Morphometry of Fish Gas Exchange Organs in Relation to their Respiratory Function

1980 ◽  
pp. 33-56 ◽  
Author(s):  
G. M. Hughes
Keyword(s):  
Gas Exchange ◽  
Respiratory Function

scholarly journals Effect of lung hypoplasia on the cardiorespiratory transition in newborn lambs

2019 ◽  
Vol 127 (2) ◽  
pp. 568-578 ◽  
Author(s):  
Erin V. McGillick ◽  
Indya M. Davies ◽  
Stuart B. Hooper ◽  
Lauren T. Kerr ◽  
Marta Thio ◽  
...  
Keyword(s):  
Blood Flow ◽  
Gas Exchange ◽  
Respiratory Function ◽  
Scientific Evidence ◽  
Management Strategies ◽  
Oxygenation Index ◽  
Fetal Lung ◽  
Lung Compliance ◽  
Lung Hypoplasia ◽  
Artery Blood Flow

Newborns with lung hypoplasia (LH) commonly have limited respiratory function and often require ventilatory assistance after birth. We aimed to characterize the cardiorespiratory transition and respiratory function in newborn lambs with LH. LH was induced by draining fetal lung liquid in utero [110–133 days (d), term = 147d, n = 6]. At ~133d gestation, LH and Control lambs ( n = 6) were instrumented and ventilated for 3 h to monitor blood-gas status, oxygenation, ventilator requirements, and hemodynamics during the transition from fetal to newborn life. Lambs with LH had significantly reduced relative wet and dry lung weights indicating hypoplastic lungs compared with Control lambs. LH lambs experienced persistent hypercapnia and acidosis during the ventilation period, had lower lung compliance, and had higher alveolar-arterial differences in oxygen and oxygenation index compared with Control lambs. As a result, LH lambs required greater respiratory support and more supplemental oxygen. Following delivery, LH lambs experienced periods of significantly lower pulmonary artery blood flow and higher carotid artery blood flow in association with the lower oxygenation levels. The detrimental effects of LH can be attributed to a reduction in lung size and poorer gas exchange capabilities. This study has provided greater understanding of the effect of LH itself on the physiology underpinning the transition from fetal to newborn life. Advances in this area is the key to identifying improved or novel management strategies for babies with LH starting in the delivery room, to favorably alter the fetal-to-newborn transition toward improved outcomes and reduced lifelong morbidity. NEW & NOTEWORTHY Current clinical management of newborns with lung hypoplasia (LH) is largely based on expert opinion rather than scientific evidence. We have generated physiological evidence for detrimental effects of LH on hemodynamics and respiratory function in newborn lambs, which mimics the morbidity observed in LH newborns clinically. The unfavorable consequences of LH can be attributed to a reduction in lung size and poorer gas exchange capabilities.

Respiratory function in a newborn marsupial with skin gas exchange

2000 ◽  
Vol 120 (1) ◽  
pp. 35-45 ◽  
Author(s):  
P.B Frappell ◽  
J.P Mortola
Keyword(s):  
Gas Exchange ◽  
Respiratory Function

Measurement of respiratory function: an update on gas exchange

2015 ◽  
Vol 16 (2) ◽  
pp. 68-73 ◽  
Author(s):  
Salahuddin Mahmood Qureshi
Keyword(s):  
Gas Exchange ◽  
Respiratory Function

scholarly journals Monitored Anesthesia Care with Dexmedetomidine Supplemented by Midazolam/Fentanyl versus Midazolam/Fentanyl Alone in Patients Undergoing Pleuroscopy: Effect on Oxygenation and Respiratory Function

2021 ◽  
Vol 10 (16) ◽  
pp. 3510
Author(s):  
Andreas Kostroglou ◽  
Emmanouil I. Kapetanakis ◽  
Paraskevi Matsota ◽  
Periklis Tomos ◽  
Konstantinos Kostopanagiotou ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Respiratory Function ◽  
Lung Mechanics ◽  
Procedural Sedation And Analgesia ◽  
Pain Scores ◽  
Secondary Endpoints ◽  
Fentanyl Consumption ◽  
Sedation And Analgesia ◽  
Clinically Significant ◽  
Fentanyl Group

