides such as methyl bromide also pose a serious risk to health and the environment, with the alkonium radicals that may be released exerting the toxic effect rather than bromide itself. Although previously used widely as fumigates for insect, weed and rodent control, their use has now been banned in most parts of the world.
Methyl bromide toxicity arises predominantly through inhalation of the colourless gas giving rise to numbness, tremors, weakness, dizziness, speech impairment, pulmonary oedema, and renal damage in severe cases.
Bromide may be measured in suspected or known exposure to alkyl bromides, however, since bromide is being used as an indirect marker of exposure to methyl bromide, much lower levels of serum bromide indicate significant exposure compared with the case for inorganic bromide.
Pathology Laboratory:Trace Elements Laboratory
Requestable Seperately?Yes
Units:mmol/L
Minimum Sample Volume:100 µL serum/plasma
Expected Turnaround Time: 3 working days.
Urgent analysis where clinically indicated may be arranged directly with the laboratory.
Test Code:BR
Sample Type:
Blood must be collected into a plastic tube containing no anticoagulant/additives.Complex Reference Range:Unexposed individuals: < 0.1 mmol/L
Inorganic bromide (bromide salts) for anticonvulsant therapy: 9.4 -18.7 mmol/L
NOTE individual responses may vary widely and toxic effects may be seen at concentrations well below those stated.
Potentially toxic concentrations: > 15.6 mmol/L
Significant toxicity: > 35 mmol/L
Organic bromide (alkyl bromides) Occupational Exposure Limit: < 0.15 mmol/L
Significant exposure to methyl bromide: > 0.38 mmol/L
NOTE much lower toxic values if exposed to alkyl bromides versus inorganic bromide
Collection Conditions / Other Information:Separate serum from cells prior to sending sample to the lab.
Note: Gel/clot activator or any anti-coagulant tubes are NOT acceptable.
Do NOT use tubes with black o-rings.
Referred to Another Laboratory?No
Reference Lab Code:Br
Storage Requirements:Store separated plasma/serum at 4 °C prior to dispatch
Posting Address / Requirements:Ambient temperature, 1st Class Post,
Sandwell Health Campus,
Pathology Department,
Specialist Chemistry,
Lyndon, B71 4HJ
NPEX / PDF Reporting Available:Yes
EQA Scheme:Participation in serum bromide sample exchange programme.
Further information:Since bromide has a long half-life of 12 days in blood, 6-8 weeks are required to reach steady state levels. Body uptake and excretion of chloride strongly influences bromide excretion and, for example, a decreased intake of salt can reduce bromide excretion markedly.
We are a designated Supra-Regional Assay Service (SAS) Laboratory for Trace Elements.
Lead Contact Details:Dr Nicola Barlow, Consultant Clinical Scientist,
SAS Director Trace Elements Laboratory
Email: nicola.barlow1@nhs.net
Email Address For Chasing Results:rwh-tr.bcpsspecialistchemistryenquiries@nhs.net
Methodology:Inductively coupled plasma mass spectrometry
Site Sample Tested:Sandwell Health Campus
Cost:Please email bcpspathology.info@nhs.net for further details
Contact Number:Tel: 0121 507 5162
