scholarly journals Changes in respiratory function following the intramuscular administration of etorphine to boer goats (Capra hircus)

2001 ◽  
Vol 72 (3) ◽  
Author(s):  
P.E. Buss ◽  
D.G.A. Meltzer
Keyword(s):  
Respiratory Function ◽  
Minute Ventilation ◽  
Minute Volume ◽  
Capra Hircus ◽  
Physiological Effects ◽  
Physiological Changes ◽  
Respiratory Effects ◽  
Physiological Dead Space ◽  
Boer Goats ◽  
Dead Space Ventilation

The physiological effects on respiratory function of etorphine (M99, Logos Agvet) (30 µg/kg) administered intramuscularly were determined in boer goats. The goats were habituated to the experimental procedures so that respiratory function could be determined while the animals stood quietly at rest. This enabled the physiological changes induced by etorphine to be measured and compared with those obtained before administration of the immobilising drug. The effectiveness of diprenorphine (M5050, Logos Agvet) (3 mg/1 mg etorphine) as an antagonist of the physiological changes induced by the etorphine treatment was also determined. Etorphine depressed respiratory function, which resulted in a decrease in PaO2 and an increase in PaCO2. These changes were limited and occurred as a result of decreases in respiratory minute volume and alveolar minute ventilation caused by a decrease in respiratory rate. The physiological shunt fraction did not change significantly but there was a significant decrease in percentage physiological dead space ventilation. It was not possible to determine how effectively diprenorphine reversed the respiratory effects due to etorphine.

scholarly journals Reductions in dead space ventilation with nasal high flow depend on physiological dead space volume: metabolic hood measurements during sleep in patients with COPD and controls

2018 ◽  
Vol 51 (5) ◽  
pp. 1702251 ◽  
Author(s):  
Paolo Biselli ◽  
Kathrin Fricke ◽  
Ludger Grote ◽  
Andrew T. Braun ◽  
Jason Kirkness ◽  
...  
Keyword(s):  
Respiratory Rate ◽  
Dead Space ◽  
Minute Ventilation ◽  
High Flow ◽  
Physiological Dead Space ◽  
Copd Patients ◽  
Dead Space Volume ◽  
Anatomical Dead Space ◽  
Dead Space Ventilation ◽  
Space Volume

Nasal high flow (NHF) reduces minute ventilation and ventilatory loads during sleep but the mechanisms are not clear. We hypothesised NHF reduces ventilation in proportion to physiological but not anatomical dead space.11 subjects (five controls and six chronic obstructive pulmonary disease (COPD) patients) underwent polysomnography with transcutaneous carbon dioxide (CO2) monitoring under a metabolic hood. During stable non-rapid eye movement stage 2 sleep, subjects received NHF (20 L·min−1) intermittently for periods of 5–10 min. We measured CO2 production and calculated dead space ventilation.Controls and COPD patients responded similarly to NHF. NHF reduced minute ventilation (from 5.6±0.4 to 4.8±0.4 L·min−1; p<0.05) and tidal volume (from 0.34±0.03 to 0.3±0.03 L; p<0.05) without a change in energy expenditure, transcutaneous CO2 or alveolar ventilation. There was a significant decrease in dead space ventilation (from 2.5±0.4 to 1.6±0.4 L·min−1; p<0.05), but not in respiratory rate. The reduction in dead space ventilation correlated with baseline physiological dead space fraction (r2=0.36; p<0.05), but not with respiratory rate or anatomical dead space volume.During sleep, NHF decreases minute ventilation due to an overall reduction in dead space ventilation in proportion to the extent of baseline physiological dead space fraction.

Measurement of dead space ventilation using a pHa servo-controlled ventilator

1981 ◽  
Vol 51 (1) ◽  
pp. 154-159 ◽  
Author(s):  
R. L. Coon ◽  
E. J. Zuperku ◽  
J. P. Kampine
Keyword(s):  
Dead Space ◽  
Close Agreement ◽  
Minute Volume ◽  
Alveolar Ventilation ◽  
Independent Method ◽  
Servo Control ◽  
Physiological Dead Space ◽  
Arterial Ph ◽  
Before And After ◽  
Dead Space Ventilation

A control system for the systemic arterial pH (pHa) servo control of mechanical ventilation has recently been developed. If pHa is maintained constant by the change, separation of minute volume into alveolar ventilation and physiological dead space ventilation (VE = fVA VDp) can be manipulated to show that VDp = (VE1 - VE 2)/(f1 - fe) where f1 and f2 are different ventilator frequencies and VE1 and VE2 are expired minute volumes at these frequencies. Also, added dead space can be measured. VDadded = (VE2 - VE1)/f where VE1 and VE2 are the minute volumes before and after the dead space was added. The validity of these equations was tested in the anesthetized dog. The measured added dead space was in close agreement with the volume of dead space which was added and with that measured by another independent method. The measurement of VDp, probably as a result of tidal volume-related changes in VDp, did not agree as well with VDp measured by an independent method.

