Handheld fans for dyspnoea in respiratory failure: randomised controlled trial

Abstract

Objective

Fan therapy is widely acknowledged as an essential component in the management of dyspnoea with numerous studies supporting its efficacy in alleviating dyspnoea among patients with chronic illnesses. However, there is limited evidence regarding the effectiveness of fan therapy in reducing dyspnoea in patients with respiratory failure undergoing continuous oxygen therapy. This study aimed to assess the efficacy of fan therapy in mitigating dyspnoea in this specific patient population through a randomised controlled trial.

Methods

Participants meeting the inclusion criteria were randomly assigned to either an experimental group or a control group. In the experimental group, a handheld fan (HHF) was directed at the face, while in the control group the fan was aimed at the legs. Both interventions were conducted at a distance of 15–30 cm for 10 min. Key physiological and subjective measures, including heart rate, respiratory rate, blood pressure, blood oxygen saturation, facial skin temperature and Visual Analogue Scale (VAS) scores, were recorded immediately after fan therapy.

Results

The experimental group demonstrated a statistically significant reduction in VAS scores (p<0.05) compared with the control group indicating that fan therapy effectively alleviates dyspnoea in patients with respiratory failure receiving continuous oxygen therapy.

Conclusion

HHFs are affordable, widely accessible and highly effective in relieving dyspnoea with minimal risk. Therefore, fan therapy should be considered as a complementary treatment for patients with respiratory failure and incorporated alongside standard therapeutic interventions for the condition.

WHAT IS ALREADY KNOWN ON THIS TOPIC

• Fan therapy can relieve breathlessness in people with respiratory failure; however, no effect on its physiological indicators.

WHAT THIS STUDY ADDS

• Added the indications of fan therapy; provide new therapies for breathlessness in this population.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

• Fan therapy can be used as a palliative treatment; follow-up studies may focus on patients with respiratory failure.

Introduction

Breathlessness, also referred to as dyspnoea, is a prevalent, disabling and distressing symptom, defined by the American Thoracic Society as ‘a subjective feeling of respiratory discomfort that varies in intensity and unpleasantness as well as in emotional and behavioural significance’.¹ Since the publication of the consensus statement on dyspnoea in 1999, significant progress has been made in understanding its pathogenesis.² However, research into the treatment of dyspnoea remains insufficient. While substantial biomedical research has focused on diagnosing and addressing the underlying causes of dyspnoea, equal emphasis must be placed on alleviating the suffering it causes.

The management of dyspnoea incorporates both pharmacological and non-pharmacological interventions with the aim of reducing the patient’s distress and improving their mobility.² In 1987, it was first reported that fan-generated airflow directed towards the face could effectively alleviate a patient’s subjective experience of dyspnoea.³ This intervention, known as fan therapy, has since emerged as a simple yet effective non-pharmacological strategy for managing dyspnoea.

Research on fans has evolved over nearly 40 years and a substantial body of evidence suggests that the airflow produced by fans can effectively alleviate dyspnoea. For instance, a study conducted on healthy participants demonstrated that directing cold air from a fan towards the face, without altering ventilation or respiratory drive, improved experimental dyspnoea whereas directing cold air to the legs did not.³ Similarly, a clinical study involving 111 participants with both malignant and non-malignant conditions found that fan therapy effectively reduced recovery time from postexercise dyspnoea and decreased the need for supplemental oxygen or inhaled β-agonists in certain patients.⁴ Furthermore, the use of fan therapy at room temperature has been shown to relieve dyspnoea in patients who meet the criteria for ‘chronic dyspnea’.^{5 6} The guidelines recommend fan therapy as an effective intervention for relieving dyspnoea in patients with chronic conditions. These guidelines highlight its utility not only in alleviating daily dyspnoea but also in managing acute episodes of chronic dyspnoea during crises.⁷ At the Cambridge Dyspnoea Intervention Service, fans were integral in managing dyspnoea across multiple studies.^{8 9} Handheld fans (HHFs) are a vital component of dyspnoea support services and are widely regarded in the UK as effective tools for dyspnoea relief. Fan therapy has been incorporated into care ‘packages’ designed to address dyspnoea.^{10 11} Chronic obstructive pulmonary disease (COPD) is a progressive condition characterised by worsening, irreversible symptoms of dyspnoea over time. During acute exacerbations of COPD, especially when accompanied by lung infections, dyspnoea is often more severe and frequently associated with respiratory failure. Despite the prevalence of these issues, no studies have investigated the efficacy of fan therapy in relieving dyspnoea in patients with respiratory failure receiving continuous oxygen therapy. To address this gap, we designed a randomised controlled trial to evaluate the effectiveness of fan therapy in this specific population. Participants included patients admitted with acute exacerbations of COPD and respiratory failure, confirmed by arterial blood gas analysis performed on the first day of admission. Patients with self-reported severe respiratory distress while on continuous oxygen therapy were enrolled to determine whether fan therapy could improve dyspnoea in this group.

