Lung Compliance, Airway Resistance, and Work of Breathing in Children After Inhalation Injury

1997 ◽  
Vol 18 (6) ◽  
pp. 531-534 ◽  
Author(s):  
R. Mlcak ◽  
J. Cortiella ◽  
M. Desai ◽  
D. Herndon
Keyword(s):  
Airway Resistance ◽  
Work Of Breathing ◽  
Lung Compliance ◽  
Inhalation Injury

Airway Physiology

2019 ◽  
Author(s):  
Gilbert S Tang
Keyword(s):  
Airway Resistance ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Work Of Breathing ◽  
Lung Compliance ◽  
Flow Volume ◽  
Carbon Dioxide Transport ◽  
Basic Principles ◽  
Pulmonary Vasoconstriction ◽  
Volume Measurements ◽  
Airway Physiology

An understanding of airway physiology is important for the anesthesiologist, tasked with supporting the patient's respiratory functions which are altered in the conduct of anesthesia and surgery, or which may be abnormal due to co-existing disease. Airflow and airway resistance, lung compliance, spirometric values, flow-volume measurements, work of breathing, ventilation-perfusion matching, and oxygen-carbon dioxide transport are some of the basic principles. Clinical application of physiology allows the anesthesiologist to anticipate and manage changes that may occur when anesthetizing the patient, altering position or manipulating the airway. This review contains 5 tables, and 25 references. Keywords: Ohm’s law, laminar vs turbulent flow, Reynold’s number, Heliox, Bernoulli’s principle, compliance vs elasticity, Law of Laplace, spirometry, dead space, hypoxic pulmonary vasoconstriction

scholarly journals To the informative value of flow-volume curve in forced expiration

2008 ◽  
pp. 91-97 ◽  
Author(s):  
G. A. Lyubimov ◽  
I. M. Skobeleva ◽  
G. M. Sakharova ◽  
A. V. Suvorov
Keyword(s):  
Airway Resistance ◽  
Lung Compliance ◽  
Forced Expiration ◽  
Flow Volume ◽  
Functional Tests ◽  
Lung Volumes ◽  
Volume Curve ◽  
Quitting Smoking ◽  
Flow Volume Curve ◽  
Airway Walls

This report introduces a mathematical model of forced expiration to analyze pulmonary function. Results of 3-year lung function monitoring of an ex-smoker have been shown in the paper. Actual values of lung volumes and airway resistance were used for modeling. The computerized data were compared to the flow-volume curve parameters and lung volumes measured during the forced expiration. Weak correlation between the "flow-volume" curve parameters and the time after quitting smoking together with significant change in the lung volumes and the airway resistance seen in the study could be due to some processes which have not been followed in this study (lung compliance, airway resistance at forced expiration, and elastic properties of airway walls).The results demonstrated that mathematical models could increase informative value of pulmonary functional tests. In addition, the model could emphasize additional functional tests for better diagnostic usefulness of functional investigations.

Abstract 108: Work of Breathing Scale to Assess Need of Intubation in Covid-19 Pneumonia

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Raul J Gazmuri ◽  
Mylene Apigo ◽  
Philip Fanapour ◽  
Amin Nadeem
Keyword(s):  
Respiratory Rate ◽  
Work Of Breathing ◽  
Invasive Mechanical Ventilation ◽  
Lung Compliance ◽  
Respiratory Physiology ◽  
High Flow Nasal Cannula ◽  
Radiographic Evidence ◽  
Multiple Risk Factors ◽  
Rate Score ◽  
Accessory Muscles