Although pleuroscopy is considered a safe and well tolerated procedure with a low complication rate, it requires the administration of procedural sedation and analgesia. The purpose of this study was to assess the effects of dexmedetomidine administration on oxygenation and respiratory function in patients undergoing diagnostic or therapeutic pleuroscopy. Through a prospective, single center, cohort study, we studied 55 patients receiving either a dexmedetomidine intravenous infusion supplemented by midazolam/fentanyl (Group DEX + MZ/F) or a conventional sedation protocol with midazolam/fentanyl (Group MZ/F). Our primary outcome was the changes in lung gas exchange (PaO2/FiO2 ratio) obtained at baseline and at predetermined end points, while changes in respiratory mechanics (FEV1, FVC and the ratio FEV1/FVC) and PaCO2 levels, drug consumption, time to recover from sedation and adverse events were our secondary endpoints (NCT03597828). We found a lower postoperative decrease in FEV1 volumes in Group DEX + MZ/F compared to Group MZ/F (p = 0.039), while FVC, FEV1/FVC and gas exchange values did not differ between groups. We also found a significant reduction in midazolam (p < 0.001) and fentanyl consumption (p < 0.001), along with a more rapid recovery of alertness postprocedure in Group DEX + MZ/F compared to Group MZ/F (p = 0.003), while pain scores during the postoperative period, favored the Group DEX + MZ/F (p = 0.020). In conclusion, the use of intravenous dexmedetomidine during pleuroscopy is associated with a smaller decrease in FEV1, reduction of the consumption of supplementary sedatives and analgesics and quicker awakening of patients postoperatively, when compared to midazolam/fentanyl. Therefore, dexmedetomidine administration may provide clinically significant benefits in terms of lung mechanics and faster recovery of patients undergoing pleuroscopy.

scholarly journals Revisiting 'Respiratory Function in Emphysema in Relation to Prognosis'

2000 ◽  
Vol 7 (3) ◽  
pp. 271-279 ◽  
Author(s):  
David V Bates
Keyword(s):  
Carbon Monoxide ◽  
Gas Exchange ◽  
Respiratory Function ◽  
Airflow Obstruction ◽  
Cor Pulmonale ◽  
Chronic Obstructive ◽  
Diffusing Capacity ◽  
Obstructive Pulmonary Disease ◽  
Clinical Criteria ◽  
Clinical Changes

BACKGROUND:The 1956 paper by DV Bates, JMS Knott and RV Christie, "Respiratory function in emphysema in relation to prognosis" Quart J Med 1956;97:137-157 is largely reprinted with a commentary by the first author, Dr David Bates. Although the pathology of emphysema was well recognized at the time, the clinical diagnosis and assessment of its severity were known to be imprecise; physiological measurements assessing and following the clinical course had not been established. The study aimed to follow systematically a group of patients, selected by clinical criteria using standardized clinical and physiological techniques, over four years and correlate physiological and clinical changes in relation to prognosis and eventually to postmortem findings. Fifty-nine patients were recruited to an emphysema clinic at St Bartholomew's Hospital, London, England. Inclusion criteria were dyspnea without other causes and no cor pulmonale present. Patients' symptoms were assessed by a standardized questionnaire, and measurements were taken of lung volumes, maximal ventilatory volume, carbon monoxide diffusing capacity at rest, exercise and oxygen saturation by oximetry.  During the four years of the study, 17 patients died (actuarial expected - four) and 13 presented with signs of pulmonary heart failure. All postmortem examinations (n=9) showed advanced emphysema. A seasonal variation in dyspnea was established (the period included the infamous 1952 London smog). Four patients improved, and the remainder were unchanged or deteriorated. Close relationships were shown between dyspnea and function results, particularly for the diffusing capacity of lungs for carbon monoxide (DLCO. A comparison among a group of patients with chronic bronchitis without dyspnea showed that the DLCOdiscriminated between them. A loss of the normal increase in DLCOduring exercise was shown in emphysema.IMPORTANCE:The study showed the value of standardized clinical and physiological techniques in following chronic obstructive pulmonary disease patients, and of separating the effects of airflow obstruction from impaired gas exchange function. Impaired gas exchange was shown to be important in influencing prognosis.

