Pandemic Flu and Anesthesia Proper use of personal protection equipment during intubation inside and outside the operating room
Overview • History of Pandemic Influenza • Modes of Transmission for Infectious Disease • Personal Protection Equipment Review • Donning/Doffing a PAPR • Protocol for Intubation Outside the O.R. • Intra-op Management of Pandemic Flu Patients
History—Pandemic Flu • 1918: worldwide influenza A pandemic • Spanish Flu (H1N1) • 675,000 U. S. deaths • 50 million deaths worldwide • Original source of the virus: waterfowl or pigs credit: Office of the Public Health Service Historian
History—Pandemic Flu • 1957: Asian flu (H2N2) • 70,000 deaths in the U.S. • 1-2 million deaths worldwide • 1968: Hong Kong flu (H3N2) • 34,000 deaths in the U.S. • 700,000 deaths worldwide
History—Pandemic Flu • 1976: Swine Flu outbreak at Fort Dix, New Jersey • 13 soldiers infected; 1 dies • Intensive epidemiologic study and isolation limit spread • More Americans perish from complications due to the vaccine than from swine flu Courtesy: The Gerald R. Ford Library
History—Pandemic Flu • 1997: Avian Flu (H5N1) • Discovered in Hong Kong • 18 infections; 6 deaths • 2004: Avian Flu moves to Thailand • 47 cases; 34 deaths
History--Avian Flu • 2006: spreads to Turkey, China, Iraq, Azerbaijan, Egypt • 2007: cases reported in Nigeria • Image from Jan Conroy, UC Davis Graphics 8/2008 Courtesy of UC Davis Newsletter
History: Avian Flu • Currently, transmission requires contact with infected birds or their secretions • When the strain becomes transmissible via human-to-human contact, how quickly would the pandemic spread?
Avian Flu Model Estimates of an Avian Flu pandemic three months after the arrival of 10 infected people to Los Angeles. Blue color: 1 or fewer cases per 1000 people Red color: 100 or more cases per 1000 people Courtesy: Los Alamos National Laboratory News April 4, 2006
History--SARS • 2003: Worldwide spread of Severe Acute Respiratory Syndrome (SARS) • Novel Coronavirus A • 29 countries affected • 8400 cases; 900 fatalities • In Toronto, of 31 health care workers performing 36 intubations, 3 (all anesthesiologists) contract SARS
Modes of Transmission • Influenza A • Multiple routes of infection • Droplet transmission: 50-100 microns in diameter travel less than one meter; aren’t suspended in air • Direct contact of contaminated hands one’s to nose, mouth or eyes • Auto-inoculation via fomites (objects contaminated with virus) • ?Potential for small droplets (less than 5 microns diameter) to aerosolize (airborne), transmitting virus beyond 1-2 meters
Modes of Transmission • Influenza and SARS may by transmitted through aerosol generating procedures: • Nebulizer treatments • High flow oxygen • Non-invasive ventilation (CPAP or BiPAP) • Bronchoscopy • High frequency oscillatory ventilation • Bag-valve ventilation • Intubation and suctioning
Personal Protection Equipment • Hand washing • Either soap and water or alcohol based cleansing solutions are effective in controlling influenza or SARS virus. • Must be done prior to patient contact, after removing masks, gloves and gowns • Health Care Workers (HCW) who consistently washed their hands during care for SARS patients had lower infection rates* • *Shaw,K Public Health, (2006) 120,8-14.
