Respiratory muscle recruitment during mechanical ventilation: Effects of ventilator settings

Abstract Although mechanical ventilation is a lifesaving treatment, abundant evidence indicates that its prolonged use (1 week or more) promotes respiratory muscle weakness due to both contractile dysfunction and atrophy. Along with the diaphragm, the intercostal muscles are one of the most important groups of respiratory muscles. In recent years, muscular ultrasound has become a useful bedside tool for the clinician to identify patients with respiratory muscle dysfunction related to critical illness and/or invasive mechanical ventilation. Images obtained over the course of illness can document changes in muscle dimension and can be used to estimate changes in function. Recent evidence suggests the clinical usefulness of ultrasound imaging in the assessment of intercostal muscle function. In this narrative review, we summarize the current literature on ultrasound imaging of the parasternal intercostal muscles as used to assess the extent of muscle activation and muscle weakness and its potential impact during discontinuation of mechanical ventilation. In addition, we proposed a practical flowchart based on recent evidence and experience of our group that can be applied during the weaning phase. This approach integrates multiple predictive parameters of weaning success with respiratory muscle ultrasound.

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Optimization of Respiratory Muscle Relaxation during Mechanical Ventilation

Anesthesiology ◽

10.1097/00000542-198807000-00005 ◽

1988 ◽

Vol 69 (1) ◽

pp. 29-35 ◽

Cited By ~ 75

Author(s):

Michael E. Ward ◽

Claude Corbeil ◽

William Gibbons ◽

Stephen Newman ◽

Peter T. Macklem

Keyword(s):

Mechanical Ventilation ◽

Respiratory Muscle ◽

Muscle Relaxation

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Efficacy of breathing retraining program on bedside assessment of pulmonary function

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v11i2.2019 ◽

2020 ◽

Vol 11 (2) ◽

pp. 1467-1471

Author(s):

Ganapathy Sankar U. ◽

Monisha R. ◽

Christopher Amalraj Vallaba Doss ◽

Palanivel R M

Keyword(s):

Pulmonary Function ◽

Pulmonary Function Test ◽

Respiratory Muscle ◽

Muscle Performance ◽

Muscle Recruitment ◽

Deep Breath ◽

Single Breath ◽

Function Test ◽

Breathing Retraining ◽

Test Distance

Breathing retraining alters respiratory muscle recruitment and improves respiratory muscle performance. However, the effectiveness of Pursed Lip Breathing in reducing dyspnoea is controversial. The aims of this study are to determine if breathing retraining is influencing the Single Breath Count performed by dyspneic subjects and to assess the correlation between Single breath Count Test and Snider match test as the standard measures of bedside pulmonary function test in patients with dyspnoea. 100 Patients with dyspnoea were assessed in the baseline with snider match test and they were asked to perform a single breath count. 5 times weekly and for 4 weeks, the participants have been practicing Breathing Retraining. Pursed lip breathing (PLB) and diaphragmatic breathing (DB) are breathing retraining strategies to subjects with dyspnoea; Single Breath Count was measured by asking patients to take a deep breath and count as far as possible in their normal speaking voice without taking another breath. Counting was timed to a metronome set at 2 counts per second. Snider match test was conducted by blowing the matches at increasing the test distance from 3, 6, 9 inches. The result of this study will determine whether breathing retraining is safe and beneficial for people with dyspnoea.

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Respiratory Muscle Effort during Expiration in Successful and Failed Weaning from Mechanical Ventilation

Anesthesiology ◽

10.1097/aln.0000000000002256 ◽

2018 ◽

Vol 129 (3) ◽

pp. 490-501 ◽

Cited By ~ 20

Author(s):

Jonne Doorduin ◽

Lisanne H. Roesthuis ◽

Diana Jansen ◽

Johannes G. van der Hoeven ◽

Hieronymus W. H. van Hees ◽

...

Keyword(s):

Mechanical Ventilation ◽

Electrical Activity ◽

Muscle Activity ◽

Respiratory Muscle ◽

Weaning From Mechanical Ventilation ◽

Expiratory Muscle ◽

Diaphragm Electrical Activity ◽

Gastric Pressure ◽

Weaning Failure ◽

Expiratory Muscles

Abstract What We Already Know about This Topic What This Article Tells Us That Is New Background Respiratory muscle weakness in critically ill patients is associated with difficulty in weaning from mechanical ventilation. Previous studies have mainly focused on inspiratory muscle activity during weaning; expiratory muscle activity is less well understood. The current study describes expiratory muscle activity during weaning, including tonic diaphragm activity. The authors hypothesized that expiratory muscle effort is greater in patients who fail to wean compared to those who wean successfully. Methods Twenty adult patients receiving mechanical ventilation (more than 72 h) performed a spontaneous breathing trial. Tidal volume, transdiaphragmatic pressure, diaphragm electrical activity, and diaphragm neuromechanical efficiency were calculated on a breath-by-breath basis. Inspiratory (and expiratory) muscle efforts were calculated as the inspiratory esophageal (and expiratory gastric) pressure–time products, respectively. Results Nine patients failed weaning. The contribution of the expiratory muscles to total respiratory muscle effort increased in the “failure” group from 13 ± 9% at onset to 24 ± 10% at the end of the breathing trial (P = 0.047); there was no increase in the “success” group. Diaphragm electrical activity (expressed as the percentage of inspiratory peak) was low at end expiration (failure, 3 ± 2%; success, 4 ± 6%) and equal between groups during the entire expiratory phase (P = 0.407). Diaphragm neuromechanical efficiency was lower in the failure versus success groups (0.38 ± 0.16 vs. 0.71 ± 0.36 cm H2O/μV; P = 0.054). Conclusions Weaning failure (vs. success) is associated with increased effort of the expiratory muscles and impaired neuromechanical efficiency of the diaphragm but no difference in tonic activity of the diaphragm.

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Emergency Pediatric Noninvasive Ventilation and Invasive Mechanical Ventilation

Pediatric Emergencies ◽

10.1093/med/9780190073879.003.0006 ◽

2020 ◽

pp. 51-63

Author(s):

Garrett S. Pacheco

Keyword(s):

Mechanical Ventilation ◽

Emergency Physician ◽

Oxygen Therapy ◽

Invasive Mechanical Ventilation ◽

Noninvasive Positive Pressure Ventilation ◽

Positive Pressure ◽

Supportive Treatment ◽

Airway Clearance Therapy ◽

Respiratory Complaints ◽

Ventilator Settings

Respiratory complaints are common conditions for children to present to emergency departments. Typically, patients respond to simple supportive treatment, whether it is airway clearance therapy, oxygen therapy, or bronchodilators. When these patients are critically ill, they often require aggressive oxygenation/ventilation with noninvasive strategies, or even tracheal intubation. The use of noninvasive positive pressure ventilation has led to a significant reduction in the necessity for endotracheal intubation in children. The emergency physician should be familiar with the indications and appropriate application of these modalities. Furthermore, when patients require invasive mechanical ventilation, the emergency physician should have an understanding of initial ventilator settings, troubleshooting alarms, and an approach to the decompensating pediatric ventilated patient.

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