Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist—Better Approaches to Patient Ventilator Synchrony?
Section snippets
Transmission of respiratory motoneuron output to ventilation: the neuroventilatory coupling
To recognize the complexity of patient-ventilator interaction, the chain-of-events that take place during spontaneous breathing are presented in Fig. 1 and explained in the rest of this section.
Voluntary and involuntary control of the respiratory muscles originate from separate sites in the central nervous system and have separate descending pathways. Voluntary control arises from the motor and premotor cortex, whereas involuntary control is mediated by both rhythmic and nonrhythmic systems
Neural feedback from the respiratory system
Respiration is regulated by a very complete feedback system, including many reflex loops, which are often not considered in the clinical application of mechanical ventilation of spontaneously breathing patients.
Integration of a mechanical ventilator
Mechanical ventilation mainly accomplishes two tasks: it provides adequate ventilation and it unloads the respiratory muscles. If mechanical ventilation is applied without coordination to inspiratory muscle activity (asynchronous), ventilation can reduce respiratory drive primarily via a chemoreceptor response. If the assist is delivered synchronously with inspiratory effort, it will overcome increased elastic and resistive loads and compensate for muscle weakness.
To ensure that assist is
Summary
Patient-ventilator interaction is a complex topic, where interaction between patient effort, triggering, assist levels, off-cycling, and sedation all play a role. Patient-ventilator asynchrony prolongs the duration of mechanical ventilation and this may be interrelated with sedation practice. It is therefore important to raise the awareness of how mechanical ventilation affects breathing pattern and effort via on-line monitoring, allowing us to better understand how to best tailor the assist
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Design Features of Modern Mechanical Ventilators
2016, Clinics in Chest MedicineVentilator Management: A Systematic Approach to Choosing and Using New Modes
2016, Advances in SurgeryCitation Excerpt :We also know that early liberation from ventilation is vital and that should be our ultimate and daily goal [5]. There are a variety of studies demonstrating increased synchrony with the vent, decreased minutes on the vent, and improved prediction for extubation success [6–8], but there is little evidence that these short-term outcomes have a long-term impact for our patients [9]. We do know that to achieve low tidal volumes in ARDS and early extubation, protocols or guidelines driven by nonphysicians are successful [10].
Mechanical Ventilation
2015, Murray and Nadel's Textbook of Respiratory Medicine: Volume 1,2, Sixth EditionApplication of neurally adjusted ventilatory assist in neonates
2014, Seminars in Fetal and Neonatal MedicineCitation Excerpt :A variety of biological sensors provides neural feedback and adjusts the respiratory drive with each spontaneous breath. This involves a very complex regulatory system including stretch receptors in the lung, the Hering–Breuer reflex, lung compliance changes, upper airway receptors, peripheral chemoreceptors in the carotid body, and central chemoreceptors located in the brain stem [23,24]. Mechanical ventilation provides appropriate unloading of the respiratory muscles and maintains adequate gas exchange until the respiratory disease that is responsible for the patient's respiratory insufficiency has improved [10,25].
Remembering Medical Ventilators and Masks in the Days of COVID-19: Patenting in the Last Decade in Respiratory Technologies
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Dr. Sinderby and Dr. Beck have made inventions related to neural control of mechanical ventilation that are patented. The license for these patents belongs to Maquet Critical Care. Future commercial uses of this technology may provide financial benefit to Dr. Sinderby and Dr. Beck through royalties. Dr. Sinderby and Dr. Beck each own 50% of Neurovent Research Inc., a research and development company that builds the equipment and catheters for research studies. Neurovent Research Inc. has a consulting agreement with Maquet Critical Care.