Name: conducting respiratory oscillometry in an outpatient setting
Uploaded: 2022-04-08T14:00:00
Duration: 14 min 49 s
Description: Watch this Scientific Journal Video about Conducting Respiratory Oscillometry in an Outpatient Setting at JoVE.com

The study was funded by CIHR-NSERC Collaborative Health Research Projects (CWC), Pettit Block Term grant (CWC), The Lung Health Foundation, and Canadian Lung Association - Breathing as One: Allied Health Grant (JW). We thank the many participants of our oscillometry research studies who have allowed us to develop expertise in conduct of oscillometry.

The respiratory oscillometry studies were approved by the University Health Network Research Ethics Board (REB# 17-5373, 17-5652 and 19-5582). Written informed consent was obtained from participants prior to oscillometry test.
NOTE: This video outlines the standard operating procedure for oscillometry. Our laboratory uses a device manufactured by Thorasys Thoracic Medical Systems Inc but the technique is the same regardless of the manufacturer. The software programs are different for each manufacturer, in the same way that different commercial spirometers have unique proprietary software for data collection and display. The protocol below is applicable for all respiratory oscillometry devices. Readers are directed to manuals of their commercial devices and refer to specific instructions regarding software of their device.
1. Pre-test patient screening/preparation
<ol>
	<li>Ensure that the patient is free of any active or suspected transmissible respiratory infection, such as coronavirus or tuberculosis.</li>
	<li>Ensure that the patient has not had any recent dental or facial surgeries, such as tooth extractions, and can form a proper tight seal around the mouthpiece.</li>
	<li>Ensure that the patient is as relaxed as possible, is not wearing tight-fitted clothing, and withholds from tobacco use and vigorous exercise at least 1 h prior to testing.</li>
	<li>Perform oscillometry prior to conventional PFTs, such as spirometry, if requested by a referring physician. 
	NOTE: Refer to Supplemental Table 1 for contraindications for spirometry/PFTs.</li>
	<li>Ensure that the patient withholds bronchodilators&#160;prior to testing, unless instructed by a referring physician to continue bronchodilator medication. 
	NOTE: Refer to Supplemental Table 2 for bronchodilator withholding times for PFTs and Supplemental Table 3 for bronchodilator withholding times for the methacholine challenge test.</li>
</ol>
2. Equipment/materials preparation
<ol>
	<li>Equipment preparation
	<ol>
		<li>Verify the resistance load of the oscillometry device by using a valid factory calibrated mechanical test load prior to patient testing.</li>
		<li>Remove the dust caps at both ends of the mechanical test load and attach onto the oscillometry device.</li>
		<li>Select calibration from the oscillometry software menu and proceed with impedance test load verification. 
		NOTE: The recommended tolerance for the verification is &#8804; &#177;10% or &#177;0.1 cmH2O&#183;s/L, whichever is met first.</li>
		<li>Upon successful verification, save and proceed with testing.</li>
	</ol>
	</li>
	<li>Materials preparation
	<ol>
		<li>Have multiple &#39;single-patient-use-bacterial/viral&#39; filters and nose clips readily available.</li>
		<li>Have personal protection equipment (PPE), such as gloves and masks, and disinfectant wipes available. 
		&#8203;NOTE: Refer to laboratory policies for donning and doffing of PPE and infection control guidelines.</li>
	</ol>
	</li>
</ol>
3. Patient preparation
<ol>
	<li>Anthropometry
	<ol>
		<li>Verify the patient&#39;s information: first and last names, date of birth, birth sex, height, weight, and gender identity, if applicable.</li>
		<li>Measure the patient&#39;s height without shoes, with feet together, standing as tall as possible with the eyes level and looking straight ahead, and the back flush against a wall or flat surface. 
		NOTE: For patients unable to stand erect, height may be estimated using arm span. For patients aged 25 years or older, where height measurement has been made previously in the same laboratory, remeasuring height at subsequent visits within 1 year may not be necessary.</li>
		<li>Update weight measurement at each visit.</li>
		<li>Record patient&#39;s usage of bronchodilators, dosage, time/date of last administration, and any medication allergies, such as salbutamol.</li>
	</ol>
	</li>
	<li>Oscillometry test preparation
	<ol>
		<li>Ask the patient to sanitize their hands prior to entering the testing station.</li>
		<li>Outline the test duration of 30 s and the minimum requirement of three trials.</li>
		<li>Explain the sensation generated by the oscillations such as &#39;vibrations&#39; or &#39;fluttering.&#39;</li>
		<li>Ensure that the patient is seated properly in a slight &#39;chin-up&#39; position with both feet on the floor. Avoid slouching against the back of the chair or leg crossing.</li>
		<li>Instruct the patient to breathe normally while holding their cheeks with their palm and fingers and using their thumbs to support the soft tissue of the jaw during measurements. 
		NOTE: Cheek and floor of the mouth support is enforced to avoid upper airway shunt. If the cheeks and soft tissues of the mouth are not supported, flow measured at the mouth is lost in the motion of the upper airway wall.</li>
		<li>Explain to the patient that swallowing should be avoided and the tongue must be below the mouthpiece during the test. 
		&#8203;NOTE: The instructions above apply to both children and adults. Depending on the age of the child, holding a picture or other forms of&#160;visual distraction in front of the child can help ensure that the head posture is maintained during the oscillometry recording period. For adults with cognitive impairment, consider having an accompanying person nearby to coach and calm the patient to breath normally. For patients with physical impairment, some oscillometry devices are portable, and can be brought to the patient bedside or wheelchair. Also consider asking the accompanying or another person to provide cheek and jaw support during tests.</li>
	</ol>
	</li>
</ol>
4. Software setup
NOTE: Please refer to the manufacturer&#39;s instruction manual for individual instructions.
<ol>
	<li>New patient setup
	<ol>
		<li>Select New Patient and enter the patient&#39;s information such as first and last names, date of birth, birth sex, height, weight, ethnicity (if applicable), and smoking history.</li>
		<li>Check that all information entered is correct prior to selecting Standard Test.</li>
		<li>Ensure that the correct wavelength setup is selected. In this demonstration, select Airwave Oscillometry from the Template dropdown menu. The choice of specific wavelengths and wavelength combinations will be different amongst the different manufacturers. Follow the software instruction manual for the specific device.</li>
		<li>Ensure the appropriate set of reference values is selected: Oostveen et al.56 or Brown et al.57 for adults, and Nowowiejska et al.58 for children ages 3 to 17. 
		NOTE: The preferred and availability of reference values may differ depending on each laboratory&#39;s policy and oscillometry device manufacturer.</li>
	</ol>
	</li>
	<li>Existing patient setup
	<ol>
		<li>Click on Select Patient and choose the correct patient&#39;s file by verifying their information such as first and last names and date of birth.</li>
		<li>Ensure patient&#39;s weight and height (if applicable) are updated prior to the start of testing.</li>
		<li>Select Standard Test and choose Airwave Oscillometry from the Template dropdown menu. See also section 4.1.3.</li>
	</ol>
	</li>
</ol>
5. Testing procedure
<ol>
	<li>Oscillometry device setup
	<ol>
		<li>Attach a &#39;single-patient-use-bacterial/viral&#39; filter to the oscillometry device.</li>
		<li>Ensure the oscillometry device is ready in the testing mode.</li>
	</ol>
	</li>
	<li>Spectral measurement 
	NOTE: Airwave oscillometry 5-37 Hz in the device shown in the video.
	<ol>
		<li>Remind the patient of the 30 s test duration and the minimum requirement of three measurements.</li>
		<li>Instruct the patient to wear a nose clip and provide instructions described in step 3.2.4 and step 3.2.5.</li>
		<li>Adjust the oscillometry device to the patient&#39;s head level.</li>
		<li>Instruct the patient to wet his/her lips before wrapping them around the mouthpiece to form a proper, tight seal. Instruct the patient to begin to breathe normally. 
		NOTE: Inspect for potential air leaks around the mouthpiece and nose clip. Supplementary oxygen must be turned off during measurements to avoid any drift into the oscillometry device.</li>
		<li>Observe the patient&#39;s breathing pattern and start recording following a minimum of three stable tidal breaths. 
		NOTE: (Optional): During the test, inform the patient of the time remaining during each measurement.</li>
		<li>Provide adequate rest time in between each measurement and adjust accordingly, based on the patient. 
		NOTE: Patients on supplemental oxygen may require longer rest intervals. Provide supplemental oxygen as needed during the rest intervals.</li>
		<li>Following a minimum of three measurements, proceed to Step 6 to assess acceptability and reproducibility.</li>
	</ol>
	</li>
	<li>Post-bronchodilator response - optional
	<ol>
		<li>Administer bronchodilator (salbutamol or ipratropium bromide) via a spacer.</li>
		<li>Record the method and number of doses administered.</li>
		<li>Wait for 10 min post-salbutamol/albuterol and 20 min post-ipratropium bromide inhalation.</li>
		<li>Repeat Step 5.2 to assess post-bronchodilator response</li>
	</ol>
	</li>
	<li>10 Hz (intra-breath) measurement - optional
	<ol>
		<li>Remind the patient that each test duration is 30 s and a minimum of three measurements will be obtained.</li>
		<li>Ensure that the correct wavelength setup for intra-breath measurement is selected.</li>
		<li>Repeat Steps 5.2.2 to 5.2.6.</li>
	</ol>
	</li>
</ol>
6. Access acceptability and reproducibility
<ol>
	<li>Acceptability
	<ol>
		<li>Ensure that the measurements have a validity greater than 70%.</li>
		<li>Check that the symbol beside the measurements have obtained a checkmark. 
		NOTE: If a &#39;Caution&#39; symbol is present, the measurement is unacceptable.</li>
		<li>Inspect each measurement for anomalies or artefacts that may be caused by coughing, tongue obstruction, glottis closure, air leakage around the mouthpiece, attempting to talk, swallowing, and taking a deep breath. 
		NOTE: If the patient is observed taking a deep breath, reset the oscillometry device, as forceful breaths disrupt the motors and the quality of subsequent measurements. To reset, stop testing and then click Zero Channels.</li>
		<li>Review measurements automatically excluded by the software; these include anomalies or artefacts such as cough or glottis closure.</li>
		<li>Exclude any unacceptable measurement with anomalies outlined in Step 6.1.3 and repeat Step 5.2 to obtain additional measurements.</li>
	</ol>
	</li>
	<li>Reproducibility
	<ol>
		<li>Ensure that a minimum of three acceptable measurements are recorded.</li>
		<li>Ensure that the coefficient of variance (CoV) of Rrs (resistance of respiratory system) is &#8804;10% in adults and &#8804;15% in children.</li>
		<li>Repeat Step 5.2 to obtain additional measurements if the 3 acceptable measurements have CoV &#62;10% in adults and &#62;15% in children.</li>
		<li>Repeat 6.1 to determine acceptability and report three acceptable measurements with CoV &#8804;10% in adults and &#8804;15% in children.</li>
	</ol>
	</li>
</ol>
7. Disinfection
<ol>
	<li>Discard patient&#39;s mouthpiece and nose clip into the wastebin.</li>
	<li>Use disinfectant wipes to clean the oscillometry device and patient&#39;s chair.</li>
	<li>Doff gloves and sanitize hands.</li>
	<li>Place the red dust cap back onto the oscillometry device to avoid any contamination. 
	NOTE: Each laboratory&#39;s infection control policy may be different.</li>
</ol>
8. Reporting results
NOTE: Refer to Figure 3 for details.
<ol>
	<li>Include patient&#39;s first and last names, height, weight, age, birth sex, BMI, and smoking history.</li>
	<li>Include device name, model, software version, and manufacturer.</li>
	<li>Include input signal frequencies and duration of individual recordings.</li>
	<li>Report the mean of acceptable and reproducible measurements and the CoV for these reported measurements. 
	NOTE: If the CoV is higher than the specified upper limit, the results should be flagged so that the interpreting physician may interpret the results with caution.</li>
	<li>Select reference equations.</li>
	<li>Include impedance graph demonstrating Rrs and Xrs versus oscillation frequency.</li>
	<li>Include post-bronchodilator response with dosage and method of administration including z-scores and absolute percentage change - optional</li>
</ol>
9. Quality control/quality assurance
<ol>
	<li>Perform regular audits (weekly or monthly) depending on the volume of oscillometry testing in the laboratory.</li>
	<li>Assess each operator using a standardized checklist to ensure oscillometry tests are conducted accurately and professionally.</li>
	<li>Provide regular feedback to operators and hold quarterly quality assurance meetings to reflect on laboratory matters.</li>
	<li>Ensure biologic&#160;quality controls are conducted weekly with at least two healthy non-smoking subjects, and measurements are within &#177;2SD of their mean baseline. 
	NOTE: This is extremely important for validating testing equipment and procedures when there are multiple oscillometry devices in the laboratory.</li>
	<li>Conduct quarterly self-inspection and annual factory maintenance of oscillometry devices for calibration and quality checks.</li>
</ol>

