Preparing for Mass Casualty and Pandemic Flu

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Preparing for Mass Casualty and Pandemic Flu

• Richard Branson MSc, RRT
• Associate Professor of Surgery
• University of Cincinnati
• Richard.branson_at_uc.edu

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Lessons from History

• Sarin gas release - Matsumoto, Japan 1994
• Most severly injured respiratory symptoms
  including copious salivation and airway
  compromise
• All who arrived at the hospital survived
• Mechanical ventilation 8 patients
• Duration of ventilation was short lt 4 hours
• Only 1 patient with anoxia remained ventilated
  longer than 1 day
• Morita H. et al. Lancet 1995346290-293.

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Lessons from History

• Sarin gas release - Tokyo, Japan 1994
• Five subway cars on three subway lines
• 5000 people sought medical evaluation
• 11 patients died
• 640 patients treated at St. Lukes International
  Hospital
• Okamura T. Ann Emerg Med 199628129

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Lessons from History

• Sarin gas release - Tokyo, Japan 1994
• 528 patients (82.5) mild injuries eye
• 107 with systemic signs and symptoms
• Dyspnea was the third most frequent complaint
• 5 (FIVE) patients required intubation and
  mechanical ventilation
• 3 required CPR 1 died
• Intubation 3 for CPR, 1 for seizure, 1 for
  secretions
• All survivors extubated in lt 24 hours
• Okamura T. Ann Emerg Med 199628129

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Lessons from History

• Copenhagen Denmark 1952 population 1.2 mil
• Polio rate was 238 per 100,000 total
• From July 24 to Jan 1953 2,241 case of polio
  1,235 were paralytic
• Tracheostomy and manual ventilation were required
  in 345 paralysis cases
• More than in the previous 10 years
• 70 patients at any one time requiring MV. 3 years
  later 25 still required MV
• Aug 28 to Sept 3 50 cases a day were admitted
• Lassen HCA. Management of Life-Threatening
  Poliomyelitis. E S Livingstone LTD, Edinburgh
  and London 1956.

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Lessons from History

• Copenhagen Denmark 1952 population 1.2 mil
• At the time of the epidemic there were 5
  ventilators in Copehagen 3 were chest cuirass
• During the first phase of the epidemic
• 31 patients treated with negative pressure
  ventilation 27 died!!
• Tracheostomy was performed
• Medical students provided manual ventilation
  bag-valve- tracheostomy tube - in 4 hour shifts
  for up to three weeks
• Lassen HCA. Management of Life-Threatening
  Poliomyelitis. E S Livingstone LTD, Edinburgh
  and London 1956.

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Lessons from History

• Manual ventilation with a self-inflating bag and
  CO2 absorber
• Rebreathing conserved oxygen (2-4 L/min)
• CO2 absorption produced heat and humidity

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Charity Hospital New Orleans 2005
A caregiver providing manual ventilation to one
patient and receiving comfort from another.
(AJRCCM deBoisblanc 2005)
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MANUAL VENTILATION MAY PROMOTE SECONDARY
TRANSMISSION
Scales DC. Emerg Infect Dis. 2003
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Siegel J, et al. Draft Guideline for Isolation
Precautions. 2004.
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Terrorist Attacks

• So called suicide attacks
• Unfortunate experience and expertise from Israel
• Use of explosives and shrapnel (bolts, nails,
  nuts)
• Predominate injury is lung injury (blast injury)
• 50 of patients who survive to hospitalization
  develop ARDS and require mechanical ventilation

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Terrorist Attacks

• 20 attacks gt 10 wounded
• Total of 1475 wounded, 92 ICU admissions, 80
  patients requiring MV
• 52 of patients had acute lung injury
• Blast injury is the major mechanism

Aschkenasy-Steuer et al Crit Care 200591186
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Pandemic Flu
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1918 Pandemic Flu
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Models of Pandemic Flu

• Planning Assumptions
• Attack rate 35 of population
• Hospitalization rate 10 of cases
• Case fatality rate 2 - 50
• Asymptomatic, presymptomatic transmission 3
  0 - 50
• Reproduction number 2 people
• Serial interval 2 4 days
• Infectious period peaks day 2(1-8)
• Incubation period 7 (1 8 days)

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Preparing for Pandemic Flu

• Florida (pop 18.3 million)
• 1st Wave/2nd Wave Total
• Cases 3.2 million 6.4 million
• Hospitalized (10) 320,000 640,000
• Dead (5) 160,000 320,000
• Tallahassee Metro (pop 250,000)
• 1st Wave/2nd Wave Total
• Cases 43,750 87,500
• Hospitalized (10) 4,375 8,750
• Dead (5) 2,188 4,375

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Lessons from History

• To date, bioterrorism has resulted in additional
  mechanical ventilation requirements, but at a
  manageable volume
• Manual ventilation via a secured artificial
  airway has been shown to be successful for weeks

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What are the Plausible Scenarios?