COVID-19 pneumonia presents in most patients with significant hypoxemia but without substantial impairment of lung compliance that would increase the work of breathing (WOB) to levels requiring invasive mechanical ventilation. Thus, the ability to assess the WOB independent of the oxygen needs could help guide management and possibly avoid intubation. We previously developed and implemented in our ICU a WOB scale based on respiratory physiology ranging from 1 to 7 by assigning points to the respiratory rate level and the use of respiratory accessory muscles. We analyzed the use of our WOB scale in 10 patients admitted to our ICU with severe COVID-19 pneumonia. All patients had radiographic evidence of extensive lung disease with significant hypoxemia and multiple risk factors associated with poor outcome. Hypoxemia was successfully managed using high-flow nasal cannula. The WOB level was measured every 4 hours. The maximum WOB was 4.3 ± 0.9, contributed primarily by the respiratory rate with a score of 3.6 ± 0.5 but with infrequent use of respiratory accessory muscles. All 10 patients survived without need of intubation. For comparison, three other patients who needed intubation had a maximal work of breathing within the preceding 24 hours of 5.3 ± 1.2 with a respiratory rate score of 3.7 ± 0.6, as in non-intubated patients, but with more often use of respiratory accessory muscles. Our data suggest that patients with COVID-19 pneumonia can be supported for extended periods using HFNC despite tachypnea provided there is only infrequent use of respiratory accessory muscles, corresponding to a WOB scale ≤ 4, prompting closer assessment for possible intubation when WOB > 4. This approach would be especially advantageous under conditions of high disease intensity when avoidance of intubation is likely to result in a better outcome.

Heavy snoring with upper airway resistance syndrome may induce intrinsic positive end-expiratory pressure

1998 ◽  
Vol 85 (3) ◽  
pp. 860-866 ◽  
Author(s):  
Frédéric Lofaso ◽  
Anne Marie Lorino ◽  
Redouane Fodil ◽  
Marie Pia D’Ortho ◽  
Daniel Isabey ◽  
...  
Keyword(s):  
Airway Resistance ◽  
Work Of Breathing ◽  
Upper Airway ◽  
Rapid Eye Movement Sleep ◽  
Positive End Expiratory Pressure ◽  
Upper Airway Resistance Syndrome ◽  
Upper Airway Resistance ◽  
Lung Resistance ◽  
Compliance Model ◽  
Inspiratory Work

We studied eight heavy snorers with upper airway resistance syndrome to investigate potential effects of sleep on expiratory airway and lung resistance, intrinsic positive end-expiratory pressure, hyperinflation, and elastic inspiratory work of breathing (WOB). Wakefulness and non-rapid-eye-movement sleep with high- and with low-resistance inspiratory effort (H-RIE and L-RIE, respectively) were compared. No differences in breathing pattern were seen across the three conditions. In contrast, we found increases in expiratory airway and lung resistance during H-RIE compared with L-RIE and wakefulness (56 ± 24, 16 ± 4, and 11 ± 4 cmH2O ⋅ l−1 ⋅ s, respectively), with attendant increases in intrinsic positive end-expiratory pressure (5.4 ± 1.8, 1.4 ± 0.5, and 1.3 ± 1.3 cmH2O, respectively) and elastic WOB (6.1 ± 2.2, 3.7 ± 1.2, and 3.4 ± 0.7 J/min, respectively). The increase in WOB during H-RIE is partly caused by the effects of dynamic pulmonary hyperinflation produced by the increased expiratory resistance. Contrary to the Starling model, a multiple-element compliance model that takes into account the heterogeneity of the pharynx may explain flow limitation during expiration.

scholarly journals PEEP and CPAP

1986 ◽  
Vol 14 (3) ◽  
pp. 236-250 ◽  
Author(s):  
A. W. Duncan ◽  
T. E. Oh ◽  
D. R. Hillman
Keyword(s):  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Work Of Breathing ◽  
Lung Compliance ◽  
Raised Intracranial Pressure ◽  
Positive End Expiratory Pressure ◽  
Pulmonary Barotrauma ◽  
Endotracheal Tubes ◽  
Wide Range ◽  
Residual Capacity