scholarly journals Physiological Effects of Exercising at Different Intensities Wearing TNT or Double-layer Cotton Facemasks Compared to Not Wearing a Mask

2020 ◽  
Author(s):  
Fabrício Braga ◽  
Gabriel Espinosa ◽  
Amanda Monteiro ◽  
Beatriz Marinho ◽  
Eduardo Drummond
Keyword(s):  
Gas Exchange ◽  
Double Layer ◽  
Breathing Pattern ◽  
Pulmonary Ventilation ◽  
Effect Sizes ◽  
Moderate Intensity ◽  
List Type ◽  
Physiological Effects ◽  
Physiological Dead Space ◽  
End Tidal

Abstract We compared the physiological differences between exercising wearing a TNT or a double-layer-cotton (DLC) facemask (FM) and not wearing a mask (NM). Sixteen volunteers underwent 4 sets (S) of 2 sequential bouts (B). B1 and B2 corresponded to light and moderate intensity cycling, respectively. FMs were used as follows: S1: NM; S2: TNT or DLC; S3: DLC or TNT; and S4: NM. Metabolic, pulmonary, and perceptual variables were collected. The main results are expressed as effect sizes and confidence intervals (ES [95%CI]) for TNT and DLC unless otherwise indicated. Compared to NM, FM increased the duty cycle (B1=1.11[0.58-1.61] and 1.53[0.81-2.18]; B2=1.27[0.63-1.84] and 1.93[0.97-2.68]) and decreased breath frequency (B1=0.59[0.23-0.94] and 1.43[0.79-2.07], B2=0.39[0.05-0.71] and 1.33[0.71-1.94]). Only B1 tidal volume increased (0.33[0.09-0.56] and 0.62[0.18-1.05]) enough to avoid a ventilation reduction with TNT but not with DLC (B1=0.52[0.23-0.79]; B2=0.84[0.44-1.22]). Both FMs reduced oxygen saturation in B1 (0.56 [0.07-1.03] and 0.69 [0.09-1.28]) but only DLC did so in B2 (0.66 [0.11-1.13]). Both end tidal CO2 (B1=0.23[0.05-0.4] and 0.71[0.38-1.02]; B2=0.56[0.2-0.9] and 1.20[0.65-1.68]) and mixed-expired-CO2 (B1=0.74[0.38-1.08] 1.71[1.03-2.37], B2=0.94[0.45-1.38] and 1.78[0.97-2.42]) increased with FMs. Ventilatory adaptations imposed during FM exercising influenced blood-lung gas exchange. Larger ESs were seen with DLC. No adverse changes to human health were observed. Novelty Bullets Facemasks affect the breathing pattern by changing the frequency and amplitude of pulmonary ventilation. The augmented ventilatory work increases VO2, VCO2, and RPE and promotes non-concerning drops in SpO2 and CO2 retention. Increased inspiratory and expiratory pressure can account for the reduction in pulmonary physiological dead space.

Evaluation of Bag-Valve-Mask Ventilation by Paramedics in Simulated Chemical, Biological, Radiological, or Nuclear Environments

2009 ◽  
Vol 24 (5) ◽  
pp. 398-401 ◽  
Author(s):  
Jan Schumacher ◽  
Lena Weidelt ◽  
Stuart A. Gray ◽  
Andrea Brinker
Keyword(s):  
Life Support ◽  
Minute Ventilation ◽  
Statistical Significance ◽  
Minute Volume ◽  
Control Group ◽  
Mask Ventilation ◽  
Breathing Resistance ◽  
Institutional Review ◽  
Filtration System ◽  
Tion System