• Trauma natural or man-made
• Nerve agents sarin, tabun, VX, soman
• Pulmonary Irritants phosgene, ammonia
• Biologic Agents plague, tularemia, anthrax,
  botulism
• Radiologic Events nuclear weapon, dirty bomb

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What are the Plausible Scenarios?
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What are the Necessary Features of a Ventilator
for Each Scenario?

• Where will mechanical ventilation be performed?
• Who will perform mechanical ventilation?
• Where will the gas supply come form?
• How long will it last?
• Does the ventilators capabilities match the
  needs of the patient, skill of the operator?

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What are the Necessary Features of a Ventilator
for Each Scenario?

• All scenarios except nerve agent exposure require
  constant volume delivery, control of airway
  pressures, monitoring, alarms, and control of
  PEEP and FIO2
• When nerve agents result in paralysis airway
  control and short term ventilation good air in
  bad air out is all that is necessary
• Airway control intubation, LMA, LT
• Ventilation can be as simple as bag-airway
  ventilation

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Device Classification
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Device Classification
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Ventilator Characteristics

• FDA approved for adults/peds
• Ability to operate without compressed gas
• Battery life 4 hrs
• Volume control
• CMV and IMV
• PEEP to 20 cm H2O

• Utilize both high and low pressure O2 sources
• Control of RR, PEEP, VT, Flow or IE
• Monitor Paw and VT
• Alarms
• Disconnect, apnea, high/low pressure, high
  pressure source gas disconnect

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Ventilator Characteristics

• Rugged
• Light weight
• Easy to use
• Gas consumption
• Battery life
• Easy to trigger

• lt10 k
• Vendor support and longevity
• Maintenance
• Training

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Specific Devices
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Critical Factors

• In a MCI many patients will need ventilation
  exceeding not only equipment but staff
  capabilities
• Likely that critical care RRT will supervise
  non-critical care RRT and others in care of the
  ventilated patients
• The ventilator must have adequate alarms and
  monitoring
• The ventilator must have a simple interface and
  be easy to use

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Critical Factors

• Battery life
• Low gas consumption
• Ability to ventilate adult and pediatric patients
• Rugged
• Ancillary devices circuits, humidifiers,
  suction catheters
• Personal protective equipment (PPE) protect
  yourself

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Gas Consumption
Branson RD AARC 2006 Open Forum
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Stockpiling vs. Distribution

• CDC has ventilators in a managed inventory
• Some states have similar stockpiles
• Another plan is to distribute ventilators to
  sites around the state where they are used in the
  ED, during transport, PACU, etc.
• Distribution assures trained staff, appropriate
  maintenance, and provides additional equipment to
  existing facilities

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Why not cheap, disposable resuscitators?

• Disadvantages
• Requirement for high pressure gas source
• Short term operation (15-40 mins E cylinder)
• Inconsistent volume and rate (pressure cycle)
• No alarms
• Failure to cycle
• Inability to operate with a leak (face mask
  ventilation pressure is not reached device sticks
  in the inspiratory phase). Questionable with
  airway other than ET intubation

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Flow Controlled, Pressure Cycled Automatic
Resuscitators

• Advantages
• Inexpensive
• Light weight
• Small easily stored

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Oxylator Pressure cycled during automatic
ventilation?
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Oxylator Automatic Resuscitator and Demand Valve
Auto-PEEP
Expiratory resistance up to 26 cm H2O/L/s (normal
is 4)
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Flow Controlled, Pressure Cycled Resuscitators

• Any role?
• In the hospital where gas supply is virtually
  limitless and skilled care givers are present to
  monitor device function
• However will not adequately ventilate the patient
  with stiff lungs (ARDS)
• No method to provide PEEP other than increase
  expiratory resistance

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The Limiting Factor in Ventilator Deployment is
Compressed Gas

• At the site or ground zero the major limitation
  is a supply of compressed gas
• Compressed gas shipping is controlled by DOT and
  delivery by air is restricted
• Cylinders are heavy, require special handling,
  and storage

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Mass Casualty Ventilator
Battery power 6 hours (if using 100 O2 26
hrs) Delivers Room air (oxygen if
available) Assist control time cycled, constant
flow and volume CPR 152 ratio (rate 12
b/min) Rate and volume adjustments are
separate High pressure and disconnect alarms
Intended for mass casualty care Pr-hospital
will not meet needs of patients with ARDS
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Why Not NIV?

