Infection control of lung function equipment: a practical approach

ARTP statement on cardiopulmonary exercise testing 2021

Cardiopulmonary exercise testing (CPET) has become an invaluable tool in healthcare, improving the diagnosis of disease and the quality, efficacy, assessment and safety of treatment across a range of pathologies. CPET's superior ability to measure the global exercise response of the respiratory, cardiovascular and skeletal muscle systems simultaneously in a time and cost-efficient manner has led to the application of CPET in a range of settings from diagnosis of disease to preoperative assessment. The Association for Respiratory Technology and Physiology Statement on Cardiopulmonary Exercise Testing 2021 provides the practitioner and scientist with an outstanding resource to support and enhance practice, from equipment to testing to leadership, helping them deliver a quality assured service for the benefit of all patient groups.

ARTP statement on pulmonary function testing 2020

The Association for Respiratory Technology & Physiology (ARTP) last produced a statement on the performance of lung function testing in 1994. At that time the focus was on a practical statement for people working in lung function laboratories. Since that time there have been many technological advances and alterations to best practice in the measurement and interpretation of lung function assessments. In light of these advances an update was warranted. ARTP, therefore, have provided within this document, where available, the most up-to-date and evidence-based recommendations for the most common lung function assessments performed in laboratories across the UK. These recommendations set out the requirements and considerations that need to be made in terms of environmental and patient factors that may influence both the performance and interpretation of lung function tests. They also incorporate procedures to ensure quality assured diagnostic investigations that include those associated with equipment, the healthcare professional conducting the assessments and the results achieved by the subject. Each section aims to outline the common parameters provided for each investigation, a brief principle behind the measurements (where applicable), and suggested acceptability and reproducibility criteria.

Suggestions for lung function testing in the context of COVID-19

The 2019 coronavirus disease (COVID-19) pandemic is currently a challenge worldwide. Due to the characteristics of lung function tests, the risk of cross infection may be high between health care workers and patients. The role of lung function testing is well defined for the diagnosis of various diseases and conditions. Lung function tests are also indispensable in evaluating the response to medical treatment, in monitoring patient respiratory and systemic pathologies, and in evaluating preoperative risk in cardiothoracic and major abdominal surgeries. However, lung function testing represents a potential route for COVID-19 transmission, due to the aerosol generated during the procedures and the concentration of patients with pulmonary diseases in lung function laboratories. Currently, the opportunities for COVID-19 transmission remain partially unknown, and data are continuously evolving. This review provides useful information on the risks and recommendations for lung function testing, which have varied according to the phase of the pandemic. This information may support national and regional boards and the health authorities to which they belong. There is a need for rapid re-opening of lung function laboratories, but maximum safety is required in the COVID-19 era.

The diagnosis of asthma. Can physiological tests of small airways function help?

Asthma is a common, chronic, and heterogeneous disease with a global impact and substantial economic costs. It is also associated with significant mortality and morbidity and the burden of undiagnosed asthma is significant. Asthma can be difficult to diagnose as there is no gold standard test and, while spirometry is central in diagnosing asthma, it may not be sufficient to confirm or exclude the diagnosis. The most commonly reported spirometric measures (forced expiratory volume in one second (FEV₁) and forced vital capacity assess function in the larger airways. However, small airway dysfunction is highly prevalent in asthma and some studies suggest small airway involvement is one of the earliest disease manifestations. Moreover, there are new inhaled therapies with ultrafine particles that are specifically designed to target the small airways. Potentially, tests of small airways may more accurately diagnose early or mild asthma and assess the response to treatment than spirometry. Furthermore, some assessment techniques do not rely on forced ventilatory manoeuvres and may, therefore, be easier for certain groups to perform. This review discusses the current evidence of small airways tests in asthma and future research that may be needed to further assess their utility.

Pediatric Pulmonary Function Testing in COVID-19 Pandemic and Beyond. A Position Statement From the Hellenic Pediatric Respiratory Society

As the COVID-19 pandemic is still evolving, guidelines on pulmonary function testing that may dynamically adapt to sudden epidemiologic changes are required. This paper presents the recommendations of the Hellenic Pediatric Respiratory Society (HPRS) on pulmonary function testing in children and adolescents during the COVID-19 era. Following an extensive review of the relevant literature, we recommend that pulmonary function tests should be carried out after careful evaluation of the epidemiologic load, structured clinical screening of all candidates, and application of special protective measures to minimize the risk of viral cross infection. These principles have been integrated into a dynamic action plan that may readily adapt to the phase of the pandemic.

