Mechanical Insufflation-Exsufflation (Cough Assist) in Critically Ill Adults (ACACIA)

Mechanical Insufflation-Exsufflation (Cough Assist) in Critically Ill Adults (ACACIA)-a Randomized Clinical Feasibility Trial

The goal of this randomized feasibility trial is to evaluate the feasibility of Mechanical Insufflation-Exsufflation (MI-E) in invasively ventilated critically ill patients. The main question[s] it aims to answer are: Is MI-E feasible? Is MI-E safe? Participants in the intervention group will receive: MI-E Airway secretions will be removed by endotracheal suctioning, as part of routine airway care. Manual hyperinflation will only be used when necessary in an emergency situation. Patients in the control group will receive endotracheal suctioning and manual hyperinflation when clinically indicated. The primary outcome is the proportion of delivered MI-E sessions (2 times per calendar day a MI-E session of 3 x 3 cycles of an in- and exsufflation) per patient according to study protocol (feasibility). Secondary outcomes are the total number of serious adverse events in relation to MI-E (safety) and preliminary exploratory data on the need for airway care interventions and clinical outcomes including duration of invasive ventilation, length of stay in ICU and mortality (efficacy).

Bedside nurses, trained in using the MI-E device, will apply MI-E sessions at two moments per calendar day (morning and afternoon) for a maximum of 7 days while a patient is invasively ventilated. MI-E settings are a 2-second insufflation and an immediate 2-second exsufflation. The cycles of the MI-E session will be performed with a positive and negative pressure of 40 cmH2O. The program is set up with the possibility of auto-triggering by the patient.

Due to the nature of the intervention, blinding of healthcare professionals and any research personnel involved in the delivery of the intervention is not possible.

Invasively ventilated patients will receive MI-E until successful extubation or for a maximum of 7 days. MI-E will be given in the morning and afternoon each calendar day. Patients will be pre-oxygenated with FiO2 100% prior to disconnection from the ventilator; additional 15 litres oxygen can be added; A pre-set program is used: three times three cycles with a 2-second insufflation and an immediate 2-second exsufflation. The cycles of the MI-E session will be performed with a positive and negative pressure of 40 cmH2O. The program is set up with the possibility of auto-triggering by the patient.

Patients in the control group will receive usual airway care which includes endotracheal suctioning and manual hyperinflation used when indicated based on clinical signs as part of regular airway care. Care protocols for endotracheal suctioning and manual hyperinflation are predefined. As with the intervention arm, there will be no use of saline instillation during suctioning. Manual hyperinflation technique is described in the care protocol of the intensive care unit and ICU nurses are trained to perform this technique.

MI-E will be applied twice a day in invasively ventilated patients. Since the severity of illness can change in the ICU, each day the attending nurse will check for clinical reasons to not apply MI-E with regard to safety. The following clinical criteria are predefined as a reason to refrain from MI-E at that day: severe ventilator instability (requiring > 12 cm H2O PEEP and dependency of > 60% FiO2); severe hemodynamic instability (a need for large and sustained increase in continuous administration of intravenous vasopressive medication that are adjusted on a frequent basis in each nursing shift); extra corporal membrane oxygenation (ECMO); and deeply sedated patient (RASS score ≤ -4).

the proportion of complete sessions of MI-E every calender day (i.e. two MI-E sessions with 3 x 3 cycles of an in- and exsufflation) for all patients with a maximum of seven days of invasive ventilation

incidence of pneumothorax for which drainage is needed attributed to MI-E or to routine airway care procedures (i.e., manual hyperinflation)

incidence of endotracheal tube obstruction due to mucus plugging attributed to MI-E or regular airway care

1 = Completely disagree, 2 = Disagree, 3 = Neither agree nor disagree, 4 = Agree, 5 = Response scale 1 (completely disagree) - 5 (completely agree)

1 = Completely disagree, 2 = Disagree, 3 = Neither agree nor disagree, 4 = Agree, 5 = Response scale 1 (completely disagree) - 5 (completely agree)

1 = Completely disagree, 2 = Disagree, 3 = Neither agree nor disagree, 4 = Agree, 5 = Response scale 1 (completely disagree) - 5 (completely agree)

Inclusion Criteria: admission to one of the participating ICUs; receiving invasive mechanical ventilation via an endotracheal tube; and expected to need invasive ventilation for more than 48 hours from consideration for inclusion. Exclusion Criteria: use of MI-E before hospital admission, i.e., at home; known presence of bullous emphysema; known bronchopleural fistula; known pneumothorax or pneumomediastinum; known rib fractures; known barotrauma; known unstable spinal fractures; unsecured subarachnoidal haemorrhage; uncontrollable intracranial pressures; and any infection, or colonization with pathogens that requires strict aerogenic isolation. With an exception for patients in cohort isolation due to COVID-19.

Stilma W, Verweij L, Spek B, Scholte Op Reimer WJM, Schultz MJ, Paulus F, Rose L. Mechanical insufflation-exsufflation for invasively ventilated critically ill patients-A focus group study. Nurs Crit Care. 2022 Dec 4. doi: 10.1111/nicc.12858. Online ahead of print.

Swingwood EL, Stilma W, Tume LN, Cramp F, Voss S, Bewley J, Ntoumenopoulos G, Schultz MJ, Scholte Op Reimer W, Paulus F, Rose L. The Use of Mechanical Insufflation-Exsufflation in Invasively Ventilated Critically Ill Adults. Respir Care. 2022 Aug;67(8):1043-1057. doi: 10.4187/respcare.09704. Epub 2022 May 24.

Rose L, Adhikari NK, Leasa D, Fergusson DA, McKim D. Cough augmentation techniques for extubation or weaning critically ill patients from mechanical ventilation. Cochrane Database Syst Rev. 2017 Jan 11;1(1):CD011833. doi: 10.1002/14651858.CD011833.pub2.