• In MCC too many patients not enough staff
• Successful NIV requires additional time up-front
• Success of NIV in hypoxemic respiratory failure
  is poor
• Airway control is important
• Possible increase in caregiver exposure to
  aerosols from coughing high flow
• Do not recommend NIV for stockpiling however
  repurposing of NIV for invasive ventilation is
  suggested

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CDC SNSCenters for Disease Control and the
Strategic National Stockpile

• Delivery to marshalling site in 24-72 hours
• 4000 ventilators currently in the stockpile
• 2000 Impact 754 (compressor driven ventilator)
• 2000 LP-10 (piston powered ventilator

SNS is intended for hospital delivery Timing
will not be helpful for EMS needs Ventilators
intended for in-hospital care
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Stockpile Ventilators
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Strategic National Stockpile
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Ventilator Management

• Stored in DSNS air cargo containers

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Additional Equipment

• Current stockpile provides additional equipment
  in cases

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Ventilators Surge Capacity

• Current hospital inventory
• Look to local resources
• Every OR has an Anesthesia Workstation including
  ventilator and monitoring
• University of Cincinnati 28 instant ICU beds
• Transport, home care ventilators
• Manual resuscitators people power

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Training Triage

• Respiratory therapists will be at the forefront
  of the pandemic
• Training of staff in PPE and disaster management
  is essential
• Cross training of non-RT staff to perform some
  procedures may be helpful
• Triage all patients will receive care some
  will receive only pallative care

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Preparation

• Coordination get to know local and state
  disaster planners
• Training
• Education
• Safety
• Staffing
• Stockpiling vs. Distribution
• Understand the threat and prepare accordingly

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Continuous En Route Care
Historical Route From Injury to Definitive Care

• STRATEGIC EVAC
• Evac Policy -
• 15 Days

• TACTICAL EVAC
• Evac Policy -
• 7 Days

Definitive Care Level 4

• CASUALTY EVAC
• Evac Policy -
• 1 Day

In Theater Hospital Level 3
Field Hospital Level 2
Battalion Aid Station Level 1
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Continuous En Route Care
CASEVAC 1 Hour
TACTICAL EVAC 1-24 Hours
BAS Level 1
STRATEGIC EVAC 24-72 Hours
Forward Surgical teams Level 2
Combat Support Hospital, EMEDS, Fleet
Hospital Level 3
Definitive Care Level 4
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The Challenge
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Tactical CCATT

• Light
• Noise
• Vibration
• Altitude
• Duration

None
Lots
High
Long
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Mission Profile

• Rotary Wing
• One tail-to-tail swap
• Space considerations
• Environmental considerations

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Current Equipment Suite

• Good news
• It works well enough
• All services have settled on the same equipment
• Bad News
• Its old
• Its heavy
• Its clumsy
• The pieces are not meant to work together

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Autonomous oxygen control

• In the deployed setting Oxygen is a critical
  resource
• Assumption-
• it is desirable to decrease FiO2 as long as SaO2
  is maintained
• Input controller- SaO2
• Output controller- FiO2

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SpO2/FIO2 Controller

• Clinical trial of up to 95 patients
• Four hours of manual and four hours of automatic
  FIO2 control in randomized fashion
• Impact 754 ventilator Masimo Oximeter
  Algorithm via PC
• Data collection every 5 seconds

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Start Controller
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480
0
240
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Results
African American male, scooter versus car, chest
pain, hemoptysis, grade IV liver laceration,
splenic laceration splenectomy, bilateral
pulmonary contusions, pulmonary laceration,
aspiration of blood, and acute lung injury.
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O2 use L/min
Patient
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Autonomous Respiratory Support System

• Integrated system includes
• 6-liter O2 concentrator
• Ventilator, as part of LTM
• Closed-loop FiO2/PEEP controller

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Portable Oxygen Generating System (POGS)

• Closed-Loop Control (CLC)
• Completed CLC between ventilator/pulse
  oximeter/O2 concentrator
• Based on SpO2, FiO2 and O2 output are regulated
• Max FiO2 0.4, with ventilator settings rate
  16 tidal volume 600 mode assist/control
• Tested 16-19 March during parabolic flight, NASA
  Johnson Space Center

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Oxygen Generation with CLC
Patient

• DARPA Grant DAAH01-03-C-R112
• FIO2 range 21-60
• Closed-loop control of oxygenation
• Feedback control of O2 generation/power
• Ventilator managing respiratory parameters

Lightweight Trauma Module
Portable Oxygen Generating System
Closed-Loop Control