AbstractIntroduction:Bag-valve-mask ventilation is a key component of life support, but only one handheld resuscitator is designed to operate in contaminated or toxic atmospheres.Methods:After Institutional Review Board approval, the efficacy of this device was evaluated. The distal trachea of a LaerdalTM Airway Management Trainer was connected to a mechanical Draeger Volumeter 3000TM to enable determination of the minute volume delivered by BVM ventilation. Nineteen paramedics wearing chemical, biological, radiological, or nuclear (CBRN) protective equipment were asked to ventilate this modified airway trainer, either with or without a CBRN filter attached to the inlet filtration system of the AMBUTM Mark III Resuscitator. The maximum levels of minute ventila-tion achieved were compared. Values are given as mean ±SD. A paired t-test was used to detect any differences between the two groups, p-values of <0.05 were defined to show statistical significance.Results:The described model allowed a reproducible and reliable measurement of the delivered minute ventilation. All paramedics were able to operate the device without prior CBRN training. The maximum minute volume achieved without the filter was 9.5 ±2.7 l/min. Use of the inlet CBRN filtra-tion system reduced the maximum minute volume to 6.3 ±2.0 l/min, reduction: 23%. The achieved maximum minute volumes ranged from 15 to 4.9 l/min in the controls and from 9.8 to 1.4 l/min in the CBRN group. Four paramedics were unable to achieve a minute volume >5 l/min in the CBRN group, one participant failed to achieve that value in the control group. The inherent breathing resistance of the CBRN filter appears to reduce the inflow of air into the self-inflatable bag. This delay in refilling may have resulted in a reduced achievable minute volume.Conclusions:The range of maximum minute volumes observed in both groups highlights the need for continuous BVM ventilator training.

Obstetric physiology and special considerations in ICU

2016 ◽  
Author(s):  
Patrick J. Neligan ◽  
John G. Laffey
Keyword(s):  
Critical Illness ◽  
Distress Syndrome ◽  
Minute Ventilation ◽  
Lower Oesophageal Sphincter ◽  
Community Acquired Pneumonia ◽  
Physiological Changes ◽  
Maternal Illness ◽  
Standard Management ◽  
Increased Risk ◽  
Management Approaches

Pregnant patients constitute less than 1% of intensive care unit admissions, and fewer than 1% of obstetric patients become critically ill. Critical illness may result from pregnancy-specific diseases, diseases that pregnancy predisposes to, or are co-incidental to pregnancy. The presence of a second patient—the foetus—may necessitate adjustments to therapeutic and supportive strategies. However, the foetus is generally robust despite maternal illness. The physiological changes of pregnancy are significant, but may delay the diagnosis of critical illness, requiring modifications to standard management approaches. These include increases in minute ventilation, resulting in a ‘low normal’ PaCO2, a reduction in mean arterial pressure, but increased heart rate, low serum creatinine, relative hypoglycaemia, relative leukocytosis, and reduced lower oesophageal sphincter tone. Pre-eclampsia is a disease of the uteroplacental unit that results in abnormal maternal physiology. Pregnant women are at risk for acute respiratory distress syndrome, due to gastropulmonary aspiration and increased risk of community-acquired pneumonia, sepsis, principally of the genito-urinary system, and thromboembolic disease.

Effects of tonic vagal input on breathing pattern in newborn rabbits

1985 ◽  
Vol 59 (1) ◽  
pp. 223-228 ◽  
Author(s):  
T. Trippenbach ◽  
G. Kelly ◽  
D. Marlot
Keyword(s):  
Breathing Pattern ◽  
Minute Ventilation ◽  
Vagal Activity ◽  
Respiratory Effects ◽  
Tracheal Pressure ◽  
Negative Pressure Breathing ◽  
Lung Deflation ◽  
Reflex Stimulation ◽  
Cardiac Receptors ◽  
Respiratory Reflex

Respiratory effects of positive and negative pressure breathing were studied in 1- and 4-day-old rabbit pups anesthetized with ketamine (50 mg/kg, im) and acepromazine (3 mg/kg, im). We recorded tidal volume (VT), tracheal pressure (Ptr), and integrated diaphragmatic EMG (DiEMG). Inspiratory (TI) and expiratory time (TE) were measured from the records of DiEMG. During breathing with increased Ptr by 1 or 2 cmH2O, VT, minute ventilation (VE), and respiratory rate (f) decreased. Changes in f relied on a TE prolongation. Neither DiEMG nor its rate of rise (DiEMGt) were affected. Except for VT decrease during positive Ptr, all other effects disappeared after vagotomy. Our results indicate that an increase in tonic vagal activity interacts with the mechanisms controlling TE and has no effect on depth and duration of inspiration. When Ptr decreased by 1 and 2 cmH2O, VE increased due to an increase in f. Increase in f relied on shortening of both TI and TE; the TE effect being more pronounced. DiEMG and DiEMGt also increased. Adverse effects of lung deflation and vagotomy strongly suggest that the respiratory reflex stimulation due to decrease in Ptr does not rely on inhibition of the slowly adapting stretch receptor activity. Therefore other excitatory vagal inputs must be responsible for this response. We propose two vagally mediated inputs: the irritant and/or the cardiac receptors.

