COVD spiro guidance BOPDHB May2020 final

Community Spirometry Testing: Guidelines for resuming testing during COVID-19 Level 2 Advice from leading Respiratory bodies indicates that pulmonary function testing including spirometry may be safe to continue. The European Respiratory Society recommendations for post pandemic phase are for a return to normal practice, while referring to local and national policy for agreement. More locally, the Thoracic Society of Australia and New Zealand also recommend a return to normal practice, as long as patient filters are used.

Bay of Plenty DHB The Tauranga and Whakatane Hospital Respiratory teams are performing pulmonary function testing with the following precautions during level 2: 

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Patients will continue to be screened at booking, and again at their appointment about any new cough, fever, flu/cold symptoms, loss of taste, travel or contact with COVID patients. If in doubt, regarding their current health patients will be rebooked.

Nebulised medications will not be used for bronchodilator responsiveness testing – MDI with spacer will be used and equipment cleaned or disposed of as per current best practice guidelines PPE for level 2 pulmonary function testing will consist of a surgical mask and eye covering E.g. glasses, face shield, goggles Staff are to change out of uniform before leaving work, and leave a pair of shoes at work for work use. Staff are encouraged to shower at work, or when they first arrive home.

Normal infection control processes for spirometry continue. Individual patient filters are used during testing. Surfaces touched by patients and staff are wiped after each test, and staff follow hand hygiene processes. Patients are asked to follow cough/sneeze etiquette and to use steriliser gel before and after their visit.

Use of filters The TSANZ and ANZSRS recommend that spirometry testing should only be performed using lung function equipment that utilises inline filters. Specific advice regarding the common NDD EasyOn device is shown below. Practices using other types of spirometer should ensure an individual patient filter is fitted (which may be standard), or contact their equipment sales representative regarding how to do this.

Addition of a filter to the NDD EasyOn spirometer NDD recommend the use of the Hudson filter with the EasyOn device.

Facilities should consider adding the following technical statement to all reports: “A bacterial/viral filter has been used as per TSANZ COVID-19 recommendations. The filter effect may be clinically negligible but the accuracy of measurements at low flow rates should be interpreted cautiously.”

Note: The filter does not have an oval shaped mouthpiece, so you will have to watch for leaks carefully. Patients may notice a difference in mouthpiece resistance with the addition of the filter.

Main Flow Bacterial/Viral Filter Item Code 1605 Individually packaged, 50 to a case.    

22 mm ID x 15 mm ID/22 mm OD Bacterial efficiency 99.999+%; viral efficiency 99.99+% Dead space is 42 mL Flow resistance approximately 1.5 cm H20 at 60 lpm

There are two ordering options: McLaren Medical – more expensive ($3.70+GST per filter or $185+GST per box of 50) Teleflex – $1.50 per filter ($75 for a box of 50). Send your purchase order to NZCS@teleflex.com The original Spirette (mouthpiece) must be replaced with an M Spirette to connect the Hudson filter. The M spirettes are the same price as the original spirettes and can be ordered from the same supplier (McLaren Medical: Nddmed2050-7/10: M Spirette $47.00 + GST Pack/10).

The M spirette can be used for multiple patients as long as the filter is replaced and the external surface of the spirette and spirometer are carefully cleaned between patients. The M spirette may replaced frequently (e.g the end of the day) to optimise infection control. Frequency of spirette replacement may depend on the number of tests being performed each day.

Picture: Original spirette (top) and M spirette with attached Hudson filter (bottom)

Calibration verification Ensure ambient conditions have been updated before performing the Calibration Check. You can access this by selecting ‘Environment’ and updating the ambient temperature and humidity. Remember to select ‘Recalculate BTPS’ if the conditions have changed.

EasyOn spirometer validation checks should be performed with the M spirometer and filter in place. You may need an adapter to connect the original grey calibration adapter to the syringe.

Note: The EasyOn device has not been developed for using with inline filters. If you are having trouble passing the verification check at low flows, we currently recommend you revert to using the original spirette setup (original spirette without filter). This is not ideal, but the key point here is we want to check that the EasyOn system is functioning correctly before patient testing.

Issued 22 May 2020 Contact: Respiratory.lab@bopdhb.govt.nz