Positive end-expiratory pressure (PEEP) maintains airway pressure above atmospheric at the end of expiration, and may be used with mechanical ventilation or spontaneous breathing. CPAP, or continuous positive airway pressure, refers to spontaneous ventilation with a positive airway pressure being maintained throughout the whole respiratory cycle. PEEP/CPAP primarily improves oxygenation by increasing functional residual capacity, and may increase lung compliance and decrease the work of breathing. PEEP/CPAP may be applied using endotracheal tubes, nasal masks or prongs, or face masks or chambers to treat a wide range of adult and paediatric respiratory disorders. Complications associated with their use relate to the pressures applied and include pulmonary barotrauma, decreased cardiac output and raised intracranial pressure.

scholarly journals Mechanisms of Orthopnoea in Patients with Advanced COPD

2020 ◽  
pp. 2000754
Author(s):  
Amany F. Elbehairy ◽  
Azmy Faisal ◽  
Hannah McIsaac ◽  
Nicolle J. Domnik ◽  
Kathryn M. Milne ◽  
...  
Keyword(s):  
Supine Position ◽  
Minute Ventilation ◽  
Pulmonary Function Tests ◽  
Work Of Breathing ◽  
Airflow Obstruction ◽  
Lung Compliance ◽  
Chronic Obstructive ◽  
Inspiratory Muscles ◽  
Elastic Loading ◽  
Dynamic Lung Compliance

Many patients with severe chronic obstructive pulmonary disease (COPD) report unpleasant respiratory sensation at rest, further amplified by adoption of supine position (orthopnoea). The mechanisms of this acute symptomatic deterioration are poorly understood.16 patients with advanced COPD and history of orthopnoea and 16 age- and sex-matched healthy controls (CTRL) underwent pulmonary function tests and detailed sensory-mechanical measurements including inspiratory neural drive (IND, diaphragm electromyography), oesophageal and gastric pressures in sitting and supine positions.Patients had severe airflow obstruction (FEV1: 40±18%predicted) and lung hyperinflation. Regardless of the position, patients had lower inspiratory capacity (IC) and higher IND for a given tidal volume (i.e. greater neuromechanical dissociation (NMD)), higher intensity of breathing discomfort, minute ventilation (⩒E) and breathing frequency (Fb) compared with CTRL (all p<0.05). In supine position in CTRL (versus sitting erect): IC increased (by 0.48L) with a small drop in ⩒E mainly due to reduced Fb (all p<0.05). By contrast, patients’ IC remained unaltered, but dynamic lung compliance decreased (p<0.05) in the supine position. Breathing discomfort, inspiratory work of breathing, inspiratory effort, IND, NMD and neuro-ventilatory uncoupling all increased in COPD in the supine position (p<0.05), but not in CTRL. Orthopnoea was associated with acute changes in IND (r=0.65, p=0.01), neuro-ventilatory uncoupling (r=0.76, p=0.001) and NMD (r=0.73, p=0.002).In COPD, onset of orthopnoea coincided with an abrupt increase in elastic loading of the inspiratory muscles in recumbency in association with increased IND and greater neuromechanical dissociation of the respiratory system.

Chronic Obstructive Pulmonary Disease Exacerbation

2019 ◽  
pp. 157-160
Author(s):  
Isabel Mira-Avendano ◽  
Minkyung Kwon
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Smooth Muscle ◽  
Pulmonary Disease ◽  
Airway Resistance ◽  
Lung Compliance ◽  
Chronic Obstructive ◽  
Copd Exacerbation ◽  
Obstructive Pulmonary Disease ◽  
Common Causes ◽  
Tract Infections

Patients with chronic obstructive pulmonary disease (COPD) have recurring or continuous obstruction of bronchial airflow. The disease is usually characterized by progressive chronic airway inflammation that results from smooth muscle hypertrophy, airway ciliary dysfunction, and excessive mucous production, which ultimately increases airway resistance and hyperactivity. Parenchymal destruction associated with emphysema increases lung compliance, which further decreases expiratory airflow. COPD exacerbation can be precipitated by several factors, but the most common causes are respiratory tract infections (viral or bacterial).

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