Use of lung expansion techniques on drained and non-drained pleural effusion: survey with 232 physiotherapists

Introduction: Techniques for lung expansion seem to benefit patients with drained and undrained pleural effusion, but there is a lack of evidence to indicate which technique is best in each situation. Currently, the therapeutic choices of respiratory physiotherapists serving this population are not known. Objective: To know which lung expansion techniques are chosen by chest physiotherapists who assist patients with

drained and non-drained pleural effusion. Method: Through the announcement of the Federal Council, 232 physiotherapists who work in hospitals in Brazil were questioned about which techniques they apply to patients with drained and non-drained effusion. Results: Initially, 512 were questioned but 232 (45.3%) answered. The physiotherapists associate more than one technique of lung expansion in both types of patients, besides walking. Deep breathing is the most used technique in patients with drained (92%) and non-drained (77%) pleural effusion. Positive pressure exercises in the airways are chosen by 60% of the physiotherapists to treat patients with drained pleural effusion and by 34% to treat patients with non-drained pleural effusion. Yet the incentive spirometry are used with 66% of patients with drained pleural effusion and 42% with nondrained ones. Conclusion: Deep breathing is the most applied lung expansion technique in the treatment of patients with drained and non-drained pleural effusion by chest physiotherapists. In addition, there is association between greatest degree and time of professional performance and the chosen techniques. Los fisioterapeutas asocian más de una técnica de expansión pulmonar en ambos tipos de pacientes, además de deambular. La respiración profunda es la técnica más utilizada en pacientes con derrame pleural drenado (92%) y no drenado (77%). Los ejercicios de presión positiva en las vías aéreas son elegidos por el 60% de los fisioterapeutas para tratar a pacientes con derrame pleural drenado y por el 34% para pacientes con derrame pleural no drenado. La espirometría de incentivo se utiliza con el 66% de los pacientes con derrame pleural drenado y el 42% con no drenado. Conclusión: La respiración profunda es la técnica de expansión pulmonar más aplicada en el tratamiento de pacientes con derrame pleural drenado y no drenado por fisioterapeutas respiratorios. Además, hay asociación entre mayor titulación y tiempo de actuación profesional y las técnicas elegidas.
Use of lung expansion techniques on drained and non-drained pleural effusion Introduction Pleural effusion affects more than a million patients only in the United States [1] and presents high mortality rate [2]. The main damages caused by pleural effusion are at gas exchange, pulmonary function and hemodynamics [2]. The treatment indicated for patients with pleural effusion of high quantity or the increase of sensation of dyspnea is the thoracic drainage [3,4]. Thoracic drainage can present complications such as tube clogging or displacement, subcutaneous emphysema, atelectasis and empyema [5]. The complications and mortality rate related to thoracic drainage reaches 17% in the United Kingdom [6] and 26.8% in Brazil [7].
For these reasons, surgical [8,9] and clinical [10,11] strategies have been adopted to accelerate the resolution time for pleural effusion and decrease the time the drain remains in the patients [8,9,10]. Even without expert consensus to guide the therapists, chest physiotherapy is one of the clinical strategies widely used at the clinical practice with the objective of expanding the lungs and helping on discharging the excess liquid of the pleural space [12]. However, there are no evidences [13] about the benefits brought to patients with drained and nondrained pleural effusion, promoted by lung expansion techniques, such as deep breathing, exercises with positive pressure and incentive spirometry.
In the absence of guidelines resulting from clinical trials with good methodological quality, chest physiotherapists base their therapeutic choices on their beliefs or knowledge acquired at clinical practice. To get to know the reality of clinical practice, a survey is the indicated investigation method [14]. Therefore, the objective of this study was to know the lung expansion techniques applied by the chest physiotherapists who treat patients with drained and non-drained pleural effusion. Moreover, to match the applied techniques with the graduation time, title and type of hospital the chest physiotherapist works.

Study design
Survey.

Participants
This study has involved chest physiotherapists who work in Brazil assisting hospitalized patients with drained and non-drained pleural effusion of any origin (infectious, oncological, trauma or surgical). This study received institutional support from the Federal Council of Physical Therapy, which provided the email address of data of 512 professionals chosen by random selection. All data were confidentially analyzed.
The study's sample size was estimated considering the response rate of 41% [15]. Simulations were performed using different samples sizes and maintaining the response rate at 41%. A sample of 512 physiotherapists was determined as a sufficiently stable. The double of sample size would not change the confidence interval [16].

