The mechanics of lung ventilation and the effects of hypercapnia on respiration in Bufo marinus

1976 ◽  
Vol 54 (8) ◽  
pp. 1364-1374 ◽  
Author(s):  
D. H. Macintyre ◽  
D. P. Toews
Keyword(s):  
Carbon Dioxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Buccal Cavity ◽  
Lung Ventilation ◽  
Minute Volume ◽  
Bufo Marinus ◽  
Pressure Measurements ◽  
Breathing Patterns ◽  
Systemic Arch

Respiratory and circulatory changes associated with exposure to elevated ambient carbon dioxide (CO2) levels were studied in free-moving Bufo marinus. The buccal cavity, lungs, and systemic arch were cannulated singly or in various combinations. Simultaneous recordings from the lungs and buccal cavity permitted analysis of respiratory rate and pattern, while systemic cannulae provided constant blood-pressure measurements. All experiments were conducted at 22 °C.Normal breathing patterns consisted of continuous buccal 'oscillations' with irregularly occurring lung 'ventilations' and occasional high pressure 'inflations.' On exposure to increased ambient CO2 levels, oscillations decreased, ventilations increased, and inflations predominated, resulting in an overall increase in lung minute-volume. Systemic pressure decreased as ambient CO2 approached 3%, but returned to normal, with an associated increase in heart rate, at the 5% level. It is postulated that the ventilatory and concomitant circulatory responses are mediated by receptors functioning in both the chemoreceptive and baroreceptive modes.

Hemodynamic response of normal men to graded treadmill exercise

1964 ◽  
Vol 19 (3) ◽  
pp. 457-464 ◽  
Author(s):  
Burton S. Tabakin ◽  
John S. Hanson ◽  
Thornton W. Merriam ◽  
Edgar J. Caldwell
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Cardiac Output ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Treadmill Exercise ◽  
Minute Volume ◽  
Peripheral Vascular ◽  
Carbon Dioxide Elimination ◽  
Oxygen Utilization

The physiologic variables defining the circulatory and respiratory state in normal man have been measured in recumbency, standing at rest and during progressively severe grades of exercise approaching near-maximal levels. Indicator-dilution technique was used for determination of cardiac output with simultaneous radio-electrocardiographic recordings of heart rate. Direct intra-arterial pressure measurements were utilized for calculation of peripheral vascular resistance. Minute volume of ventilation, oxygen utilization, and carbon dioxide elimination were obtained from analysis of expired air collected at the time of each cardiac output determination. A peak mean workload of 1,501 kg-m/min was realized during the treadmill exercise. Increases in cardiac output over the range of exercise employed correlated well with indices of workload such as heart rate, oxygen utilization, and minute volume of ventilation. There was no correlation of stroke volume with these indices. It is concluded from examination of individual stroke-volume responses that a progressive increase in stroke volume is not a necessary or constant phenomenon in adapting to increasing workload. cardiac output in treadmill exercise; dye-dilution cardiac output determinations; arterial pressure during upright exercise; stroke-volume response to graded treadmill exercise; exercise response of cardiac output and stroke volume; peripheral vascular resistance response to position and exercise; treadmill exercise—effects on cardiac output, stroke volume, and oxygen uptake; minute ventilation, cardiac output, and stroke volume during exercise; carbon dioxide elimination during treadmill exercise; heart rate and cardiac output during treadmill exercise; exercise; physiology Submitted on July 12, 1963

scholarly journals Development of blood pressure and cardiac reflexes in the frog Pseudis paradoxsus

1992 ◽  
Vol 263 (3) ◽  
pp. R602-R608
Author(s):  
W. W. Burggren ◽  
J. E. Bicudo ◽  
M. L. Glass ◽  
A. S. Abe
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Body Mass ◽  
Mean Arterial Blood Pressure ◽  
Lung Ventilation ◽  
Air Breathing ◽  
Paulo State ◽  
Arterial Blood ◽  
Nearly Continuous

Systemic arterial blood pressure and heart rate (fH) were measured in unanesthetized, unrestrained larvae and adults of the paradoxical frog, Pseudis paradoxus from Sao Paulo State in Brazil. Four developmental groups were used, representing the complete transition from aquatic larvae to primarily air-breathing adults. fH (49-66 beats/min) was not significantly affected by development, whereas mean arterial blood pressure was strongly affected, being lowest in the stage 37-39 larvae (10 mmHg), intermediate in the stage 44-45 larvae (18 mmHg), and highest in the juveniles and adults (31 and 30 mmHg, respectively). Blood pressure was not significantly correlated with body mass, which was greatest in the youngest larvae and smallest in the juveniles. In the youngest larvae studied (stages 37-39), lung ventilation was infrequent, causing a slight decrease in arterial blood pressure but no change in heart rate. Lung ventilation was more frequent in stages 44-45 larvae and nearly continuous in juveniles and adults floating at the surface. Bradycardia during both forced and voluntary diving was observed in almost every advanced larva, juvenile, and adult but in only one of four young larvae. Developmentally related changes in blood pressure were not complete until metamorphosis, whereas diving bradycardia was present at an earlier stage.

