he Ontario SARS report on the severe acute respiratory syndrome-coronavirus (SARS-CoV) epidemic in Toronto in 2003 provides an ominous preview of an anticipated influenza A pandemic. Many health care workers (HCWs), including at least one anesthesiologist, became ill and died from SARS. Initially, the N95 respirator, known commonly as the TB mask, was not thought to be necessary. The SARS Report promotes “The Precautionary Principle,” wherein “action to reduce risk should not await scientific certainty” in situations of potentially grave consequence. The SARS Report also advises that infection control and health care professionals’ safety should be handled as one instead of as separate entities.¹

A pandemic influenza virus could arise out of the co-mingling of H5N1 avian influenza and a seasonal influenza A genetic material. The Centers for Disease Control (CDC) infection control precautions for pandemic influenza are the same as those for SARS.^2,3 The modes of transmission of SARS and influenza A are by direct and indirect (fomite) contact, by droplet and, most probably, by short-range airborne aerosol, which arises during aerosol-generating procedures. Procedures that generate aerosol include high-flow oxygen delivery, aerosolized or nebulized medication administration, diagnostic sputum induction, bronchoscopy, airway suctioning, endotracheal intubation and extubation, bag-mask positive-pressure ventilation, noninvasive ventilatory methods (e.g., BiPAP, CPAP) and high-frequency oscillatory ventilation.^2,3,4 Spontaneous coughing and sneezing also generate aerosol.⁵

The CDC provides a highly informative review of transmission modes, masks and respirators.³ The N95 respirator is the minimum respiratory protection mandated by the CDC and Occupational Safety and Health Administration (OSHA) when the health care provider is in close contact with patients with the highly pathogenic respiratory illnesses of SARS or pandemic or avian influenza. Both the CDC and OSHA advise that additional respiratory precautions are warranted (but not mandated) for health care personnel performing aerosol-generating procedures on victims of these diseases.^3,4

Under test conditions, the N95 inhibits passage of 95 percent of 0.3 micron saline particles. In clinical settings, the optimal level of protection will hold only if the wearer has been successfully fit-tested and if no leakage around the edges occurs at any time during patient care. The N95 increases the work of breathing, making it uncomfortable to wear for extended periods, and it is likely to be adjusted, displaced or periodically lifted. Fit-testing requires trained personnel, specialized equipment and substantial time per subject to complete. Facial hair or facial structure may preclude a satisfactory fit test. The reuse of N95 respirators is discouraged but may be necessary if supplies are insufficient for single use.^2,3,4

The powered air purifying respirator (PAPR) is a nondisposable full hood or enclosed face cover system that provides a higher level of respiratory protection than the N95 respirator.^2,3,4 Some of the manufacturers are 3M, Bullard, MSA and North Safety. A blower worn on a waist belt draws air through a high-efficiency particulate air filter. The filtered air passes through a corrugated tube into the hood and prevents — contaminated air from entering. PAPRs for chemical protection contain an absorbent cartridge, and the hood is made of a chemical-resistant material.

In addition to providing a higher level of respiratory protection than the N95, further advantages of the PAPR are that it does not require fit-testing, is more comfortable to wear for an extended period, and provides contact protection for the entire head, neck and shoulders when the full hood style is chosen. Disadvantages of the PAPR are that it requires initial and periodic training and practice, is nondisposable, is expensive, requires a regular maintenance program, is not autoclavable, requires cleaning after use, may contain latex, and the blower noise may impede communication.^3,4

The University of Wisconsin Hospital requires use of PAPRs for aerosol-generating procedures as does the California State Pandemic Influenza Preparedness and Response Plan.⁶ Other state, local and hospital pandemic influenza plans may not. PAPRs will be in extremely short supply once a pandemic starts. N95 supplies may also be very limited unless hospitals have stocked beyond the usual “just in time” supply. Upon request through the regional 3M sales representative and the 3M Occupational Safety Division, the 3M company can provide education and training assistance with PAPRs and N95s.⁷

The OSHA Pandemic Influenza document is concise, eminently readable and very helpful.⁴ It can be obtained in booklet form by calling your region’s OSHA office listed at the end of the online document. It includes synopses of background information, infection control issues, personal protective equipment (PPE), a description of masks and respirators, Internet resources for diagnosis and treatment, and planning checklists. For all industrial and medical respiratory protection systems, OSHA requires that PPE be used within a context of a respiratory protection program, which includes a written protocol, medical clearance of the PPE wearer, training and at least yearly practice.⁴ 3M has developed an OSHA-compliant respiratory PPE medical clearance form (www.respexam.com) and a record-keeping system.⁷

Contact precautions for SARS/pandemic/avian influenza include gown, gloves, hat, foot covers, close-fitting goggles and a face shield if the N95 is used.^2,4,6 Both the chosen PPE, whether N95 or PAPR, and the unprotected skin can be contaminated by droplets and aerosols, thus providing a fomite from which the individual may self-inoculate by transferring the infectious agent by hand to the eyes, nose or mouth. It is advisable therefore to cover all exposed skin wherever possible and observe strict hand hygiene following removal of the PPE.

