Ventilatory Response In Patients Research Articles

Effect of autonomic neuropathy on ventilatory response to progressive hypercapnia in dialysis patients

The impact of autonomic neuropathy (common in patients on haemodialysis) on ventilatory response to hypercapnia has been studied. We investigated cardiac reflex tests in 20 patients on chronic haemodialysis (8 patients were found with and 12 without neuropathy of the autonomic nervous system). Using the hyperoxic CO2-rebreathing method (according to Read), we tested the above-mentioned two groups of patients and compared them with 14 healthy control subjects. Accumulation of CO2 in blood with hyperoxic CO2 rebreathing stimulates central chemoreceptors, and therefore causes a progressive rise in minute ventilation. In patients with autonomic neuropathy (n = 8), ventilatory response to increasing pCO2 was significantly lower than that in the controls (1.7 +/- 0.3 versus 3.2 +/- 0.5 l/min/mmHg, P < 0.001). On the other hand ventilatory response in patients without autonomic damage (n = 12) showed no significant difference when compared to controls (3.1 +/- 0.8 l/min/mmHg). There were no differences in lung function, arterial blood gas analysis, blood chemistry, duration on dialysis, and demographic data when comparing the patients with and those without autonomic damage. Our analysis shows different patterns of ventilatory response to increasing pCO2 in patients on haemodialysis. Autonomic neuropathy has to be considered when rebreathing tests are interpreted. The clinical relevance of these findings needs further investigation.

Hypercapneic ventilatory response in patients with panic disorder before and after alprazolam treatment and in pre- and postmenstrual women

We tested the ventilatory and anxiety response to hypercapneic (CO 2) challenge in women with panic disorder as well as in normal women in the premenstrual phase and mid-points of their menstrual cycles. Panic disorder patients were challenged on two occasions, each time while in the premenstrual phase of the menstrual cycle, receiving an open trial of alprazolam through the intervening 8 weeks between tests. This study confirms previous reports indicating increased sensitivity to CO 2 in patients with panic disorder and that this sensitivity can be attenuated by treatment. We found a significant decrease in the ventilatory response of panic disorder patients comparing pre- and post-therapy. We also observed that normal females, while in the premenstrual phase of their menstrual cycle, have a heightened anxiety response to CO 2 challenge.

Ventilatory control in lung transplantation

Heart/lung transplantation offers a unique opportunity for studying the role of pulmonary innervation on control of breathing. In heart/lung transplant patients the pattern of breathing has been found to remain unaffected at rest and when asleep. In contrast, CO2 breathing studies have yield conflicting results. In heart/lung transplant recipients with normal pulmonary function, the hypercapnic ventilatory response was not different from that seen in control subjects, whereas heart/lung transplant recipients with moderate restriction had a profound depression in the ventilatory response to CO2. These results suggested that pulmonary vagal afferent fibers may have a facilitating effect on the hypercapnic ventilatory response in patients with restriction. This result is in opposition with data from airway anesthesia studies. In studies of the effects of exercise in transplant patients, control of breathing was affected in the same way as in normal subjects with anesthetized airways: transplant patients had an appropriate level of ventilation with a disproportionate increase in tidal volume. In normal subjects after suppression of inspiratory activity by mechanical hyperventilation, hypercapnia at which inspiratory activity muscle recruitment appeared was lower when arterial CO2 was raised by decreasing ventilator ventilation rather than by adding CO2 in the inspiratory line. This was not the case in double lung transplant subjects. These findings suggest that pulmonary afferent nerves have an inhibitory effect on inspiratory activity in humans. In conclusion, pulmonary afferent play a negligible role in the control of breathing of human at rest but are important in regulating the pattern of ventilation during stress conditions and large tidal volume conditions.

