Can the Flutter Valve improve respiratory mechanics and sputum production in mechanically ventilated patients? A randomized crossover trial

An Update on Cardiorespiratory Physiotherapy during Mechanical Ventilation

Physiotherapists are integral members of the multidisciplinary team managing critically ill adult patients. However, the scope and role of physiotherapists vary widely internationally, with physiotherapists in some countries moving away from providing early and proactive respiratory care in the intensive care unit (ICU) and focusing more on early mobilization and rehabilitation. This article provides an update of cardiorespiratory physiotherapy for patients receiving mechanical ventilation in ICU. Common and some more novel assessment tools and treatment options are described, along with the mechanisms of action of the treatment options and the evidence and physiology underpinning them. The aim is not only to summarize the current state of cardiorespiratory physiotherapy but also to provide information that will also hopefully help support clinicians to deliver personalized and optimal patient care, based on the patient's unique needs and guided by accurate interpretation of assessment findings and the current evidence. Cardiorespiratory physiotherapy plays an essential role in optimizing secretion clearance, gas exchange, lung recruitment, and aiding with weaning from mechanical ventilation in ICU. The physiotherapists' skill set and scope is likely to be further optimized and utilized in the future as the evidence base continues to grow and they get more and more integrated into the ICU multidisciplinary team, leading to improved short- and long-term patient outcomes.

Comparison of the effects of voluntary and involuntary breath stacking techniques on respiratory mechanics and lung function patterns in tracheostomized patients: a randomized crossover clinical trial

Objective:

To compare the effects of voluntary breath stacking (VBS) and involuntary breath stacking (IBS) techniques on respiratory mechanics, lung function patterns, and inspiratory capacity in tracheostomized patients.

Methods:

This was a randomized crossover clinical trial involving 20 tracheostomized patients admitted to the ICU and submitted to the VBS and IBS techniques, in random order, with an interval of 5 h between each. Ten cycles of each technique were performed with an interval of 30 s between each cycle. In VBS, patients performed successive inspirations for up to 30 s through a one-way valve, whereas in IBS, successive slow insufflations were performed with a resuscitator bag until the pressure reached 40 cmH₂O. Respiratory mechanics, inspiratory capacity, and the lung function pattern were evaluated before and after the interventions.

Results:

After IBS, there was an increase in static compliance (p = 0.007), which was also higher after IBS than after VBS (p = 0.03). There was no significant difference between the pre-VBS and post-VBS evaluations in terms of static compliance (p = 0.42). Inspiratory capacity was also greater after IBS than after VBS (2,420.7 ± 480.9 mL vs. 1,211.3 ± 562.8 mL; p < 0.001), as was airway pressure (38.3 ± 2.6 cmH₂O vs. 25.8 ± 5.5 cmH₂O; p < 0.001). There were no changes in resistance or lung function pattern after the application of either technique.

Conclusions:

In comparison with VBS, IBS promoted greater inspiratory capacity and higher airway pressure, resulting in an increase in static compliance.

Comparing the Effect of Incentive Spirometry with Acapella on Blood Gases in Physiotherapy After Coronary Artery Bypass Graft

Objective

To compare the effect of incentive spirometry with Acapella (Smiths Medical Inc, Carlsbad, California) in physiotherapy after coronary artery bypass surgery.

Methods

A randomized controlled trial comparing incentive spirometry with Acapella was conducted in the intensive care unit of Chaudhary Pervaiz Elahi Institute of Cardiology (CPEIC) Multan. The study began from December 2017 to August 2019 after getting approval from the ethical committee of the hospital. Informed written consent was taken from all 270 patients who were included in the study. Patients who underwent coronary artery bypass graft (CABG) were divided into two groups by the lottery method. The primary end-point of the study was to check the blood gases on Day 3 after the procedure at room air and compare it with the baseline and with blood gases immediately after the procedure. SPSS 23 (IBM Corp., Armonk, NY) was used to analyze the data of this study. For qualitative variables in data such as gender, place of living, patients with any comorbidities, and education status were statistically analyzed in percentage and frequencies. For numerical variables, such as age, body mass index, blood gases values, distance covered in a six-minute walk test, and spirometry values were analyzed and statistically measured as mean and standard deviation. A P-value of less than .05 was considered significant.

