2. Methods
fracture
SUBCUTANEOUS EMPHYSEMA, HEMODYNAMIC INSTABILITY, DECUBITUS, BRONCHOSPASM
This is a cross-randomized clinical trial developed at the Instituto de Cardiologia de Porto Alegre/RS Brazil, following the rules of the Consort Statement [The survey was carried out from February 2021 to December 2021, when all individuals were admitted to the Post-Operative Unit or Intensive Care Unit. We included hemodynamically stable male and female patients aged over 18 years who used invasive mechanical ventilation for at least 48 h. Exclusion criteria were the presence of a chest drain, subcutaneous emphysema, rib fracture, hemodynamic instability (BP < 59 mmHg or 120 mmHg), severe bronchospasm, peak pressure > 40 cmHOf the 36 subjects, 31 met the inclusion criteria and were randomized by a blinded researcher, using the randomization.com program in a 1:1 crossover block, allocating the patient to one of the groups, and thus determining which of the techniques would be performed on the first day. Mucolytics were not administered in patients.The control group was established for the bag-squeezing technique and the intervention group for the PEEP-ZEEP maneuver associated with manual chest compression. In both, tracheal aspiration was performed 2 h before in order to match the groups in relation to the volume of secretion, and also immediately after the end of the techniques in order to measure the amount of secretion collected.Control tracheal aspiration was performed with the patient in dorsal decubitus and the headboard elevated at 30°, using a size-12 probe (Mark Med), with vacuum set at −40 cmHIn the control group, patients were in the supine position, and manual and rhythmic hyperinflations were performed, alternating with manual chest compressions during expiration. Insufflation was performed slowly with a high tidal volume, followed by an inspiratory pause of two to three seconds and then the rapid release of the resuscitator. The technique was performed for 10 uninterrupted minutes [Patients in the intervention group had their ventilatory mode adjusted to volume-cycled assist-controlled, and 6 mL/kg of predicted weight was calculated. During the maneuver, during the inspiratory phase, PEEP (positive end-expiratory pressure) was increased to 15 cmHHemodynamic data were recorded using the multiparameter monitor at the inpatient units (Philips), and respiratory mechanics data were collected from the mechanical ventilator screen (Servo S; Drager; Newport; Leistung) before and after the techniques. The amount of aspirated secretion was deposited in the collection flask (Water Seal 120 mL) and weighed on a high-precision Ohaus AdventurerTM scale, deducting the weight of the flask.