Measuring Peak Inspiratory Flow in Patients with Chronic Obstructive Pulmonary Disease

Figures & data

Table 1 Inhaler Classification Based on Internal Resistance^8,29,95,96

Inhaler Resistance	Resistance Class of Inhaler	Inhalers
Zero	R0	Multiple pMDIs
Zero	R0	Respimat^® (SMI)
Low	R1	Breezhaler^® (Neohaler^®a in the United States)
Medium low	R2	Accuhaler^®/Diskus^®a
Medium low	R2	Diskhaler^®
Medium low	R2	Ellipta^®a
Medium low	R2	Inhub^®
Medium	R3	Genuair^® (Pressair^®a in the United States)
Medium	R3	Spiromax^® (RespiClick^®a in the United States)/Digihaler™
Medium	R3	Clickhaler™
Medium	R3	Turbuhaler^® (Symbicort^®)
Medium high	R4	Turbuhaler^® (Pulmicort™) (Flexhaler^® in the United States)
Medium high	R4	Easyhaler^® C (combination)
Medium high	R4	Twisthaler^®
Medium high	R4	NEXThaler^®
High	R5	Easyhaler^® M (monotherapy)
High	R5	HandiHaler^®a

Note: ^aIncluded in the present analysis.

Abbreviations: pMDI, pressurized metered-dose inhaler; SMI, soft-mist inhaler.

Table 2 Instructions for Use of the In-Check™ DIAL

In-Check™ DIAL^Citation30 2010

In-Check™ DIAL G16^Citation36 2016

1. Reset the In-Check™ DIAL: hold the instrument vertically with the mouthpiece uppermost, so that the rounded end of the meter can be tapped against the other hand or a horizontal surface, such as a table. A gentle tap will dislodge the magnetic resetting weight, which will return the red cursor to a start position. When this has happened, the meter must turn through 180 degrees to return the magnetic weight to its resting position 2. Align the scale with the desired inhaler device–an audible “click” should be heard 3. Attach a clean mouthpiece (small mouthpieces can be used with the supplied adaptor) 4. Ask the patient to exhale slowly and deeply 5. Seal lips around the mouthpiece. According to the inhaler chosen, instruct the patient to inhale in the manner recommended by the manufacturer 6. Record the inspiratory flow from the position of the red cursor against the scale. Reset, and repeat 2 more times 7. Compare values achieved with target flows for that device. To operate an inhaler device optimally, the patient should be able to achieve a flow rate within the optimal range. If other inhalers are used, then repeat steps 1 to 7

1. Reset the In-Check™ DIAL G16: hold the instrument vertically with the mouthpiece uppermost, so that the rounded end of the meter can be tapped against the other hand or a horizontal surface, such as a table. A hard tap will dislodge the magnetic resetting weight, which will return the red cursor to a start position 2. Align the dial selector with the desired colored icon–an audible “click” should be heard 3. Attach a clean mouthpiece. Disposable 1-way inspiratory mouthpieces are preferred 4. Ask the patient to exhale fully 5. Ask the patient to seal their lips around the mouthpiece. According to the inhaler chosen, instruct the patient to inhale in the manner recommended by the manufacturer 6. Record the inspiratory flow from the position of the red cursor against the scale. Reset, and repeat 2 more times, ensuring correct technique each time 7. Compare values achieved with target flows for that device. To operate an inhaler device correctly, the patient should be able to achieve a flow rate within the clinically effective range (eg, Accuhaler^®: clinically effective flow rate 30–90 L/min) 8. If after repeated training the patient is not able to achieve these values, then the healthcare professional may wish to assess the patient’s ability to use an alternative type of inhaler

Notes: Consult the Instructions for Use and manufacturer’s website for cleaning/hygiene instructions.⁹⁰

Table 3 Instructions for Daily Use of DPIs That Are Approved by the Food and Drug Administration for the Treatment of COPD and Currently Prescribed in the United States