Measurement of respiratory function: gas exchange

2005 ◽  
Vol 6 (11) ◽  
pp. 366-369 ◽  
Author(s):  
Iain Campbell ◽  
James Waterhouse
Keyword(s):  
Gas Exchange ◽  
Respiratory Function

The limits of respiratory function: External and internal constraints on insect gas exchange

2018 ◽  
Vol 106 ◽  
pp. 153-154
Author(s):  
Philip G.D. Matthews ◽  
Kendra J. Greenlee ◽  
Wilco C.E.P. Verberk
Keyword(s):  
Gas Exchange ◽  
Respiratory Function ◽  
Internal Constraints

scholarly journals Lung volume dependence of respiratory function in rodent models of diabetes mellitus

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Roberta Südy ◽  
Álmos Schranc ◽  
Gergely H. Fodor ◽  
József Tolnai ◽  
Barna Babik ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Smooth Muscle ◽  
Gas Exchange ◽  
Smooth Muscle Cells ◽  
Lung Tissue ◽  
Respiratory Function ◽  
Muscle Cells ◽  
High Dose ◽  
The Impact ◽  
Respiratory Tissue

Abstract Background Diabetes mellitus causes the deterioration of smooth muscle cells and interstitial matrix proteins, including collagen. Collagen and smooth muscle cells are abundant in the lungs, but the effect of diabetes on airway function and viscoelastic respiratory tissue mechanics has not been characterized. This study investigated the impact of diabetes on respiratory function, bronchial responsiveness, and gas exchange parameters. Methods Rats were allocated randomly to three groups: a model of type 1 diabetes that received a high dose of streptozotocin (DM1, n = 13); a model of type 2 diabetes that received a low dose of streptozotocin with a high-fat diet (DM2, n = 14); and a control group with no treatment (C, n = 14). Forced oscillations were applied to assess airway resistance (Raw), respiratory tissue damping (G), and elastance (H). The arterial partial pressure of oxygen to the inspired oxygen fraction (PaO2/FiO2) and intrapulmonary shunt fraction (Qs/Qt) were determined from blood gas samples at positive end-expiratory pressures (PEEPs) of 0, 3, and 6 cmH2O. Lung responsiveness to methacholine was also assessed. Collagen fibers in lung tissue were quantified by histology. Results The rats in groups DM1 and DM2 exhibited elevated Raw, G, H, and Qs/Qt, compromised PaO2/FiO2, and diminished airway responsiveness. The severity of adverse tissue mechanical change correlated with excessive lung collagen expression. Increased PEEP normalized the respiratory mechanics, but the gas exchange abnormalities remained. Conclusions These findings indicate that diabetes reduces airway and lung tissue viscoelasticity, resulting in alveolar collapsibility that can be compensated by increasing PEEP. Diabetes also induces persistent alveolo-capillary dysfunction and abnormal adaptation ability of the airways to exogenous constrictor stimuli.

Histological study of different regions of the skin and gills in the mudskipper, Boleophthalmus boddarti with respect to their respiratory function

1988 ◽  
Vol 68 (3) ◽  
pp. 413-422 ◽  
Author(s):  
N. K. Al-Kadhomiy ◽  
G. M. Hughes
Keyword(s):  
Gas Exchange ◽  
Respiratory Function ◽  
Alimentary Canal ◽  
Histological Study ◽  
Respiratory Organ ◽  
Air Breathing ◽  
Body Regions ◽  
General Importance ◽  
Physiological Adaptations

Gills are the typical respiratory organ of fish in their usual habitat of well-aerated water. The transition from water- to air-breathing required many modifications to the structural and physiological adaptations of the gas-exchange surfaces, i.e. gill, skin, swimbladder and other accessory organs of the alimentary canal. The skin is particularly important among air-breathing fish. This histological study showed varying degrees of adaptation of parts of the skin from different body regions, paying particular attention to the water/blood barrier. The results suggest a general importance in gas exchange in the following order: gill, inner operculum, nasal, body and outer opercular skin, as indicated by increasing thickness of the water/blood barrier.

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