Effect of manual hyperinflation on haemodynamics in an animal model

Abstract

Significant haemodynamic changes occurred in this animal model. The increased intrathoracic pressure, applied for an increased period during inspiration, decreased cardiac output with compensatory vasoconstriction evident by the increased systemic vascular resistance and mean arterial pressure. The results suggest that there may be a decrease in cardiac output after increased positive pressure in subjects with normal cardiac and respiratory function.

Acute bag-valve breathing maneuvers plus manual chest compression is safe during stable septic shock: a randomized clinical trial

“…(4,9,19) A previous randomized clinical trial has shown that the use of a positive expiratory pressure (PEP) mask can significantly increase mean arterial pressure, mean pulmonary artery pressure, central venous pressure and pulmonary artery occlusion pressure. However, these differences were considered not to have a relevant harmful clinical impact on hemodynamic stability.…”

“…(9) These data were chosen because, to the best of our knowledge, the study from which it came was the most similar to ours at the time of the study design. Heart rate, MAP, and pulmonary artery pressure were used as the main endpoints.…”

“…(9) Thus, hemodynamic changes that are inherent to the procedure might contraindicate chest physiotherapy in some clinical conditions, such as septic shock.…”

Manual hyperinflation causes norepinephrine release

“…We have also demonstrated clinically significant decreases in CO in an animal model with normal cardiac function during MHI. 41 An FiO 2 of 1.0 was used during MHI because it was believed that if alveoli were recruited by the hyperinflation procedure, desaturation caused by pulmonary hypoxemic vasoconstriction may have occurred. 42 This, however, could have had an effect on hemodynamics because an FiO 2 of 1.0 can decrease CO and peripheral resistance.…”

Experimental Model of Atelectasis in Newborn Piglets

“…3 A study group in Australia used a healthy adult sheep model to evaluate variability in the performance of manual physical therapy by physiotherapists. 4,5 Adult rabbits were used as an experimental model in Japan, in studies of the effectiveness of rib cage compression in removing secretions and improving the resolution of obstructive atelectasis, 6,7 and the effectiveness of physical therapy techniques in removing secretions from the trachea, using a meconium aspiration syndrome model. 8 Brazilian researchers proposed a model that mimics respiratory physiotherapy in Wistar rats.…”