Results

The mean partial pressure of oxygen (PaO2) of incentive spirometry was 58.1±2.31 and 67.2±3.24 after extubation and after three days, respectively. While the PaO2 of Acapella was 56.3±3.43 and 66.4±3.54 after extubation and after three days, respectively. The mean PCO2 of incentive spirometry was 41.4±3.26 and 36.1±2.11 after extubation and after three days, respectively. While the partial pressure of carbon dioxide (PCO2) of Acapella was 39.4±2.55 and 37.5±3.58 after extubation and after three days, respectively. The differences were statistically significant at p-value ≤0.05.

Conclusion

It was concluded that both Acapella and incentive spirometry treatment after coronary artery bypass graft improved blood gases.

Temporal Changes in Ventilator Settings in Patients With Uninjured Lungs: A Systematic Review

In patients with uninjured lungs, increasing evidence indicates that tidal volume (VT) reduction improves outcomes in the intensive care unit (ICU) and in the operating room (OR). However, the degree to which this evidence has translated to clinical changes in ventilator settings for patients with uninjured lungs is unknown. To clarify whether ventilator settings have changed, we searched MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science for publications on invasive ventilation in ICUs or ORs, excluding those on patients <18 years of age or those with >25% of patients with acute respiratory distress syndrome (ARDS). Our primary end point was temporal change in VT over time. Secondary end points were changes in maximum airway pressure, mean airway pressure, positive end-expiratory pressure, inspiratory oxygen fraction, development of ARDS (ICU studies only), and postoperative pulmonary complications (OR studies only) determined using correlation analysis and linear regression. We identified 96 ICU and 96 OR studies comprising 130,316 patients from 1975 to 2014 and observed that in the ICU, VT size decreased annually by 0.16 mL/kg (-0.19 to -0.12 mL/kg) (P < .001), while positive end-expiratory pressure increased by an average of 0.1 mbar/y (0.02-0.17 mbar/y) (P = .017). In the OR, VT size decreased by 0.09 mL/kg per year (-0.14 to -0.04 mL/kg per year) (P < .001). The change in VTs leveled off in 1995. Other intraoperative ventilator settings did not change in the study period. Incidences of ARDS (ICU studies) and postoperative pulmonary complications (OR studies) also did not change over time. We found that, during a 39-year period, from 1975 to 2014, VTs in clinical studies on mechanical ventilation have decreased significantly in the ICU and in the OR.

Acute effects of ventilator hyperinflation with increased inspiratory time on respiratory mechanics: randomized crossover clinical trial

Objective

To evaluate the effects of ventilator hyperinflation on respiratory mechanics.

Methods

A randomized crossover clinical trial was conducted with 38 mechanically ventilated patients with pulmonary infection. The order of the hyperinflation and control (without changes in the parameters) conditions was randomized. Hyperinflation was performed for 5 minutes in pressure-controlled ventilation mode, with progressive increases of 5cmH₂O until a maximum pressure of 35cmH₂O was reached, maintaining positive end expiratory pressure. After 35cmH₂O was reached, the inspiratory time and respiratory rate were adjusted so that the inspiratory and expiratory flows reached baseline levels. Measurements of static compliance, total resistance and airway resistance, and peak expiratory flow were evaluated before the technique, immediately after the technique and after aspiration. Two-way analysis of variance for repeated measures was used with Tukey's post hoc test, and p < 0.05 was considered significant.

Results

Ventilator hyperinflation increased static compliance, which remained at the same level after aspiration (46.2 ± 14.8 versus 52.0 ± 14.9 versus 52.3 ± 16.0mL/cmH₂O; p < 0.001). There was a transient increase in airway resistance (6.6 ± 3.6 versus 8.0 ± 5.5 versus 6.6 ± 3.5cmH₂O/Ls^-1; p < 0.001) and a transient reduction in peak expiratory flow (32.0 ± 16.0 versus 29.8 ± 14.8 versus 32.1 ± 15.3Lpm; p <0.05) immediately after the technique; these values returned to pretechnique levels after tracheal aspiration. There were no changes in the control condition, nor were hemodynamic alterations observed.

Conclusion

Ventilator hyperinflation promoted increased compliance associated with a transient increase in airway resistance and peak expiratory flow, with reduction after aspiration.

The immediate effects of breathing with oscillated inspiratory and expiratory airflows on secretion clearance in intubated patients with cervical spinal cord injury

STUDY DESIGN

A prospective, randomized crossover trial.

