Effects of Mechanical Insufflation-Exsufflation With Optimized Settings on Wet Mucus Volume During Invasive Ventilation

N/ANot Yet RecruitingNCT06491017

Hospital Clinic of Barcelona26 enrolled

Overview

Retention of airway secretions is a frequent complication in critically ill patients requiring invasive mechanical ventilation (MV).This complication is often due to excessive secretion production and ineffective secretion clearance. Mechanical insufflator-exsufflator (MI-E) is a respiratory physiotherapy technique that aims to assist or simulate a normal cough by using an electro-mechanical dedicated device. A positive airway pressure is delivered to the airways, in order to hyperinflate the lungs, followed by a rapid change to negative pressure that promotes a rapid exhalation and enhances peak expiratory flows. However, there is no consensus on the best MI-E settings to facilitate secretion clearance in these patients. Inspiratory and expiratory pressures of ±40 cmH2O and inspiratory-expiratory time of 3 and 2 seconds, respectively, are often used as a standard for MI-E programming in the daily routine practice, but recent laboratory studies have shown significant benefits when MI-E setting is optimized to promote an expiratory flow bias. The investigators designed this study to compare the effects of MI-E with an optimized setting versus a standard setting on the wet volume of suctioned sputum in intubated critically ill patients on invasive MV for more than 48 hours.

Retention of airway secretions is a frequent complication in critically ill patients requiring invasive mechanical ventilation (MV). This complication is often due to excessive secretion production and ineffective secretion clearance. One of the main causes is the presence of an endotracheal tube (ETT) which has been shown to decrease mucociliary clearance and hinders the generation of adequate peak expiratory flows when coughing. Other factors such as suboptimal airway humidification, inspiratory flow bias, semi-recumbent position, prolonged immobilization and respiratory muscles weakness further impair sputum clearance. Mucus retention may impede optimal gas exchange, and lead to atelectasis, increased work of breathing, bacterial colonization and development of pulmonary infections, prolonging the need for MV. These conditions, added to initial factors, increase morbidity and mortality in critically ill patients, making secretion clearance an essential factor for patients' prognosis. Secretion removal techniques, such as, manual or mechanical hyperinflations, chest vibrations or expiratory rib cage compressions, prior to suctioning, are commonly used by physiotherapists in intensive care units (ICU). However, the evidence assessing respiratory physiotherapy techniques in critically ill patients is scant and sometimes inconsistent, making it difficult to extrapolate the results and standardize the clinical practice. Moreover, the execution of these techniques often differs among professionals based on their experience, training, and resources availability. Mechanical insufflator-exsufflator (MI-E) is a respiratory physiotherapy technique that aims to assist or simulate a normal cough by using an electro-mechanical dedicated device. A positive airway pressure is delivered to the airways, in order to hyperinflate the lungs, followed by a rapid change to negative pressure that promotes a rapid exhalation and enhances peak expiratory flows. MI-E is commonly used in patients with ineffective cough mainly due to respiratory pump failure (i.e: neuromuscular patients), and has been proposed in recent years as a technique with great potential to non-invasively clear secretions in the critically ill. Indeed, recent studies have evaluated safety and efficacy of MI-E in intubated critically ill patients with promising results and no associated adverse events. However, there is no consensus on the best MI-E settings to facilitate secretion clearance in these patients. Inspiratory and expiratory pressures of ±40 cmH2O and inspiratory-expiratory time of 3 and 2 seconds, respectively, are often used as a standard for MI-E programming in the daily routine practice, but recent laboratory studies have shown significant benefits when MI-E setting is optimized to promote an expiratory flow bias. For instance, Volpe et al. achieved significant differences in artificial mucus displacement when inspiratory flows were lowered, inspiratory time was increased to 4 seconds, and expiratory flow bias was enhanced by increasing the expiratory pressure over the inspiratory pressure. More recently, evidence from a swine model confirmed the improvement in mucus movement velocity when expiratory pressure was enhanced to increase the difference between inspiratory and expiratory pressures (i.e: +40/-70cmH2O). Importantly, increased inspiratory pressures should be avoided to prevent movement of mucus toward the lungs and potential associated detrimental effects such as alveolar damage or hemodynamic impairment. The investigators designed this study to compare the effects of MI-E with an optimized setting versus a standard setting on the wet volume of suctioned sputum in intubated critically ill patients on invasive MV for more than 48 hours.