CWC has received speaking fees for webinars supported by Thorasys Thoracic Medical Systems Inc. and consulting fees from Theravance Biopharma, Inc.

The critical steps in a high quality oscillometry measurement can be categorized into the domains of patient, equipment, and operator. Ensuring that the patient is relaxed and comfortable so that the measurements collected are at resting functional residual volume is key. The patient posture is very important; ensure that the patient is sitting upright with both feet on ground with no crossing of legs. The enforcement of cheek and jaw support, good placement of the nose clip, and ensuring lips are sealed around the mouthpiece will eliminate shunting and air leaks1,2,3. The equipment must be calibrated and verified prior to use. The operator must be able to recognize acceptable and unacceptable recordings and able to troubleshoot the underlying cause of unacceptable readings or artefacts to ensure reported measurements have CoV &#8804;10%1,2,3. Quality control and assurance must be maintained to not only ensure the oscillometry device is validated, but also the quality of tests.
Training of the operator to recognize the patterns produced by common artefacts such as swallowing, leaks, and shunting will allow for timely repeated measurements to obtain quality tests. There are instances when oscillometry is performed at different lung volumes, (e.g., in supine position). Under these circumstances, all the steps described in the protocol can still be applied.
While oscillometry is an easier and more rapid modality of pulmonary function testing, errors in measurements, and thus interpretation, will occur if deviations from the standardized protocol and quality control steps occur. Our protocol is based on the device used at our center. The conduct of oscillometry will be the same across devices. However, there will be differences in the technical aspect of calibration and software applications. Readers are advised to follow the manual for the different instruments.
Oscillometry is faster and easier to perform than spirometry. Moreover, young children and adults with language, physical, and/or cognitive impairment that impede the ability to perform the forced expiratory maneuvers needed for spirometry can still perform oscillometry as it is conducted during normal breathing. In some centers, oscillometry has supplanted spirometry as the initial screening tool for lung disease. Enhancing training in the conduct of oscillometry will facilitate its wider application as a diagnostic tool and ensure quality control of the tests conducted.
Although oscillometry is a fast and easy technique, quality controls are needed to ensure accurate and reproducible measurements. By following international guidelines, research and clinical oscillometry data can be interpreted appropriately so that findings can be applied across different patient populations.

Respiratory oscillometry measures the impedance of the lung and is exquisitely sensitive to changes in respiratory mechanics1, particularly to the peripheral lung and small airways, regions of the lung that are not well assessed by traditional pulmonary function tests.
Over the last several years, the availability of commercial devices and updated technical and quality control/assurance standards2,3 have led to increasing use of oscillometry for clinical and research purposes. However, to date it is not a routine test in the repertoire of pulmonary function modalities, but the technique is anticipated to become more widely used with increasing recognition of its clinical utility. The overall goal of respiratory oscillometry is to provide measurement of respiratory mechanics during normal breathing and assessment of lung function, that is not discernible by current methods of spirometry and plethysmography. Oscillometry offers other advantages over traditional pulmonary function tests as it can be performed in the very young, the elderly, or in patients with cognitive impairment where forced expiratory maneuvers needed for spirometry are impossible. Furthermore, oscillometry can be conducted in anyone who can breathe spontaneously while wearing a nose clip. Unlike standard pulmonary function tests, it is not contraindicated following cataract, intra-abdominal or cardiothoracic surgery, nor following acute myocardial infarction and heart failure. Lastly, several of the oscillometry devices currently available are portable, and can be used in settings outside of a diagnostic laboratory, including clinic and office settings, bedside, or in workplaces.
Oscillometry measures the total respiratory impedance (Zrs) to multi-frequency oscillatory pressure waves1,2,4,5,6. Impedance is composed of the complex sum of respiratory resistance (Rrs) and reactance (Xrs). Rrs reflects the resistance of airways and is largely frequency-independent in health4,7,8. In small airway diseases, Rrs becomes frequency-dependent and increases more in the lower frequencies5,9,10, so that a difference in Rrs&#160;at frequencies between 5 and 19 Hz (R5-19) or 5 and 20 Hz (R5-20) indicates small airway obstruction and heterogeneity of ventilation in different regions of the lung 10,11,12.&#160;Xrs measures the balance of elastic and inertial impedances of the respiratory system. At lower frequencies (e.g., 5 to 11 Hz), Xrs reflects the stiffness or elastance of the pulmonary and chest wall tissues13,14. At higher frequencies, Xrs is dominated by the inertia of the air column in the conducting airways. The resonance frequency (Fres) is the point at which the magnitudes of elastic and inertive reactance are equal. AX is an integrative index of Xrs and is calculated as the area under the Xrs versus frequency graph between 5 Hz and Fres. AX has the units of elastance and is inversely related to the volume of the lung in communication with ventilation. AX increases with restrictive processes and peripheral inhomogeneity. X5 becomes increasingly negative while AX and Fres are increased in both obstructive and restrictive lung diseases4,5. See Figure 1 for depiction of these metrics.
While initially focused on measurement of lung function in children, emerging data show that oscillometry provides useful clinical information in adults as well. It is increasingly used in the clinical setting15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45. Oscillometry has been most extensively studied in obstructive lung diseases where it has been found to offer better diagnostic information than spirometry with respect to asthma control31,32,33,34,35, better correlation with symptoms23,34, and earlier detection36,37,38 of chronic obstructive lung disease (COPD). Our group has shown oscillometry to be more sensitive than spirometry for tracking graft injury following lung transplant46. Several studies have shown that Xrs, specifically&#160;the difference in the mean inspiratory and expiratory reactance at 5 Hz, can distinguish restrictive defects in interstitial lung disease (ILD) from asthma and COPD47, and can differentiate combined pulmonary fibrosis and emphysema from ILD-only48,49. Figure 2 demonstrates the typical oscillometry patterns for normal, restrictive, and obstructive lung diseases. There has been increasing interest to implement oscillometry as another routine modality of pulmonary function testing to supplement and potentially replace some of the current testing modalities for lung function monitoring50,51.
We suggest that oscillometry is useful for screening of lung diseases, in follow-up of patients with known obstructive and restrictive lung diseases, and following lung transplant. The commercial devices are suitable for use in children as young as 2 years old. There is ongoing research with even younger populations52, and as the field grows it may be possible to evaluate infants and newborns.
The goal of the current manuscript is to provide a training manual for clinicians, technologists, and research personnel on the appropriate conduct of oscillometry, following international standard operating protocols and quality control guidelines. Due to the small footprint of most commercial oscillometers, oscillometry can be implemented in multiple settings. The protocol outlined is appropriate for pulmonary function laboratories, physician offices, clinic settings, and other outpatient settings such as workplace occupational health units.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Accel Prevention Disinfectant wipes - 160/canister</td>
			<td>Diversey Care</td>
			<td>100906721</td>
			<td>https://diversey.com/en/</td>
		</tr>
		<tr>
			<td>clearFlo F-100 - 100 Airwave Oscillometry filters</td>
			<td>Thorasys</td>
			<td>101635</td>
			<td>https://www.thorasys.com/</td>
		</tr>
		<tr>
			<td>Noseclip w/cushions, &#34;Snuffer&#34;, bx/1000</td>
			<td>McArthur Medical Sales Inc.</td>
			<td>785-1008BULK</td>
			<td>https://mcarthurmedical.com/</td>
		</tr>
		<tr>
			<td>Tremoflo C-100 Airwave Oscillometry System</td>
			<td>Thorasys</td>
			<td>101969</td>
			<td>https://www.thorasys.com/ 
			Software verison: 1.0.43 build 43 
			Signal Type: Pseudo-random, relative primes 
			Frequencies (Hz): 5, 10, 11, 14, 17, 19, 23, 29, 31, 37</td>
		</tr>
		<tr>
			<td>Tremoflo C-100 Calibrated Reference Load 15 cm H2O. s/L</td>
			<td>Thorasys</td>
			<td>101059</td>
			<td>https://www.thorasys.com/</td>
		</tr>
	</tbody>
</table>

conducting respiratory oscillometry in an outpatient setting

Respiratory oscillometry is a different modality of pulmonary function testing that is increasingly used in a clinical and research setting to provide information regarding lung mechanics. Respiratory oscillometry is conducted through three acceptable measurements of tidal breathing and can be performed with minimal contraindications. Young children and patients who cannot perform spirometry due to cognitive or physical impairment can usually complete oscillometry. The main advantages of respiratory oscillometry are that it requires minimal patient cooperation and is more sensitive in detecting changes in small airways than conventional pulmonary function tests. Commercial devices are now available. Updated technical guidelines, standard operating protocols, and quality control/assurance guidelines have recently been published. Reference values are also available. 
We conducted oscillometry test audits before and after implementing a formal respiratory oscillometry training program and standard operating protocol. We observed improvement in the quality of tests completed, with a significant increase in the number of acceptable and reproducible measurements. 
The current paper outlines and demonstrates a standard operating protocol to conduct respiratory oscillometry in an outpatient setting. We highlight the key steps to ensuring acceptable and reproducible quality measurements according to the recommended European Respiratory Society (ERS) guidelines, as quality control is critical to measurement accuracies. Potential problems and pitfalls are also discussed with suggestions to resolve technical errors.

