Occupational and Environmental Health
New guidelines for latent TB testing in health-care personnel
Latent infection with Mycobacterium tuberculosis (TB) infection is of public health concern because of the lifetime risk of reactivation, a risk highest in the first 2 years after TB infection. Treatment of latent TB infection (LTBI) reduces the risk of reactivation by as much as 90%, and, thus, screening for LTBI in high-risk populations can identify patients eligible for treatment (Horsburgh & Rubin.). The Centers for Disease Control and Prevention (CDC) previously recommended annual testing for LTBI in health-care personnel (HCP) as a high-risk group for developing LTBI (Jensen et al. ).
The annual national TB rate in the United States has decreased by 73% since 1991 (Stewart et al.), and surveillance data show that TB incidence among HCPs does not differ significantly from the general population. The CDC thus formed the National Tuberculosis Controllers Association (NTCA)-CDC work group to revisit the recommendations for LTBI screening in HCPs. A systematic evidence review of all studies of LTBI testing in HCPs since 2005 was performed. Analysis of data from identified studies showed that less than 5% of HCPs converted from baseline negative to positive on routine annual screening.
Based on this, the CDC updated their recommendations from the 2005 guidelines: (1) Serial annual LTBI testing is no longer routinely recommended for all HCPs but may be considered for select HCPs (eg, pulmonologists, infectious disease specialists, respiratory therapists); (2) Treatment is encouraged for all HCPs with positive LTBI testing, unless medically contraindicated; (3) The recommendations for baseline LTBI and postexposure testing in all HCPs remain unchanged (Sosa et al.).
Sujith Cherian, MD, FCCP
Steering Committee Member
Amy Ahasic, MD, MPH, FCCP
Aerosol drug delivery via high-flow nasal cannula
As a noninvasive, easy-to-use oxygen device, high-flow nasal cannula (HFNC) meets patients’ inspiratory demands, increases functional residual capacity, and decreases the need for intubation (Rochwerg, et al.).
Using HFNC for aerosol drug delivery is an innovative approach (Ari, et al.) and the seven most important things about aerosol delivery via HFNC are listed below for clinicians:
1. Aerosols can be delivered via HFNC in the treatment of patients with respiratory distress through all age groups.
2. Delivery efficiency of mesh nebulizers is greater than jet nebulizers during HFNC. Unlike jet nebulizers, they do not interfere with FiO2 and the function of HFNC by adding extra gas flow to the system.
3. Placing mesh nebulizers before the humidifier improves aerosol delivery via HFNC.
4. Higher inspiratory flow rates with HFNC decreases aerosol delivery due to increased turbulence and impactive loss of aerosols during therapy.
5. While aerosol deposition is greater with the larger prong sizes, its size should not block more than 50% of the cross-sectional area of each nostril to allow gas leakage around the cannula.
6. Although oxygen is commonly used with HFNC, administering aerosolized medications with heliox during HFNC improves lung deposition more than oxygen.
7. Training patients on the closed mouth technique and nasal breathing during therapy may improve aerosol drug delivery via HFNC.
HFNC is a promising tool in aerosol therapy, and developing clinical guidelines on aerosol delivery via HFNC is needed to improve its effectiveness in drug delivery.
Arzu Ari, PhD, RRT
Steering Committee Member
Jessica Overgoner, RRT