Radiation sickness
| Classification according to ICD-10 | |
|---|---|
| T66 | Radiation sickness |
| ICD-10 online (WHO version 2019) | |
The radiation sickness occurs after acute, that is, short-time irradiation of the human organism by ionizing radiation such as X-ray or gamma radiation on, for example after radiation accident or nuclear explosions .
pathology
The course of radiation sickness depends heavily on the radiation dose received . It can mean only minor long-term damage , but also death within minutes. At medium doses, symptoms appear within hours and days, including damage to the skin and mucous membranes, internal bleeding and changes in the blood count and the immune system.
- Dermatological symptoms:
-
Gastrointestinal symptoms:
- nausea
- Vomit
- Diarrhea (diarrhea)
- Loss of appetite
-
Haematopoietic symptoms ( myelosuppression ):
- increased risk of infection due to fewer white blood cells ( leukopenia )
- increased bleeding due to fewer platelets
- Anemia due to fewer red blood cells
- Arterial hypotension
-
Neurological symptoms:
- dizziness
- a headache
- Drowsiness
- Central nervous system disorders ( seizures , tremors , ataxia )
- Other symptoms:
Human and animal tissue have different levels of radiation sensitivity to ionizing radiation, depending on the type of tissue . It used to be assumed that the higher the rate of division, the more damaged the tissue ( Bergonié and Tribondeau law , 1906). That has now been refuted. Rather, the sensitivity of an organ or tissue system depends on the lifespan of the functional cells and the size of the stem cell fraction, because radiation does not usually lead to immediate death of the irradiated cells, but to the loss of their ability to divide. For example, the skin and mucous membranes have a very high daily cell exchange rate . If the supply from the stem cells is switched off by radiation, the entire skin perishes within a few days. A slowly exchanged tissue such as bones, on the other hand, only develops radiation damage after many months. This fact is used in radiation therapy , since tumor tissue normally has a faster cell exchange and a higher growth fraction than the surrounding healthy tissue.
Some animal species are much more tolerant to ionizing radiation than humans. Scorpions are said to be a hundred times more resistant to harmful gamma radiation, which is probably due to the low DNA content in the body cells of the scorpions.
The extent of radiation sickness is also dependent on the type and energy of the radiation and on whether the radiation only acts on the body from the outside or whether it acts directly inside the body through incorporated radioactive substances.
Symptoms
In general, the following applies to radiation sickness: the higher the dose,
- the more serious the effects,
- the faster the symptoms appear,
- the longer the recovery phase lasts,
- the longer the disease persists and
- the lower the chances of survival.
The dose equivalent decides on the course and chances of survival . It is given in Sievert (Sv) .
The following dose indications refer to acute radiation of the whole body. Acute here means short-term compared to the duration of physiological healing processes. With protracted , i.e. H. If the same dose is distributed over a period of hours or longer, the harmful effect is less, just as if not the whole body but only less sensitive parts of the body such as B. arms or legs are irradiated.
The assignment of dose values → symptoms differs somewhat in various publicly accessible documents, as the values have not been "tested" experimentally on humans. The values given below are mainly based on experience with X-rays or gamma rays . They were determined statistically on the basis of the consequences of atom bombs and other events.
| Equivalent dose | rating | Symptoms |
|---|---|---|
| up to 0.2 Sv | Possible assumed long-term effects: cancer , genetic changes . These do not count as radiation sickness in the strict sense; they are stochastic radiation damage (see radiation risk ). | |
| 0.2 to 0.5 Sv | No symptoms, only laboratory-detectable reduction in red blood cells . | |
| 0.5 to 1 Sv | Slight "radiation hangover" with headache and increased risk of infection . Temporary sterility in men is possible. | |
| 1 Sv to 2 Sv | mild radiation sickness |
10% deaths after 30 days ( Lethal Dose (LD) 10/30).
