Urban Nuclear Detonation: Operational Conditions, Human Response and Casualty Management

Transcription

1 Armed Forces Radiobiology Research Institute (AFRRI, since 1961) Urban Nuclear Detonation: Operational Conditions, Human Response and Casualty Management 26 June 2008 NAS/IOM Nuclear Medical Preparedness Workshop COL John Mercier, Ph.D., PE, DABR Director, Military Medical Operations OIC, Medical Radiobiology Advisory Team 1

2 DISCLAIMERS The ideas, concepts and opinions expressed in this lecture are attributable to the speaker and not the Department of Defense (DoD). Any reference to commercial products or services in this lecture are presented for educational purposes and are not to be taken as DoD endorsements. The speaker has no financial affiliations to disclose with regard to this lecture. 2

3 Objectives Describe the Operational Environment Understand Hiroshima Fast forward to modern city center Add ground burst fallout Add EMP effects on modern technology Briefly describe the human response to initial nuclear weapons effects (NWE) Radiation Blast Thermal Discuss management of nuclear casualties 3

4 Urban Nuclear Detonation Case Study: Hiroshima Little Boy (gun type wpn) 0815 a.m., 6 Aug 1945 (Enola Gay) 16 kt, 600m HOB (insignificant fallout) Clear weather, dense urban flat land ~10,000 people/sq km in city center 255,000 pop 119,000 okay (47%) 136,000 casualties (53%) 64,000 deaths 4 mo ½ to 1/3 in 1 st day Mostly those close in 72,000 injured H + 1 Further out w/lower pop density 4

5 Medical Statistics: Hiroshima Hospitals: 3/45 were functional (6.7%). Physicians: 59/298 were functional; only 28 without significant injury (9.4%). Nurses: 1654/1780 were casualties (92.9%). 10,000 injured patients went on their own or with assistance within 12 hours to the Red Cross Hospital (600 beds). In the biggest hospital, the Red Cross Hospital, only 6 out of 30 physicians were able to function. And only 10 out of 200 nurses were able to provide patient care. 70% of patients with combined injury. 5

6 Hiroshima Casualties at the Red Cross Hospital (D +2, 1.6 km) 6

7 Hiroshima Diary (Dr. Michihiko Hachiya) takes You Here During the Period 6Aug 30Sep,

8 Case Study: Hiroshima 25 July August

9 Case Study: Hiroshima 9

10 Case Study: Hiroshima 10

11 Case Study: Hiroshima 11

12 12

13 Radiation Injury Annulus m 250 m per dash 13

14 Annulus Indicating Injured Survivors m 250 m per dash 14

15 Ponder Some of the Effects from a Low- Yield Nuclear Detonation in a Modern City 15

16 Ponder Some of the Effects from a Low- Yield Nuclear Detonation in a Modern City Power grid down for weeks to months Phone communications down for weeks to months Vehicle accidents from the flash and EMP effects Fried medical equipment from EMP effects Roads, rails, runways limited/unusable for days Fuel distribution limited for days to weeks Water pressure gone for days to weeks Sanitary water systems down for weeks 16

17 Ponder Some of the Effects from a Low- Yield Nuclear Detonation in a Modern City Human and animal remains scattered about for days to weeks Food may be in short supply for days Hospitals overwhelmed and remaining medical staff exhausted within 72 hours What about a ground bursts Need to mitigate loss of life from fallout. Displaced persons and evacuees into the hundreds of thousands. 17

18 Military MASCAL Medical Guidance 1. Resources cannot handle patient load 2. Clinical standards of care need not apply Provide the maximum care for the maximum number of patients. Favor those who are more likely to respond to treatment at the time and place. So the less severely wounded receive a higher priority because their earlier return to duty will be of greatest benefit to the military effort. Determine if it may be more effective to move hospitals to the impacted area to free up limited patient evacuation assets. Determine methods for rapid evacuation of patients to tertiary care centers that can provide maximal care. 18

19 Military MASCAL Medical Guidance Conserve/Economize medical resources Limit treatment to those expected to die Avoid procedures which will reduce any patient s ability to care for himself Do not use trained medical personnel for first aid or rescue operations. Train all personnel and rescue teams in first aid (applying dressings, controlling hemorrhage, field splints, handling the injured) Perform only the most expedient treatments sufficient to meet immediate medical requirements of the patient. Use only simple bandages, splints, etc., for evac prep. Sorting is the key to the effective management of a MASCAL event. Triage IDME or D I M E 19

20 SIMPLE TRIAGE AND RAPID TREATMENT (START) START Sorting Algorithm: Triage IDME or D I M E Yellow - Delayed Non-critical, normal, or expected findings Red - Immediate Abnormal or critical findings Requires minimal action Correction of airway blockage, uncontrolled bleedings Green - Minimal Walking wounded/worried well Direct to collection point/reception area that has medical supervision Black - Expectant Deceased Exceeds medical capabilities Need a new color! 20