Phase I Safety Assessment of Intrathecal Neostigmine Methylsulfate in Humans 

1995 ◽  
Vol 82 (2) ◽  
pp. 331-343 ◽  
Author(s):  
David D. Hood ◽  
James C. Eisenach ◽  
Robin Tuttle
Keyword(s):  
Carbon Dioxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Side Effects ◽  
Healthy Volunteers ◽  
Nausea And Vomiting ◽  
Severe Nausea ◽  
End Tidal Carbon Dioxide ◽  
End Tidal ◽  
Ice Water

Background In dogs, sheep, and rats, spinal neostigmine produces analgesia alone and enhances analgesia from alpha 2-adrenergic agonists. This study assesses side effects and analgesia from intrathecal neostigmine in healthy volunteers. Methods After institutional review board approval and informed consent, 28 healthy volunteers were studied. The first 14 volunteers received neostigmine (50-750 micrograms) through a #19.5 spinal needle followed by insertion of a spinal catheter. The remaining 14 volunteers received neostigmine through a #25 or #27 spinal needle without a catheter. Safety measurements included blood pressure, heart rate, oxyhemoglobin saturation, end-tidal carbon dioxide, neurologic evaluation, and computer tests of vigilance and memory. Analgesia in response to ice water immersion was measured. Results Neostigmine (50 micrograms) through the #19.5 needle did not affect any measured variable. Neostigmine (150 micrograms) caused mild nausea, and 500-750 micrograms caused severe nausea and vomiting. Neostigmine (150-750 micrograms) produced subjective leg weakness, decreased deep tendon reflexes, and sedation. The 750-micrograms dose was associated with anxiety, increased blood pressure and heart rate, and decreased end-tidal carbon dioxide. Neostigmine (100-200 micrograms) in saline, injected through a #25 or #27 needle, caused protracted, severe nausea, and vomiting. This did not occur when dextrose was added to neostigmine. Neostigmine by either method of administration reduced visual analog pain scores to immersion of the foot in ice water. Conclusions The incidence and severity of these adverse events from intrathecal neostigmine appears to be affected by dose, method of administration, and baricity of solution. These effects in humans are consistent with studies in animals. Because no unexpected or dangerous side effects occurred, cautious examination of intrathecal neostigmine alone and in combination with other agents for analgesia is warranted.

scholarly journals Increase of Short-Term Heart Rate Variability Induced by Blood Pressure Measurements during Ambulatory Blood Pressure Monitoring

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Attila Frigy ◽  
Annamária Magdás ◽  
Victor-Dan Moga ◽  
Ioana Georgiana Coteț ◽  
Miklós Kozlovszky ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Ambulatory Blood Pressure ◽  
Pressure Measurement ◽  
Blood Pressure Monitoring ◽  
Blood Pressure Measurement ◽  
Pressure Measurements ◽  
Pressure Monitoring ◽  
Short Term

Objective.The possible effect of blood pressure measurements per se on heart rate variability (HRV) was studied in the setting of concomitant ambulatory blood pressure monitoring (ABPM) and Holter ECG monitoring (HM).Methods.In 25 hypertensive patients (14 women and 11 men, mean age: 58.1 years), 24-hour combined ABPM and HM were performed. For every blood pressure measurement, 2-minute ECG segments (before, during, and after measurement) were analyzed to obtain time domain parameters of HRV: SDNN and rMSSD. Mean of normal RR intervals (MNN), SDNN/MNN, and rMSSD/MNN were calculated, too. Parameter variations related to blood pressure measurements were analyzed using one-way ANOVA with multiple comparisons.Results.2281 measurements (1518 during the day and 763 during the night) were included in the analysis. Both SDNN and SDNN/MNN had a constant (the same for 24-hour, daytime, and nighttime values) and significant change related to blood pressure measurements: an increase during measurements and a decrease after them (p<0.01for any variation).Conclusion.In the setting of combined ABPM and HM, the blood pressure measurement itself produces an increase in short-term heart rate variability. Clarifying the physiological basis and the possible clinical value of this phenomenon needs further studies.

scholarly journals Incidence of Artifacts and Deviating Values in Research Data Obtained from an Anesthesia Information Management System in Children

2018 ◽  
Vol 128 (2) ◽  
pp. 293-304 ◽  
Author(s):  
Anne-lee J. Hoorweg ◽  
Wietze Pasma ◽  
Leo van Wolfswinkel ◽  
Jurgen C. de Graaff
Keyword(s):  
Carbon Dioxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Saturation ◽  
Information Management ◽  
Information Management System ◽  
Noninvasive Blood Pressure ◽  
Invasive Blood Pressure ◽  
End Tidal Carbon Dioxide ◽  
End Tidal

