Katia de Miranda Avena, Antonio Carlos Magalhães Duarte, Sergio Luiz Domingues Cravo,
Maria José Junho Sologuren, Ada Clarice Gastaldi
Objective: Manually assisted coughing (MAC) consists of a vigorous thrust applied to the chest at the beginning of a spontaneous expiration
or of the expiratory phase of mechanical ventilation. Due to routine use of MAC in intensive care units, the objective of this study was to
assess the effects of MAC on respiratory system mechanics in patients requiring full ventilatory support. Methods: We assessed 16 sedated
patients on full ventilatory support (no active participation in ventilation). Respiratory system mechanics and oxyhemoglobin saturation
were measured before and after MAC, as well as after endotracheal aspiration. Bilateral MAC was performed ten times on each patient, with
three respiratory cycle intervals between each application. Results: Data analysis demonstrated a decrease in resistive pressure and respiratory
system resistance, together with an increase in oxyhemoglobin saturation, after MAC combined with endotracheal aspiration. No evidence of
alterations in peak pressures, plateau pressures or respiratory system compliance change was observed after MAC. Conclusions: The use of
MAC alters respiratory system mechanics, increasing resistive forces by removing secretions. The technique is considered safe and efficacious
for postoperative patients. Using MAC in conjunction with endotracheal aspiration provided benefits, achieving the proposed objective: the
displacement and removal of airway secretions.
Keywords: Cough; Sputum; Respiratory mechanics; Respiration, artificial.