A BASIC software program to estimate cardiac output and alveolar ventilation

1990 ◽  
Vol 20 (4) ◽  
pp. 261-265
Author(s):  
Alain Varray ◽  
Jacques Mercier ◽  
Christian Prefaut
Keyword(s):  
Cardiac Output ◽  
Alveolar Ventilation ◽  
Basic Software ◽  
Software Program

Cardiopulmonary effects of continuous pressure breathing in hypothermic dogs

1965 ◽  
Vol 20 (4) ◽  
pp. 669-674 ◽  
Author(s):  
J. Salzano ◽  
F. G. Hall
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Negative Pressure ◽  
Alveolar Ventilation ◽  
Positive Pressure ◽  
Negative Pressure Breathing ◽  
Continuous Positive Pressure ◽  
Respiratory Dead Space

Continuous pressure breathing was studied in hypothermic anesthetized dogs. Alveolar ventilation decreased during continuous positive-pressure breathing and increased during continuous negative-pressure breathing. The changes in alveolar ventilation were due to changes in respiratory rate as well as in respiratory dead space. Cardiac output fell significantly during continuous positive-pressure breathing due to a reduction in heart rate and stroke volume. During continuous negative-pressure breathing cardiac output was only slightly greater than during control as a result of a fall in heart rate and an increase in stroke volume. Oxygen consumption was reduced to 60% of control during continuous positive-pressure breathing of 16 cm H2O but was 25% greater than control during continuous negative-pressure breathing. Qualitatively, CO2 production changed as did O2 consumption but was different quantitatively during continuous negative-pressure breathing indicating hyperventilation due to increased respiratory rate. Mean pulmonary artery pressures and pulmonary resistance varied directly with the applied intratracheal pressure. The results indicate that the hypothermic animal can tolerate an imposed stress such as continuous pressure breathing and can increase its oxygen consumption during continuous negative-pressure breathing as does the normothermic animal. hypothermia; respiratory dead space; metabolic rate; cardiac output Submitted on December 8, 1964

Carbon monoxide exchanges between the human fetus and mother: a mathematical model

1977 ◽  
Vol 232 (3) ◽  
pp. H311-H323 ◽  
Author(s):  
E. P. Hill ◽  
J. R. Hill ◽  
G. G. Power ◽  
L. D. Longo
Keyword(s):  
Mathematical Model ◽  
Air Pollution ◽  
Carbon Monoxide ◽  
Cardiac Output ◽  
Human Fetus ◽  
Alveolar Ventilation ◽  
Co Concentration ◽  
Fetal Oxygenation ◽  
Ventilation Rates ◽  
Co Concentrations

A mathematical model was developed to calculate maternal and fetal carboxyhemoglobin concentrations, [HbCO], as functions of time during and after exposure of the mother to various inspired CO concentrations. Effects of variation in alveolar ventilation rates, pulmonary and placental fiffusing capacities, cardiac output, endogenous carbon monoxide production and other factors were studied. Following a change in the inspired CO concentration, fetal HbCO lags behind maternal HbCO by several hours. During CO uptake, fetal HbCO eventually overtakes maternal, and approaches an equilibrium value as much as 10% higher than the mother's. During CO washout the fetal levels again lag behind the mothers. Results indicate that treatment of pregnant women who have elevated HbCO levels with 100% oxygen reduces the time necessary to reduce the maternal HbCO level as expected, but that the rate of fetal CO elimination is not increased as much as that of the mother. Changes in maternal and fetal HbCO were also calculated for a representative exposure to changing inspired CO levels produced by fluctuating levels of air pollution. Finally, the effects of carboxyhemoglobin on fetal oxygenation were studied, including the effects of high altitude and exercise.

The Effect of Aminophylline on the Respiration and Pulmonary Circulation

1970 ◽  
Vol 38 (5) ◽  
pp. 549-554 ◽  
Author(s):  
V. Ježek ◽  
A. Ouředník ◽  
J. Štěpánek ◽  
F. Boudík
Keyword(s):  
Cardiac Output ◽  
Arterial Pressure ◽  
Chronic Bronchitis ◽  
Pulmonary Circulation ◽  
Pulmonary Arterial Pressure ◽  
Alveolar Ventilation ◽  
Arterial Oxygen ◽  
Bronchial Obstruction ◽  
Arterial Blood ◽  
Pulmonary Arterial

1. We have examined the effects of aminophylline on the respiration and pulmonary circulation of eleven patients with chronic bronchitis and six patients with peripheral bronchial carcinoma; the latter were free from bronchial obstruction at the time of study. 2. Aminophylline caused an increase in total and alveolar ventilation and a decrease in arterial carbon dioxide tension. Lung diffusing capacity was unaltered in subjects with marked respiratory insufficiency but increased slightly in an additional group of less severely affected patients, and in the control subjects. 3. Mean pulmonary arterial pressure decreased significantly in the patients with chronic bronchitis but not those with lung cancer. A positive correlation was observed between the level of pulmonary arterial pressure during the control period and the decrease after aminophylline. 4. For the group as a whole there was no significant change in cardiac output or arterial oxygen saturation or tension. However, in those subjects in whom the cardiac output was increased, the arterial blood oxygen was reduced despite an increase in alveolar ventilation. The data are interpreted as evidence for a disproportionate part of the increase in cardiac output being directed to poorly ventilated areas of the lung.

