Acute radiation syndrome
(Redirected from Acute Radiation Syndrome)
Background
- Also called radiation poisoning, radiation toxicity, or radiation sickness.
- Acute illness caused by exposure to high doses (at least 1 Gy)[1] of ionizing radiation over a short period of time.
- 1 Gray (Gy) = 100 rads
- Generally requires exposure of whole body (or most of the body)
- Fast-replicating cell lines most affected - GI, lymphohematopoietic, spermatocytes
- Healthcare providers should use isolation precautions and decontamination procedures
- Geiger counters may be useful in identifying contamination
Clinical Features
Clinical Syndromes[1][2]
Bone Marrow Syndrome
- Clinical syndrome seen at doses >100-200 rad (1-2 Gy)
- Smaller doses cause clinically insignificant pancytopenia
- Lymphocytes depleted first, then granulocytes, platelets, and RBCs
- Lymphocyte depletion is predictable based on dose
- Death usually secondary to infection or hemorrhage and poor healing
- Doses >350 rad fatal within several months if untreated
Gastrointestinal (GI) Syndrome
- Syndrome occurs at 600-1000 rad (6-10 Gy)
- Abdominal pain, nausea/vomiting, diarrhea, ileus
- Death occurs within weeks secondary to multiorgan failure and sepsis if untreated
Cardiovascular (CV)/Central Nervous System (CNS) Syndrome
- Syndrome occurs at >1000-2000 rad (10-20 Gy)
- At this dose, vomiting is suppressed
- Dizziness, LOC, papilledema, ↓ DTRs, ataxia, coma
- Doses >3500 rad (35 Gy) damage large blood vessels → cardiovascular failure, cerebral edema
- Doses >5000 rad (50 Gy) cause death within 48 hours
Clinical Course[1][2]
- Each ARS syndrome typically progresses through 4 stages of disease
Prodromal Stage
- Characterized by nausea and vomiting
- Other symptoms include: malaise, fever, conjunctivitis
- Doses over 1000 rad (10 Gy), vomiting is not seen in early symptoms
- Occurs within 48h-6d of exposure (at higher doses, can begin within minutes)
- Lasts up to 2 days
Latent Stage
- Short period of symptom improvement
- Lasts several days to 1 month
Manifest Illness Stage
- Manifestation of symptoms of clinical syndromes
- Severity based on, among other things:
- Overall dose
- Irradiated body volume
- Comorbidities and overall health status
- Age
- Characterized by significant immunosuppression
- Lasts for days to months
Recovery or Death
- If patient survives manifest illness stage, recovery is slow (weeks to years)
- If lethal dose received, death can occur within days (very high, rapid doses) or may be delayed up to several months
- Doses over 1000 rad (10 Gy) are uniformly fatal
Differential Diagnosis
Mass casualty incident
- Radiation exposure (disaster)
- Dirty bomb
- Bioterrorism
- Chemical weapons
- Mass shooting
- Natural Disaster (e.g. Hurricane, Earthquake, Tornado, Tsunami, etc)
- Unintentional large-scale incident (e.g. building collapse, train derailment, etc)
- Major pandemic
- Explosions
Nausea and vomiting
Critical
Emergent
- Acute radiation syndrome
- Acute gastric dilation
- Adrenal insufficiency
- Appendicitis
- Bowel obstruction/ileus
- Carbon monoxide poisoning
- Cholecystitis
- CNS tumor
- Electrolyte abnormalities
- Elevated ICP
- Gastric outlet obstruction, gastric volvulus
- Hyperemesis gravidarum
- Medication related
- Pancreatitis
- Peritonitis
- Ruptured viscus
- Testicular torsion/ovarian torsion
Nonemergent
- Acute gastroenteritis
- Biliary colic
- Cannabinoid hyperemesis syndrome
- Chemotherapy
- Cyclic vomiting syndrome
- ETOH
- Gastritis
- Gastroenteritis
- Gastroparesis
- Hepatitis
- Labyrinthitis
- Migraine
- Medication related
- Motion sickness
- Narcotic withdrawal
- Thyroid
- Pregnancy
- Peptic ulcer disease
- Renal colic
- UTI
Evaluation
- Clinical diagnosis, based on history and physical
- Absolute lymphocyte count is the best prognosticator at 48hrs post-exposure[3] (<1500 is abnormal and indicates a significant exposure)
Management
- Typically risk of contamination to clinicians is minimal, therefore immediate treatment of life-threatening conditions takes precedence[4]
- Aggressive supportive care is hallmark of ED management
- Potassium iodide as thyroid protectant, at 130mg QD for adults, until radiation exposure ceases[5]
Disposition
- Admit
See Also
External Links
References
- ↑ 1.0 1.1 1.2 Waselenko JK, MacVittie TJ, Blakely WF, et al. Medical management of the acute radiation syndrome: recommendations of the Strategic National Stockpile Radiation Working Group. Ann Intern Med. 2004 Jun 15;140(12):1037-51.
- ↑ 2.0 2.1 Donnelly EH1, Nemhauser JB, Smith JM, et al. Acute radiation syndrome: assessment and management. South Med J. 2010 Jun;103(6):541-6.
- ↑ Colwell CB: Radiation injuries, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2013, (Ch) 146: pp 1945-1951.
- ↑ Hryhorczuk D, Theobald JL: Radiation injuries, in Walls RM, Hockberger RS, Gausche-Hill M, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 9. Philadelphia, Elsevier 2018, (Ch) 138:p 1805-1812
- ↑ New York State Potassium Iodide (KI) and Radiation Emergencies: Fact Sheet. https://www.health.ny.gov/environmental/radiological/potassium_iodide/fact_sheet.htm.