Effects of Chronic Acid-Base Changes on the Rebreathing Hypercapnic Ventilatory Response in Man

The CO2 rebreathing method can be very useful to test the hypercapnic ventilatory response in patients, including those with chronic acid-base changes (e.g. chronic metabolic acidosis due to renal failure). The ventilatory response to hypercapnia (CO2-R) was measured in 4 normal men by the rebreathing method under control conditions (CaCO3: 0.1 g.kg-1.day-1) and with induced metabolic acidosis (NH4Cl: 0.3 g.kg-1.day-1) and alkalosis (NaHCO3: 0.7 g.kg-1.day-1). The slope of the CO2-R did not change as a result of the acid-base alterations, but was shifted to the left of normal by metabolic acidosis, and to the right by metabolic alkalosis. These results compare favorably with previous reports on the CO2-R as measured by the steady-state technique, and validate the rebreathing method as a reliable and useful technique for evaluating CO2-R in man with altered acid-base states.

Ventilatory Responses in Patients with Essential Hypertension.

We investigated the ventilatory responses to hypoxia and hypercapnia in patients with essential hypertension (HT) as compared with healthy subjects (NV). Further, to evaluate the contribution of the peripheral chemoreceptors to ventilatory response, we used a withdrawal test. Hypoxic ventilatory drive (HVR) was measured as the parameter A denoting the shape of VI (inspiratory minute ventilation)-PETO2 (end-tidal PO2) curve which was calculated by the empirical equation: VI = V0 + A/(PETO2-32). Hypercapnic ventilatory drive (HCVR) was measured as the parameter S denoting the shape of the VI-PETCO2 (end-tidal PCO2) relation which was calculated by the empirical equation: VI = S(PETCO2-B). There were no significant differences in the parameters of HVR and HCVR between NV and HT. A positive correlation between A/BSA and S/BSA was found to be significant in NV (r = 0.873, p less than 0.05). Conversely, there was no significant correlation between A/BSA and S/BSA (r = 0.547) in HT. On the other hand, the withdrawal responses (delta VI/BSA and % delta VI:delta VI/VI x 100%) were obtained from the magnitude of depression in ventilation caused by two breaths of O2 in hypoxic hypercapnia. In the withdrawal responses, delta VI/BSA and % delta VI in HT were significantly higher than those in NV. A/BSA significantly correlated with delta VI/BSA (NV, r = 0.684, p less than 0.05; HT, r = 0.648, p less than 0.05) in both NV and HT. However, delta VI/BSA in HT tended to be higher than that in NV, under the same value of A/BSA. These results suggested that the peripheral chemoreceptor activity was augmented in HT.

A new method for studying the ventilatory response in patients

A method for clinical studies of the ventilatory response to carbon dioxide and to hypoxaemia in patients is described. The main parameters with this method are respiratory frequency, tidal volume, minute volume, timing, and drive. The ventilation of volunteers was not affected while breathing air through the designed apparatus. The response to carbon dioxide and to hypoxaemia in volunteers was reproducible and similar to what has previously been described. Our method proved suitable to test the ventilatory responses in patients with varying degrees of impaired ventilation-perfusion ratios and thus also in patients with a low PaO2. Our method has a higher accuracy than earlier methods.

Ventilatory response in patients with acute lactic acidosis.

The ventilatory response in acute lactic acidosis was assessed in 39 patients. In 18 patients, the acidosis was associated with phenformin ingestion and in 21, with other causes such as shock and sepsis, but not pulmonary edema. Arterial blood CO2 tensions and plasma bicarbonate concentrations were compared to those previously found in patients with uncomplicated diabetic ketoacidosis. In most of the lactic acidosis patients, arterial blood CO2 fell within the 95% confidence band calculated from the data in the ketoacidotic patients. Only 1 lactic acidotic patient had a triflingly lower CO2 tension. Shock was present in 8 of the 9 lactic acidotic patients whose CO2 tensions were more than 2 torr above the 95% confidence band.

The hypoxic ventilatory response in patients with high-affinity hemoglobin.

