scholarly journals Carbon Dioxide Reactivity of the Cerebral Circulation in Extremely Premature Infants: Effects of Postnatal Age and Indomethacin

1988 ◽  
Vol 24 (2) ◽  
pp. 175-179 ◽  
Author(s):  
Malcolm I Levene ◽  
David Shortland ◽  
N Gibson ◽  
David H Evans
Keyword(s):  
Carbon Dioxide ◽  
Premature Infants ◽  
Cerebral Circulation ◽  
Carbon Dioxide Reactivity

Effect of CO2 and 100% O2 on cerebral blood flow in preterm infants

1980 ◽  
Vol 48 (3) ◽  
pp. 468-472 ◽  
Author(s):  
F. A. Leahy ◽  
D. Cates ◽  
M. MacCallum ◽  
H. Rigatto
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Preterm Infants ◽  
Cerebral Circulation ◽  
Pressure Change ◽  
Venous Occlusion ◽  
Co2 Sensitivity ◽  
Important Regulator ◽  
Carbon Dioxide Pressure

To determine 1) the effect of arterial CO2 change on the neonatal cerebral circulation and 2) whether 100% O2 would produce significant decrease in cerebral blood flow (CBF), we studied 24 preterm infants to explain the late (5 min) hyperventilation observed in them during hyperoxia. Of these, 12 were studied before and during inhalation of 2-3% CO2 and 12 before and during the inhalation of 100% O2. We measured CBF by a modification of the venous occlusion plethysmography technique and found that CBF increased 7.8% per Torr alveolar carbon dioxide pressure change and that it decreased 15% with 100% O2. These findings suggest that 1) CO2 is an important regulator of CBF in the perterm infant, 2) CBF-CO2 sensitivity in these infants may be greater than in adult subjects, 3) 100% O2 reduced CBF significantly, and 4) a decrease in CBF during administration of 100% O2 may be at least partially responsible for the increase in ventilation with hyperoxia.

scholarly journals The effects of sleeping position on ventilatory responses to carbon dioxide in premature infants

Thorax ◽  
2010 ◽  
Vol 65 (9) ◽  
pp. 824-828 ◽  
Author(s):  
A. P. R. Smith ◽  
T. Saiki ◽  
S. Hannam ◽  
G. F. Rafferty ◽  
A. Greenough
Keyword(s):  
Carbon Dioxide ◽  
Premature Infants ◽  
Sleeping Position ◽  
Ventilatory Responses

High-dose Remifentanil Does Not Impair Cerebrovascular Carbon Dioxide Reactivity in Healthy Male Volunteers

2003 ◽  
Vol 99 (4) ◽  
pp. 834-840 ◽  
Author(s):  
Walter Klimscha ◽  
Roman Ullrich ◽  
Christian Nasel ◽  
Wolfgang Dietrich ◽  
Udo M. Illievich ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
High Dose ◽  
Healthy Male ◽  
Duration Of Action ◽  
Remifentanil Infusion ◽  
Healthy Male Volunteers ◽  
Male Volunteers ◽  
Carbon Dioxide Reactivity ◽  
Cerebrovascular Carbon Dioxide Reactivity ◽  
Relative Change

Background Cerebrovascular carbon dioxide reactivity during high-dose remifentanil infusion was investigated in volunteers by measurement of regional cerebral blood flow (rCBF) and mean CBF velocity (CBFv). Methods Ten healthy male volunteers with a laryngeal mask for artificial ventilation received remifentanil at an infusion rate of 2 and 4 microg x kg-1 x min-1 under normocapnia, hypocapnia, and hypercapnia. Stable xenon-enhanced computed tomography and transcranial Doppler ultrasonography of the left middle cerebral artery were used to assess rCBF and mean CBFv, respectively. If required, blood pressure was maintained within baseline values with intravenous phenylephrine to avoid confounding effects of altered hemodynamics. Results Hemodynamic parameters were maintained constant over time. Remifentanil infusion at 2 and 4 microg x kg-1 x min-1 significantly decreased rCBF and mean CBFv. Both rCBF and mean CBFv increased as the arterial carbon dioxide tension increased from hypocapnia to hypercapnia, indicating that cerebrovascular reactivity remained intact. The average slopes of rCBF reactivity were 0.56 +/- 0.27 and 0.49 +/- 0.28 ml. 100 g-1 x min-1 x mmHg-1 for 2 and 4 microg x kg-1 x min-1 remifentanil, respectively (relative change in percent/mmHg: 1.9 +/- 0.8 and 1.6 +/- 0.5, respectively). The average slopes for mean CBFv reactivity were 1.61 +/- 0.95 and 1.54 +/- 0.83 cm x s-1 x mmHg-1 for 2 and 4 microg x kg-1 x min-1 remifentanil, respectively (relative change in percent/mmHg: 1.86 +/- 0.59 and 1.79 +/- 0.59, respectively). Preanesthesia and postanesthesia values of rCBF and mean CBFv did not differ. Conclusion High-dose remifentanil decreases rCBF and mean CBFv without impairing cerebrovascular carbon dioxide reactivity. This, together with its known short duration of action, makes remifentanil a useful agent in the intensive care unit when sedation that can be titrated rapidly is required.

