Human Lung Compliance During Prolonged Positive Pressure Ventilation

1967 ◽  
Vol 28 (1) ◽  
pp. 257-257 ◽  
Author(s):  
BRIAN C. JUDD ◽  
BENTON. D. KING
Author(s):  
Marco Betello ◽  
Raphael Giraud ◽  
Karim Bendjelid

AbstractUnderstanding the respiratory mechanics of ARDS patients is crucial to avoid ventilator-induced lung injury (VILI), and this is much more challenging if not only lung compliance is altered but the whole compliance of the respiratory system is abnormal, as in obese patients. We face this problem daily in the ICU, and to optimize ventilation, we estimate respiratory mechanics using an oesophageal balloon. The balloon position is crucial to assess reliable values. In the present technical note, we describe the use of echocardiography to confirm the correct position of this instrument.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Thomas Berlet ◽  
Mathias Marchon

This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were <3.5% of the delivered minute volume. At body temperature, the leakage rates of these tracheostomy tubes were <1%. The tracheal tube design was the main factor that determined the leakage characteristics. Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema.


Author(s):  
Jessica Leung ◽  
Thierry Beths ◽  
Michael Lynch ◽  
Sarah Frith ◽  
Sebastien H. Bauquier

Hypoxaemia is a common complication in anaesthetised or immobilised elephants. It is presumably because of hypoventilation and ventilation-perfusion mismatch. To prevent hypoxaemia, orotracheal intubation and positive pressure ventilation are recommended. This case report describes a hypoxaemic period despite positive pressure ventilation in a 46-year-old female Asian elephant (Elephas maximus) anaesthetised with azaperone-etorphine, medetomidine and an etorphine constant rate infusion in lateral recumbency for a dental procedure. The hypoxaemia was corrected utilising positive end-expiratory pressure (PEEP) of 5 cm – 10 cm H2O, a technique that has not previously been reported in the management of anaesthetised elephants. PEEP decreases atelectasis, shunt fraction, and increases lung compliance. Positive end-expiratory pressure was achieved by partial occlusion of the tailpiece of a manually triggered demand valve ventilator during expiration. This is a simple effective method of generating PEEP and correcting hypoxaemia without the need for any additional specialised equipment. However, PEEP decreased arterial blood pressure and should be implemented with caution if arterial blood pressure is not monitored.


2021 ◽  
Author(s):  
Randy Scott Carpenter ◽  
Mark F Brady ◽  
Ethan Monhollon ◽  
Samantha Ni ◽  
Shane Young ◽  
...  

Abstract Background: During positive pressure ventilation, peak inspiratory pressure (PIP) and Tidal Volume (TV) must be kept at optimal levels to achieve appropriate ventilation without causing complications, such as trauma to the lung parenchyma or stomach insufflation. Manual ventilation using a Bag-valve-mask (BVM) results in highly variable TVs and PIPs that could increase the risk of volutrauma and barotrauma. It is unknown whether pathologic changes in lung compliance alter the TV and PIP during manual ventilation. Methods: This study used a lung simulator and volunteer medical students, medics and nurses to assess whether the pressure and flow limiting SotairTM device resulted in more appropriate TVs and PIPs during manual ventilation compared to BVM only, using a mechanical ventilator as the standard. The secondary aim was to determine whether decreased lung compliance, which simulates the physiology of lungs with Acute Respiratory Distress Syndrome (ARDS), affected the conclusion. Results: We found that the SotairTM device helped maintain PIP and TV closer to mechanical ventilator baseline levels than BVM only ventilation across lung compliance settings. The SotairTM device also helped providers maintain PIP levels below the threshold of pressures known to cause gastric insufflation and barotrauma. Conclusions: This data indicates that manual ventilation using the SotairTM device is a safer option than unmitigated BVM only ventilation in both normal and decreased lung compliance conditions.


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