THE PART PLAYED BY CAROTID BODY REFLEXES IN THE RESPIRATORY RESPONSE OF THE DOG TO SMALL CHANGES IN THE CARBON DIOXIDE TENSION IN THE ARTERIAL BLOOD

1939 ◽  
Vol 128 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Carl F. Schmidt ◽  
Paul R. Dumke ◽  
Robert D. Dripps
Keyword(s):  
Carbon Dioxide ◽  
Carotid Body ◽  
Carbon Dioxide Tension ◽  
Respiratory Response ◽  
Arterial Blood

Clinical evaluation of an instrument to measure carbon dioxide tension at the oxygenator gas outlet in cardiopulmonary bypass

Perfusion ◽  
2006 ◽  
Vol 21 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Frode Kristiansen ◽  
Jan Olav Høgetveit ◽  
Thore H Pedersen
Keyword(s):  
Carbon Dioxide ◽  
Cardiopulmonary Bypass ◽  
Venous Blood ◽  
Carbon Dioxide Tension ◽  
Circuit Board ◽  
Separate Analysis ◽  
Blood Gas ◽  
Arterial Blood ◽  
Gas Measurement ◽  
Venous Blood Gas

This paper presents the clinical testing of a new capno-graph designed to measure the carbon dioxide tension at the oxygenator exhaust outlet in cardiopulmonary bypass (CPB). During CPB, there is a need for reliable, accurate and instant estimates of the arterial blood CO2 tension (PaCO2) in the patient. Currently, the standard practice for measuring PaCO2 involves the manual collection of intermittent blood samples, followed by a separate analysis performed by a blood gas analyser. Probes for inline blood gas measurement exist, but they are expensive and, thus, unsuitable for routine use. A well-known method is to measure PexCO2, ie, the partial pressure of CO2 in the exhaust gas output from the oxygenator and use this as an indirect estimate for PaCO2. Based on a commercially available CO2 sensor circuit board, a laminar flow capnograph was developed. A standard sample line with integrated water trap was connected to the oxygenator exhaust port. Fifty patients were divided into six different groups with respect to oxygenator type and temperature range. Both arterial and venous blood gas samples were drawn from the CPB circuit at various temperatures. Alfa-stat corrected pCO2 values were obtained by running a linear regression for each group based on the arterial temperature and then correcting the PexCO2 accordingly. The accuracy of the six groups was found to be (±SD): ±4.3, ±4.8, ±5.7, ±1.0, ±3.7 and ±2.1%. These results suggest that oxygenator exhaust capnography is a simple, inexpensive and reliable method of estimating the PaCO2 in both adult and pediatric patients at all relevant temperatures.

Interaction of dopamine and haloperidol with O2 and CO2 chemoreception in carotid body

1980 ◽  
Vol 49 (1) ◽  
pp. 45-51 ◽  
Author(s):  
S. Lahiri ◽  
T. Nishino ◽  
A. Mokashi ◽  
E. Mulligan
Keyword(s):  
Carbon Dioxide ◽  
Carotid Body ◽  
Intravenous Infusion ◽  
Dopamine Release ◽  
Carbon Dioxide Tension ◽  
Arterial Oxygen ◽  
Carotid Body Chemoreceptors

Effects of dopamine and of a dopaminergic blocker, haloperidol, on the responses of carotid body chemoreceptors to hypoxia and hypercapnia were investigated in 16 anesthetized cats. Intravenous infusion of dopamine (10-20 micrograms.min-1) decreased carotid body chemoreceptor responses to hypoxia and hypercapnia. The effect was greater at higher levels of arterial oxygen and carbon dioxide tension (PaO2 and PaCO2) stimulus. Thus, the magnitude of the dopamine effect depended on the degree of both PO2- and PCO2-mediated excitation of the receptors. Haloperidol potentiated responses to both hypoxia and hypercapnia but apparently did not stimulate the receptors in the absence of these stimuli. Potentiation by haloperidol and inhibition by dopamine of excitatory effects due to PaO2 decrease and PaCO2 increase are complementary. The data suggest that chemoreception of dopamine, O2, and CO2 converge at some site in the carotid body. Persistence of hypoxic and hypercapnic responses, following dopamine-blocking doses of haloperidol, does not support the theory that regulation of dopamine release is responsible for O2 and CO2 chemoreception in carotid body of the cat.

scholarly journals Effect of Nitric Oxide Blockade by NG-Nitro-l-Arginine on Cerebral Blood Flow Response to Changes in Carbon Dioxide Tension

1992 ◽  
Vol 12 (6) ◽  
pp. 947-953 ◽  
Author(s):  
Qiong Wang ◽  
Olaf B. Paulson ◽  
Niels A. Lassen
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Blood Pressure ◽  
Control Level ◽  
Inhibitory Effect ◽  
Carbon Dioxide Tension ◽  
Extracellular Acidosis ◽  
Flow Response ◽  
Arterial Blood ◽  
Oxide Synthase