Non-ventilator health care-associated pneumonia (NV-HAP): Long-term care

Nonventilator health care-associated pneumonia (NV-HAP) is costly and preventable with significant impact on patient morbidity and mortality. This chapter outlines the increased risk of NV-HAP among individuals residing in long-term care facilities and the incidence of pneumonia in this health care setting which accounts for up to 18% of all persons admitted to acute care hospital for pneumonia. A description of prevention strategies with detail on modifiable and Nonmodifiable risk factors for acquiring pneumonia are presented along with the need for a robust interdisciplinary team and approach for this vulnerable population. In addition, the lack of active surveillance and infection prevention expertise may result in the spread of pathogens that can cause NVHAP outbreaks.

Turkish Thoracic Society Experts Consensus Report: Recommendations for Pulmonary Function Tests During and After COVID 19 Pandemic

The recommendation of conducting pulmonary function tests (PFTs) from different societies during and after the coronavirus disease (COVID-19) pandemic was rated by the experts of the Turkish Thoracic Society (TTS) and presented as the TTS experts consensus report. Information about the topic has been provided.Globally, as of mid-May 2020, there have been over 4.4 million confirmed cases of COVID-19. There are two main routes of transmission of COVID-19: respiratory droplets and contact transmission. PFTs are non-invasive tests that are commonly performed in routine assessment and follow-up of patients in the pulmonology units. However, PFTs may generate aerosols and require sharing common surfaces. With regard to the high prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the community, PFTs should not be performed routinely in confirmed or suspected patients with COVID-19 during the pandemic. Because of the risk of human-to-human transmission of COVID-19, PFTs should be restricted to a small patient population with selected indications. Triage for COVID-19 should be performed prior to testing. Only essential PFTs such as spirometry, diffusion capacity of the lungs for carbon monoxide (DLCO), arterial blood gas analysis, or pulse oximetry should be performed in the selected cases. Tests should be scheduled to allow sufficient time for donning and doffing of the technical personnel with the full personal protective equipment (PPE) (gown, a filtering respirator mask, goggles or full-face shield, and disposable gloves), ventilation of the room, and application of post-test cleaning and disinfection procedures of the equipment and the testing room.

Standardization of Spirometry 2019 Update. An Official American Thoracic Society and European Respiratory Society Technical Statement

Background: Spirometry is the most common pulmonary function test. It is widely used in the assessment of lung function to provide objective information used in the diagnosis of lung diseases and monitoring lung health. In 2005, the American Thoracic Society and the European Respiratory Society jointly adopted technical standards for conducting spirometry. Improvements in instrumentation and computational capabilities, together with new research studies and enhanced quality assurance approaches, have led to the need to update the 2005 technical standards for spirometry to take full advantage of current technical capabilities.Methods: This spirometry technical standards document was developed by an international joint task force, appointed by the American Thoracic Society and the European Respiratory Society, with expertise in conducting and analyzing pulmonary function tests, laboratory quality assurance, and developing international standards. A comprehensive review of published evidence was performed. A patient survey was developed to capture patients' experiences.Results: Revisions to the 2005 technical standards for spirometry were made, including the addition of factors that were not previously considered. Evidence to support the revisions was cited when applicable. The experience and expertise of task force members were used to develop recommended best practices.Conclusions: Standards and consensus recommendations are presented for manufacturers, clinicians, operators, and researchers with the aims of increasing the accuracy, precision, and quality of spirometric measurements and improving the patient experience. A comprehensive guide to aid in the implementation of these standards was developed as an online supplement.

ERS statement on standardisation of cardiopulmonary exercise testing in chronic lung diseases

The objective of this document was to standardise published cardiopulmonary exercise testing (CPET) protocols for improved interpretation in clinical settings and multicentre research projects. This document: 1) summarises the protocols and procedures used in published studies focusing on incremental CPET in chronic lung conditions; 2) presents standard incremental protocols for CPET on a stationary cycle ergometer and a treadmill; and 3) provides patients' perspectives on CPET obtained through an online survey supported by the European Lung Foundation. We systematically reviewed published studies obtained from EMBASE, Medline, Scopus, Web of Science and the Cochrane Library from inception to January 2017. Of 7914 identified studies, 595 studies with 26 523 subjects were included. The literature supports a test protocol with a resting phase lasting at least 3 min, a 3-min unloaded phase, and an 8- to 12-min incremental phase with work rate increased linearly at least every minute, followed by a recovery phase of at least 2–3 min. Patients responding to the survey (n=295) perceived CPET as highly beneficial for their diagnostic assessment and informed the Task Force consensus. Future research should focus on the individualised estimation of optimal work rate increments across different lung diseases, and the collection of robust normative data.

