- Diagnosing contamination is fairly easy
- Diagnosing and quantifying exposure is more difficult and probably require expert consultation
Signs and Symptoms
- Vary based on dose; see remm.nlm.gov for quick reference
- Overall:
- Whole-body exposure: Syndrome similar to high-dose chemotherapy toxicity
- ARS progresses more rapidly the higher the absorbed dose
- Local exposure:
- Early resembles thermal or UV burn
- Later resembles ischemic ulcer
History
- Recognized exposure:
- Occupational, medical, transportation accident
- Unrecognized or cland estine exposure:
- Radiologic dispersal device (RDD), concealed or unrecognized source
- Industrial and medical radiography sources may be pellets, only a few millimeters in diameter, and are highly radioactive
- Suspect if multiple patients present with symptoms of ARS at any stage, burns without history of thermal exposure, or ischemic ulcers in unusual locations (e.g., hand from hand ling unrecognized source, hip from placing source in pocket)
Physical Exam
- Whole-body exposure:
- Nausea, vomiting:
- Within 3-6 hr for >100 rad exposure; sooner with higher exposures
- Vomiting within 1 hr of exposure indicates potentially lethal injury (>600 rad)
- Confusion and weakness (>200 rad)
- Fever:
- Acutely, from inflammation
- During manifest illness, from infection
- Hair loss, hemorrhage, diarrhea may develop with doses >300 rad
- Dermal exposure:
- Initial erythema
- Blistering and ischemic necrosis may follow
Essential Workup
- Survey for radiation using a Geiger counter, which can be found in any nuclear medicine or radiation therapy department:
- Any probe style is acceptable for survey
- Cover probe with exam glove:
- Prevents contamination of probe
- Blocks radiation but detects /
- Measure background radiation away from patient
- Move probe slowly over patient's skin:
- 1-2 cm from skin
- Move probe only 2-3 cm/s
- Contamination is >2× background radiation level
- Note any contaminated areas
- Follow systematic pattern to avoid missing areas
- Remember to survey palms, soles, hair
- Absolute lymphocyte count (ALC) is the best indicator of severity of ARS:
- <1,000/mm3: Moderate exposure, 200-600 rad
- <500/mm3: Severe exposure, >600 rad
Diagnostic Tests & Interpretation
Lab
- CBC with differential every 4-6 hr (for 24 hr or until stable)
- Swab both nares and survey swab for inhaled contaminants
- Type and cross-match blood
- 24-hr stool for radioassay if GI contamination suspected
- 24-hr urine for radioassay if any internal contamination is suspected
Imaging
- Diagnostic imaging as clinically indicated
- Whole-body gamma camera (without collimator) is best for ruling out internal contamination with low levels of radioisotopes, if suspicion is high and survey with Geiger counter is negative
Diagnostic Procedures/Surgery
Cytogenetics allows more accurate dose assessment:
- 10 mL blood in lithium-heparin tube (ethylenediaminetetraacetic acid also acceptable)
- Draw 24 hr postexposure
- Refrigerate (4°C) and ship cold to Radiation Emergency Assistance Center/Training Site (REAC/TS)
- Only limited number of samples can be processed due to resources required
Differential Diagnosis
- Systemic illness (lymphopenia, weakness, nausea):
- Psychological effects are common in both exposed and unexposed patients and may mimic ARS:
- Radiation casualty with vomiting from ARS should have falling ALC; if ALC normal and stable, consider psychological stress reaction or other type of illness
- Hematologic malignancy
- Chemical warfare agents (blister/mustard)
- HIV disease, immunosuppression
- Skin injuries:
- Ischemic ulcer
- Brown recluse spider bite
- Pyoderma gangrenosum
Personal protective equipment (PPE):
- Must provide protection from dust (particulate respirator; e.g., N-95, gown, gloves, hair, and shoe covers)
- Radiography aprons are of no value - they do not protect against most radiation
Prehospital
- Treat life threats (airway, breathing, and circulation management [ABCs])
- Assess any bombing scene for radioactive contamination (RDD)