Interventions

MI-E Intervention protocolDEVICE

The endotracheal tube cuff will be inflated to 40 cmH2O and MI-E device will be used to deliver MI-E in automatic mode, with 4 sets of 5 respiratory cycles each and a 1-minute interval between each set. Before initiation of the MI-E intervention protocol, the investigators will carry out a short-period test to find the appropriate MI-E settings to achieve inspiratory volumes of ≥1 liter and PEF ≥80 L/min. Concretely, inspiratory and expiratory time will always be set at 4 seconds and 2 seconds, respectively, and inspiratory flow will always be in slow mode. Once the appropriate inspiratory pressure will be found, the expiratory pressure will be initially set to exceed in 30 cmH2O the inspiratory pressure and, if required, this will be increased by 5 cmH2O until achieving a PEF ≥80 L/min with a maximum expiratory pressure of 70 cmH2O.

Standard MI-E settingDEVICE

Cough Assist E70 device (Philips Respironics, USA, Andover, Massachusetts) will be used to deliver MI-E in automatic mode, with 4 sets of 5 respiratory cycles each and a 1-minute interval between each set. During the 1-minute pause between sets, the patient will be reconnected to the ventilator to avoid desaturation and de-recruitment during procedures. PEEP will remain stable during the protocol. The standard MI-E setting will consist of in-expiratory pressures of +40/-40 cmH2O, medium inspiratory flow, with 3 seconds and 2 seconds of in-expiratory time, respectively, and 1-second pause.

Outcomes

Primary Outcomes

Wet volume of sputum

Airway suctioning will be carried out using an open aspiration procedure, using a 12French catheter connected to a sterile collection container. The suction procedure will be performed according to international guidelines . If necessary, 5 ml of saline solution will be used to rinse the catheter in case of impacted secretions inside the catheter; later this volume will be subtracted from the final volume of secretions, thus obtaining the exact amount of wet sputum.

Time frame: Immediately after each intervention

Secondary Outcomes

Respiratory parameters: Inspiratory flow (PIF)

Flow will be measured with a heated pneumotachograph (Fluxmed GrH monitor MBMED, Buenos Aires, Argentina) inserted between the proximal tip of the endotracheal tube and the Y-piece of the breathing circuit. All signals will be recorded on a personal computer for subsequent analysis with dedicated software (FluxReview software MBMED, Buenos Aires, Argentina)

Time frame: Before and during MI-E interventions, delivered tidal volumes will be recorded, PIF and PEF will be assessed for each insufflation-exsufflation cycle, and the PEF-PIF difference and the PEF:PIF ratio will be calculated

Respiratory parameters: Peak expiratory flow (PEF)

Respiratory parameters: difference between PEF-PIF;

Respiratory parameters: PEF:PIF ratio

Pulmonary mechanics parameters: Static Compliance (Cst)

Pressure signals will be measured with a heated pneumotachograph (Fluxmed GrH monitor MBMED, Buenos Aires, Argentina) inserted between the proximal tip of the endotracheal tube and the Y-piece of the breathing circuit. All signals will be recorded on a personal computer for subsequent analysis with dedicated software (FluxReview software MBMED, Buenos Aires, Argentina)

Time frame: Airway pressures will be recorded before, immediately after MI-E intervention, after endotracheal suctioning, and 1h after endotracheal suctioning. Respiratory system compliance and airway resistance will be calculated using standard formulas.

Pulmonary mechanics parameters: Airway resistance (Raw)

Hemodynamics values: Heart rate

Hemodynamics parameters will be recorder from the patient's monitor.

Time frame: Before, immediately after MI-E interventions and after endotracheal suctioning.

Hemodynamics values: Mean arterial pressure

Hemodynamics parameters will be recorded from the patient's monitor.

Time frame: Before, immediately after MI-E interventions and after endotracheal suctioning.

Gas exchange: Arterial blood gas analysis

Parameters will be recorded from the patient's monitor arterial blood gas analysis.

Time frame: Before, immediately after endotracheal suctioning and 1 hour after interventions.

Gas exchange: Pulseoximeter oxygen saturation (SpO2)

Parameters will be recorded from patient's pulseoximetry.

Time frame: Before, immediately after endotracheal suctioning and 1 hour after interventions.

Adverse events

All adverse events that force the interruption of the interventions will be recorded. Reasons to stop MI-E will be haemodynamic instability, severe desaturation, structural damage caused to the airway (i.e. pneumothorax), airway obstruction or difficulty in correct ventilation of the patient.

Time frame: During the intervention/procedure and immediately after the intervention/procedure.

Numbers of participants with adverse events

Relationship between the participants who have reported adverse effects and the number of adverse effects in the study.

Time frame: During the intervention/procedure and immediately after the intervention/procedure.

Effects of Mechanical Insufflation-Exsufflation With Optimized Settings on Wet Mucus Volume During Invasive Ventilation

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts