COMBINED RADIATION INJURIES

Effects of nuclear weapons and nuclear accident Chernobyl nuclear reactor accident on 26 April 1986 The detonation of atomic bombs over Hiroshima and Nagasaki on 6 & 9 August 1945

Combined radiation injuries is the kind of defeats arising at simultaneous or consecutive influence on an organism of ionizing radiation and non-radiation factors Combined radiation injuries is the kind of defeats arising at simultaneous or consecutive influence on an organism of ionizing radiation and non-radiation factors

Classification of combined radiation injures According to radiation dose combined with other factors, combined radiation injures (CRI) can be classified as:  thermal CRI: external/internal irradiation with thermal burns  mechanical CRI: external/internal irradiation with wound or fracture, or haemorrhage  thermal-mechanical CRI: external/internal irradiation with thermal burns and wound (fracture, haemorrhage)  chemical CRI: external/internal irradiation with chemical burns or chemical intoxication

Predicted distribution of injuries from nuclear explosion Single injuries 30 % to 40 % – Ionizing radiation 15 % to 20 % – Burns 15 % to 20 % – Wounds Up to 5 % Combined injuries: 65 % to 70 % Combined injuries: 65 % to 70 % – Irradiation, burns, wounds 20 % – Irradiation, burns 40 % – Irradiation, wounds 5 % – Wounds, burns 5 %

Distinctive features of combined radiation injures Presence at the victim of attributes two or more pathologies Prevalence of one, heavier and expressed during the concrete moment of pathological process, so-called “a leading component” Interference (mutual burdening) radiation and non-radiation factors, shown as heavier current of pathological process, than it is peculiar to each component

Phases (periods) of combined radiation injuries The acute phase or the period of primary reactions to radiation and non-radiation traumas The period of prevalence of non-radiation components The period of prevalence of radiation components The recovery phase or the period of restoration

Burns and radiation Boy was 1.5 km from the detonation of the Nagasaki atomic bomb

Radiation and burns Radiation burns on Japanese atomic bomb victim

Sytemic response to burn injury Early period Early period – shock with hypovolemia – gastrointestinal ileus – oligouria yperdynamic state: After adequate resuscitation – hyperdynamic state: increased cardiac output diuresis peripheral catabolism

Causes of burn deaths Direct results of accident 13 %Direct results of accident 13 % Sepsis 45 %Sepsis 45 % Organ /system failureOrgan /system failure (burn shock, acute renal failure) 41 % (burn shock, acute renal failure) 41 % Yatrogenic intervention 1 %Yatrogenic intervention 1 %

Expected mortality from thermal injuries Burn area, % of body surface area Expected mortality > % 10 – 30 Survive possible with specific treatment < 10 Survive even without treatment

Combined effects of simultaneous whole body irradiation and burns

Principles of burn therapy Topical antimicrobials Topical antimicrobials Early grafting Early grafting Stimulation of the bone marrow and possibly of skin regeneration with cytokines Stimulation of the bone marrow and possibly of skin regeneration with cytokines

Initial surgery Major skin necrosis on both legs, extending to subcutaneous tissue Epifascial excision of necrotic skin Complete graft healing after 8 days

 Gentle decontamination after stabilization  Passive tetanus immunization even in previously immunized patients Treatment of contaminated burn injuries

Classification of Chernobyl victims Radiation injury Dose, Gy Number of hospitalized patients Total Death Radiation burns Slight 1 – Moderate 2 – Severe 4 – Extremely severe 6 –

Chernobyl conclusions Radiation burns frequent Burns over 50 % of body surface led to death in 19 out of 28 cases Internal contamination was present in most of patients, however, it was significant just in a few cases Sepsis uniform cause of death Bone marrow transplantation is very limited indications Some radiation burns did not reepithelialize and required surgery

Wounds and radiation

Trauma repair

Effects of persistent pancytopenia Decreased oxygen capacity Lack of release of new erythrocytes and aging of red cell population Decreased clotting ability Megakaryocytes unable to replicate, plateletes consumed Altered wound healing Fibroblasts damaged by irradiation do not replicate at normal rate Immunosuppression

Immunosuppressive effect Bone marrow suppression Consumption of inflamatory reserves Disruption of epidermal barriers Depression of reticuloendothelial system

Principles of treatment Control haemorrhage Control haemorrhage Examine and remove all questionable tissue and foreign material Examine and remove all questionable tissue and foreign material Repair vital structures Repair vital structures Irrigate Irrigate Consider wound closure Consider wound closure

Problems of wound treatment Wound colonization Wound colonization Wound sepsis Wound sepsis Failed delayed primary closure Failed delayed primary closure Delay in healing Delay in healing Occasional amputation Occasional amputation Radioactive nuclides contaminated wound Radioactive nuclides contaminated wound

Timing of surgical management

Hiroshima and Nagasaki Hiroshima and Nagasaki conclusions Complications developed 2 to 3 weeks after exposure characteristic of bone marrow depression effects Open wounds stopped healing, haemorrhaged Many patients died of sepsis

Medical management Triage Triage Emergency care Emergency care Definitive care Definitive care

Triage In radiation accident or nuclear detonation, many patients can suffer from burns and traumatic injuries in addition to radiation Initial triage of combined injury patients based on conventional injuries Treat associated injuries first

Emergency procedures First actions standard emergency medical procedures: First actions standard emergency medical procedures: – ventilation – circulation – stop haemorrhage Decontamination after stabilization Decontamination after stabilization Survivable radiation injury not acutely life threatening Survivable radiation injury not acutely life threatening

Secondary assessment of combined injury Primary surgical responsibilities: Primary surgical responsibilities: – stabilize – set surgical priorities – perform surgery Secondary responsibilities: Secondary responsibilities: – manage post-operative course – assess radiation exposure in post- operative or post-stabilization period

Prognosis Prognosis for all combined injuries worse than for radiation injury alone Prognosis for all combined injuries worse than for radiation injury alone Infections much more difficult to control Infections much more difficult to control Burns, wounds and fractures heal more slowly Burns, wounds and fractures heal more slowly

Summary of lecture Diagnosis, treatment and prognosis are much more complex in combined radiation injures Haematological indices and other laboratory tests can be modified in a way that makes diagnosis of radiation component difficult Because radiation injury is not immediately life threatening, initial care should address emergency medical procedures for ventilation, perfusion and treatment of haemorrhage Combined injury requires all urgent surgery to be completed within 48 hours of irradiation

Lecture is ended THANKS FOR ATTENTION In lecture materials of the International Atomic Energy Agency (IAEA), kindly given by doctor Elena Buglova, were used