Questionnaire
There was not any adequate questionnaire to collect the necessary information from the target population, so we built a questionnaire based on the previously developed protocol [17]. To assure the best quality for the questionnaire, it was submitted to a specialists' committee, formed by eight physiotherapists specialized in respiratory care and with more than ten years professionally working with this kind of patient. The committee analyzed the content, ambiguities, terminologies and the questionnaire's structure. The questions were analyzed and modified according to the commission's suggestions.
The questionnaire consisted of questions divided into five sections: 1) demographic information and type of hospital they work (private, public or university); 2) time since graduation and professional performance (less than 5 years, between 5 and 10 years, between 11 and 20 years, between 21 and 30 years or more than 30 years); 3) highest degree (graduation, specialization, master's degree or doctor's degree); 4) therapeutic techniques used in patients with non-drained pleural effusion (deep breathing, incentive spirometry, exercises with positive pressure and walking); 5) therapeutic used in patients with drained pleural effusion (deep breathing, incentive spirometry, exercises with positive pressure and walking). The chest physiotherapists could choose more than one technique in each situation, without prioritizing the order of using.

Procedure
The data collection was performed by questionnaire applied through Survey Monkey website. The questionnaire was forwarded to chest physiotherapists via e-mail, which contained the invitation to join the study and information about its objective, ethics committee approval, confidentiality assurance, contact of the authors for further clarifications and link to the online questionnaire.
After the questionnaires had been sent, the participants had three weeks to answer. For the ones who did not answer within this period it was sent a new e-mail with a two-week period for answering, considered as the last chance to answer the questions.

Statistical analysis
Data was submitted to descriptive analysis. Chisquare test was used to compare the indication of each technique for the drained and non-drained pleural effusions. The influence of the chosen techniques, time since graduation and chest physiotherapist's highest degree were analyzed by Odds Ratio. The software Sigma Plot 12.25 (San Jose, CA, USA) was used.
Results 232 chest physiotherapists who assist patients with drained and non-drained pleural effusions answered this survey. The answer rate of collected data through the first e-mail was 22.8% (117/512 with 13 physiotherapists' refusals). E-mails were sent again to 382 chest physiotherapists who had not answered the first email with 30.1% (115/382) answers with confirmed participations. Thus, the total answer rate was 45.31% (232/512). Figure 1 shows the flowchart of the phases of the study.  The average age of the questioned chest physiotherapists was 31.8 ± 7.17 years old. Most of them were female, specialists in respiratory or hospital physical therapy, with time since graduation between 5 and 10 years and working at public hospitals. (Table 1).

Lung expansion techniques applied to patients with drained and non-drained pleural effusion
Deep breathing was the most chosen lung expansion technique for the treatment of patients with drained and non-drained pleural effusion. Yet, exercises with positive pressure was the technique least chosen in both situations, however, more applied to patients with drained effusion than to the ones with non-drained effusions ( Table 2). Time since graduation, highest degree and type of hospital are associated with the technique choice applied to patients with drained and non-drained pleural effusion. Being only graduated decreases the chances of the chest physiotherapist choosing exercises with positive pressure, deep breathing and walking as treatment techniques (Table 3).

Discussion
Our study shows that chest physiotherapists, who work with respiratory care of patients with pleural effusion, have been graduated for 5 to 10 years, having specialist degrees and working in public hospitals. Deep breathing was the most chosen technique and exercises with positive pressure was the least chosen one by the physiotherapists to deal with pleural effusion. Besides, highest degree and time since graduation seem to be associated to the technique choice for lung expansion.

Chest physiotherapists characteristics
Like other countries, in our Brazilian sample, there was a predominance of chest physiotherapists of the female sex [18], however, this factor does not seem to interfere in the therapeutic choices. On the other hand, higher degree [19,20], which is associated to time since graduation, were connected to techniques chosen by the chest physiotherapists. Possibly, more years of professional education, with consequent increase of degree level, allow the chest physiotherapist to associate a larger number of techniques to the treatment of the patient. This fact positively affects the health system [21], once the chest physiotherapist himself will be able to identify his needs at the clinic practice [22].