The document facilitates standardisation of conducting, reporting and interpreting cardiopulmonary exercise tests in chronic lung diseases for comparison of reference data, multi-centre studies and assessment of interventional efficacy.http://bit.ly/31SXeB5

2017 ERS/ATS standards for single-breath carbon monoxide uptake in the lung

This document provides an update to the European Respiratory Society (ERS)/American Thoracic Society (ATS) technical standards for single-breath carbon monoxide uptake in the lung that was last updated in 2005. Although both D_LCO (diffusing capacity) and T_LCO (transfer factor) are valid terms to describe the uptake of carbon monoxide in the lung, the term D_LCO is used in this document. A joint taskforce appointed by the ERS and ATS reviewed the recent literature on the measurement of D_LCO and surveyed the current technical capabilities of instrumentation being manufactured around the world. The recommendations in this document represent the consensus of the taskforce members in regard to the evidence available for various aspects of D_LCO measurement. Furthermore, it reflects the expert opinion of the taskforce members on areas in which peer-reviewed evidence was either not available or was incomplete. The major changes in these technical standards relate to D_LCO measurement with systems using rapidly responding gas analysers for carbon monoxide and the tracer gas, which are now the most common type of D_LCO instrumentation being manufactured. Technical improvements and the increased capability afforded by these new systems permit enhanced measurement of D_LCO and the opportunity to include other optional measures of lung function.

Infection control in the pulmonary function test laboratory

Pulmonary function testing plays a crucial role in the diagnostic evaluation of patients with lung diseases. Cases of cross infection acquired from the pulmonary function laboratory, although rare, have been reported from various countries. It is therefore imperative to identify the risks and potential organisms implicated in cross infections in a pulmonary function test (PFT) laboratory and implement better and more effective infection control procedures, which will help in preventing cross infections. The infrastructure, the daily patient flow, and the prevalent disinfection techniques used in a PFT laboratory, all play a significant role in transmission of infections. Simple measures to tackle the cross infection potential in a PFT laboratory can help reduce this risk to a bare minimum. Use of specialized techniques and equipment can also be of much use in a set up that has a high turnover of patients. This review aims at creating awareness about the possible pathogens and situations commonly encountered in a PFT laboratory. We have attempted to suggest some relevant and useful infection control measures with regard to disinfection, sterilization, and patient planning and segregation to help minimize the risk of cross infections in a PFT laboratory. The review also highlights the lacuna in the current scenario of PFT laboratories in India and the need to develop newer and better methods of infection control, which will be more user-friendly and cost effective. Further studies to study the possible pathogens in a PFT laboratory and evaluate the prevalent infection control strategies will be needed to enable us to draw more precious conclusions, which can lead to more relevant, contextual recommendations for cross infections control in PFT lab in India.

Risk of bacterial cross infection associated with inspiration through flow-based spirometers

BACKGROUND

Bacterial contamination of spirometers has been documented in water-sealed devices, mouthpieces, and connection tubes. Little information is available about bacterial contamination of flow-based apparatuses such as turbine-type spirometers and pneumotachographs. Inspiration through contaminated equipment is a potential source of cross infection. To investigate bacteria mobilization (ie, bacteria detachment and aerosolization from the instrument) during routine spirometric testing, 2 types of flow-based spirometers were used. Bacteria mobilization during artificial inspiration through in-line filters or cardboard mouthpieces was evaluated.

METHODS

Nine hundred workers undergoing periodic spirometric testing were enrolled at the occupational physician office in 30 sessions of 30 subjects each. The participants were asked to perform a forced vital capacity test in a turbine-type spirometer and in an unheated pneumotachograph fitted with disposable in-line filters or cardboard mouthpieces. To evaluate bacterial mobilization, an artificial inspiration was performed and bacterial growth determined. The bacterial growth analysis was assessed after the first and the thirtieth spirometric tests of each session without disinfecting the instruments between tests. In addition, instrument bacterial contamination was evaluated.

RESULTS

No significant bacterial mobilization and instrument contamination were found in spirometric tests executed with in-line filters. Conversely, a significant bacterial mobilization and instrument contamination were observed in tests performed with cardboard mouthpieces. Differences between the 2 spirometers were not significant.

CONCLUSION

In-line filters may effectively reduce the risk of bacterial cross infection. Inspiration through flow-based spirometers fitted with disposable cardboard mouthpieces is completely safe when combined with spirometer disinfection/sterilization between subjects.

