Mass Casualty Respiratory Failure Lewis Rubinson Disaster Medicine Director Public Health- Seattle & King County
Objectives • List the medical response circumstances anticipated for mass casualty respiratory failure. • List the benefits of repurposing hospital wards rather than “non-medical” areas such as gymnasiums for augmenting critical care treatment space. • Describe crucial characteristics for surge positive pressure ventilation equipment. • List recommended ancillary respiratory equipment for mass casualty critical care.
Localized Events and Critical Care Conventional traumatic emergencies: • Multiple shooting victims, conventional explosions, limited natural disaster (tornado) • Most frequent events • Critically injured survivors may stress local receiving facilities critical care capability • Requires organized, optimal local/institutional critical care response
Localized Events and Critical Care Needs Immediate to ICU 12% Intensive Care unit 3.4 ± 3.0 /event Immediate surgery 36% Post-op ICU 31% 2.3 ± 2.5 /event Emergency department Operating room Other surgery 25% CT scan 40% 4.0 ± 3.2 CT/event Einav et al, Ann Surg 2006; 243: 533-40
Plausible Future Events United States Congress, Office of Technology Assessment. 1993.
National Planning Scenarios Catastrophic numbers of critically ill and injured
Chlorine Tanker Explosion US Dept of Homeland Security National Planning Scenarios 2005
Critical Care Demand • Number of critically ill and injured victims surviving initial event • Rate of development of critical illness and injury • Duration of critical illness and injury • Specialized needs (e.g. renal replacement therapy, burn care)
Disasters May Cause Critical Illness and Injury in Survivors Estimated Maximal Critically Ill and Injured Patients Needing Care Multiple Shootings Conventional Explosions Open-space Closed space Densely-populated structure fire Large-scale toxic inhalations Serious natural disasters Epidemic with serious pathogen Large nuclear detonation 1-10 10’s 100’s 1000’s 10,000’s
Critical Care Capability Demand Resources
ICUs Have Limited Reserve Space 87,400 ICU beds in non-federal US hospitals • ~3600 acute care hospitals • 13% of total hospital beds (most countries have fewer ICU beds) • ICU occupancy 65-80%
ICUs Have Limited Reserve Equipment Just-in-time purchasing Breadth of ICU meds and equipment create financial barriers to building reserve ICUs Maintenance/storage of reserve ICU equipment very expensive
ICUs Have Limited Reserve Staff Shortages of critical care nurses, pharmacists, respiratory therapists and intensivists in most communities • > 10% of ICUs have beds closed due to nursing shortage
What should you do if the previous critical care surge processes do not provide enough additional critical care capability?
Emergency Mass Critical Care Caring for critically ill/injured patients whose needs far exceed traditional, available hospital critical care capacity and when timely evacuation is not available?
Emergency Mass Critical Care Emergency changes in: • Spectrum of critical care interventions • Medical equipment • Triage • Staffing Provide circumscribed set of key critical care interventions to many patients rather than maximalcritical care to far fewer Derived from recommendations of a working group of 33 North American experts
Which critical care interventions should be provided if resources are limited and usual critical care cannot be provided to all in need?
Frequently Used ICU Interventions • Conventional mechanical ventilation • Vasopressor infusion • Large volume blood product transfusions • Intra-arterial blood pressure monitoring • Continuous renal replacement therapy • Intra-aortic counter-pulsation device • ICP monitoring • High-frequency oscillatory ventilation • Activated protein C infusion
Emergency Mass Critical Care Interventions • Supports the organ systems most likely to cause death • Demonstrated effectiveness or best professional judgment to improve survival in similar clinical conditions • Do not require prohibitively expensive equipment • Not staff or resource intensive
Emergency Mass Critical Care Interventions Mechanical ventilation • Basic mode(s) Hemodynamic support • IV fluids, vasopressor(s) Set of prophylactic interventions • Thromboembolism prophylaxis, elevation of head of bed and ? GI prophylaxis
Positive Pressure Ventilation Capability Demand Resources Roughly one full-feature mechanical ventilator per ICU bed in countries with widespread critical care availability MASS CASUALTY RESPIRATORY FAILURE
Mass Respiratory FailureSurge Capability • Space • Where should patients receive sustained mechanical ventilation when ICUs are full? • Stuff • Which respiratory equipment is necessary for mass casualty respiratory failure? • Staff • Who can help care for surge of patients with respiratory failure?
Space Where should patients receive sustained mechanical ventilation when ICUs, EDs and PACUs are full and timely evacuation is not possible?
Challenges of Critical Care Mgmt Outside of Hospitals • Expensive hospital beds • Difficult to manage pts on cots for sustained periods • Oxygen!! • Suction • Infection control • Broad diagnostic capability • Specialty consulation
Oxygen May be a Crucial Scarce Resource Non-medical spaces likely to require compressed oxygen source • Require numerous tanks to support pts 24 hrs/day on oxygen Portable oxygen generation systems and port. liquid oxygen systems cost prohibitive for most communities to manage many critically ill/injured patients for days outside of hospitals Hospital liquid oxygen best option • Capacity is large • One caveat is dependent on distribution by vendor
Non-hospital sites Nursing homes Home Health Alternate care facilities Least sick pts General hospital wards Step-down and telemetry units Pts w/ resp failure Pts w/ resp failure Usual step-down & tele pts ICU, ED, PACU Pts w/ resp failure
Emergency Mass Critical Care Beds • ICUs usually 5-15% of total inpatient beds • In past, hospitals have made approximately 20% inpatient beds available within 24 hours by recalling staff, canceling surgeries, expedited discharges • Within 24 hrs increase hospital total critical care space by 2-4 fold if critically ill/injures given admission priority • For sustained events likely increase critical care space 5-10 fold over traditional ICU capacity.