Contamination of exposed skin occurred more often with N95, but breeches in don/doff sequence were more frequent with PAPR.^8,9 Training and practice in the don/doff sequence and in performing procedures while wearing a PAPR are extremely important aspects of provider and patient safety. The PAPR don/doff sequence involves an assistant or buddy to remove the belt that supports the blower and filter and a re-gloving to remove part of the contact PPE.⁹

The OSHA General Duty Clause mandates that the employer is responsible for providing a safe work environment. For many anesthesiologists, the medical group we belong to is our employer, as opposed to the hospital. Therefore, we ourselves, not the hospital, may be accountable for our colleagues’ and our own safety or failure to provide for that safety. Further, ethical concepts, in addition to OSHA, suggest that the employer may not demand that the employee report for work when available safety protection is not provided.⁴

In contrast to “just in time” PPE training, OSHA implies that if PPE is likely to be needed when performing a procedure common to a specialty, then that specialist is obligated to become familiar and facile with the use of the PPE in advance of the anticipated need.⁴

Anesthesiology departments are advised to prepare for managing SARS and pandemic influenza patients by:

1. Contacting your infection control nurse and the hospital emergency preparedness or disaster committee. Inquire about SARS/pandemic influenza plans, especially the choice between N95 or PAPR for respiratory PPE during intubation and other aerosol-generating procedures. Chances are that you will need to take leadership in physician preparedness for pandemic influenza and other all-hazard events.

2. Contacting critical care physicians, hospitalists, pulmonary specialists and emergency medicine physicians to develop a consensus regarding preparation and PPE for SARS/pandemic influenza.

3. Being aware that physicians are often not hospital employees. You may ask the hospital to budget for PAPRs, but you may in fact need to buy and maintain them yourself and conduct training.

4. Contacting the PAPR manufacturer of your choice for product information and training assistance. 3M is a leader in this area.

5. Obtaining PPE equipment, conduct training and practice until proficient in the PPE don/doff sequence. Perform procedures while wearing PPE. Initiate or join a hospital OSHA Respiratory Protection Program.

6. Becoming familiar with the OSHA pandemic influenza document.⁴ OSHA also has publications on emergency preparedness and on guidelines for hospital-based first receivers of victims of hazardous materials exposure.

7. Writing a section for your anesthesia department policy and procedure manual on intubating pandemic influenza/SARS patients. The Joint Commission has greatly expanded its emergency preparedness requirements.

8. Refering to the ASA Committee on Trauma and Emergency Preparedness “Statement on Pandemic Influenza Preparedness” posted online at www.ASAhq.org/clinical/PandemicDocument.pdf in December 2006.¹⁰

In summary, respiratory and contact PPE are needed for SARS/avian influenza/pandemic influenza. In addition to full-contact protection of the head and neck, the PAPR offers a higher level of respiratory protection than the N95 respirator. The CDC and OSHA suggest, but do not mandate, use of the PAPR for aerosol-generating procedures. Regardless of which PPE system is used, following correct protocol and performing procedures while wearing PPE will reduce health care provider infection and increase patient safety.

References:
1. Initial Report of the Ontario Expert Panel on SARS and Infectious Disease Control www.health.gov.on.ca/english/public/pub/ministry_reports/walker_panel_2003/walker_panel.html. Accessed on November 21, 2007.

2. The Centers for Disease Control: Public Health Guidance for Community-Level Preparedness and Response to Severe Acute Respiratory Syndrome (SARS) Version 2, Supplement I: Infection Control in Healthcare, Home, and Community Settings, III. Infection Control in Healthcare Facilities, May 3, 2006 www.cdc.gov/ncidod/sars/guidance/I/healthcare.htm#3d1. Accessed on November 27, 2007.

3. Department of Health and Human Services (HHS) Interim Guidance on Planning for the Use of Surgical Masks and Respirators in Health Care Settings During an Influenza Pandemic, October 2006. www.pandemicflu.gov/plan/healthcare/maskguidancehc.html#appB. Accessed on November 27, 2007.

4. Pandemic Influenza Preparedness and Response Guidelines for Healthcare Workers and Healthcare Employers, OSHA 3328-05 2007. www.osha.gov/Publications/OSHA_pandemic_health.pdf. Accessed on November 27, 2007.

5. Tellier R. Review of aerosol transmission of influenza A virus. Emerg Infect Dis.(serial on Internet) 2006; 12 (11). www.cdc.gov/ncidod/EID/vol12no11/06-0426.htm.

6. California Influenza Preparedness and Response Plan, September 8 2006. www.dhs.ca.gov/ps/dcdc/izgroup/pdf/pandemic.pdf. Accessed on November 27, 2007

7. Personal Communication, November 28, 2007, with permission: Jim Brachmann, Homeland Security Specialist, 3M Occupational Health & Environmental Safety Division. (Office) (815) 477-1342; (Cell) (815) 341-3253; (Fax) 815-477-0385; jfbrachmann1@mmm.com; www.pandemicpreparation.com.

8. Zamora JE, Murdoch J, Simchison B, Day AG. Contamination: A comparison of 2 personal protective systems. CMAJ. 2006; 175:249-254. And editorial: Conly JM. Personal protective equipment for preventing respiratory infections: What have we really learned? CMAJ. 2006; 175(3):263.

9. Minnesota Department of Health: Full Barrier Personal Protective Equipment (PPE) with Powered Air Purifying Respirator (PAPR), Donning and doffing of PPD when using a PAPR. www.health.state.mn.us/divs/idepc/dtopics/infectioncontrol/ppe/ppepapr.html. Accessed on November 21, 2007.

10. Tompkins BM, Antoine J, Stackhouse R, Barach P, Katz J. The ASA Committee on Trauma and Emergency Preparedness Statement on Pandemic Influenza Preparedness. www.ASAhq.org/clinical/PandemicDocument.pdf.

Bonnie M. Tompkins, M.D., is Clinical Assistant Professor of Anesthesiology, (retired from clinical practice), University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.

Jill A. Antoine, M.D., is Associate Clinical Professor of Anesthesiology, University of California at San Francisco, San Francisco, California.