Typical symptoms include mild to moderate nausea (50% probably at 2 Sv) with occasional vomiting - starting within 3 to 6 hours after radiation and lasting from a few hours to a day . This is followed by a recovery phase in which the symptoms subside. Mild symptoms return after 10 to 14 days. These symptoms last about four weeks and consist of loss of appetite (50% likely at 1.5 Sv), malaise, and fatigue (50% likely at 2 Sv). Recovery from other injuries is impaired and there is an increased risk of infection. Temporary male infertility is the norm. |
| 2 Sv to 3 Sv | severe radiation sickness |
35% deaths after 30 days (LD 35/30).
Illnesses are on the increase and a significant mortality rate sets in. Nausea is the rule (100% at 3 Sv), the incidence of vomiting reaches 50% at 2.8 Sv. The initial symptoms begin within one to six hours and last for one to two days. This is followed by a 7 to 14 day recovery phase. When this is over, the following symptoms occur: hair loss all over the body (50% likely at 3 Sv), malaise and fatigue. The loss of white blood cells is massive and the risk of infection is increasing rapidly. Long-term sterility can occur in women. Recovery takes one to several months. |
| 3 Sv to 4 Sv | severe radiation sickness |
50% deaths after 30 days (LD 50/30).
After the recovery phase, the following symptoms also occur: diarrhea (50% probably at 3.5 Sv) and uncontrolled bleeding in the mouth , under the skin and in the kidneys (50% probably at 4 Sv). |
| 4 Sv to 6 Sv | severe radiation sickness |
60% deaths after 30 days (LD 60/30).
The mortality increases gradually from approx. 50% at 4.5 Sv to 90% at 6 Sv (except in the case of massive medical intensive care). The onset of initial symptoms begins within 30 to 120 minutes and lasts up to two days. This is followed by a 7 to 14 day recovery phase. When this is over, the symptoms are generally the same as with 3 to 4 Sv, more pronounced. Recovery takes several months to 1 year. Death usually occurs 2 to 12 weeks after radiation exposure from infection and bleeding . |
| 6 Sv to 10 Sv | severe radiation sickness |
100% deaths after 14 days (LD 100/14).
The chance of survival depends on the quality and the earliest possible start of intensive medical care. The bone marrow is nearly or completely destroyed and a bone marrow transplant is required. The stomach and intestinal tissue is badly damaged. The initial symptoms appear within 15 to 30 minutes and last up to two days. This is followed by a 5 to 10 day recovery phase, known as the walking ghost phase . The final phase ends with death from infection and internal bleeding . If recovery does occur, it takes several years and is unlikely to be complete. |
| 10 Sv to 20 Sv | severe radiation sickness |
100% deaths after 7 days (LD 100/7).
This high dose leads to spontaneous symptoms within 5 to 30 minutes. After the immediate nausea due to the direct activation of the chemoreceptors in the brain and great weakness, a phase of well-being ( walking ghost phase ) follows for several days . This is followed by the dying phase with rapid cell death in the gastrointestinal tract , which leads to massive diarrhea, intestinal bleeding and water loss as well as disruption of the electrolyte balance. Death occurs with febrile delirium and coma from circulatory failure . Treatment can only be palliative . |
| 20 Sv to 50 Sv | severe radiation sickness | 100% deaths after 3 days (LD 100/3) , otherwise as for "10 to 20 Sv" |
| over 50 Sv | Immediate disorientation and coma within seconds or minutes. Death occurs in a few hours due to a complete failure of the nervous system . | |
| over 80 Sv | The US armed forces reckon with a dose of 80 Sv fast neutron radiation with immediate onset of death. |
Comparison with annual dose values
The annual doses that normally occur and are permitted under the German Radiation Protection Ordinance are specified below (mSv / a means millisievert per year). This is the dose gradually accumulated over the course of a year. The comparison with the above figures shows that even the short-term administration of the entire permissible annual dose would not lead to radiation sickness.
| Annual dose | description |
|---|---|
| 1-5 mSv / a | Usual exposure to environment, indoor air ( radon ), medical examinations (X-ray) and air travel ( cosmic radiation ) |
| additionally 1–6 mSv / a | According to the current legal situation, additional occupational exposure for monitoring category B. |
| an additional 6–20 mSv / a | According to the current legal situation, additional occupational exposure for monitoring category A (since 2001) is still permitted.