OBJECTIVES

To evaluate the efficacy of the combination of incentive spirometry with oscillation (OIS) and positive expiratory pressure with oscillation (OPEP) to promote secretion clearance in intubated patients with cervical spinal cord injury.

SETTING

Spinal cord unit, tertiary care hospital, North East Thailand.

METHODS

Thirteen intubated patients (C4-7, AIS score C) with secretion retention performed three interventions randomly allocated on consecutive days, a Sham deep breathing, OPEP and OPEP + OIS breathing exercise. Secretions were collected by sterile suction for 3 h before, and 3 h after, each intervention and wet weight recorded. Cardiopulmonary parameters were measured before and after each intervention.

RESULTS

The median (IQR) secretion wet weight pre-intervention was 2.61 g (2.21, 3.85) and in the 3 h after Sham there was an increase of 1.97 g (0.6, 3.6). The increase after OPEP was 2.67 g (1.7, 3.9) and after OPEP + OIS, 4.28 g (2.4, 6.7); all the increases being significant (p ≤ 0.007). The clearance after OPEP and OPEP + OIS were both greater than Sham while OPEP + OIS was greater than OPEP (p ≤ 0.019). There were no significant changes in cardiopulmonary measures following any intervention or when compared between interventions.

CONCLUSIONS

Deep breathing with an oscillated and humidified air flow in a combination of OIS + OPEP more than doubled secretion clearance and was more effective than OPEP or Sham deep breathing. There were no adverse effects of the procedures which were well tolerated by the patients and may be used to complement existing methods for secretion clearance.

Respiratory physiotherapy in intensive care unit: Bibliographic review

INTRODUCTION AND AIMS

Patients in intensive care unit are susceptible to complications due to different causes (underlying disease, immobilisation, infection risk…) The current main intervention in order to prevent these complications is respiratory physiotherapy, a common practice for nurses on a daily basis. Therefore, we decided to carry out this bibliographic review to describe the most efficient respiratory physiotherapy methods for the prevention and treatment of lung complications in patients in intensive care, taking into account the differences between intubated and non-intubated patients.

METHODOLOGY

The bibliographic narrative review was carried out on literature available in Pubmed, Cinahl and Cochrane Library. The established limits were language, evidence over the last 15 years and age.

RESULTS

Techniques involving lung expansion, cough, vibration, percussion, postural drainage, incentive inspirometry and oscillatory and non-oscillatory systems are controversial regarding their efficacy as respiratory physiotherapy methods. However, non-invasive mechanical ventilation shows clear benefits. In the case of intubated patients, manual hyperinflation and secretion aspirations are highly efficient methods for the prevention of the potential complications mentioned above. In this case, other RP methods showed no clear efficiency when used individually.

DISCUSSION AND CONCLUSIONS

Non-invasive mechanical ventilation (for non-intubated patients) and manual hyperinflation (for intubated patients) proved to be the respiratory physiotherapy methods with the best results. The other techniques are more controversial and the results are not so clear. In both types of patients this literature review suggests that combined therapy is the most efficient.

Positive expiratory pressure - Common clinical applications and physiological effects

Breathing out against resistance, in order to achieve positive expiratory pressure (PEP), is applied by many patient groups. Pursed lips breathing and a variety of devices can be used to create the resistance giving the increased expiratory pressure. Effects on pulmonary outcomes have been discussed in several publications, but the expected underlying physiology of the effect is seldom discussed. The aim of this article is to describe the purpose, performance, clinical application and underlying physiology of PEP when it is used to increase lung volumes, decrease hyperinflation or improve airway clearance. In clinical practice, the instruction how to use an expiratory resistance is of major importance since it varies. Different breathing patterns during PEP increase or reduce expiratory flow, result in movement of EPP centrally or peripherally and can increase or decrease lung volume. It is therefore necessary to give the right instructions to obtain the desired effects. As the different PEP techniques are being used by diverse patient groups it is not possible to give standard instructions. Based on the information given in this article the instructions have to be adjusted to give the optimal effect. There is no consensus regarding optimal treatment frequency and number of cycles included in each treatment session and must also be individualized. In future research, more precise descriptions are needed about physiological aims and specific instructions of how the treatments have been performed to assure as good treatment quality as possible and to be able to evaluate and compare treatment effects.