Abstract Background Vital parameter data collected in anesthesia information management systems are often used for clinical research. The validity of this type of research is dependent on the number of artifacts. Methods In this prospective observational cohort study, the incidence of artifacts in anesthesia information management system data was investigated in children undergoing anesthesia for noncardiac procedures. Secondary outcomes included the incidence of artifacts among deviating and nondeviating values, among the anesthesia phases, and among different anesthetic techniques. Results We included 136 anesthetics representing 10,236 min of anesthesia time. The incidence of artifacts was 0.5% for heart rate (95% CI: 0.4 to 0.7%), 1.3% for oxygen saturation (1.1 to 1.5%), 7.5% for end-tidal carbon dioxide (6.9 to 8.0%), 5.0% for noninvasive blood pressure (4.0 to 6.0%), and 7.3% for invasive blood pressure (5.9 to 8.8%). The incidence of artifacts among deviating values was 3.1% for heart rate (2.1 to 4.4%), 10.8% for oxygen saturation (7.6 to 14.8%), 14.1% for end-tidal carbon dioxide (13.0 to 15.2%), 14.4% for noninvasive blood pressure (10.3 to 19.4%), and 38.4% for invasive blood pressure (30.3 to 47.1%). Conclusions Not all values in anesthesia information management systems are valid. The incidence of artifacts stored in the present pediatric anesthesia practice was low for heart rate and oxygen saturation, whereas noninvasive and invasive blood pressure and end-tidal carbon dioxide had higher artifact incidences. Deviating values are more often artifacts than values in a normal range, and artifacts are associated with the phase of anesthesia and anesthetic technique. Development of (automatic) data validation systems or solutions to deal with artifacts in data is warranted.

scholarly journals Evaluation of acute cardiorespiratory and hemodynamic changes in perioperative intravenous antimicrobial applications in cats

2021 ◽  
Vol 73 (1) ◽  
pp. 91-98
Author(s):  
P.R.S. Gomide ◽  
R.C. Costa ◽  
L.G. Faria ◽  
J.T. Brondani ◽  
A.P. Gering ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Reference Interval ◽  
The Other ◽  
Antimicrobial Use ◽  
Hemodynamic Changes ◽  
Healthy Female ◽  
Invasive Method ◽  
The Times

ABSTRACT The metabolic peculiarities of felines favor an intoxication. Fifty healthy female cats were divided into five groups: PG (placebo group), G2 (cefazolin), G3 (ceftriaxone), G4 (enrofloxacin) and G5 (ampicillin) were used. The parameters evaluated were: total expired carbon dioxide (ETCO2), oxygen saturation in hemoglobin (SpO2), heart rate (HR), respiratory rate (RR), body temperature (BT), systolic, mean and diastolic blood pressure (SBP, mBP and DBP) by invasive method, at T0, 5 (T5), 10 (T10), 15 (T15), 20 (T20), 25 (T25) and 30 (T30) minutes after administration of the treatments. HR presented reduction in G2 compared to PG at all times, except T20, and in G4, T25 and T30 were lower than the T0 values (P<0.05). BT showed increase in the G3 at T0 and T5 and all groups showed reduction in the values of BT relative to T0 (P<0.05). ETCO2 increased in G2 and G5 at all times compared to PG (P<0.05) and there were no differences among the times within each group. It was concluded that ceftriaxone is safer for the prophylactic antimicrobial use in cats, however the other antimicrobials are also indicated, because all the parameters, in all groups, basically did not change over the study and when this occurs it remains in reference interval.

Development of the Sex Difference in Blood Pressure of the Chick

1957 ◽  
Vol 188 (2) ◽  
pp. 383-386 ◽  
Author(s):  
Harold S. Weiss ◽  
Robert K. Ringer ◽  
Paul D. Sturkie
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Sex Difference ◽  
Diastolic Pressure ◽  
Rapid Development ◽  
Systolic Pressure ◽  
Pressure Measurements ◽  
White Leghorn ◽  
Rate Of Development ◽  
White Leghorn Chicken

In order to establish the age and manner in which the sex difference in blood pressure of the adult white leghorn chicken develops, periodical blood pressure measurements were made on chicks between 3 and 34 weeks of age. There were no consistent differences in pressure between the sexes under 8 weeks of age. Between the 8th and 13th weeks, pressures began to diverge, and within 4–8 weeks a 26–30-mm sex difference in systolic pressure developed. Significant divergences occurred also in diastolic and pulse pressure. The sex divergence was due primarily to a rise in male pressure, the female level remaining comparatively stable. Net changes in male parameters during the period of rapid development of the sex difference in pressure were: body weight + 219 gm, systolic pressure + 26 mm, diastolic pressure + 16 mm and heart rate –22/ min. The age at which the sex difference in pressure begins and its rate of development appear to be related to sexual maturation in the male. However, no significant correlation between the rising male pressure and testes or comb size could be shown. Normal chick blood pressure values prior to the sex divergence differ within strains of white leghorns and for the two groups used here, between 7 and 9 weeks of age, were 150/130 and 162/136 mm Hg.

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