Discussion
atelectasis, desaturation, chest block
RECRUITMENT, ATELECTASIS, SECONDARY
This study evaluated the effects of chest compression-decompression and chest block manoeuvres compared to usual care in patients receiving mechanical ventilation. Our results revealed that the individuals who received the expansion manoeuvres did not experience improvements in ventilatory mechanics and exhibited worse results in oxygenation when compared to the control group. However, the magnitude of this difference (-1.05%) was negligible since a decrease of 4% or more is considered the desaturation criterion [The results found in our study are alarming. A therapeutic approach that is widely used in clinical practice [The manual therapies investigated in this study did not cause changes in static lung compliance. Static compliance refers to the change in lung volume for each unit of change in transpulmonary pressure. It is an important indicator for detecting atelectasis [Several studies have assessed manual manoeuvres’ effectiveness for lung expansion [Our study also found no significant differences between groups in the incidence of atelectasis, length of mechanical ventilation, length of ICU and hospital stay, extubation rate and success, or in-hospital mortality. As expected, since ventilatory mechanics and oxygenation did not show any benefits from applying expansion manoeuvres, the clinical outcomes that these factors could have influenced the improvement also remained unchanged.Our study makes an important contribution to clinical practice by demonstrating the lack of benefits in adopting compression-decompression and chest block manoeuvres during therapy for hospitalized individuals undergoing mechanical ventilation. This provides an opportunity for applying or optimizing other therapeutic strategies that are known to be effective. Evidence-based practice needs to be adopted in managing these patients so that there is a real benefit from a therapeutic intervention.Another strength of this study is its external validity. The inclusion criteria were comprehensive, including a diverse sample of individuals with different diagnoses, severity levels, and clinical conditions, thus simulating a real-life situation encountered by physiotherapists in their clinical practice. Therefore, the study provides a basis for therapeutic decision-making and interventions.This study has some limitations. The evaluator who performed the ventilatory mechanics and oxygenation measurements was not blinded to the participants’ allocation. We attempted to mitigate this limitation by recruiting individuals who were blinded to the evaluation of other study outcomes. In clinical practice, the studied manoeuvres exhibit variability in their execution and application time. Since there is no consensus or guideline on the techniques, these findings may be subject to modification due to methodological differences. The interventions were administered by different physiotherapists, which could introduce variability in the techniques employed. However, the team responsible for conducting the interventions received training and continuous supervision from the researchers to mitigate this potential effect. The sample did not include patients with preexisting atelectasis. However, one of the indications for lung expansion manoeuvres is the prevention of atelectasis [After the research ethics committee approved the research project, the following changes were made to the study: the participant recruitment date was adjusted from October 2019 and February 2020 to March and October 2021 due to delays in obtaining approval from the administrative authorities and the ethics committee. Static compliance is a variable directly related to the response to lung expansion, so it was maintained as the primary outcome, while the other outcomes were classified as secondary. Driving pressure was included as an outcome due to its relevance in assessing lung expansion. Tidal and minute volume outcomes were removed because many patients were receiving mechanical ventilation via the volume-controlled mode. Therefore, no changes in ventilation would be observed in these individuals after the interventions. The appropriate number of participants for the study was revised from 34 to 44 due to an error in the sample size calculation. It was discovered that the effect size in the study conducted by Unoki et al. [