Lung expansion techniques applied by chest physiotherapists
In patients with drained pleural effusion, the lung expansion techniques, in descending order, were: deep breathing, incentive spirometry and positive pressure exercises, consecutively. Most of the chest physiotherapists associate lung expansion techniques with walking.
Exercises with deep breathing, when applied at the pre-operative period, decrease hospitalization time and lung complications after open-heart surgeries [23]. However, there is no evidence of the long-term benefit of this technique after hospital discharge [24]. The low cost, easy use, and the possibility of association with other techniques can be the justification for the interviewed chest physiotherapists' high choice percentage of exercises with deep breathing for the treatment of patients with drained and non-drained pleural effusion.
While the deep breathing seems to benefit patients submitted to heart surgeries, the use of incentive spirometry instigators seems to present positive effects in different clinic situations [25,26]. On the other hand, one of the negative aspects of the incentive spirometry use is the low treatment adherence [27]. Probably this low adherence occurs because, unlike in Brazil, where the use of this equipment is incorporated to the therapy and monitored by the therapist, in other places of the world, the patient is only instructed to use the equipment hourly [26].
Regarding the use of positive pressure, despite many studies having been testing the benefits of its application in surgical patients [28][29][30][31], the results are still controversial [32]. We believe that, besides the weak evidence of the positive pressure use in patients with pleural effusion [19], the little familiarity with the use of this technique and the risk of Broncho pleural fistula might have restricted the choice for this lung expansion technique [33,34].
In patients with non-drained pleural effusion, deep breathing, incentive spirometry, and exercises with positive pressure were consecutively chosen as treatment techniques for them. In this population, walking also seems to be motivated by most of the chest physiotherapists, associated to the use of lung expansion technique. Walking on the first day after lung surgeries seems to have some benefits [35], including the early removal of the thoracic drainage tube [36]. The mobilization of patients submitted to thoracic surgeries seems to positively impact the recuperation of the patients' functionality [37,38]. It is possible that these benefits have also influenced the chest physiotherapists' answers regarding the non-drained patients. Although the most applied technique for the respiratory care was deep breathing and the least used was exercise with positive pressure, in both conditions we observed that, in patients with drained pleural effusion, all the techniques were considerably mentioned because they are probably applied jointly and not individually. Besides, we believe that when breathing therapy involves two or more techniques, it improves patient adherence to the treatment because the therapy is less monotonous and their confidence in overcoming the challenges proposed by the therapist increases.

Factors that influence in the choice of therapeutic techniques
This survey shows that there is association between the graduation degree in physical therapy and the choice for deep breathing, indicating that being solely graduated Use of lung expansion techniques on drained and non-drained pleural effusion decreases the chance of electing this technique for the treatment of non-drained pleural effusion patients. It is possible that the academic degree influences the therapeutic choices because, as the physiotherapist acquires more information, more scientific criteria should be used on making a decision. There also is association connecting the time of professional performance between 5 and 11 years to the choice of the walking and positive pressure exercise techniques, indicating that the physiotherapists with this time of performance are more prone to indicate these two practices when compared to non-drained patients. Thus, the higher their experience with clinic practice, higher will be their perception of the need of practices considered as remedial. This requires physiotherapists to be not only competent in their therapeutic choices, but also able to apply the knowledge based on evidence when handling and treating patients [39]. The beneficial potential of the use of positive pressure exercises has been reported at the prevention of complications and treatment of patients submitted to thoracic surgery, being associated to the physiotherapist's experience on dealing with these resources [40].
The fact of the working environment of most chest physiotherapists being the public hospital increases the chances of using positive pressure exercises on respiratory care of drained and non-drained patients. The hypothesis to this end is the great demand for servicing, once the use of positive pressure seems to increase the lung ventilation by pressure difference [40] more efficiently than deep breathing exercises, which would optimize the result of the therapy. The university hospital environment increases the chances to indicate walking as the therapy for drained patients, stimulating the functioning based on scientific evidences [41]. In addition, the strong benefit indicators of walking at the post-surgery period of placing thoracic tube support these findings [42].
In the attempt of implementing the best treatment strategy in patients with drained and non-drained pleural effusion, there are some barriers at the enforcement of practice based on evidence. Among these barriers, which should always be investigated at each service in order to be identified and overcome, there is the full download of scientific articles and the language of the published article [43].
One of the main limitations of this study was the answering rate of 45.31%, which, despite matching with the ones found in the literature [18,[44][45][46][47][48], may not be representative of the whole wide world. Another limitation was the physiotherapists' questioning through a multiple choice and not through an open answer questionnaire. However, due to the regional differences in nomenclature, we opted to try to homogenize the answers by means of a quantitative technique survey. Finally, we have not questioned the chest physiotherapists the reasons for their choices, but opted for a short questionnaire to increase the adhesion to the survey.

Conclusions
Our results show that deep breathing associated to walking is the treatment most applied by chest physiotherapists on assisting patients with drained and non-drained pleural effusion. Moreover, highest educational degrees, time of professional performance, and the type of hospital where the chest physiotherapists work seem to interfere in their therapeutic choices. Our results suggest that, besides the search for evidences that support the assistance to this population, experience time and more time investment in studying can improve the professional practice in this field.
Use of lung expansion techniques on drained and non-drained pleural effusion