Personal Protective Equipment • Masks • Facemasks (surgical masks) • Loose fitting disposable masks that stop droplets, skin or hair particles falling onto the patient from the HCW • Prevent splashes from contacting the HCW’s face • Respirators • Air filtering devices that protect against inhalation of both large and small particles • OSHA requires their use as part of a hospital respiratory protection program:
Personal Protection Equipment • OSHA Respiratory Protection Plan requirements: • Qualified program administrator • A written protocol including: • Appropriate respirator selection • Medical certification for the PPE wearer • Fit testing • Maintenance and cleaning of equipment • Program review Pandemic Influenza Preparedness and Response Guidelines for Healthcare Workers and Healthcare Employerswww.osha.gov/Publications/OSHA_pandemic_health.pdfaccessed 8/18/08
Personal Protection Equipment • Respirators1 --Air-purifying respirators • Remove contaminants by filtration or absorption • May be passive or powered • N-95 (filtering face mask) • Powered Air Purifying Respirator (PAPR) • Atmosphere-supplying respirators • Provide clean breathing air from an uncontaminated source • Self-contained breathing apparatus (SCBA) • Allow entry into an oxygen depleted environment 1Szeinuk J et al Am Jour Indust Med (2000) 37:142-157
PPE: N-95 Respirators • Passive air filtration • Industrial uses also require identification of resistance of filter degradation to oil • N means not oil resistant • R means somewhat oil resistant • P means strongly oil resistant • Respirators are also classified by the percent of small particles are filtered (95, 99, or 99.97%) • Thus N-95 respirators are not oil resistant and filter about 95% of small particles.
PPE: N-95 Respirators • Advantages • Readily available • No interference to using a stethoscope • Not powered, noiseless • Disadvantages • Requires fit testing—only works with a tight seal • Leaves some of the face and neck exposed to droplets • Increases the work of breathing, uncomfortable • Not generally reusable • Can’t be used for men with beards
PPE: Powered Air Purifying Respirators (PAPR) • Advantages • Doesn’t require fit testing • Completely covers the face; some also cover the neck • Doesn’t increase the work of breathing • Most components reusable
PPE: PAPR • Disadvantages • Requires ongoing training to put on (Don), use safely, and take off (Doff) • Fan noise impedes conversation • Can’t use a stethoscope • May cause claustrophobia • Limited availability, some models can’t be used in an OR • More challenging to use during a difficult intubation
PPE: Comparing N-95 vs. PAPR • Most of the HCW’s in Toronto who contracted SARS did so before N-95 masks/droplet precautions were utilized1 • One intensivist contracted SARS during a difficult intubation in spite of wearing a N-95/goggles/gown and gloves • PPE only work when used appropriately • 1Nicolle L, Can J Anesth (2003) 50:983-988.
PPE: Comparing N-95 vs. PAPR • Prospective, randomized, controlled crossover study of 50 subjects comparing contamination following use of PAPR vs. N-95 respirator • Subjects using the N-95 had more frequent and larger areas of skin contamination • Subjects using the PAPR had increased risk of self-contamination while doffing their PPE • Zamora J et al. CMAJ (2006) 175:249-254.
PPE: Comparing N-95 vs. PAPR • Unanswered Questions: • Minimal infective dose of viruses • Safe distance away from patients to prevent HCW infection • Issues of PAPR use: • Claustrophobic reactions to HCW wearing a PAPR • Difficulty in communication due to Blower noise • Scary appearance of PAPR wearer to pediatric patients • Increased complexity of PPE increasing confusion and thus self-contamination of HCW
PPE: Comparing N-95 vs. PAPR • Recommendations • The CDC and OSHA mandate using a N-95 respirator as the minimum respiratory protection when in close contact with SARS/pandemic flu patients • The CDC and OSHA note that further respiratory precautions are warranted (but not mandated) • California and some hospitals have required using a PAPR during aerosol-generating procedures • Rush’s policy also states that a PAPR will be used in aerosol-generating procedures
What’s a PAPR? Breathing Tube and airflow indicator Air-Mate Blower
What’s a PAPR? Tyvek Head Cover--Rascal Tyvek Hood
PAPR Head Covers in Use Rascal Headgear PAPR Hood
Donning/Doffing a PAPR • Prior to entering the patient’s room • Put on shoe covers • Put on hair cover (if Rascal is being used) • Prepare the Air-Mate blower:
Preparing the Air-Mate Blower • Remove the back cover • Check the filter is clean • Ensure the filter arrows point into the unit • Replace the back cover
Preparing a PAPR • Attach the air hose to the Air-Mate Blower by inserting the male end of the hose and turning it clockwise until a click is felt.
