Acute radiation syndrome (also called radiation sickness) consists of four stages: [1] prodromal radiation syndrome, [2] latent period, [3] manifest illness, and [4] recovery or death.

Of these, the prodromal syndrome is the first stage where early symptoms occur appear 10-15 min after exposure, peak at 30 min and last for a few days.

“Prodromal” means “symptomatic of the onset of a disease” indicating an early stage of a disease. Prodromal symptoms are gastrointestinal, neuromuscular or neurovascular.

Gastrointestinal symptoms include anorexia, nausea, vomiting (emesis), diarrhea, intestinal cramps, salivation, fluid loss, dehydration, and weight loss. Symptoms after about half lethal dose include anorexia, nausea, vomiting, and those after supralethal dose include immediate diarrhea.

Neuromuscular or neurovascular symptoms include easy fatigability, apathy or listlessness, sweating, fever, headache, hypotension, neurological and cognitive deficits, and cardiovascular collapse. Symptoms after about half lethal dose include easy fatigability, and those after supralethal dose include fever and hypotension.

The proposed mechanisms for prodromal emesis involve triggering of the vomiting center in the area postrema near the fourth ventricle in the brain by a combination of humoral and neural stimuli. Those for prodromal diarrhea include changes in gastric emptying and intestinal motility involving neurohumoral mechanisms.

References for the above information are:

Seventh edition of Radiobiology for the Radiologist by Eric J. Hall and Amato J. Giaccia.

ICRP Publication 118 “ICRP Statement on Tissue Reactions / Early and Late Effects of Radiation in Normal Tissues and Organs – Threshold Doses for Tissue Reactions in a Radiation Protection Context”.

FYI, ICRP Publication 118 translated into Chinese, Italian, Japanese or Russian can be freely downloaded from

http://www.icrp.org/publication.asp?id=ICRP%20Publication%20118

For the dose range, the following article will be useful, especially table entitled “Effects of Whole-Body Irradiation From External Radiation or Internal Absorption”

http://www.merckmanuals.com/professional/injuries-poisoning/radiation-exposure-and-contamination/radiation-exposure-and-contamination

5-hydroxytryptamine-3 receptor antagonists (5HT3 RAs), dexamethasone, metoclopramide, haloperidol, metoclopramide, dexamethasone and lorazepam have been used for prophylaxis of radiation-induced nausea and vomiting (RINV) following radiation therapy. Aprepitant (substance P neurokinin 1 receptor antagonist) is the newer antiemetic agent.

https://www.ncbi.nlm.nih.gov/pubmed/28249542

https://www.ncbi.nlm.nih.gov/pubmed/27701875

 ARS time phases and approximate whole body dose from exposure: 1-2 Gy

first stage of ARS

https://www.remm.nlm.gov/ars_timephases1.htm

Thank You So Much Sir!!!

The “prodromal syndrome” is not a diagnosis, but the technical term used by mental health professionals to describe a specific group of symptoms that may precede the onset of a mental illness. For example, a fever is “prodromal” to measles, which means that a fever may be a risk factor for developing this illness. However, not everyone who has a fever goes on to develop measles. In order to prevent measles from developing, you would try to get rid of your fever and take care of any other symptoms you might have. At CAPPS, we focus on taking care of symptoms that may precede the onset of psychosis.

Psychosis affects between 1% and 3% of the population, and typically emerges between the ages of 15 and 30. The prodromal phase of psychosis is the critical time period when individuals are showing signs that they are at risk for developing a psychotic illness. This at risk phase may last anywhere from a couple of days to a couple of years. During this time, individuals often experience symptoms of psychosis at a subthreshold level of intensity or at full intensity for short periods of time. Individuals and their families may also notice changes in functioning, such as trouble with school or work and social withdrawal or anxiety.

If you receive a radiation dosis of 1-2 GY then you will fell the first reaction (vomiting) after 2 hours exposure. If the dosis is higher, then the reaction will begin earlier.

The following new paper reports changes in the serum lipidome in nonhuman primates Macaca mulatta with radiation-induced hematopoietic syndrome, at the time of 4 hours - 28 days after exposure to 6.5 Gy of gamma-rays (LD50/30).

https://www.researchgate.net/publication/319337380_Lipidomic_Signatures_of_Nonhuman_Primates_with_Radiation-Induced_Hematopoietic_Syndrome

Article Lipidomic Signatures of Nonhuman Primates with Radiation-Ind...