From October 17, 2017 to April 6, 2018, we conducted the first quality assurance/quality control (QA/QC) audit of the 197 oscillometry tests3. Although all of the operators were trained prior to testing patient with a one hour seminar and on-site testing, 10 (5.08%) unacceptable and/or irreproducible measurements were identified. These measurements were excluded due to cough, tongue obstruction, and CoV greater than 15% following the initial suggested ERS guidelines52. Biologic&#160;quality control (BioQC) was not conducted regularly. The research personnel underwent additional oscillometry training and developed a standard operating protocol to ensure proper ERS guidelines and medical professionalism were in place. The importance of BioQC, a tool to validate testing equipment and procedures, was highlighted to the research personnel, who were reminded to perform regular BioQC tests.3 Improvements were found in subsequent QA/QC audits. Out of the total of 1930 oscillometry tests conducted from April 9, 2018 to June 30, 2019, only three (0.0016%) tests were invalid measurements; these had CoV greater than 15%. Between July 2, 2019 and March 12, 2020, there were 1779 oscillometry tests performed and nine (0.005%) were considered unacceptable, including measurements that had glottis closure, air leakage, and CoV greater than 15%. Refer to Table 1 for additional information.
Since the reinforcement of BioQC in April 2018, research personnel conducted BioQC regularly. At our center, four healthy non-smoking individuals conducted oscillometry daily for the initial 2 weeks to gather a minimum of 10 measurements with the mean with the upper and lower limit (&#177;2SD or standard deviation) with coefficient of variation &#8804;10% between Rrs in the two oscillometry devices in our laboratory. On August 30, 2021, we observed a BioQC measurement that fell outside the individual&#39;s mean &#177;2SD. The individual&#39;s observed R5 was 3.36 cmH2O&#183;s/L (open circle), while R5 mean from the 20 most recent recordings was 4.95 cmH2O.s/L &#177;2SD (dotted line with lower limit at 4.03 and upper limit at 5.86; Figure 4). A second individual conducted their BioQC oscillometry on the same day with the same oscillometry device, and the observed R5 measurement was also outside the mean &#177;2SD. These findings indicate problems related to the instrument rather that than the procedure. Subsequently, the manufacturer was contacted and the device was sent for repair. Upon return of the device, BioQC was repeated on October 15, 2021 to ensure it was within the individual&#39;s R5 measurement range prior to redeployment of device in our laboratory.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63243/63243fig01.jpg" /> 
Figure 1: The impedance versus frequency oscillogram with the resistance curve (solid line) and reactance curves (dotted line), and frequencies at which the measurements are made (solid and open circles in each curve) shown. The area of reactance (AX, hatched area), resonant frequency (Fres. X), and resistance between 5 Hz to 19 Hz (R5-19; two-sided arrow) are illustrated. <a href="https://www.jove.com/files/ftp_upload/63243/63243fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/63243/63243fig02.jpg" /> 
Figure 2: The typical oscillometry pattern differences between normal (A), restrictive (B) and obstructive (C) lung diseases. Note the rightward shift of the reactance curve (open circle, dotted line) in the restrictive disease (B), and the trumpet shaped pattern of the obstructive oscillogram (C) with upward shift of the resistance curve (solid circle and line), increased R5-19, and the downward and rightward shift of the resistance curve (broken line; open circles). <a href="https://www.jove.com/files/ftp_upload/63243/63243fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/63243/63243fig03.jpg" /> 
Figure 3: The standard template for reporting of oscillometry in our institution. We display the oscillogram using a standardized X-Y axis, and highlight the relevant pre- and post-bronchodilator measurements in different colors to facilitate interpretation of the results. <a href="https://www.jove.com/files/ftp_upload/63243/63243fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/63243/63243fig04v2.jpg" /> 
Figure 4: The biologic&#160;quality control (BioQC) summary of R5 measurements from one individual from May 2020 to November 2021. The measurement that fell outside (open circle) the individual&#39;s mean (solid grey line) &#177;2SD (dotted line) was observed in August 30, 2021. <a href="https://www.jove.com/files/ftp_upload/63243/63243fig04largev2.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td rowspan="2"></td>
			<td>First Audit</td>
			<td>Second Audit</td>
			<td>Third Audit</td>
		</tr>
		<tr>
			<td>October 17, 2017 to April 6, 2018</td>
			<td>April 9, 2018 to June 30, 2019</td>
			<td>July 2, 2019 to March 12, 2020</td>
		</tr>
		<tr>
			<td>Valid</td>
			<td>187</td>
			<td>1927</td>
			<td>1770</td>
		</tr>
		<tr>
			<td>Invalid</td>
			<td>10</td>
			<td>3</td>
			<td>9</td>
		</tr>
	</tbody>
</table>
Table 1: Comparison of oscillometry tests acceptability at three time-points 
Personnel underwent refresher training in conduct of oscillometry following the first audit. We also implemented a standard operating protocol for conduct of oscillometry in the pulmonary function laboratory. Significant improvements in the percentage of tests meeting acceptable quality control occurred and were sustained over time. These results demonstrate the effectiveness of developing and adhering to standard operating protocols and quality control guidelines.
Supplemental Table 1. Contraindications for Spirometry53,54 <a href="https://www.jove.com/files/ftp_upload/63243/STable1.xlsx" target="_blank">Please click here to download this Table.</a>
Supplemental Table 2. Bronchodilators Withholding Times for Pulmonary Function Tests53,54 <a href="https://www.jove.com/files/ftp_upload/63243/STable2.xlsx" target="_blank">Please click here to download this Table.</a>
Supplemental Table 3. Bronchodilators Withholding Times for Bronchial Challenge Test53,55 <a href="https://www.jove.com/files/ftp_upload/63243/STable3.xlsx" target="_blank">Please click here to download this Table.</a>

Watch this Scientific Journal Video about Conducting Respiratory Oscillometry in an Outpatient Setting at JoVE.com

Conducting Respiratory Oscillometry in an Outpatient Setting

We demonstrate a standard operating protocol to conduct respiratory oscillometry, highlighting key quality control and assurance procedures.

Respiratory oscillometry is a different modality of pulmonary function testing that is increasingly used in a clinical and research setting to provide ...

conducting-respiratory-oscillometry-in-an-outpatient-setting

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Unit 1

An Overview of the Respiratory System: Anatomy, Physiology, Assessment, and Abnormalities

Vital Signs: Respiration

SCIENTISTS IN ACTION

Using Quantitative Real-time PCR to Determine Donor Cell Engraftment in a Competitive Murine Bone Marrow Transplantation Model

