Explore chapters and articles related to this topic
Anaesthetic Management of Early-Onset Scoliosis
Published in Alaaeldin (Alaa) Azmi Ahmad, Aakash Agarwal, Early-Onset Scoliosis, 2021
Damarla Haritha, Souvik Maitra
Respiratory System: The deformity of the chest wall leads to a restrictive kind of lung disease due to limitation of the movement of the rib cage upon inspiration and compression of the lung tissue; however mixed or obstructive lung disease may be present in 46% of the patients [10,11]. Altered respiratory mechanics and reduced lung volume leads to restrictive lung disease, and airway narrowing leads to obstructive lung diseases in some cases [12]. Total lung capacity (TLC) is reduced whereas residual volume (RV) usually remains within normal limit, hence RV/TLC ratio is increased [13]. The forced vital capacity (FVC) and forced expiratory volume in the first-second (FEV1) both are reduced so that the ratio of FEV1 /FVC almost remains normal [14]. The reduction in the vital capacity represents the inability to cough and clear lung secretions effectively, leading to frequent lower respiratory tract infections [15]. The limitation of expansion of lung tissue leads to a decrease in respiratory compliance and, when combined with stretching of the intercostal muscles, leads to increase in work of breathing, resulting in decreased tidal volume and increased respiratory rate. The inspiratory capacity is maximally affected, while the functional residual capacity (FRC) is not that severely affected. In severe cases, as the curve progresses, an increase in residual volume may develop due to inadequate expiration as a result of muscle dysfunction.
Positions in neurosurgery
Published in Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor, Essentials of Geriatric Neuroanesthesia, 2019
Zilvinas Zakarevicius, Mikhail Gelfenbeyn, Irene Rozet
In the awake patient, lung mechanics and gas exchange in the lungs are optimal regardless of positioning because of perfectly matched ventilation and perfusion across the lungs (14,15). In contrast, anesthesia, muscle paralysis, and positive pressure mechanical ventilation inevitably cause ventilation-perfusion mismatch. In anesthetized prone position, however, ventilation-perfusion matching is better than in supine position predominantly due to (i) more even distribution of the perfusion because of higher pulmonary blood flow in the dorsal parts of the normal lungs compared to the ventral parts, and (ii) decrease of gravitational pressure of the abdomen improving respiratory mechanics by the released pressure on the diaphragm with subsequent increase in lung volume, functional residual capacity, and transpulmonary pressure (16,17). Therefore, a Jackson table supporting the chest and the pelvis but leaving the abdominal wall free is the best table for optimal gas exchange in the lungs and venous return to the heart (Figure 13.4). Aside from the surgical preference, use of the Jackson table and frame should be considered in patients undergoing prolonged surgery with potential risk of respiratory compromise, such as respiratory disease or morbid obesity.
Coordination of Locomotion and Respiration
Published in Alan D. Miller, Armand L. Bianchi, Beverly P. Bishop, Neural Control of the Respiratory Muscles, 2019
In conclusion, the ability to integrate locomotor and respiratory mechanics appears to be an evolutionary process which has been crucial to allow aerobic ventilation during sustained locomotor exercise in birds and mammals. Reptiles are unable to achieve effective lung ventilation during rapid locomotion.10 High levels of coupling between breathing and locomotor rhythms are functionally important because, by reducing oxygen consumption, fatigue is postponed. Locomotor performance can be improved for different locomotor gaits.5,21 Passive piston mechanisms and active central interactions between CPGs contribute to this coupling. Afferent feedback improves the efficiency of the process at usual gaits.