- Removing clothing will eliminate about much of external contamination
- Survey for residual contamination:
- No contamination: Patient may be cared for as usual
- If contamination is present, assess medical condition:
- Stable: Proceed with decontamination
- Unstable: Provide necessary care and transport; use sheets to control contamination
Initial Stabilization/Therapy
- ABCs
- Assess for contamination
- If patient condition permits, perform decontamination before patient enters (and contaminates) facility
- Minimize staff exposure:
- Time: Limit time in contaminated area, remove contaminated material often
- Distance: Use long-hand led instruments to hand le contaminated material
- Shielding: Place contaminated material in a lead container (available in nuclear medicine department); radiography lead aprons are not effective
ED Treatment/Procedures
- Hospital issues:
- Activate hospital disaster plan, if indicated, to mobilize resources
- Designate contaminated and “clean” treatment areas
- Appoint a temporary radiation safety officer (RSO) for incident to survey all patients and staff and all materials leaving treatment area:
- Any staff member who is trained to use Geiger counter and dosimeters may fill RSO role initially if necessary
- Patients and materials that are not contaminated do not need decontamination or containment
- Call for expert assistance: Hospital RSO, state department of nuclear safety, poison center, health department, or REAC/TS
- Staff issues:
- Provide PPE and psychological support as described above
- Assign pregnant personnel to “clean” areas only
- Decontamination:
- Priorities: Wounds > mucous membranes > intact skin
- Use fenestrated drapes to shield adjacent skin
- Use soap and water; no harsh chemicals
- Diaper wipes work well for intact skin; wipe from edges of area to center, then lift away
- Irrigate wounds - avoid splashing, contain runoff to prevent spread of contamination
- Resurvey frequently to assess effectiveness of decontamination
- Do not abrade skin
- If contamination cannot be removed, cover area to prevent spread and move on - residual contamination can be controlled
- RDD:
- Necessary surgery must be done immediately (36-48 hr), or else delayed 1-2 mo, with exposure >200 rad
- Any bombing victim must be assessed for RDD until it is ruled out by assessment of scene
- Preserve evidence for criminal investigation
- Treat vomiting and dehydration:
- Antiemetics (5-HT3 antagonists)
- IV fluids
- Decorporation agents for internal decontamination are specific to each radionuclide:
- Contact REAC/TS for guidance (see below)
- Prussian blue (insoluble) enhances elimination of radioactive thallium or cesium from the body
- Calcium DTPA and zinc DTPA enhance elimination of plutonium, americium, and curium
- Cytokines (G-CSF or GM-CSF) and transfusions may be needed with doses >200 rad
- Potassium iodide:
- Useful only to prevent thyroid uptake of radioactive iodine (found in nuclear reactors), and only if given within 4 hr after contamination. See www.remm.nlm.gov/potassiumiodide.htm for more information
Medication
- Ca DTPA (for pregnant women Zn DTPA preferred, if available): For all patients switch to Zn DTPA for subsequent chelation therapy after initial dose of Ca DTPA
- Adults: 1 g IV over 3-4 min
- Children:
- 14 mg/kg slow IV push, up to 1 g
- Myeloid cytokines (filgrastim, PEG-filgrastim):
- Ondansetron 8 mg IV (or equivalent 5-HT3 serotonin antagonist)
- Potassium iodide:
- Adults: 130 mg PO per day
- Children:
- 3-18 yr: 65 mg PO per day
- 1 mo-3 yr: 32 mg PO per day
- <1 mo: 16 mg PO per day
- Prussian blue insoluble:
- Adults: 3 g PO, t.i.d
- Children:
- 2-12 yr: 1 g PO, t.i.d
- Dose not defined under 2 yr
- Zn DTPA: For initial decorporation dose in pregnant patients, and for second dose and beyond in all patients following initial dose of Ca-DTPA
- Adults: 1 g IV over 3-4 min
- Children:
- 14 mg/kg slow IV push, up to 1 g
24-hr emergency radiation injury response line: (865) 576-1005 (ask for REAC/TS).
See Also (Topic, Algorithm, Electronic Media Element)
Chemical Weapons Poisoning