Murine bone marrow transplantation models provide an important tool in measuring hematopoietic stem cell (HSC) functions and determining genes/molecules that regulate HSCs. In these transplant model systems, the function of HSCs is determined by the ability of these cells to engraft and reconstitute lethally irradiated recipient mice. Commonly, the donor cell contribution/engraftment is measured by antibodies to donor- specific cell surface proteins using flow cytometry. However, this method heavily depends on the specificity and the ability of the cell surface marker to differentiate donor-derived cells from recipient-originated cells, which may not be available for all mouse strains. Considering the various backgrounds of genetically modified mouse strains in the market, this cell surface/ flow cytometry-based method has significant limitations especially in mouse strains that lack well-defined surface markers to separate donor cells from congenic recipient cells. Here, we reported a PCR-based technique to determine donor cell engraftment/contribution in transplant recipient mice. We transplanted male donor bone marrow HSCs to lethally irradiated congenic female mice. Peripheral blood samples were collected at different time points post transplantation. Bone marrow samples were obtained at the end of the experiments. Genomic DNA was isolated and the Y chromosome specific gene, Zfy1, was amplified using quantitative Real time PCR. The engraftment of male donor-derived cells in the female recipient mice was calculated against standard curve with known percentage of male vs. female DNAs. Bcl2 was used as a reference gene to normalize the total DNA amount. Our data suggested that this approach reliably determines donor cell engraftment and provides a useful, yet simple method in measuring hematopoietic cell reconstitution in murine bone marrow transplantation models. Our method can be routinely performed in most laboratories because no costly equipment such as flow cytometry is required.

Determining donor cell engraftment presents a challenge in mouse bone marrow transplant models that lack well-defined phenotypical markers. We described a methodology to quantify male donor cell engraftment in female transplant recipient mice. This method can be used in all mouse strains for the study of HSC functions.

Murine bone marrow transplantation models provide an important tool in measuring hematopoietic stem cell (HSC) functions and determining genes/molecules ...

Setting Up a Stroke Team Algorithm and Conducting Simulation-based Training in the Emergency Department - A Practical Guide

Time is of the essence when caring for an acute stroke patient. The ultimate goal is to restore blood flow to the ischemic brain. This can be&#160;achieved by either&#160;thrombolysis with recombinant tissue-plasminogen activator (rt-PA), the standard therapy for stroke patients who present within the first hours of symptom onset without contraindications, or by an endovascular approach, if a proximal brain vessel occlusion is detected. As the efficacy of both therapies declines over time, every minute saved along the way will improve the patient&#39;s outcome.
This critical situation requires thorough work and precise communication with the patient, the family and colleagues from different professions to acquire all relevant information and reach the right decision while carefully monitoring the patient. This is a high fidelity situation. In nonmedical high-fidelity environments such as aviation, Crew Resource Management (CRM) is used to enhance safety and team efficiency.
This guide shows how a Stroke Team algorithm, which is transferable to other hospital settings, was established and how regular simulation-based trainings were performed. It requires determination and endurance to maintain these time-consuming simulation trainings on a regular basis over the course of time. However, the resulting improvement of team spirit and excellent door-to-needle times will benefit both the patients and the work environment in any hospital.
A dedicated Stroke Team of 7 persons who are notified 24/7 by a collective call via speed dial and run a binding algorithm that takes approximately 20 min, was established. To train everybody involved in this algorithm, a simulation-based team training for all new Stroke Team members was conceived and conducted at monthly intervals. This led to a relevant and sustained reduction of the mean door-to-needle time to 25 min, and enhanced the feeling of stroke readiness especially in junior doctors and nurses.

Every min counts in acute stroke care. This guide shows how to establish a Stroke Team algorithm and enhance its performance with regular simulation training. The principles of Crew Resource Management (CRM) facilitate a straight workflow, reduce door-to-needle times and increase staff satisfaction.

Time is of the essence when caring for an acute stroke patient. The ultimate goal is to restore blood flow to the ischemic brain. This can ...

A Component-resolved Diagnostic Approach for a Study on Grass Pollen Allergens in Chinese Southerners with Allergic Rhinitis and/or Asthma

Sensitization to grass pollen imposes a global risk for allergic airway diseases. Although prevention relies on local investigation of the pollen allergens, data on this topic are limited in southern China. Any available data were obtained by self-report questionnaires, skin prick tests, and total or specific IgE tests using crude extracts. For many reasons, these methods are unreliable. Serum sIgE reactivity to Bermuda grass, Timothy grass, and Humulus scandens allergens in a cohort of patients from Greater Guangzhou (southern China&#39;s largest city and its outskirts) with allergic rhinitis and/or asthma were examined using a fully-automated immunoassay analyzer as a component-resolved diagnostics (CRD) tool.
For the first time, a considerably high prevalence of Bermuda grass sIgE positivity was demonstrated in Chinese southerners with allergic rhinitis and/or asthma. In these patients, a subtle prevalence of sensitization to Timothy grass and Humulus scandens was also noted, which may arise from cross-reactivity, as the latter two are not common in the region. This was also supported by the detection of allergen components.
Fully-automated immunoassay analyzers may offer satisfactory consistency between regions, laboratories, and institutions and over time. The automaticity of the instrument may enable a standardized detection that would not have been readily revealed before the advent of CRD.
This is a study that uses a CRD approach to investigate sensitization to grass pollen allergens in southern China. It adds to current evidence in the literature. Future studies are needed to validate these findings. However, although CRD is a useful tool, the findings made with the fully-automated immunoassay analyzer should not substitute for other laboratory investigations, clinical evaluations, and physician expertise.

This work describes a protocol that uses a component-resolved approach to study sensitization to grass pollen allergens in a cohort of patients from southern China with allergic rhinitis and/or asthma.

Sensitization to grass pollen imposes a global risk for allergic airway diseases. Although prevention relies on local investigation of the pollen ...

An Improved and High Throughput Respiratory Syncytial Virus (RSV) Micro-neutralization Assay

Respiratory syncytial virus-specific neutralizing antibodies (RSV NAbs) are an important marker of protection against RSV. A number of different assay formats are currently in use worldwide so there is a need for an accurate and high-throughput method for measuring RSV NAbs. We describe here an imaging-based micro-neutralization assay that has been tested on RSV subgroup A and can also be adapted for RSV subgroup B and different sample types. This method is highly reproducible, with inter-assay variations for the reference antiserum being less than 10%. We believe this assay can be readily established in many laboratories worldwide at relatively low cost. Development of an improved, high-throughput assay that measures RSV NAbs represents a significant step forward for the standardization of this method internationally as well as being critical for the evaluation of novel RSV vaccine candidates in the future.