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

scholarly journals 35% Carbon Dioxide Reactivity In A Bulimia Nervosa Sample

2021 ◽  
Author(s):  
Andrea Woznica
Keyword(s):  
Carbon Dioxide ◽  
Eating Disorder ◽  
Bulimia Nervosa ◽  
Vital Capacity ◽  
Distress Tolerance ◽  
Self Report ◽  
Discomfort Intolerance ◽  
State And Trait Anxiety ◽  
Carbon Dioxide Reactivity ◽  
Anxiety Depression

This study extended research on the specificity of the effects of the carbon dioxide (CO₂) challenge by examining panic reactivity in participants with bulimia nervosa (BN) (n=15) compared to those without bulimia nervosa (n=31). All participants completed self-report measures assessing state and trait anxiety, depression, anxiety sensitivity (AS), distress tolerance (DT), discomfort intolerance (DI), and eating disorder features. They subsequently breathed two vital capacity inhalations; room air and 35% CO₂-enriched air. Reactivity to room air was not different between groups. However, participants with BN displayed greater reactivity to CO₂ compared to the participants with BN. AS, DI, and DT could not be tested as potential mediators in the association between diagnostic group and reactivity because these constructs were not associated with reactivity. Eating disorder features and frequency of binges and purges were also not associated with reactivity. Detailed implications and suggestions for further research are discussed.

ALVEOLAR-ARTERIAL O2 AND CO2 DIFFERENCES AND THEIR RELATION TO LUNG VOLUME IN THE NEWBORN

PEDIATRICS ◽  
1968 ◽  
Vol 41 (3) ◽  
pp. 574-587 ◽  
Author(s):  
D. W. Thibeault ◽  
E. Poblete ◽  
P. A. M. Auld
Keyword(s):  
Carbon Dioxide ◽  
Premature Infants ◽  
Lung Volume ◽  
Term Infant ◽  
Full Term ◽  
Arterial Oxygen ◽  
Term Infants ◽  
Oxygen Gradient ◽  
Thoracic Gas Volume ◽  
Gas Volume

Twenty-six premature and five full-term infants, ranging in birth weight from 860 to 4,040 gm and in age from 3 hours to 98 days, were the subjects of this study. Measurements of thoracic gas volume and determination of alveolar-arterial oxygen gradient and arterial-alveolar carbon dioxide gradient were performed. All infants showed a decrease in thoracic gas volume in the first days of life. The initial high thoracic gas volume is thought to be due to trapped gas. The ability to trap gas was demonstrated in a number of infants. In the full-term infant the decrease in thoracic gas volume is associated with improvement in lung function. In the premature infants the decrease in lung volume is associated with a persistently elevated alveolar-arterial oxygen gradient and in an inequality of perfusion and ventilation, as evidenced by the large arterial-alveolar carbon dioxide gradient. In a small group of infants increase in functional residual capacity produced by negative pressure around the chest resulted in a decrease in the carbon dioxide and oxygen gradients, indicating that the infant's lung volume is less than optimum. These observations characterize in physiological terms some of the respiratory difficulties in small premature infants.

CARBONIC ANHYDRASE IN THE PREMATURE

PEDIATRICS ◽  
1968 ◽  
Vol 42 (3) ◽  
pp. 429-436
Author(s):  
E. Poblete ◽  
D. W. Thibeault ◽  
P. A. M. Auld
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Premature Infants ◽  
Carbonic Anhydrase Activity ◽  
Full Term ◽  
Term Infants ◽  
Low Levels

Carbonic anhydrase activity was measured in the blood of premature and full-term infants to determine if the arterial-alveolar carbon dioxide gradient was related to low levels of carbonic anhydrase. The time at which levels in these infants approached the adult was studied as well. The study demonstrates that CO2 gradients do not correlate with blood carbonic anhydrase activity, and minimal or no activity can be associated with a small gradient. An increase in the carbonic anhydrase activity-produced by transfusion did not significantly change the CO2 gradient. Premature infants approach adult levels of activity in 6 to 7 months.

Sign in / Sign up

Export Citation Format

Share Document