In an attempt to determine whether PO2 or O2 saturation is stimulus for the hypoxic ventilatory drive, we studied 2 brothers with the high O2 affinity hemoglobin Ranier (P50 approximately equal to 12 mm Hg). The ventilatory response to PO2 was normal. The O2 saturation did decrease slightly, and the ventilatory response to the decrease in O2 saturation was greatly exaggerated. We conclude that these findings are consistent with either of 2 possibilities: (1) that PO2 provides the stimulus to the hypoxic ventilatory response, or (2) that patients with high-affinity hemoglobin have increased sensitivity to arterial O2 desaturation.

Alveolar-arterial PCO2 difference during rebreathing in patients with chronic hypercapnia.

ArticleAlveolar-arterial PCO2 difference during rebreathing in patients with chronic hypercapnia.J D McEvoy, N L Jones, and E J CampbellJ D McEvoy, N L Jones, and E J CampbellPublished Online:01 Oct 1973https://doi.org/10.1152/jappl.1973.35.4.542MoreSectionsPDF (968 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByA quick and easy method of measuring the hypercapnic ventilatory response in patients with COPDRespiratory Medicine, Vol. 103, No. 2CO2 rebreathing model in COPD: blood-to-gas equilibration8 September 2006 | European Journal of Applied Physiology, Vol. 98, No. 5Mesure non invasive du débit cardiaque par réinhalation de CO2 chez le patient en ventilation contrôléeRéanimation Urgences, Vol. 2, No. 4CapnographyAutomated non-invasive measurement of cardiac output: comparison of electrical bioimpedance and carbon dioxide rebreathing techniques.Heart, Vol. 59, No. 3Blood/gas equilibrium of carbon dioxide in lungs. A critical reviewRespiration Physiology, Vol. 39, No. 1Blood–Gas Equilibration in LungsMeasurements of Cardiac Output in Seriously Ill Patients Using a CO2 Rebreathing MethodChest, Vol. 73, No. 2Symptomatic Osseous Sarcoidosis with Findings on Bone ScanChest, Vol. 73, No. 2Reproducibility of Data on Steady-State Gas Exchange and Indices of Maldistribution of Ventilation and Blood FlowChest, Vol. 71, No. 6 More from this issue > Volume 35Issue 4October 1973Pages 542-5 https://doi.org/10.1152/jappl.1973.35.4.542PubMed4743014History Published online 1 October 1973 Published in print 1 October 1973 Metrics

Effect of P CO2 level on alveolar-arterial P CO2 difference during rebreathing.