StuffPositive Pressure Ventilation (PPV) and ancillary respiratory equipment for mass casualty respiratory failure
Mass Respiratory Failure Situational Context • Many sick patients will die without sustained PPV • Hypoxemic respiratory failure, hypercapnic ventilatory failure, or airway protection/ pulmonary toilet • Anticipated PPV needs > 12 hrs • Limited specialized staff • Oxygen may be limited resource • Not provided with US SNS vent stockpile • ? consistent electrical supply, medical equipment distribution system • Possible secondary disease transmission
Manual Inexpensive Available Easy to use Difficult to use well Requires operator with patient Not oxygen conserving Inconsistent minute ventilation Mechanical Alarms allow mgmt of multiple pts Consistent minute ventilation Oxygen conserving More expensive More complex to operate Maintenance Manual vs MechanicalVentilation Acceptable short term strategy Better long-term strategy (hrs, days or weeks)
AUGMENTING POSITIVE PRESSURE VENTILATION • Reserve full-feature ventilators • Ventilator rental supply • Many hospitals dependent on the same vendors • Anesthesia machines • Cannot be repurposed for long response • NiPPV equipment • Stockpiled PPV • May be used earlier if rapidly deployable Increasing numbers of victims needing PPV and timely evacuation not possible
PPV CATEGORIES Sophisticated Transport Vents EMS transport vents Full-feature vents Automatic resuscitators Manual ventiators
Optimal PPV Equipment for Mass Respiratory Failure * • Operating Characteristics • Volume control mode (needs to work for most respiratory failure but simple to use) • Internal PEEP w/ PEEP compensation • Flow > 70 L/min and < 10 L/min • Pediatric approved • FiO2 range (~.21 to ~1.0) on 50 psi oxygen source • Operates w/ low pressure oxygen source • Capable of battery operation • Control of RR, VT, flow (or I:E), PEEP • Displays delivered VT Study Group on Mass Casualty Mechanical Ventilation and US Homeland Security Council Action ID 22.214.171.124 Mass Casualty Respiratory Failure Panel
Optimal PPV Equipment for Mass Respiratory Failure * • Performance • Ruggedized (can withstand fall from 4 feet) • Minimization of oxygen consumption • Engineered so circuit and all connections cannot be attached incorrectly • Safety • Audible/visible alarms (disconnect, high pressure, low source gas pressure) Study Group on Mass Casualty Mechanical Ventilation and US Homeland Security Council Action ID 126.96.36.199 Mass Casualty Respiratory Failure Panel
US Consensus for Sophisticated Transport Vents for Disasters • 2000 US CDC National Stockpile Advisory Panel • Impact Uni-vent 754 (2001) and Puritan Bennett LP-10 (2002) • 2004 Working Group on Emergency Mass Critical Care • Society of Crit. Care Med (SCCM) and Center for Biosecurity of UPMC • All survivable pts with resp failure should get at least basic mode of mech vent • 2004 Study Group on Mass Casualty Mechanical Ventilation • CDC’s Strategic National Stockpile, SCCM, and Center for Biosecurity of UPMC • Recommended sophisticated transport vents • 2005 Guidelines for Acquisition of Ventilators to Meet Demands for Pandemic Flu and Mass Casualty Incidents • American Association of Respiratory Care • Recommended sophisticated transport vents
US SNS Mechanical Ventilators As a critical care provider, you cannot directly request equipment from the SNS! Process Summary Local emergency management (EM) State EM Governor Federal approval Distributed to state from Managed Inventory Distributed to local facility Will be delay from need determination locally to arrival of equipment For multiple regions concurrently involved, total numbers of ventilators may be insufficient to meet surge need
Investigate Your Local PPV Surge Preparation • Is stockpiled PPV equipment available? • Which PPV equipment and ancillary respiratory equipment is provided? • What is process to request and receive? • How long to receive and how many will be provided? • What may be logistical barriers to delivery? • What is the oxygen surge and backup plan?
Minimum Recommended Ancillary Respiratory Equipment • Airway • Manual ventilator with face mask (adult and peds sizes) • External PEEP valve • Endotracheal intubation equipment • Endotracheal tubes (ETT)(7.5 or 8.0 mm for most adults, peds sizes) • ETT securing device • NiPPV not recommended for most victims of mass casualty respiratory failure unless experienced staff available to closely monitor patients • Closed circuit suction catheter * • Single use suction catheters (if required after extubation) • Vacuum source, suction regulator, suction trap and hoses ** * Not provided w/ SNS equipment ** Limited quantities in SNS Study Group on Mass Casualty Mechanical Ventilation and US Homeland Security Council Action ID 188.8.131.52 Mass Casualty Respiratory Failure Panel
Minimum Recommended Ancillary Respiratory Equipment • Circuits • Ventilator circuits (1 per pt, adult and peds) • Must work with surge PPV equipment • If using heated humidifier w/ or w/o wire must have appropriate circuit and additional equipment * • Humidification and Filtration • HME for most pts • Heated humidifier w/ or w/o circuit wire (and addl equipment such as chambers, sterile water) * • Filter for expiratory limb (can be HMEF rather than separate HME and filter) * Not provided w/ SNS equipment Study Group on Mass Casualty Mechanical Ventilation and US Homeland Security Council Action ID 184.108.40.206 Mass Casualty Respiratory Failure Panel
Minimum Recommended Ancillary Respiratory Equipment • Respiratory Medication Delivery • MDI adapter * • Patient monitoring • Pulse oximeter (may use one device for multiple pts) * • Disposable probes (for each pt) * * Not provided w/ SNS equipment Study Group on Mass Casualty Mechanical Ventilation and US Homeland Security Council Action ID 220.127.116.11 Mass Casualty Respiratory Failure Panel