Aqueous Pyrostegia venusta (Ker Gawl.) Miers extract attenuates allergen-induced asthma in a mouse model via an antioxidant mechanism
Published in Journal of Asthma, 2021
Andiamira Cagnoni Balestra, Camila Mira Sandy, Fernando Ramalho, Alceu Afonso Jordão Júnior, Silvia Helena Taleb Contini, Eduardo José Crevelin, Fabio Carmona, Ana Maria S. Pereira, Marcos C. Borges
Measurements of respiratory parameters were performed as previously described (19–21). Briefly, 24 h after the last challenge, mice were anesthetized ip (10 mg/kg xylazine and 100 mg/kg ketamine), and a tracheal cannula was inserted. Mice were then connected to a small animal ventilator (FlexVent®, Scireq, Montreal, QC, Canada) and ventilated with a respiratory rate of 150 breaths/min and a positive end-expiratory pressure (PEEP) of 3 cm H2O. Then, pancuronium bromide (1.2 mg/kg) was administered and, after the animal was totally paralyzed, airway hyperresponsiveness was measured at baseline and after increasing concentrations (6.25, 12.5, 25, 50 mg/mL) of methacholine (Sigma-Aldrich, Dorset, UK) delivered via an ultrasonic nebulizer (Aeroneb® Lab, Aerogen, Galway, Ireland). Respiratory mechanics were measured with the forced oscillation technique, using the single compartment and the constant phase model, a mathematical model that allows to partition the changes into the large airway and peripheral compartments (21). Airway hyperresponsiveness was expressed as total resistance (RRS), total elastance (ERS), tissue resistance (G), and tissue elastance (H).
Applications of oscillometry in clinical research and practice
Published in Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 2021
Lennart K. A. Lundblad, Salman Siddiqui, Ynuk Bossé, Ronald J. Dandurand
Global estimates of obstructive lung disease now approach 1 billion people55,56 and a fast, accurate, objective measure of lung function will be critical to deliver effective respiratory care on such a large scale. While spirometry has a 72-year history as the cornerstone of asthma and COPD diagnosis and management,57,58 its shortcomings and potential problems are increasingly reported.59,60 Deployment outside of the academic setting is sparse61,62 and, when used, is usually of sufficiently poor quality to be of questionable value.63 The maneuver itself changes the respiratory mechanics of many subjects.64,65 Furthermore, given the biologic variation in airway size to lung volume, termed dysanapsis,66,67 spirometry has the potential to misclassify some pathology-free individuals as having obstructive lung disease. Finally, spirometry is increasingly recognized as insensitive to early disease.60,67,68 Clearly, from a clinical perspective, a faster, easier, more sensitive and more specific form of lung function metric is needed to tackle the juggernaut of obstructive lung disease that will have to be diagnosed and managed in the coming decades.
Pediatric Glittre ADL-test in cystic fibrosis: Physiological parameters and respiratory mechanics
Published in Physiotherapy Theory and Practice, 2021
Ana Carolina Almeida, Renata Maba Gonçalves Wamosy, Norberto Ludwig Neto, Francieli Camila Mucha, Camila Isabel Santos Schivinski
Cystic fibrosis (CF) is a genetic disease with progressive deterioration of lung function, which impairs overall quality of life (QoL) in both adults and children (Saglam et al., 2016). The impact of spirometric parameters is well established in the literature; however, the behavior of parameters of respiratory mechanics with the progression of pulmonary disease has been sparsely investigated. Despite the improvement in the health-care management and survival of children with CF in the last years, typical factors of the disease such as: impairment of the metabolic system; the progressive character of the pulmonary disease (Burtin and Hebestreit, 2015); chronic infection (van de Weert-van Leeuwen et al., 2012); nutritional deficiency (Klijn et al., 2003); loss of bone mineral density (Dodd et al., 2008); peripheral muscle weakness (Hussey, Gormley, Leen, and Greally, 2002); exacerbation (Wieboldt et al., 2012); and typical CF genetic defects (Lamhonwah et al., 2010) are known factors that may contribute to reduced habitual physical activity in young people with CF (Almajed and Lands, 2012). Thus, current recommendations (Burtin and Hebestreit, 2015) indicate that patients with CF should perform an exercise test annually in order to assess the general responses of the bodily systems, identify physical limitations, determine conditioning programs, predict mortality prognosis, schedule lung transplantation and monitor quality of life.