Object and Method

Participants

Participants were recruited from the respiratory ward of the Affiliated Hospital of Zunyi Medical University. The inclusion criteria were as follows: (1) Met the diagnostic criteria for acute exacerbation of COPD based on the Chinese Expert Consensus on the Diagnosis and Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease—Revised 2023; (2) Dyspnea Exertion Scale(DES) score for the degree of dyspnoea≥grade 2; (3) Met the diagnostic criteria for respiratory failure (oxygenation index: arterial oxygen pressure/fractional inspired oxygen < 300 mm Hg); (4) Receiving continuous oxygen therapy for severe respiratory distress.

Exclusion criteria were any one or more of the following:⁵ (1) Inability to complete the Visual Analogue Scale (VAS) score or use an HHF, etc, (2) Presence of trigeminal nerve disease or other contraindications related to the treatment area, (3) Peripheral vascular disease, severe cardiac or intrapulmonary arteriovenous shunts or other life-threatening conditions, and (4) other patients unable to cooperate with the study.

The DES, adapted from the Medical Research Council breathlessness scale, was used to assess dyspnoea. The DES provides better face validity in patients with severe COPD who experience dyspnoea at rest or with light activity. It asks: ‘How dyspneic are you right now?’^{12 13} The DES consists of five levels: Level 1: I am able to walk at my own pace on the level without getting out of breath; Level 2: I become breathless if I walk around the house or on the ward on the level at my own pace; Level 3: I become breathless if I move around in bed or get out of bed; Level 4: I become breathless on talking and Level 5: I am breathless at rest.

This study was a single-centre, randomised controlled trial. Before the study began, potential participants were provided with oral and written descriptions of the procedures and written consent was obtained. Participants were informed that they could withdraw from the study at any time.

Interventions

After obtaining written consent from the participants, the researchers measured and collected baseline data including gender, age, DES classification, partial pressure of carbon dioxide (PCO₂), partial pressure of oxygen (PO₂) and other relevant parameters. Participants who completed the data collection were then randomly assigned to either the experimental group or the control group. In the experimental group, the fan airflow was directed at the face whereas in the control group, the airflow was directed at the legs. The fan was positioned at a distance of 15–30 cm, a range determined to be optimal for the patient and each session lasted 10 min. Heart rate (HR), respiratory rate (RR), blood pressure (BP), oxygen saturation, facial skin temperature, VAS score and other relevant indicators were measured before the start and immediately after the conclusion of the fan therapy. Following the session, researchers used a handheld infrared thermometer to measure and record the participants’ facial skin temperature. Immediately afterwards, participants were asked to recall the degree of dyspnoea they experienced during the fan therapy and to rate it using the VAS scale. To ensure clarity, the researcher explained the VAS scale by indicating its endpoints: the starting point represented ‘no shortness of breath’ while the endpoint indicated ‘shortness of breath at its worst’. Participants were instructed to use a pen to mark their current level of dyspnoea on the scale. The scale was a 100-mm horizontal line where 0 corresponded to no dyspnoea and 100 to the worst possible dyspnoea. Participants were informed that each millimetre closer to the endpoint represented an increase of one point in the degree of dyspnoea.