Reducing the risk: the use of placebo respiratory equipment in clinical practice

Placebo respiratory devices, such as inhalers, large volume spacers and peak flow meters provide reli able methods of teaching patients effective drug able methods of teaching patients effective drug delivery techniques and monitoring compliance and treatment progress. Concern has been raised that using such demonstration devices on more than one person may expose patients to the risk of cross-infection with pathogenic organisms. The lack of regulation and guidance on the use and decontamination of placebo devices prompted us to complete a risk assessment, examining the likelihood and consequence of acquisition of pathogens and resultant illness in our respiratory patient group.

Is disinfection of mechanical ventilation tubing needed at home?

INTRODUCTION

Home mechanical ventilation is used to treat chronic alveolar hypoventilation. Maintenance protocols for home ventilation circuits (HVC) remain empirical and unproven. We have investigated (1) the cleanliness and sterility of the HVC used by home ventilated patients and (2) the efficiency of tubing cleaning and decontamination protocols recommended to them and used for 12 months or more.

METHOD

HVC cleanliness was assessed in 39 severe restrictive ventilated patients (16 (T) tracheostomy vs. 23 (N) noninvasive) and in 7 new valves as control. In the first experiment (Exp1), a visual and bacteriologic inspection of the expiratory valve (Eva) was conducted during a consultation in our centre. Eva visual cleanliness was assessed on a 10-point scale and Eva bacteriologic contamination analysis was performed on a dry smear. In the second experiment (Exp2), these analyses were repeated after a cleaning sequence chosen at random, either chemical (ammonium-chlorhexidine complex) (A) or mechanical by dishwasher (B).

RESULTS

In Exp1, 69% of Eva were dirty. Dirtiness was worse in (T) than in (N) (5.3 vs. 2; p<0.001). There was a significant positive correlation between visual cleanliness and bacteriologic contamination (r=0.56; p<0.001). Eva in group (T) were more contaminated than in group (N) (p<0.001). Eva contamination rates reached 22% in group (N) but without the presence of any potentially pathogenic organisms (PPO) and 81% in group (T) where 19% were PPO. In Exp2, EVA visual cleanliness was better after dishwasher cleaning (B) compared to chemical (A) (0.16 vs. 1.05; p<0.001) with similar bacteriological decontamination.

CONCLUSION

HVC from noninvasive ventilated patients are dirty but not contaminated by PPO. We recommend washing them in a dishwasher or with detergent and hot water without specific disinfection. PPO contaminated 1/5 of invasive HVC, for which we recommend dishwasher cleaning. Decontamination is only indicated when tubing is visually very dirty or/and when tracheostomized patients are particularly sensitive to respiratory tract infections. The expiratory valve must be carefully washed specifically, with care that its balloon is not placed under water.

An audit into the efficacy of single use bacterial/viral filters for the prevention of equipment contamination during lung function assessment

Lung function testing has been suggested to provide a potential risk regarding cross-infection between patients. About 155 patients (86 infectious, 69 non-infectious) used a single use bacterial/viral filter when performing routine lung function tests. Swabs from the patient side of the filter (Proximal) and the equipment side (Distal), and two sections of the filter itself were cultured. About 33/155 samples showed bacterial growth on the Proximal compared with 2/155 on the Distal side (P<0.01). Growth was obtained from the filter in 125/155 (80.6%) of cases. Pathogenic micro-organisms such as Pseudomonas aeruginosa (4 cases) and Staphylococcus aureus (5 cases) were isolated. Appropriate infection control measures should be used when performing lung function tests.

How do patients use their nebuliser in the community?

BACKGROUND

Nebulised therapy is commonly used in the management of patients with asthma and chronic obstructive pulmonary disease (COPD). There are guidelines setting out standards for maintenance of the compressor and replacement and care of consumables. This study surveys patients using nebulisers to ascertain the reported use and maintenance of the nebulisers and any side effects related to therapy.

METHODS

An anonymous postal questionnaire, requesting information on nebuliser use and maintenance, and side effects was sent to 200 patients who had been maintained on nebuliser therapy and had been in contact with the nebuliser service at Glasgow Royal Infirmary within the last year.

RESULTS

One hundred and seventeen (58.5%) questionnaires were returned completed or partially completed for analysis. The majority of patients who replied were female (median age of 69 years). The most commonly reported diagnosis was COPD (87/117); 92/117 (79%) were smokers or ex-smokers. The most commonly reported side effects associated with treatment are dry mouth, tremor and chest tightness. The responses to questions on servicing, maintenance and replacement of consumables indicate that patients comply poorly with these activities. Additionally compliance with the prescribed drug regimen occurs in less than 50% of the patient cohort.

CONCLUSIONS

The results of this study indicate that compliance with instructions given on the care and maintenance of home nebulisers may be suboptimal. Additionally patients reported poorer compliance than was predicted. These areas may be improved with the introduction of a new patient information leaflet.