21 START ALGORITHM (1 minute / patient) ALL WALKING WOUNDED MINIMAL YES RESPIRATIONS R - 30 P - Radial M can do NO OVER 30/MIN IMMEDIATE NO UNDER 30/MIN PERFUSION Radial Pulse Present POSITION AIRWAY YES NO IMMEDIATE EXPECTANT YES MENTAL STATUS Control Bleeding IMMEDIATE Cannot Follow Simple Commands IMMEDIATE Can Follow Simple Commands DELAYED 21

22 Flash Burns Negligible Injury: Moderate Injury: <1% BSA 3deg 1-5% BSA 3deg <5% BSA 2deg 5-15% BSA 2deg <50% BSA 1deg % BSA 1deg Serious Injury: Fatal Injury: 5-25% BSA 3deg >25% BSA 3deg 15-50% BSA 2deg >50% BSA 2deg >40% BSA 2&3deg (any combo) ~2 km at 3-4 cal/cm2 22

23 Thermal Injury Flame Burns (< 2% of 20-day survivors) Flash (Profile) Burns (> 50% patients) Flash blindness & retinal burns 23 Photos: DOE, National

24 Blast Injuries Direct overpressure Crushed building victims Air cavity injuries (e.g., ear, lung, gut) ruptured viscera (organs) alveolar hemorrhage pulmonary edema Dynamic pressure (nuclear winds) Translational effects Decelerative tumbling (fractures, lacerations) Impact with a solid surface (blunt trauma) Missiling effects (e.g., projectiles, flying shards of glass) 24 Photos: DOE, National

25 Blast Effects Wood Frame: 5 psi peak overpressure 25

26 Acute Radiation Syndrome (ARS) Classical Subsyndromes: H, GI, CV Phases: Prodromal Latent Manifest Illness New Paradigm: Grading of Multi-Organ Response Skin injuries Erythema Epilation Purpura Other effects Gingivitis Conjunctivitis Hypotension Radiation Injuries Adequate for MASCAL Hiroshima ARS Victim (~D +20) Hiroshima ARS Victim (~D 26+20)

27 Radiation Injuries- Dose vs Severity and Time of Onset 27

28 Combined Injury Patient Triage is Based on Traditional Triage Methods Physical injury without irradiation Expected changes in triage categories after whole-body irradiation >6 Gy <2 Gy 2~6 Gy Vomit <1 hr Vomit >4 hrs Vomit 1-4 hrs early erythema Uninjured Ambulatory monitoring Ambulatory monitoring, routine care and delayed hospitalization Minimal Minimal Delayed Delayed Variable Immediate Immediate Expectant Expectant After: Ann Intern Med 2004;140:

29 Early Treatment Fundamentals Patient history remains paramount (Where were you?) Unlike trauma, symptoms for survivable radiation doses are not immediate and NOT acutely life threatening First Actions are Medical not Radiological EXCEPTION: If Expectant is ruled in due to radiation dose, limit treatment and redirect resources Early wound closure (36-48 hours) is a priority for doses above 1-2 Gy. Else, delay surgery until hematopoietic recovery. Never delay critical care because a patient is contaminated 29

30 On-scene Medical Management Scene Commander must set and enforce dose-limits for rescuers. Rescuers who reach dose-limit are removed from the scene and cannot return. Trapped victims in high-dose-rate areas cannot be rescued. Primary rescue effort should be evacuation of uninjured from high-dose areas Contaminated but not injured transfer for decon to some place other than hospitals 30

31 On-scene Medical Management Arrange for clinical teams from neighboring cities to conduct mass evacuation of casualties via rail heads Set up airlift for casualties to distant cities 31

32 Advising Individuals 1.Leave the immediate area of the blast zone (go upwind or lateral) 2.Locate shelter (preferably reinforced concrete type) 3.Remove outer layer of clothing (place it in a sealed bag and store the bag at least 3 meters away from yourself and others) 4.Take a shower (shampoo twice) As a minimum try to clean body areas not protected by 95% EFFECTIVE clothing 5.Watch or listen for emergency personnel and then follow their directions Also, listen to radio broadcasts 32

33 Good Prognosis ARS Vomiting starts > 4 hours after incident No significant change in serial lymphocyte counts within 48 hours after an incident Erythema absent in first 24 hours No other significant injuries 33

34 Poor Prognosis ARS CNS Syndrome (e.g., Coma, Seizures) Erythema within 2-3 h of exposure indicates dose of >10 Gy Vomiting less than 1 hour after incident Serial Lymphocyte counts drop more than 50% within 48 hours Gastrointestinal Syndrome (e.g., Bloody vomitus or stool) ( > 6 Gray) Other serious injuries Cause of death in ARS victims is almost always sepsis with bleeding that follows neutropenia and thrombocytopenia. 34

35 ARS Clinical Management Prophylaxis Therapy S U R V I V A L Protection Assessment Treatment 35

36 Radiation Dose Assessment Multiparametric Patient History Early Symptoms Prodromal phase (A, H, N, V, F, D, F/W) Conjunctivitis, erythema, hypotension Laboratory Tests Watch for early drop in Lymphocyte Counts. Obtain a CBC with differential and q 6-12 h. Analysis may take several days. Trauma confounds data. Chromosomal Studies - the Gold Standard only two labs in US takes at least a week keep blood samples refrigerated Other biomarkers (e.g., 24 hr serum amylase) Coming: Fingernail EPR, tooth enamel OSL, IR dose mapping, etc. Acute psychosomatic mimic symptoms (e.g., nausea, vomiting) 36