Methods of investigation

General Information

The participants’ gender, age, DES grading, PCO₂, PO₂ and other relevant parameters were recorded for analysis.

Observational indexes

The researcher recorded the participants’ HR, RR, BP, oxygen saturation (under inspired oxygen flow: 2 L/min), facial skin temperature and VAS score. No adverse events were reported during the study.

Statistical analysis

All data were analysed using SPSS V.29.0 software. The χ² test was applied to compare count data. Measurement data conforming to a normal distribution were expressed as () and the independent sample t-test was used for comparisons between the two groups. Differences were considered statistically significant at p<0.05.

Results

Comparison of baseline data between the two groups

A total of 75 patients were enrolled in the study. Among these, 17 patients declined to participate, 9 patients voluntarily withdrew during fan therapy due to embarrassment and 4 patients were unable to accurately follow the researcher’s instructions and were excluded. Consequently, 45 participants completed the study (figure 1). The experimental group consisted of 16 men and 10 women while the control group included 12 men and 7 women. There was no significant difference in gender distribution between the two groups (p>0.05). The mean age of the experimental group was 64.15±12.57 years compared with 65.95±12.79 years in the control group; this difference was not statistically significant (p>0.05). The DES grades were primarily concentrated in grades 2, 3 and 4 with no significant difference in the distribution of DES grades between the experimental and control groups (p>0.05). Additionally, there were no statistically significant differences in the comparison of PCO₂ and PO₂ levels between the groups before the intervention (p>0.05). Similarly, no significant differences were observed in baseline HR, RR, BP, oxygen saturation, facial skin temperature or VAS scores between the experimental and control groups (p>0.05) (online supplemental table 1).

Figure 1. Outcome of screened patients.

Comparison of experimental indicators between the two groups before and after intervention

The difference in VAS scores before and after the intervention was statistically significant in the experimental group but not in the control group. However, differences in HR, RR, BP, oxygen saturation and facial skin temperature between the two groups before and after the fan therapy intervention were not statistically significant in either the experimental group or the control group (p>0.05) (online supplemental table 2).

Currently, a VAS decrease greater than 10 mm is considered to represent a minimal clinically important difference (MCID) in the evaluation of dyspnoea.¹⁴ In this study, the mean VAS decline was 9.52 mm in the experimental group and 1.13 mm in the control group. Although the mean decline in the experimental group did not meet the threshold of 10 mm, seven participants in the experimental group experienced a VAS decline greater than 10 mm following fan treatment compared with only one participant in the control group. Therefore, these differences, while not meeting the defined MCID threshold on average, are still clinically relevant and warrant further consideration.

Discussion

This randomised controlled trial investigated whether fan therapy is effective in alleviating dyspnoea in patients with respiratory failure receiving continuous oxygen therapy. The results demonstrated a statistically significant reduction in VAS scores in the experimental group after the intervention (p<0.05) while no significant change in VAS scores was observed in the control group. These findings suggest that directing HHF airflow to the face significantly improves dyspnoea in patients with respiratory failure compared with directing the airflow to the legs. However, no significant differences were observed in HR, RR, BP or oxygen saturation between the experimental and control groups before and after the intervention. This aligns with prior findings on electric fan therapy in patients without respiratory failure.³

The airflow generated by an HHF can alleviate discomfort during physical activity, reduce mental distress, enhance confidence in managing dyspnoea and improve the ability to participate in daily activities and exercise.415,17 Several participants provided subjective evaluations reporting that fan therapy effectively relieved their dyspnoea and facilitated quicker recovery.^{5 18 19} Additional reported benefits of fan therapy include decreased reliance on β-agonists and oxygen therapy, reduced side effects, lower healthcare costs and a favourable safety profile compared with many medications.²⁰ Furthermore, HHFs can be used as a symptomatic intervention in the early stages of chronic respiratory diseases and may serve as a valuable tool in clinical practice for managing dyspnoea.²¹