The importance of nitric oxide (NO) for CBF variations associated with arterial carbon dioxide changes was investigated in halothane-anesthetized rats by using an inhibitor of nitric oxide synthase, NG-nitro-l-arginine (NOLAG). CBF was measured by intracarotid injection of 133Xe. In normocapnia, intracarotid infusion of 1.5, or 7.5, or 30 mg/kg NOLAG induced a dose-dependent increase of arterial blood pressure and a decrease of normocapnic CBF from 85 ± 10 to 78 ± 6, 64 ± 5, and 52 ± 5 ml 100g−1 min−1, respectively. This effect lasted for at least 2 h. Raising Paco2 from a control level of 40 to 68 mm Hg increased CBF to 230 ± 27 ml 100g−1 min−1, corresponding to a percentage CBF response (CO2 reactivity) of 3.7 ± 0.6%/mm Hg Paco2 in saline-treated rats. NOLAG attenuated this reactivity by 32, 49, and 51% at the three-dose levels. Hypercapnia combined with angiotensin to raise blood pressure to the same level as the highest dose of NOLAG did not affect the CBF response to hypercapnia. l-Arginine significantly prevented the effect of NOLAG on normocapnic CBF as well as blood pressure and also abolished its inhibitory effect on hypercapnic CBF. d-Arginine had no such effect. Decreasing Paco2 to 20 mm Hg reduced control CBF to 46 ± 3 ml 100g−1 min−1 with no further reduction after NOLAG. Furthermore, NOLAG did not change the percentage CBF response to an extracellular acidosis induced by acetazolamide (50 mg/kg). The results suggest that NO or a closely related compound is involved in the regulation of CBF in normocapnia and even more so in hypercapnia.

Aortic body chemoreceptor responses to changes in PCO2 and PO2 in the cat

1979 ◽  
Vol 47 (4) ◽  
pp. 858-866 ◽  
Author(s):  
S. Lahiri ◽  
E. Mulligan ◽  
T. Nishino ◽  
A. Mokashi
Keyword(s):  
Carbon Dioxide ◽  
Discharge Rate ◽  
Arterial Oxygen Tension ◽  
Blood Gases ◽  
Carbon Dioxide Tension ◽  
Steady States ◽  
Arterial Oxygen ◽  
Arterial Blood ◽  
Discharge Rates ◽  
End Tidal

Responses of aortic chemoreceptor afferents to a range of arterial carbon dioxide tension (Paco2) changes at various levels of arterial oxygen tension (Pao2) were investigated in 18 cats anesthetized with alpha-chloralose and maintained at 38 degrees C. Aortic chemoreceptor activity, end-tidal oxygen pressure, end-tidal carbon dioxide pressure, and arterial blood pressure were continuously monitored. Arterial blood gases were measured in steady states. Single or a few clearly identifiable afferents were studied during changes and steady states of Pao2 and Paco2. All the aortic chemoreceptor afferent discharge rates increased with Paco2 increases from hypercapnia (10–15 Torr) to normocapnia and moderate hypercapnia (30–50 Torr) and with Pao2 decreases from above 400 to 30 Torr. Hypoxia augmented the response to Paco2 most effectively in the range of 10–40 Torr. At any Pao2, the discharge rate reached a plateau with sufficient intensity of hypercapnia. The Paco2 stimulus threshold at a Pao2 of 440 Torr was about 15 Torr, and at a Pao2 of 60 Torr it was 10 Torr. In the transition from hypocapnia to hypercapnia, responses increased gradually, usually without an overshoot. The steady-state responses to Paco2 of the majority of aortic chemoreceptors resembled those of carotid chemoreceptors. The responses of both receptors can be attributed to the same basic type of mechanism.

scholarly journals Selected Arterial Blood Gasometry Parameters as Indicators of Blood Transfusion Effectiveness in Foals with Haemolytic Disease

2014 ◽  
Vol 58 (3) ◽  
pp. 467-471
Author(s):  
Artur Stopyra ◽  
Anna Snarska
Keyword(s):  
Carbon Dioxide ◽  
Blood Transfusion ◽  
Partial Pressure ◽  
Carbon Dioxide Tension ◽  
Haematological Parameters ◽  
Haemolytic Disease ◽  
Transfusion Therapy ◽  
Arterial Blood ◽  
Blood Ph ◽  
Ph Increase

Abstract The aim of the study was to determine the suitability of basic haematological, biochemical, and gasometric tests in checking the effectiveness of transfusion therapy in foals during isoerythrolysis. The number of red blood cells, haemoglobin, haematocrit, and partial pressure of carbon dioxide, oxygen, and blood pH was determined immediately before and several times after blood transfusion. The concentration of serum free bilirubin was also measured to confirm haemolysis. Fluids (0.9% NaCl, multielectrolytic fluid, 5% glucose) and antibiotics (penicillin, amikacin) were provided to the foals. The lowest values of haematological parameters were observed before transfusion. This was accompanied by decreased partial pressure of oxygen, low pH, and increased arterial carbon dioxide tension. Transfusion of whole blood led to a gradual normalisation of the haematological parameters, also accompanied by the normalisation of gasometric indicators (decrease in pCO2 and pO2 and pH increase). Monitoring of selected haematological and gasometric parameters allows to evaluate the efficacy of blood transfusion during treatment of haemolytic disease of foals.

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