Effects of manual chest compression on expiratory flow bias during the positive end-expiratory pressure-zero end-expiratory pressure maneuver in patients on mechanical ventilation

Abstract

Objective: To investigate the effects of manual chest compression (MCC) on the expiratory flow bias during the positive end-expiratory pressure-zero end-expiratory pressure (PEEP-ZEEP) airway clearance maneuver applied in patients on mechanical ventilation. The flow bias, which influences pulmonary secretion removal, is evaluated by the ratio and difference between the peak expiratory flow (PEF) and the peak inspiratory flow (PIF). Methods: This was a crossover randomized study involving 10 patients. The PEEP-ZEEP maneuver was applied at four time points, one without MCC and the other three with MCC, which were performed by three different respiratory therapists. Respiratory mechanics data were obtained with a specific monitor. Results: The PEEP-ZEEP maneuver without MCC was enough to exceed the threshold that is considered necessary to move secretion toward the glottis (PEF − PIF difference > 33 L/min): a mean PEF − PIF difference of 49.1 ± 9.4 L/min was achieved. The mean PEF/PIF ratio achieved was 3.3 ± 0.7. Using MCC with PEEP-ZEEP increased the mean PEF − PIF difference by 6.7 ± 3.4 L/min. We found a moderate correlation between respiratory therapist hand grip strength and the flow bias generated with MCC. No adverse hemodynamic or respiratory effects were found. Conclusions: The PEEP-ZEEP maneuver, without MCC, resulted in an expiratory flow bias superior to that necessary to facilitate pulmonary secretion removal. Combining MCC with the PEEP-ZEEP maneuver increased the expiratory flow bias, which increases the potential of the maneuver to remove secretions.

Value of Peak Expiratory Flow Rate in Evaluating Cough Ability in Patients Undergoing Lung Surgery

“…If the ineffective cough occurred after operation, timely detection and effective measures will also help to prevent the occurrence of PPCs. Commonly used clinical auxiliary cough and expectoration methods include airway atomization, knocking on the back, vibration expectoration, pressing stimulation, and compressing the chest wall [ 9 – 12 ]. The ineffective cough caused by decreased muscle strength could be solved by compressing the chest wall.…”

PEEP: dos lados de la misma moneda

“…71 En los escenarios críticos donde el PEEP ofrezca Tabla 3: Cambios fisiológicos en la vía aérea/ventilación de la embarazada. www.medigraphic.org.mx más riesgo que beneficio es donde se debe de tomar esta actitud, en aquéllas donde genere presión al borde del colapso o la falla hemodinámica, como lo son la falla ventricular derecha, hay que recordar que el PEEP ofrece una presión sobre el alveolo y puede repercutir directamente sobre el VD, 72,73 tromboembolia pulmonar (TEP), esto debido a que el PEEP incrementa la sobrecarga del VD, por lo que debe evitarse incluso la intubación en el paciente con TEP (Figura 10), 74 éstas son dos indicaciones del ZEEP, existen puntos controversiales como el paciente con hipertensión pulmonar severa y fallo ventricular izquierdo con choque cardiogénico, 75 hay que recordar las dos indicaciones puntuales de ZEEP; TEP y fallo del VD, siempre individualizar al paciente y recordar las dos preguntas iniciales: ¿existe el PEEP fisiológico? y ¿qué ofrece el PEEP al alveolo?…”

Airway Clearance Techniques for Mechanically Ventilated Patients: Insights for Optimization

“…Regarding its objectives, ERRC is usually applied either to assist with secretion movement from distal to proximal airways, or to remove secretion from large airways. 45,46 In theory, if ERRC is applied with gradual intensity (from gentle to strong) to prolong exhalation after the onset of the expiratory phase, it removes secretions from distal airways. On the other hand, if ERRC is applied with hard compressions to increase PEF and synchronized with the onset of expiration, it removes secretions from proximal airways.…”

“…Another study from the same group also confirmed that combining the hard/brief ERCC with PEEP-ZEEP increased the expiratory flow bias. 46 Figure 4 illustrates the effect of combining ERCC with PEEP-ZEEP. One limitation of this technique is that using PEEP-ZEEP may induce alveolar collapse in patients with high lung elastance and unstable alveoli.…”