An Improved and High Throughput Respiratory Syncytial Virus RSV Micro-neutralization Assay

This study describes a high throughput, imaging-based micro-neutralization assay to determine the titer of neutralizing antibodies specific for respiratory syncytial virus (RSV). This assay format has been tested on different sample types.

Respiratory syncytial virus-specific neutralizing antibodies (RSV NAbs) are an important marker of protection against RSV. A number of different assay ...

Application of Lucilia sericata Larvae in Debridement of Pressure Wounds in Outpatient Settings

Biological therapy using Lucilia sericata larvae has numerous advocates worldwide, yet it is still fairly unknown and not commonly applied in daily practice because of the limited awareness and insufficient experience of medical and nursing personnel. There are case reports suggesting that maggot therapy can be applied and supported by lay caregivers, provided they are supervised and informed by physicians/nurses. The foregoing observation suggests that the method should be considered for implementation by a wider group of caregivers if accepted and meticulously supervised by trained and experienced medical staff. The concerns related to the therapeutic use of maggots in certain regions seem understandable, but are not supported by scientific facts. It should be noted that many therapeutic agents (including brood) used in medicine are of natural origin, and are associated with low production costs and high possibilities of implementation in the course of therapy. By analyzing the literature and using our own clinical and research experience, we have come to conclusions related to using larvae therapy, as a quick and safe method providing cleaning and revitalization in the process of treating wounds of various etiologies, especially pressure ulcers. In the current study, medical-grade Lucilia sericata maggots were applied to remove necrotic tissue from deep pressure sores. The treatment is mostly accepted by both caregivers and patients. In most cases, it is conducted by trained and experienced medical personnel in home and outpatient settings. Over the course of the conducted analyzes involving the collected specimens, there were no statistically significant relationships (p&gt; 0.05) confirmed between the wound surface successfully cleared by brood and variables, such as time from wound formation, location, surface size, and the depth of damage to the tissue structure. The lack of statistical dependence may result from the small size of the studied group. Based on the current findings, we have formulated the following conclusions: Maggot Debridement Therapy (MDT) is a fast and effective method enabling the preparation of the wound bed. The use of MDT in outpatient settings is safe and acceptable for patients and their caregivers.

Application of Lucilia sericata Larvae in Debridement of Pressure Wounds in Outpatient Settings

Maggots of Lucilia sericata were used in the debridement of deep pressure sores in outpatient settings for the treatment of pressure sores involving the complete skin thickness. The technique presented in the article does not pose risks for the patient.

Biological therapy using Lucilia sericata larvae has numerous advocates worldwide, yet it is still fairly unknown and not commonly applied in daily ...

3D Reconstruction for the Diagnosis and Treatment of Pulmonary Nodules

A 3D Digital Model for the Diagnosis and Treatment of Pulmonary Nodules

The three-dimensional (3D) reconstruction of pulmonary nodules using medical images has introduced new technical approaches for diagnosing and treating pulmonary nodules, and these approaches are progressively being acknowledged and adopted by physicians and patients. Nonetheless, constructing a relatively universal 3D digital model of pulmonary nodules for diagnosis and treatment is challenging due to device differences, shooting times, and nodule types. The objective of this study is to propose a new 3D digital model of pulmonary nodules that serves as a bridge between physicians and patients and is also a cutting-edge tool for pre-diagnosis and prognostic evaluation. Many AI-driven pulmonary nodule detection and recognition methods employ deep learning techniques to capture the radiological features of pulmonary nodules, and these methods can achieve a good area under-the-curve (AUC) performance. However, false positives and false negatives remain a challenge for radiologists and clinicians. The interpretation and expression of features from the perspective of pulmonary nodule classification and examination are still unsatisfactory. In this study, a method of continuous 3D reconstruction of the whole lung in horizontal and coronal positions is proposed by combining existing medical image processing technologies. Compared with other applicable methods, this method allows users to rapidly locate pulmonary nodules and identify their fundamental properties while also observing pulmonary nodules from multiple perspectives, thereby providing a more effective clinical tool for diagnosing and treating pulmonary nodules.

Author Spotlight: A 3D Digital Model for the Diagnosis and Treatment of Pulmonary Nodules  

The objective of this study is to develop a novel 3D digital model of pulmonary nodules that serves as a communication bridge between physicians and patients and is also a cutting-edge tool for pre-diagnosis and prognostic evaluation.

The three-dimensional (3D) reconstruction of pulmonary nodules using medical images has introduced new technical approaches for diagnosing and treating ...

Enhancing Pulmonary Nodule Diagnosis Using Whole-Lung 3D Reconstruction

Three-Dimensional Reconstruction for the Whole Lung with Early Multiple Pulmonary Nodules

For patients with early multiple pulmonary nodules, it is essential, from a diagnostic perspective, to determine the spatial distribution, size, location, and relationship with surrounding lung tissue of these nodules throughout the entire lung. This is crucial for identifying the primary lesion and developing more scientifically grounded treatment plans for doctors. However, pattern recognition methods based on machine vision are susceptible to false positives and false negatives and, therefore, cannot fully meet clinical demands in this regard. Visualization methods based on maximum intensity projection (MIP) can better illustrate local and individual pulmonary nodules but lack a macroscopic and holistic description of the distribution and spatial features of multiple pulmonary nodules.
Therefore, this study proposes a whole-lung 3D reconstruction method. It extracts the 3D contour of the lung using medical image processing technology against the background of the entire lung and performs 3D reconstruction of the lung, pulmonary artery, and multiple pulmonary nodules in 3D space. This method can comprehensively depict the spatial distribution and radiological features of multiple nodules throughout the entire lung, providing a simple and convenient means of evaluating the diagnosis and prognosis of multiple pulmonary nodules.