37 B L A K L E Y C H A R T Biodosimetry Based on Acute Photon Equivalent Exposures Dose Gy Onset of vomiting % Time, hr Lymphocyte count (x10 9 /liter) at day * < < *The normal range for lymphocytes in human blood is between 1.4 and 3.5 x 10 9 per liter. Ref: Recommendations of the Strategic National Stockpile Radiation Working Group, Ann Intern Med. 140: , <.001 Lymphocyte depletion rate Rate constant Number of dicentrics Per 50 cells Per 1000 cells

38 ARS Treatment Supportive Care & Cytokines Focus on prevention of infection and sepsis Clean environment IV fluids, antiemetics, blood products Antibiotics against Bacterial, Viral, and Fungal Infections Cytokines to reduce risk of infection from neutropenia [Determine 2-6 Gy, Must be given early Not likely available in time] Oral diet if tolerated Low microbial content (e.g., Choose canned fruits over fresh produce) Address psychological issues 38

39 Medical intervention can reduce dose effects by a factor of

40 Manage Contamination Fallout contamination is simply dirt and dust that is radioactive. Decon is easy. Remove the dirt. Decon forward as much as possible (e.g., Locate decon at casualty collection points) Identify/tag those who have gone through decon 40

41 PATIENT DECON FIXED SHELTER PORTABLE Fire Truck 41

42 Decontamination Procedures Remove patient s clothing. Wash patient with soap and water. 95% EFFECTIVE 42

43 Scan Patients (Frisking) 2-3 min per scan 1-2 s per scan Begin with most sensitive setting Hold probe about 1 2 cm from the person s skin. Move slowly (~1 inch/sec) Hands, face, and feet most important (30s scans) Modify scan for large MASCAL 43

44 Patient Management Decontamination Remove and bag patient s clothing and personal belongings Survey patient and, if practical, collect samples Decontamination priorities: Decontaminate wounds first, then intact skin Start with highest levels of contamination Change outer gloves frequently to minimize spread of contamination Use survey meter to monitor progress of decontamination Cease decontamination of skin and wounds When the area is less than twice background, or When there is no significant reduction between decon efforts, and Before intact skin becomes abraded. 44

45 Techniques for Skin Decontamination Soap and water or normal saline Shower head on flexible hose Sponges Work from head down, avoid contaminating eyes and mouth Dawn TM with EDTA works well Betadine scrub water Phisoderm water Shaving foam water 3% Hydrogen peroxide water Baby wipes Masking tape Plastic wrap/bag to induce sweating (especially extremities) 45

46 Decontamination of Hair Shampoo Mild acid water 3% lemon juice Household vinegar Remove with scissors or electric clippers (no razors) 46

47 Decontamination of Eyes Saline/sterile water rinse Isotonic irrigation solution (e.g., 0.9% Sodium Chloride) 47

48 Wound Decontamination Wound decon system Water or saline rinse/flush Betadine scrub water 3% Hydrogen peroxide water Plastic wrap for small wounds Extend wound debridement for removal of contamination only in extreme cases and upon expert advice Change dressings frequently Contaminated burns Gently rinse. Washing may increase severity of injury. Additional contamination will be removed when dressings are changed. pulsating flusher with vacuum cup 48

49 Staff Protection Patients are not hazardous to medical providers PPE = UNIVERSAL PRECAUTIONS ++ Plastic or water repellant gowns Prevent the spread of contamination Surgical mask or N95 Gloves (2-5x) change often and between patients Shoe covers Secure ankles and wrists with tape Survey hands and clothing with radiation meter Replace gloves or clothing that is contaminated 49

50 Guidance for Contaminated Remains DoD Hiroshima Field Expedient Cremations [The dead were not contaminated] CDC 50

51 WMD Psychosocial Impacts Extraordinary demands on health system Tokyo, Japan) Acute psychosomatic mimic symptoms (e.g., nausia and vomiting) Expect large number of self-reporting victims, the media, etc. High risk groups include responders, disaster workers and medical personnel More from other speakers 51

52 Expert Resources The Armed Forces Radiobiology Research Institute, Medical Radiobiology Advisory Team (MRAT) - The Radiation Emergency Assistance Center / Training Site (REAC/TS) - CDC US Department of Health Radiation Event Medical Management (REMM) Website 52

53 AFRRI/MMO SME Operational Products AFRRI Pocket Guide (2008) -- NEW AFRRI website: 53

54 Summary Operational Environment Understand Hiroshima Fast forward to modern city center Human response to initial nuclear weapons effects (NWE) Radiation Blast Thermal Management of nuclear casualties 54

55 Questions? How can you distinguish erythema from a flash burn? Hiroshima, H +3, 2 km 55

56 Thank You for Listening