ICRP recommendation from 1991: 0.05 Sv per year, 0.1 Sv per 5 years, 0.4 Sv over the lifetime |
prevention
In the case of radioactive contamination of the patient, decontamination (removal of the radioactive contamination) takes place first in order to reduce the exposure time to the radiation and thus the dose. In the event of nuclear reactor accidents, the administration of iodine makes sense to saturate the thyroid gland with non-radioactive iodine so that as little released 131 I as possible accumulates here. However, this measure is only effective if it is carried out before or within two hours of the possible intake of 131 I. At least the retention time of the radioiodine in the body can be shortened by taking it later.
therapy
The haematological damage (damage in the blood ) is treated with blood transfusions or stem cell transplants or bone marrow transplants. An attempt can be made to accelerate blood regeneration with vitamin preparations . Furthermore, the loss of fluid and electrolyte must be compensated for. It is also important to repair skin damage, since the body is particularly susceptible to infection after radiation. That is why there is often accompanying therapy with antibiotics .
Strong radiation damages or destroys the intestinal mucosa to such an extent that intestinal bacteria get into the bloodstream. This activates the body's own immune defense so strongly that severe inflammatory reactions occur. If the bacteria multiply due to the weakened immune system, sepsis occurs , which requires intensive medical treatment and is often the cause of a fatal course of radiation sickness. The drug treatment of radiation sickness is therefore part of the research in which the first successes have already been reported. A team of researchers from Boston has succeeded in developing a drug therapy that has already shown significant success in animal experiments. The highly irradiated mice were given BPI in combination with a broad spectrum antibiotic. BPI is a protein produced by the body that not only helps fight bacteria, but also prevents an inflammatory response.
Radio protectors such as amifostine have a preventive effect .
literature
- Kauffmann u. a .: Radiology. 3rd edition, Urban & Fischer Munich / Jena 2006, ISBN 3-437-44415-8 .
- Igor A. Gusev: Medical management of radiation accidents . CRC Press, Boca Raton 2001, ISBN 0-8493-7004-3 .
- Klaus Gerosa: Protection in case of nuclear accidents. Be prepared for an emergency. Gustav Lübbe Verlag, Bergisch Gladbach 1986, ISBN 3-404-60171-8 .
- Robert Peter Gale , Alexander Baranov: If the unlikely becomes likely: Medical response to nuclear accidents. In: Bulletin of the Atomic Scientist. Volume 67, 2011, No. 2, pp. 10-18.
Individual evidence
- ↑ Hans-Peter Beck-Bornholdt , Hans-Hermann Dubben , H. Willers: Proliferation rate and radiation sensitivity. The error of Bergonié and Tribondeau . In: Radiation Therapy and Oncology . tape 173 , no. 6 , 1997, pp. 335-337 , doi : 10.1007 / BF03038917 , PMID 9235641 .
- ↑ Research News: With antibiotics against radiation sickness on: Deutschlandradio November 24, 2011.
- ↑ CR Culy, CM Spencer: Amifostine: an update on its clinical status as a cytoprotectant in patients with cancer receiving chemotherapy or radiotherapy and its potential therapeutic application in myelodysplastic syndrome. In: Drugs Volume 61, Number 5, 2001, pp. 641-684, ISSN 0012-6667 . PMID 11368288 . (Review).
- ↑ CM Spencer, KL Goa: Amifostine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential as a radioprotector and cytotoxic chemoprotector. In: Drugs Volume 50, Number 6, December 1995, pp. 1001-1031, ISSN 0012-6667 . PMID 8612469 . (Review).