DPI (Medication)	Inhalation Maneuver Instructions (Based on Prescribing Information)	Peak Inspiratory Flow (Range) Through Inhaler as Reported in the Applicable Prescribing Information
Diskus^® (salmeterol)^Citation40	● Always use the Diskus^® in a level, flat position with the mouthpiece toward you ● Before you breathe in your dose from the Diskus^®, breathe out (exhale) as long as you can while you hold the Diskus^® level and away from your mouth. Do not breathe into the mouthpiece ● Put the mouthpiece to your lips. Breathe in quickly and deeply through the Diskus^®. Do not breathe in through your nose ● Remove the Diskus^® from your mouth and hold your breath for about 10 seconds, or for as long as is comfortable for you ● Breathe out slowly as long as you can	Mean: 82.4 L/min (46.1–115.3 L/min) in adult subjects with obstructive lung disease and severely compromised lung function (mean FEV1 20%–30% of predicted)
Ellipta^® (vilanterol and umeclidinium)^Citation41	● While holding the inhaler away from your mouth, breathe out (exhale) fully. Do not breathe out into the mouthpiece ● Put the mouthpiece between your lips and close your lips firmly around it. Your lips should fit over the curved shape of the mouthpiece ● Take a long, steady, deep breath in through your mouth. Do not breathe in through your nose ● Do not block the air vent with your fingers ● Remove the inhaler from your mouth and hold your breath for about 3 to 4 seconds (or for as long as is comfortable for you) ● Breathe out slowly and gently	Mean: 66.5 L/min (43.5–81.0 L/min) in adult subjects with COPD with FEV1/FVC <70% and FEV1 <30% of predicted or FEV1 <50% of predicted plus chronic respiratory failure
HandiHaler^® (tiotropium)^Citation42	● Breathe out completely in one breath, emptying your lungs of any air. Do not breathe into your HandiHaler^® device ● Hold your head in an upright position while you are looking straight ahead ● Raise your HandiHaler^® device to your mouth in a horizontal position. Do not block the air intake vents ● Close your lips tightly around the mouthpiece ● Breathe in deeply until your lungs are full. You should hear or feel the Spiriva^® capsule vibrate (rattle) ● Hold your breath for a few seconds and, at the same time, take your HandiHaler^® device out of your mouth ● Breathe normally again ● To get your full daily dose, you must again breathe out completely, and for a second time, breathe in from the same Spiriva^® capsule	Median: 30.0 L/min (20.4–45.6 L/min) in adult patients with COPD and severely compromised lung function (mean FEV1: 1.02 L [range: 0.45–2.24 L]; 37.6% of predicted [range: 16%–65%])
Neohaler^® (indacaterol and glycopyrrolate)^Citation43	● Hold the inhaler as shown in the figure in the prescribing information ● Before placing the mouthpiece in your mouth, breathe out fully. Do not blow into the mouthpiece ● Before breathing in make sure that the piercing buttons are to the left and right of the inhaler (not up and down) ● Place the mouthpiece in your mouth and close your lips firmly around the mouthpiece ● Breathe in rapidly but steadily, as deeply as you can. Do not press the piercing buttons ● As you breathe in through the inhaler, the capsule spins around in the chamber and you should hear a whirring noise ● Continue to hold your breath for at least 5 to 10 seconds or for as long as comfortably possible while removing the inhaler from your mouth. Then breathe out	Mean: 95 L/min (52–133 L/min) in adult patients with COPD of varying severity
Pressair^® (aclidinium)^Citation44	● Hold the inhaler horizontally with the mouthpiece facing you and the green button on top ● Hold the inhaler away from your mouth and breathe out completely. Never breathe out into the inhaler ● Hold your head upright, put the mouthpiece between your lips, and close your lips tightly around the mouthpiece ● Take a strong, deep breath through your mouth. Keep breathing in for as long as possible ● Take the inhaler out of your mouth. Hold your breath for as long as possible. Slowly breathe out, away from the inhaler	Mean: 63 L/min by in vitro testing
RespiClick^® (albuterol sulfate)^Citation45 and Digihaler™ (albuterol sulfate)^Citation46	● Hold the inhaler upright and open the red cap fully until you feel and hear a “click” ● Each time you open the red cap and it “clicks”, a dose of ProAir RespiClick^®/Digihaler^TM is ready to be inhaled ● Before you inhale, breathe out (exhale) through your mouth and push as much air from your lungs as you can ● Do not exhale into the inhaler mouthpiece ● Put the mouthpiece in your mouth and close your lips tightly around it ● Do not block the vent above the mouthpiece with your lips or fingers ● Breathe in quickly and deeply through your mouth, to deliver the dose of medicine to your lungs ● Remove the inhaler from your mouth ● Hold your breath for about 10 seconds or for as long as you comfortably can	Mean: >60 L/min (31–110 L/min)
Inhub^® (fluticasone propionate and salmeterol)^Citation47	● Hold the Inhub^® in the vertical position ● Before you breathe in your dose from the Inhub^®, breathe out (exhale) as long as you can while you hold the Inhub^® away from your mouth. Do not breathe into the mouthpiece ● Put the mouthpiece to your lips. Breathe in quickly and deeply through the Inhub^®. Do not breathe in through your nose ● Remove the Inhub^® from your mouth and hold your breath for about 10 seconds, or for as long as is comfortable for you ● Breathe out slowly for as long as you can	60 L/min under standardized in vitro test conditions

Abbreviations: COPD, chronic obstructive pulmonary disease; DPI, dry powder inhaler; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.