The mechanism by which fan therapy alleviates dyspnoea remains unclear but several hypotheses have been proposed:

1. Fan therapy may induce a diving response by stimulating receptors on the skin in areas innervated by the trigeminal nerve or by activating upper respiratory mucosal receptors innervated by the second and third branches of the trigeminal nerve. This stimulation affects the afferent source of respiratory sensation, potentially reducing central respiratory drive and diminishing the sensation of dyspnoea.^{3 22 23}

2. Increased ventilation airflow generated by a fan passing over the face, nasal mucosa or pharynx may alter ventilation, increase gas inhalation and alleviate dyspnoea.^{3 24} Marchetti et al observed that facial airflow improved diaphragmatic electromechanical coupling reduced central respiratory drive and decreased the diaphragmatic electromyographic activity-to-tidal volume ratio.²⁵ However, in this study, participants were treated with fans while receiving supplemental oxygen, suggesting that the mechanism of fan therapy may not rely on increased airflow inhalation. The additional airflow generated by fans may be negligible compared with the volume provided by oxygen therapy.

3. Distraction: Some participants reported that fan therapy provided a sense of distraction and relaxation. Neuroimaging studies suggest that facial airflow may alter sensory attention related to central respiration, thereby reducing dyspnoea.²⁶

4. Perception of increased ventilation: Another hypothesis is that fan-generated airflow ‘tricks the brain’ by stimulating trigeminally innervated receptors, creating the perception of increased ventilation which alleviates dyspnoea.²⁷

5. Reduced facial skin temperature: A study of 10 healthy participants found that higher fan speeds decreased dyspnoea recovery time after exercise and resulted in more pronounced reductions in facial skin temperature compared with controls. However, in this study, no significant differences in facial skin temperature were observed between the experimental and control groups before or after the intervention. This finding does not support the hypothesis that reduced facial skin temperature is the primary mechanism by which fan therapy relieves dyspnoea.²⁸

The 2024 European Respiratory Society Clinical Practice Guidelines for Symptom Management in Adults with Severe Respiratory Disease highlight that HHF therapy requires minimal training is readily accepted by patients and has the potential for widespread use. These guidelines recommend focusing fan therapy on acute dyspnoea and emphasise the need for future research involving robust clinical trials to evaluate the effects of increased airflow on dyspnoea relief.²⁹

Most existing studies on fan therapy for dyspnoea relief have focused on short-term applications with limited exploration of sustained use over time. Data on long-term follow-up is scarce. A clinical study with a 2-month follow-up found no significant differences in dyspnoea relief between the intervention and placebo groups.³⁰ Possible reasons include the progressive worsening of dyspnoea in patients with advanced or terminal illnesses and participants’ inability to use the fan consistently over extended periods for various reasons.³⁰ These challenges make conducting long-term studies on fan therapy for dyspnoea relief particularly difficult.

This study, with its small sample size and simple design, serves as a preliminary exploration of fan therapy and does not address the underlying mechanisms or ways to optimise its efficacy. Future research should investigate the pathophysiological mechanisms involved in dyspnoea relief through fan therapy and identify strategies to enhance its effectiveness. This may include creating detailed clinical guidelines for ‘fan therapy’ and integrating them into routine clinical management programmes.¹⁹

Conclusion

Our study demonstrates that fan therapy is as effective in relieving dyspnoea in patients with respiratory failure as it is in those with other chronic diseases. HHFs are inexpensive, easy to acquire and have demonstrated efficacy in reducing dyspnoea with minimal associated risks, making them a highly cost-effective intervention. Therefore, fan therapy is recommended as an adjunctive treatment for dyspnoea in patients with respiratory failure and should be used alongside mainstream treatments for this condition.

Data availability statement

Data are available upon reasonable request. All data relevant to the study are included in the article or uploaded as supplementary information.