Author Spotlight: Advancing 3D Modeling for Enhanced Diagnosis and Treatment of Pulmonary Nodules in Early-Stage Lung Cancer 

This study introduces a three-dimensional (3D) reconstruction method for the entire lung in patients with early multiple pulmonary nodules. It offers a comprehensive visualization of nodule distribution and their interplay with lung tissue, simplifying the assessment of diagnosis and prognosis for these patients.

For patients with early multiple pulmonary nodules, it is essential, from a diagnostic perspective, to determine the spatial distribution, size, location, ...

Assessing Leg Blood Flow in Training Workloads

Doppler Ultrasound-Based Leg Blood Flow Assessment During Single-Leg Knee-Extensor Exercise in an Uncontrolled Setting

Doppler ultrasound has revolutionized the assessment of organ blood flow and is widely used in research and clinical settings. While Doppler ultrasound-based assessment of contracting leg muscle blood flow is common in human studies, the reliability of this method requires further investigation. Therefore, this study aimed to investigate the within-day test-retest, between-day test-retest, and inter-rater reliability of Doppler ultrasound for assessing leg blood flow during rest and graded single-leg knee-extensions (0 W, 6 W, 12 W, and 18 W), with the ultrasound probe being removed between measurements. The study included thirty healthy subjects (age: 33 &#177; 9.3, male/female: 14/16) who visited the laboratory on two different experimental days separated by 10 days. The study did not control for major confounders such as nutritional state, time of day, or hormonal status. Across different exercise intensities, the results demonstrated high within-day reliability with a coefficient of variation (CV) ranging from 4.0% to 4.3%, acceptable between-day reliability with a CV ranging from 10.1% to 20.2%, and inter-rater reliability with a CV ranging from 17.9% to 26.8%. Therefore, in a real-life clinical scenario where controlling various environmental factors is challenging, Doppler ultrasound can be used to determine leg blood flow during submaximal single-leg knee-extensor exercise with high within-day reliability and acceptable between-day reliability when performed by the same sonographer.

Author Spotlight: Assessing the Reliability of Doppler Ultrasound in Measuring Leg Blood Flow 

This test-retest study evaluated leg blood flow measured by the Doppler ultrasound technique during single-leg knee-extensor exercise. The within-day, between-day, and inter-rater reliability of the method was investigated. The approach demonstrated high within-day and acceptable between-day reliability. However, the inter-rater reliability was unacceptably low during rest and at low workloads.

Doppler ultrasound has revolutionized the assessment of organ blood flow and is widely used in research and clinical settings. While Doppler ...

Enhancing Pulmonary Infection Treatment Using M-ROSE

Microbiological Rapid On-Site Evaluation for Pulmonary Infectious Diseases

The prompt initiation of empirical anti-infective therapy is crucial in patients presenting with unexplained pulmonary infection. Although imaging acquisition is relatively straightforward in clinical practice, its lack of specificity often necessitates additional time-consuming tests such as sputum culture, bronchoalveolar-lavage fluid culture, or genetic sequencing to identify the underlying etiology of the disease accurately. Moreover, the limited efficacy of empirical anti-infective treatment may contribute to antibiotic misuse. Recent advancements in interpreting microbial background on rapid on-site evaluation (ROSE) slides have enabled clinicians to promptly obtain samples through bronchoscopy (e.g., alveolar lavage, mucosal brushing, tissue clamp), facilitating bedside staining and interpretation that provides essential microbial background information. Consequently, this establishes a foundation for developing targeted anti-infection treatment and individualized drug therapy plans. With a better understanding of which pathogens are causing infections in real-time, physicians can avoid unnecessary broad-spectrum antibiotics contributing to antibiotic resistance. Establishing a rapid and standardized M-ROSE workflow within respiratory medicine departments or intensive care units will greatly assist physicians in formulating accurate treatment strategies for patients, which holds significant clinical implications.

Author Spotlight: Advancing Pathogen Detection and Disease Assessment in Real-Time Using M-ROSE

The protocol here demonstrates a fast and standardized microbiological rapid on-site evaluation (M-ROSE) workflow, including three steps: slide making, staining, and interpretation. This protocol will help physicians make rapid clinical decisions.

The prompt initiation of empirical anti-infective therapy is crucial in patients presenting with unexplained pulmonary infection. Although imaging ...

Traditional Chinese Medicine Ear Point Therapy for Wheezing in COPD Patients

Auricular Acupressure as an Adjuvant Treatment for Wheezing in Stable Chronic Obstructive Pulmonary Disease 

Chronic obstructive pulmonary disease (COPD) is a major public health problem. Due to the restriction of expiratory airflow, it is characterized by emphysematous destruction of the lungs. Shortness of breath is one of the main clinical symptoms. Auricular acupressure is a clinical therapy characteristic of Chinese medicine that treats the disease by compressing ear points. Usually, the seeds of Vaccaria segetalis are used to stimulate ear points, which has the effect of regulating qi and alleviating wheezing. In this paper, we propose this characteristic therapy of traditional Chinese medicine (TCM) for the clinical symptoms of wheezing of lung and kidney qi deficiency type in stable COPD patients. Ear points are selected as the treatment protocol for Lung (CO14), Spleen (CO13), Kidney (CO10), Shen Men (TF4), and Ping Chuan (AT1.2.4i) points. The protocol describes a case study using auricular acupressure for a patient with chronic obstructive pulmonary disease to relieve wheezing symptoms.

Author Spotlight: Efficacy of Auricular Pressure Bean Therapy in Reducing Wheezing Symptoms

This protocol describes an effective therapy using auricular acupressure to relieve wheezing symptoms in stable chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a major public health problem. Due to the restriction of expiratory airflow, it is characterized by ...