Table 4 Summary of Main Recommendations

Variables	Recommendations	Rationale
Position	Maintain an upright seated or erect standing position—with the chin pointed slightly upward—during the PIF assessment process	Positioning the patient’s head to have the chin slightly upward has been shown to affect drug deposition and, subsequently, outcomes in asthma^Citation82
Exhalation	Breathe out slowly and fully	Patients who exhale “fully and completely” could cause collapse of their small airways at low lung volumes. During the subsequent inhalation phase, the “energy” generated by the inhaled breath/volume has to overcome the “opening” of the collapsed small airways that have been induced by exhaling “fully and completely.” The resultant energy available during inhalation to overcome airway collapse may be (not yet proven) inadequate to generate the required inspiratory acceleration and energy necessary to optimally activate the DPI
Inhalation	Inhale as fast, forcefully, and deeply as you can once your lips are sealed around the mouthpiece and maintain this level of inhalation for as long as possible	PIF needs to be reached almost immediately (approximately 1 second) after the inhalation maneuver begins, and the achieved level of inspiration needs to be maintained during the entire inhalation maneuver (inspiratory profile) for effective drug release

Abbreviations: DPI, dry powder inhaler; PIF, peak inspiratory flow.

Ghosh S, Pleasants RA, Ohar JA, Donohue JF, Drummond MB. Prevalence and factors associated with suboptimal peak inspiratory flow rates in COPD. Int J Chron Obstruct Pulmon Dis. 2019;14:585–595. doi:10.2147/COPD.S195438

 PubMed Web of Science ®Google Scholar

Sanders MJ. Guiding inspiratory flow: development of the In-Check DIAL G16, a tool for improving inhaler technique. Pulm Med. 2017;2017:1495867. doi:10.1155/2017/1495867

 PubMed Web of Science ®Google Scholar

Symbicort® (budesonide and formoterol fumarate dihydrate) [prescribing information]. Delaware: AstraZeneca Pharmaceuticals LP; 2006.

 Google Scholar

Stiolto® Respimat® (tiotropium bromide and oladeterol) [prescribing information]. Connecticut: Boehringer Ingelheim Pharmaceuticals, Inc.; 2015.

 Google Scholar

In-Check Dial. How to reset and use the In-Check DIAL: instructions. Alliance Tech Medical. Available from: http://alliancetechmedical.com/educationclinicals/. Accessed May 13, 2020.

 Google Scholar

In-Check Dial G16. Clement Clarke International. Available from: https://www.haag-streit.com/clement-clarke/products/inhaler-technique/in-check-dial-g16/. Accessed May 13, 2020.

 Google Scholar

Hygiene instructions for In Check and In Check DIAL. Alliance Tech Medical; April 13, 2020. Available from: https://www.alliancetechmedical.com/files/8915/7443/9937/2019_HYGIENE_INSTRUCTIONS_FOR_In_Check_and_In_Check_DIAL.pdf. Accessed April 27, 2020.

 Google Scholar

Serevent® Diskus® (salmeterol xinafoate) [prescribing information]. North Carolina: GlaxoSmithkline; 2018.

 Google Scholar

Anoro™ Ellipta™ (umeclidinium and vilanterol) [prescribing information]. North Carolina: GlaxoSmithkline; 2014.

 Google Scholar

Spiriva® HandiHaler® (tiotropium bromide) [prescribing information]. Connecticut: Boehringer Ingelheim Pharmaceuticals, Inc.; 2015.

 Google Scholar

UtibronTM Neohaler® (indacaterol and glycopyrrolate) [prescribing information]. Massachusetts: Sunovion Pharmaceuticals Inc.; 2016.

 Google Scholar

Tudorza® Pressair® (Aclidinium bromide) [prescribing information]. Delaware: AstraZeneca Pharmaceuticals LP; 2019.

 Google Scholar

Proair RespiClick® (albuterol sulfate) [prescribing information]. Pennsylvania: Teva Respiratory, LLC; 2015.

 Google Scholar

Proair® DigihalerTM (albuterol sulfate) [prescribing information]. Pennsylvania: Teva Respiratory, LLC; 2018.

 Google Scholar

Wixela™ Inhub™ (fluticasone propionate and salmeterol) [prescribing information]. West Virginia: Mylan Pharmaceuticals Inc.; 2019.

 Google Scholar

Price DB, Roman-Rodriguez M, McQueen RB, et al. Inhaler errors in the CRITIKAL study: type, frequency, and association with asthma outcomes. J Allergy Clin Immunol Pract. 2017;5(4):1071–1081.e1079. doi:10.1016/j.jaip.2017.01.004

 PubMed Web of Science ®Google Scholar