What is the Pendelluft effect?
Background: Pendelluft phenomenon is defined as the displacement of gas from a more recruited nondependent (ND) lung region to a less recruited dependent (D) lung region. This phenomenon may cause lung injury.
What is Pendelluft ventilation?
Pendelluft is a phenomenon known as the pendular movement of gas between different lung regions; classically it is described during controlled mechanical ventilation when regional heterogeneity in time constants (compliance * resistance) is present: after the tidal volume has been delivered, the gas moves from “faster” …
What is FiO2 on ventilator?
FiO2: Percentage of oxygen in the air mixture that is delivered to the patient. Flow: Speed in liters per minute at which the ventilator delivers breaths. Compliance: Change in volume divided by change in pressure.
What is high frequency oxygen ventilation?
High-frequency ventilation (HFV) is a form of mechanical ventilation that combines very high respiratory rates (>60 breaths per minute) with tidal volumes that are smaller than the volume of anatomic dead space [1].
What is paradoxical chest movement?
Paradoxical breathing is the term for a sign of respiratory distress associated with damage to the structures involved in breathing. Instead of moving out when taking a breath, the chest wall or the abdominal wall moves in. Often, the chest wall and the abdominal wall move in opposite directions with each breath.
What is normal fi02?
FIO2 is typically maintained below 0.5 even with mechanical ventilation, to avoid oxygen toxicity, but there are applications when up to 100% is routinely used. Often used in medicine, the FIO2 is used to represent the percentage of oxygen participating in gas-exchange.
What is normal FiO2 percentage?
21%
The natural air we breathe contains 21% oxygen (21% FiO2) and 79% nitrogen at all times (with some trace gases). The FiO2 coming from a portable oxygen concentrator can vary anywhere from 90–96% FiO2.
What does Pendelluft stand for in medical terms?
/pen·del·luft/ (pen´del-looft) the movement of air back and forth between the lungs, resulting in increased dead space ventilation.
Why does Pendelluft occur in assisted mechanical ventilation?
Pendelluft, the movement of gas within different lung regions, is present in animal models of assisted mechanical ventilation and associated with lung overstretching. Due to rebreathing of CO 2 as compared to fresh gas, pendelluft might reduce ventilatory efficiency possibly exacerbating patient’s respiratory workload during weaning.
What causes Pendelluft in an injured lung?
Abstract. However, in a patient with injured lungs, we observed (using electrical impedance tomography) a pendelluft phenomenon (movement of air within the lung from nondependent to dependent regions without change in tidal volume) that was caused by spontaneous breathing during mechanical ventilation.
Which is the best description of Pendelluft theory?
There are several theories to explain this idea of a better ventilation-perfusion ratio: bulk flow, coaxial flow, Taylor dispersion, pendelluft, and augmented molecular diffusion. Pendelluft is one theory among those studying HFOV and attempts explain why HFOV succeeds in preventing ALI in patients with varying time constants.