Preparing the Air-Mate Blower • Turn on the power • Check the airflow with the airflow indicator • The indicator should float on the air coming out; the lower band of the indicator should be visible • If this test fails do not attempt to use the unit
Donning a PAPR • Attach the breathing tube into the headgear • If present, remove the tissue covering the faceplate • Place the Air-Mate on mid-back; attach and secure belt around waist
Donning a PAPR • Pull the face piece over your head • Adjust the headpiece for comfort • Verify adequate airflow • Remove PAPR if: • Breathing becomes difficult • You feel dizzy or anxious • You smell or taste contaminants • Your eyes, nose, or mouth become irritated • Remove a PAPR only outside a contaminated room
Donning a PAPR • Put on gown and gloves • If using a hood, the inner shroud tucks inside the gown; the outer shroud hangs outside the protective clothing. • You may now enter the patient’s room
Doffing a PAPR • Before leaving the room: • Remove shoe covers • Remove gown by grasping the shoulders pull forward, rolling the outside of the gown inward and keeping the contaminated surface away from your body; remove gloves • Discard gown and gloves in the red biohazard bag
Doffing a PAPR • Wash your hands! • Put on new gloves • Exit the room, close the door
Doffing a PAPR • Assistant (wearing gloves) supports the PAPR power source while the wearer takes off the belt • Take off the hood from the inside, disconnect the breathing tube (from the inside of the hood) • Place hood in reprocessing bag or waste
Doffing a PAPR • The assistant places the breathing tube and Air Mate in a biohazard bag for reprocessing • Both remove their gloves • Wash your hands!!
Donning a PAPR Doffing a PAPR 1. Put on shoe covers and hair cover 1. Inside the room take off shoe covers, gown and gloves. Wash hands and put on new gloves 2. Check the HEPA filter on the Airmate blower unit 3. Check air flow out of the blower hose using the bullet 2. Outside the room, your assistant holds the Airmate while you unsnap the belt 3. Disconnect the hose from the inside of the PAPR headpiece 4. Snap the blower hose into the PAPR hood; attach the Airmate belt securely on your waist 4. Place PAPR headpiece, hose and Airmate in Red Bag for cleaning 5. Put on PAPR headpiece or hood; verify adequate air flow 5. Waste gloves; WASH HANDS! 6. Put on gown and gloves; remember the gown goes over the inner shroud of a PAPR hood
Intubation Outside an O.R. • Primary service or nursing staff notify Anesthesia On-Call that a patient requires intubation using SARS/Flu protocol • Anesthesia PAPR’s from the local room brought with anesthesia personnel to the patient’s room • 2 on-call anesthesia providers don PAPR’s for intubation; assist with doffing PAPR’s
Intubation Outside an O.R. • Determine if the intubation is elective or emergent(i.e.. respiratory arrest) • Perform focused H & P1: • AMPLE: Allergies, Medications, PMH, Last meal, Events • Airway exam • Difficult airway? Ensure a fiberoptic cart is immediately available • 1Cooper A et al. CMAJ.ca Sept. 17, 2003
Intubation Outside an O.R. • Anesthetic technique—minimize coughing • Normal airway • Pre-oxygenate for 5 minutes—avoid bag-mask ventilation if possible • Use a muscle relaxant prior to intubation • Consider giving glycopyrrolate IVP prior to intubation
Intubation Outside an O.R. • Difficult Airway • Experienced Anesthesia Provider to intubate the patient • Have a difficult airway cart immediately available • Avoid nebulized/topical/transtracheal lidocaine • Consider deep sedation: midazolam 0.05 mg/kg IVP and/or fentanyl 1 mcg/kg IVP every 3 to 5 minutes until the patient is unresponsive to deep painful stimuli, low spontaneous minute ventilation1 • Consider ketamine as an alternative sedative • Lidocaine 1.5 mg/kg IVP one minute before intubation • After intubation is confirmed, administer a muscle relaxant 1Cooper A et al.