Many health care workers have been fitted. I have!

Clinicians raise questions about respirator use in pandemic

Lisa Schnirring * Contributing Writer

Nov 16, 2006 (CIDRAP News) – Last month the US Department of Health and Human (HHS) called for a greater role for N95 respirators in protecting healthcare workers in the event of an influenza pandemic, and now clinicians are raising questions about potential problems such as inadequate supplies and poor fit.

The Centers for Disease Control and Prevention (CDC) fielded questions from clinicians today during a teleconference with Michael Bell, MD, associate director for infection control in the CDC's Division of Healthcare Quality Promotion.

In October, HHS issued new interim guidance saying that the use of N95 respirators, designed to stop 95% of small airborne particles, is "prudent" for medical workers providing direct care for patients with confirmed or suspected pandemic fu and is recommended when caring for patients with pneumonia. HHS also said that respirator use is prudent for support workers who have direct contact with patients.

The recommendations were a departure from guidance in the HHS pandemic influenza plan released last year, which urged healthcare workers to wear simple surgical masks, designed to block large respiratory droplets, for routine care of pandemic flu patients. Both documents recommend use of N95 protection during procedures likely to generate airborne infectious particles, such as nebulization or endotracheal intubation.

Bell emphasized that the new HHS guidance is not intended to change how clinicians respond to patients who have seasonal influenza. He said the difference in recommendations between seasonal and pandemic influenza stems from uncertainty about inherent immunity to a pandemic flu strain and potential shortages of antiviral medication and vaccines in a pandemic. "As a result, there's more attention being paid to personal protective equipment," he said.

He predicted that recommendations about respirator use will continue to evolve as researchers learn more about flu virus particle size and virulence. "The interim guidance is very much interim," he said.

Another useful thing the recent HHS respirator recommendations do is to make a distinction between respirator use and use of negative-pressure isolation rooms, Bell said. "It's one thing to supply respirators and another thing to reengineer rooms," he said.

The HHS guidance states that negative-pressure isolation is not required for routine care of patients with pandemic influenza, though such rooms should be used whenever possible for performing aerosol-generating procedures such as inhalational intubation. If negative-pressure rooms aren't available, it is prudent to perform such procedures in private rooms with the door closed or other enclosed areas, the document says.

One clinician who took part in the teleconference said she and her colleagues were worried about the supply of N95 respirators and said her hospital had difficulty obtaining enough even for routine tuberculosis care.

Another clinician had questions about reusing respirators if a pandemic occurs and the devices are in short supply. Bell said healthcare workers had to be creative during the SARS (severe acute respiratory syndrome) outbreak; some kept their masks in plastic bags and reused them. He said breathing through the mask, over time, could reduce some the electrostatic charge that provides some of the filtering mechanism. "There are no clear recommendations, though the Institute of Medicine says they are disposable and not suitable for reuse," Bell said. "There may be safer ways to reuse them."

Bell said HHS officials and other healthcare groups are brainstorming about how to stimulate more production of N95 respirators. "The companies are concerned about liability. They want to be free of that before they produce mass quantities," he said.

Other clinicians had questions about how well the N95 respirators have to fit to provide adequate protection. They said respirator products range from models that don't require any fitting to ones that require time-consuming fitting procedures. Bell said that from a regulatory perspective, OSHA recommends strict attention to the fit of the respirator. "But in a pinch, you'd expect some benefit, even if the respirator isn't a perfect fit," he said.

Some clinicians said they were already fielding questions about community use of N95 respirators. Bell responded that HHS has just drafted guidance on such use. He anticipated that the recommendations would be posted on the government's pandemic flu Web site within the next 3 or 4 weeks. Bell said HHS probably won't recommend N95 respirators to the general public unless people are caring for family members or neighbors who have pandemic influenza.

from CIDRAP