ArticleEffect of P CO2 level on alveolar-arterial P CO2 difference during rebreathing.N L Jones, D G Robertson, J W Kane, and E J CampbellN L Jones, D G Robertson, J W Kane, and E J CampbellPublished Online:01 Jun 1972https://doi.org/10.1152/jappl.1972.32.6.782MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByMeasuring Cerebrovascular Reactivity: Sixteen Avoidable Pitfalls7 July 2021 | Frontiers in Physiology, Vol. 12Ventilation, Blood Flow, and Their Inter‐Relationships21 February 2020The CO 2 stimulus for cerebrovascular reactivity: Fixing inspired concentrations vs. targeting end-tidal partial pressures21 March 2016 | Journal of Cerebral Blood Flow & Metabolism, Vol. 36, No. 6Theory of gastric CO2 ventilation and its control during respiratory acidosis: Implications for central chemosensitivity, pH regulation, and diseases causing chronic CO2 retentionRespiratory Physiology & Neurobiology, Vol. 175, No. 2The caudal solitary complex is a site of central CO2 chemoreception and integration of multiple systems that regulate expired CO2Respiratory Physiology & Neurobiology, Vol. 173, No. 3A quick and easy method of measuring the hypercapnic ventilatory response in patients with COPDRespiratory Medicine, Vol. 103, No. 2Mitochondrial coupling in humans: assessment of the P/O2 ratio at the onset of calf exercise6 January 2007 | European Journal of Applied Physiology, Vol. 99, No. 6CO2 rebreathing model in COPD: blood-to-gas equilibration8 September 2006 | European Journal of Applied Physiology, Vol. 98, No. 5Estimation of Mixed Venous Pco2 for Determination of Cardiac Output in ChildrenChest, Vol. 111, No. 2Cardiac output in single-lead VDD pacing versus rate-matched VVIR pacingThe American Journal of Cardiology, Vol. 75, No. 14Effect of body training position on outcomes of an aerobic training study on individuals with quadriplegiaArchives of Physical Medicine and Rehabilitation, Vol. 76, No. 2Cardiac output determined by the CO 2 rebreathing method during arm exerciseClinical Physiology, Vol. 14, No. 1Measurement of Cardiac Output during ExerciseChest, Vol. 102, No. 4The effects of arm crank training on the physiological responses to silbmaximal wheelchair ergometryEuropean Journal of Applied Physiology and Occupational Physiology, Vol. 57, No. 1Transient PO2 and PCO2 differencese between end-tidal gas and arterial blood during rebreathing in awake dogsRespiration Physiology, Vol. 60, No. 2The Controversy about Blood-Gas CO2 Equilibrium in Lungs: Reinvestigation by Prolonged CO2 Rebreathing in Awake Dogs during Rest and ExerciseEffects of positive and negative exercise on ventilatory CO2 sensitivityEuropean Journal of Applied Physiology and Occupational Physiology, Vol. 47, No. 1Reliability of the cardiac output measurement with the indirect Fick-principle for CO2 during exercisePflügers Archiv, Vol. 385, No. 1Blood/gas equilibrium of carbon dioxide in lungs. A critical reviewRespiration Physiology, Vol. 39, No. 1Blood–Gas Equilibration in LungsCO2 dissociation curves of oxygenated whole blood obtained at rest and in exerciseEuropean Journal of Applied Physiology and Occupational Physiology, Vol. 39, No. 1Comparison of methods to calculate cardiac output using the CO2 rebreathing methodEuropean Journal of Applied Physiology and Occupational Physiology, Vol. 35, No. 3Ventilatory responses to hypercapnia and hypoxia at 1 and 4 ATARespiration Physiology, Vol. 18, No. 3Comparison of blood and alveolar gas composition during rebreathing in the dog lungRespiration Physiology, Vol. 17, No. 2 More from this issue > Volume 32Issue 6June 1972Pages 782-7 https://doi.org/10.1152/jappl.1972.32.6.782PubMed5034343History Published online 1 June 1972 Published in print 1 June 1972 Metrics

Effect of chronic exposure to hypoxia on ventilatory response to CO 2 and hypoxia.

Effect of chronic exposure to hypoxia on ventilatory response to CO 2 and hypoxia.

Alveolar-arterial gas tension differences during graded exercise.

Alveolar-arterial gas tension differences during graded exercise.

Continuous measurement of blood pH with an indwelling arterial glass electrode.

