Effects of Instructions given to the User on the performance of volume-oriented and flow-oriented Incentive Spirometers In Healthy Subjects

Daniel Arellano, Yessenia Montenegro, María Jose Martin, Nadia González, Rodrigo Cornejo, Marioli Lazo
Purpose:

This study aims to evaluate the volume, flow, and pressure delivered by volume-oriented and flow-oriented IS in healthy subjects and analyze how usage instructions impact device performance.

Methods:

The study involved subjects aged 18–29 who had never used IS devices. Exclusion criteria included smokers and individuals unable to follow instructions or use the devices. Participants first used the IS devices without any guidance, followed by providing instructions. Two models of volume-oriented IS (Spiroball® and Coach II®) and one flow-oriented IS (Triflo II®) model were tested. In the volume-oriented IS, participants were instructed to reach the maximum volume measured by the device (4000 mL). In flow-oriented IS, a flow of 600 mL/sec and 1200 mL/sec was requested to be maintained for as long as possible. The flow, volume, and pressure parameters were measured with a pneumotachometer (Fluxmed®). Ten measurements were made for each device. All participants signed an informed consent; Ethical approval was obtained (File Nº 195). The data were analyzed using the Stata 14.1 software. 

Results:

Sixty subjects (31 male, 23.8±1.2 years) participated. During the first, uninstructed use, 84% of participants exhaled through the device, and only 16% took a correct breath. For the volume-oriented IS, the volume mobilized was significantly lower than that indicated on the device (Spiroball® 2946±128 mL vs 4000 mL, p0.001; Coach II® 3579±1221 mL vs 4000 mL, p0.01), with corresponding flows of 43.0±3.0 L/min and 39.6±3.4 L/min, respectively. The pressures generated during the inspiration were -15.2±2.4 cmH2O (Spiroball®) and -12.2±2.2 cmH2O (Coach II®). For flow-oriented IS, the 600 mL/sec flow volume was 3963±436 mL with an inspiratory time of 5.1±1.1 sec. At a 1200 mL/sec flow, the volume mobilized was 4093±640 mL with an inspiratory time of 2.9±0.8 sec. Pressures generated at 1200 mL/sec flows were significantly higher than at 600 mL/sec (-34.9±8.3 vs -6.7±0.8 cmH2O, p0.001). No significant differences were observed in the volume mobilized across different flows. 

Conclusion(s):

In volume-oriented IS, the achieved volume differs from the indicated volume and inversely correlates with the pressure generated. Higher flows result in significantly greater pressures but similar volumes for flow-oriented IS. The effectiveness of IS devices heavily depends on the instructions provided, which should be tailored to each device's technical features.

Implications:

 This study emphasizes the need to provide clear and specific instructions to patients to optimize the use of incentive spirometers, as the results vary significantly depending on how the devices are used. Additionally, it highlights that the volumes measured may not correspond with the values indicated by the devices, which could lead to an underestimation of lung capacity

Funding acknowledgements:
The work has no sources of financing
Keywords:
Incentive Spirometers
Respiratory Therapy
Pulmonary function
Primary topic:
Cardiorespiratory
Second topic:
Disability and rehabilitation
Third topic:
Critical care
Did this work require ethics approval?:
Yes
Name the institution and ethics committee that approved your work:
Universidad de Chile
Provide the ethics approval number:
File Nº 195
Has any of this material been/due to be published or presented at another national or international conference prior to the World Physiotherapy Congress 2025?:
No

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