Cervical spinal cord injury alters the pattern of breathing in anesthetized rats

2001 ◽  
Vol 91 (6) ◽  
pp. 2451-2458 ◽  
Author(s):  
Francis J. Golder ◽  
Paul J. Reier ◽  
Paul W. Davenport ◽  
Donald C. Bolser
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Respiratory Function ◽  
Cervical Spinal Cord ◽  
Minute Ventilation ◽  
Cervical Spinal Cord Injury ◽  
Respiratory Pattern ◽  
Time Intervals ◽  
Cord Injury ◽  
Bilateral Vagotomy

The mechanisms by which chronic cervical spinal cord injury alters respiratory function and plasticity are not well understood. We speculated that spinal hemisection at C2 would alter the respiratory pattern controlled by vagal mechanisms. Expired volume (Ve) and respiratory rate (RR) were measured in anesthetized control and C2-hemisected rats at 1 and 2 mo postinjury. C2 hemisection altered the pattern of breathing at both postinjury time intervals. Injured rats utilized a higher RR and lower Ve to maintain the same minute ventilation as control rats. After bilateral vagotomy, the pattern of breathing in injured rats was not different from controls. The frequency of augmented breaths was higher in injured rats at 2 mo postinjury before vagotomy; however, the Ve of augmented breaths was not different between groups. In conclusion, C2 hemisection alters the pattern of breathing at 1 and 2 mo postinjury via vagal mechanisms.

Ventilatory Responses to Exercise and to Carbon Dioxide in Mitral Stenosis before and after Valvulotomy: Causes of Tachypnoea

1978 ◽  
Vol 54 (1) ◽  
pp. 9-16 ◽  
Author(s):  
J. W. Reed ◽  
M. Ablett ◽  
J. E. Cotes
Keyword(s):  
Carbon Dioxide ◽  
Tidal Volume ◽  
Mitral Stenosis ◽  
Vital Capacity ◽  
Minute Ventilation ◽  
Residual Effect ◽  
Minute Volume ◽  
Cardiac Frequency ◽  
Control Subjects ◽  
Exercise Ventilation

1. The ventilation and cardiac frequency during progressive exercise and the respiratory responses to breathing carbon dioxide have been measured in 33 female patients with mitral stenosis and in 31 control subjects. Compared with the control subjects, the patients' exercise ventilation and cardiac frequency were increased; the exercise tidal volume at standard minute volume, the vital capacity and the ventilatory response to carbon dioxide were reduced. The extent to which the standardized tidal volume was lower during exercise than during breathing carbon dioxide was correlated with the severity of the stenosis, as gauged by the increase in exercise cardiac frequency above the level predicted from anthropometric measurements. 2. Twenty patients were studied postoperatively. In the 12 who showed clinical improvement the exercise ventilation and cardiac frequency were reduced and the exercise tidal volume at a given minute ventilation was increased. The latter change occurred despite a reduction in vital capacity, which was probably a residual effect of thoractomy. There was no significant change in the response to breathing carbon dioxide. No material change in function was observed in the patients whose condition was not improved by the operation. 3. It is suggested that in mitral stenosis the tachypnoea which occurs during exercise, whilst mainly a mechanical consequence of the reduced vital, capacity, is also partly due to pulmonary congestion stimulating intrapulmonary receptors.

Physiological bases for parasite-induced alterations of host behaviour

Parasitology ◽  
1994 ◽  
Vol 109 (S1) ◽  
pp. S119-S138 ◽  
Author(s):  
S. N. Thompson ◽  
M. Kavaliers
Keyword(s):  
Physiological Responses ◽  
Disease Process ◽  
Host Responses ◽  
Parasitic Infections ◽  
Physiological Effects ◽  
Physiological Changes ◽  
Behavioural Patterns ◽  
Behavioural Interactions ◽  
Host Behaviour ◽  
Pathological Consequence

SUMMARYParasitism is defined in various ways as an intimate relationship in which one partner, the parasite, lives on or in another, the host, generally at the expense of the latter. Parasitism commonly results in a unique array of host physiological responses and adaptations. Most studies of the physiological effects of parasitism have focused on the pathological consequence of infection and disease. While many physiological changes contribute to pathogenesis, it is now recognized that parasitic infections at sub-clinical levels also produce physiological effects that either ameliorate or may not contribute to the disease process. Moreover, these physiological changes are often manifested by altered host behaviour. Behavioural studies have enabled an ecological- and evolutionary-oriented evaluation of host responses. In this fashion, physiological effects may be assessed as to whether they affect fitness and confer benefit or harm to one or both of the symbionts involved. We briefly examine how these physiological responses, specifically neural, endocrine, neuromodulatory, and immunomodulatory components, may interact to modify host behaviours. We consider the adaptiveness of these responses and how the behavioural patterns elicited may simultaneously appear adaptive for the parasite as well as the host. In addition, we address how parasite-host physiological and behavioural interactions may be altered during the course of parasitism.

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