Influence of vagal blockade on respiratory and circulatory functions in hypothermic dogs

1962 ◽  
Vol 17 (5) ◽  
pp. 833-836 ◽  
Author(s):  
John Salzano ◽  
F. G. Hall
Keyword(s):  
Cardiac Output ◽  
Body Temperature ◽  
Dead Space ◽  
Alveolar Ventilation ◽  
Normal Body Temperature ◽  
Vagal Blockade ◽  
Physiologic Dead Space ◽  
Anesthetized Dogs ◽  
Output Ratio ◽  
Carbon Dioxide Pressure

Anatomical and physiological dead spaces were enlarged as a result of reduction in body temperature to 28 C in spontaneously respiring anesthetized dogs. Respiratory dead space at 32 C was not significantly different from that at normal body temperature. Vagal blockade resulted in an increase in tidal volume and decrease in respiratory frequency and increased anatomic and physiologic dead space at normal and reduced temperatures. Alveolar ventilation and cardiac output declined equally (percentagewise) with reduction in body temperature to 32 C; at 28 C alveolar ventilation fell more precipitously so that alveolar ventilation-cardiac output ratio (ventilation-perfusion) at 28 C was approximately one-half that at 37 and 32 C. Arterial-alveolar carbon dioxide pressure differences were independent of temperature and vagal blockade. The results indicate no impairment of gas transport or gas exchange at 32 or 28 C in spontaneously respiring anesthetized dogs. Submitted on January 11, 1962

Mechanism and pharmacology of shock due to rattlesnake venom in sheep

1965 ◽  
Vol 20 (4) ◽  
pp. 709-718 ◽  
Author(s):  
D. F. J. Halmagyi ◽  
B. Starzecki ◽  
G. J. Horner
Keyword(s):  
Cardiac Output ◽  
Arterial Pressure ◽  
Intravenous Infusion ◽  
Respiratory Arrest ◽  
Systemic Arterial Pressure ◽  
Alveolar Ventilation ◽  
Continuous Intravenous Infusion ◽  
Rattlesnake Venom ◽  
Acute Hypotension ◽  
Therapeutic Doses

Acute hypotension produced by the intravenous injection of 20 μg/kg of rattlesnake (Crotalus atrox) venom in sheep was spontaneously restored within frac12—2 hr (crotalin collapse). Slow continuous intravenous infusion of larger doses of crotalin produced a fall in cardiac output and systemic arterial pressure, hemoconcentration, and hypoventilation. This condition could only be reversed by therapeutic intervention and was termed “crotalin shock.” Administration of antivenin in crotalin shock proved to be ineffective. Intravenous dextran infusion restored cardiac output and accentuated respiratory depression. Administration of steroids in conventional therapeutic doses resulted in a rise in systemic arterial pressure and alveolar ventilation with little change in blood flow. Simultaneous administration of dextran and corticosteroids gave better results than either material used alone. Continuous intravenous infusion of isoproterenol improved alveolar ventilation and restored spontaneous breathing in some cases of crotalin-induced respiratory arrest. dextran; ventilation; steroids; antivenin; isoproterenol; respiratory failure; hemoconcentration Submitted on September 29, 1964

Cardiopulmonary readjustments in passive tilt

1979 ◽  
Vol 47 (3) ◽  
pp. 503-507 ◽  
Author(s):  
S. V. Matalon ◽  
L. E. Farhi
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Random Sequence ◽  
Upright Position ◽  
Alveolar Ventilation ◽  
Gravity Effect ◽  
Threshold Values ◽  
Ample Evidence ◽  
Residual Capacity ◽  
End Tidal

There is ample evidence that posture affects many cardiorespiratory variables, but the extent to which secondary reflex mechanisms complement or oppose the primary gravity effect is not clear. We have addressed ourselves to this problem by studying five normal volunteers, passively tilted from the supine to the upright position in 15 degrees increments, in random sequence, determinging cardiac output (Q), heart rate (HR), stroke volume (SV), minute and alveolar ventilation (VE and VA), functional residual capacity (FRC), and arterial-end-tidal PCO2 pressure difference. In each position, four to five measurements were obtained by noninvasive techniques. Changes in Q and in FRC were linearly related to the sine of the tilt angle, indicating that reflexes were either absent or that their net effect was proportional to the effects of gravity; this was clearly not the case for other variables (HR, SV, VE, VA) in which it was possible to demonstrate threshold values for the appearance of secondary changes.

scholarly journals Prediction of expiratory desflurane and sevoflurane concentrations in lung-healthy patients utilizing cardiac output and alveolar ventilation matched pharmacokinetic models

Medicine ◽  
2021 ◽  
Vol 100 (6) ◽  
pp. e23570
Author(s):  
Jonas Weber ◽  
Claudia Mißbach ◽  
Johannes Schmidt ◽  
Christin Wenzel ◽  
Stefan Schumann ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Alveolar Ventilation ◽  
Pharmacokinetic Models
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