Pulmonary artery pulsatility is the main cause of cardiogenic oscillations

Abstract

The genesis of cardiogenic oscillations, i.e. the small waves in airway pressure (COS(paw)) and flow (COS(flow)) signals recorded at the airway opening is under debate. We hypothesized that these waves are originated from cyclic changes in pulmonary artery (PA) pressure and flow but not from the physical transmission of heartbeats onto the lungs. The aim of this study was to test this hypothesis. In 10 anesthetized pigs, COS were evaluated during expiratory breath-holds at baseline with intact chest and during open chest conditions at: (1) close contact between heart and lungs; (2) no heart-lungs contact by lifting the heart apex outside the thoracic cavity; (3) PA clamping at the main trunk during 10 s; and (4) during manual massage after cardiac arrest maintaining the heart apex outside the thorax, with and without PA clamping. Baseline COS(paw) and COS(flow) amplitude were 0.70 ± 0.08 cmH(2)O and 0.51 ± 0.06 L/min, respectively. Both COS amplitude decreased during open chest conditions in step 1 and 2 (p < 0.05). However, COS(paw) and COS(flow) amplitude did not depend on whether the heart was in contact or isolated from the surrounding lung parenchyma. COS(paw) and COS(flow) disappeared when pulmonary blood flow was stopped after clamping PA in all animals. Manual heart massages reproduced COS but they disappeared when PA was clamped during this maneuver. The transmission of PA pulsatilty across the lungs generates COS(paw) and COS(flow) measured at the airway opening. This information has potential applications for respiratory monitoring.

Aneurysmal Oscillation of the Capnogram: A Case Report

“…The normally smooth alveolar plateau phase seen with mechanical ventilation can be disrupted by cardiogenic oscillations, spontaneous ventilatory efforts, or surgical movement artifacts. 3,4…”

“…The normally smooth alveolar plateau phase seen with mechanical ventilation can be disrupted by cardiogenic oscillations, spontaneous ventilatory efforts, or surgical movement artifacts. 3,4 cases-anesthesia-analgesia.org a & a pRaCtICe Contribution: This author helped with data collection and manuscript preparation. This manuscript was handled by: BobbieJean Sweitzer, MD, FACP.…”

Delayed tracheal extubation after cardiac surgery due to cardiogenic ventilator auto-triggering: a case report

“…The mechanism of cardiogenic oscillation is not completely clear, but there are several possible contributory factors. Pulmonary artery pulsatility is reported to be the main cause of cardiogenic oscillations [ 9 ]. Additionally, changes in heart volume during systole and diastole may change intrathoracic pressure, which may change airway pressure or cause compression and expansion of the lung [ 10 ].…”

Assessment and determining factors of the awareness and knowledge of healthcare providers about Cardiogenic Oscillations and its effect on mechanically ventilated patients: A multivariate logistic modeling

“…In addition, heart movement can cause compression or expansion of the adjacent lung, resulting in gas movement in the airways (Imanaka et al, 2000;West and Hugh-Jones, 1961). Because the two organs are still in close contact, many researchers conclude that the primary cause of COs is the purely physical transmission of heartbeats to the lungs (Ferrando et al, 2018;Shaffer et al, 2014;Suarez-Sipmann et al, 2013).…”