ArticleContinuous measurement of blood pH with an indwelling arterial glass electrode.D M Band, and S J SempleD M Band, and S J SemplePublished Online:01 Apr 1967https://doi.org/10.1152/jappl.1967.22.4.854MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByMonitoring with In Vivo Electrochemical Sensors: Navigating the Complexities of Blood and Tissue Reactivity2 June 2020 | Sensors, Vol. 20, No. 11A quick and easy method of measuring the hypercapnic ventilatory response in patients with COPDRespiratory Medicine, Vol. 103, No. 2Alveolar Pco2 oscillations and ventilation at sea level and at high altitudeD. J. Collier, A. H. Nickol, J. S. Milledge, H. J. A. van Ruiten, C. J. Collier, E. R. Swenson, Avijit Datta, and C. B. Wolff1 February 2008 | Journal of Applied Physiology, Vol. 104, No. 2In-Line Blood Gas MonitoringThe Respiratory SystemContinuous intra-arterial blood gas monitoringIntensive Care Medicine, Vol. 22, No. 8Aortic pH oscillations in conscious humans and anaesthetised cats and rabbitsRespiration Physiology, Vol. 102, No. 1International Meetings on Arterial Chemoreceptors: Historical PerspectivesThe physiological control of respirationMolecular Aspects of Medicine, Vol. 13, No. 6Carotid chemoreceptor response to increases in CO2 outputRespiration Physiology, Vol. 81, No. 1In vivo chemical sensors for intensive-care monitoringMedical and Biological Engineering and Computing, Vol. 28, No. 3The effect of potassium and venous CO2 loading on chemoreceptor firing in anaesthetized catsRespiration Physiology, Vol. 76, No. 2Online patient-monitoring system for the simultaneous analysis of blood K+, Ca2+, Na+ and pH using a quadruple-function ChemFET integrated-circuit sensorMedical & Biological Engineering & Computing, Vol. 23, No. 4Plastic H+-Sensitive Membranes for In Vivo pH MeasurementsIn Vivo Performance of an Intravascular pH Monitoring CatheterIn vivo experiments with a pH-ISFET electrodeMedical and Biological Engineering and Computing, Vol. 22, No. 1A miniature flow-through cell with a four-function chemfet integrated circuit for simultaneous measurements of potassium, hydrogen, calcium and sodium ionsAnalytica Chimica Acta, Vol. 159Respiratory Oscillations in Health and DiseaseArterial pH monitoring with monocrystalline antimony sensors17 March 2010 | Scandinavian Journal of Clinical and Laboratory Investigation, Vol. 42, No. 4Ventilatory response to inhaled and infused CO2: Relationship to the oscillating signalRespiration Physiology, Vol. 44, No. 3Reflex effects on human breathing of breath-by-breath changes of the time profile of alveolar $$P_{CO_2 } $$ during steady hypoxiaPfl�gers Archiv European Journal of Physiology, Vol. 389, No. 3Continuous intra-arterial pH-monitoring using monocrystalline antimony as sensor: A study in non-heparinized dogs8 July 2009 | Scandinavian Journal of Clinical and Laboratory Investigation, Vol. 41, No. 4An iridium-iridium oxide electrode for in vivo monitoring of blood pH changes9 July 2009 | Journal of Medical Engineering & Technology, Vol. 5, No. 2Carotid Arterial Blood Gas Oscillations and the Phase of the Respiratory Cycle During Exercise in Man: Testing a ModelRole of PCO2 oscillations and chemoreceptors in ventilatory response to inhaled and infused CO2Respiration Physiology, Vol. 29, No. 2On-line, computer-controlled potentiometric analysis system1 May 2002 | Analytical Chemistry, Vol. 48, No. 2Glass microelectrode probes for routine pH measurements1 May 2002 | Analytical Chemistry, Vol. 48, No. 2Disorders of RespirationContinuous Measurement of Po2, Pco2 and pH During Total Body Perfusion in Dogs12 July 2009 | Scandinavian Journal of Thoracic and Cardiovascular Surgery, Vol. 6, No. 2Continuous blood pH monitoring using an indwelling catheterThe American Journal of Surgery, Vol. 116, No. 2Enhancement of the ventilatory response to carbon dioxide by tube breathingRespiration Physiology, Vol. 4, No. 1Continuous Measurement of Po 2 , Pco 2 and pH in Blood8 July 2009 | Scandinavian Journal of Clinical and Laboratory Investigation, Vol. 22, No. 1 More from this issue > Volume 22Issue 4April 1967Pages 854-7 https://doi.org/10.1152/jappl.1967.22.4.854PubMed6023208History Published online 1 April 1967 Published in print 1 April 1967 Metrics