Ventilatory response to 100% and 15% O2 during wakefulness and sleep in preterm infants

Rigatto, Henrique; Kalapesi, Zarin; Leahy, Fergus; Durand, Manuel; MacCallum, Marilyn; Cates, Don

doi:10.1016/0378-3782(82)90002-0

Cited by 76 publications

(41 citation statements)

References 15 publications

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“…single chemoreceptor fiber also showed an immediate (after a few seconds) decrease in the number of nerve impu lses per unit of time when the animal was made hyperoxic by breathing pure O2 (12)(13)(14). In the present study, the speed of the response (3.6 ± 0.6 and 6.8 ± 1 s for the 1st breath with hypoventilation and maximal response, respectively) was similar to that found by Girard et al The decrease in ventilation with inhaled O 2 is related to a primary decrease in frequency in preterm infants (2)(3)(4)16). The decrease in frequency is related to apnea, which commonly occurs with 100% O 2 • Term infants and adult subjects do not become apneic with high inhaled O 2 mixtures, but they change ventilation by primarily decreasing tidal volume (1,11,(17)(18)(19)(20).…”

Section: Discussionsupporting

confidence: 88%

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Speed and Profile of the Arterial Peripheral Chemoreceptors as Measured by Ventilatory Changes in Preterm Infants

et al. 1992

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MATERIALS AND METH ODSchemo receptor response could be determined in "healthy" preterm infants by measuring the changes in ventilation indu ced by inha lation of 100% O 2 • Subjects. We studied 13 healthy preterm infants with a birth weight of 1602 ± 230 g (mean ± SEM), a study weight of 1652 ± 260 g, a gestational age of 31 ± 1 wk, and a postnatal age of 15 ± 1 d. The study was approved by the faculty committee on the use of human subjects in research, University of Manitoba, and written parental consent was obtained from one of the parents.M ethods. We have previously described the system to measure ventilation (6, 7). Briefly, we used a nosepiece and a screen flowmeter to measure respiratory minu te volume and alveolar gases. We used a constant background flow (3 L'min) to eliminate valves and to reduce dead space. T he infant breathed through the nostril adapters and added to (expiration) or subtracted (inspiration) flow from the background flow. This background flow was electrically balan ced to an artificial zero.We monitored breath-to-breath alveolar P0 2 and Pco, using Beckman analyzers. The 95% rise times of the analyzers were 0. 16 and 0.18 s for CO2 and O2, respectively. T he EEG was monitored using a single channel with an electrode placed in the right frontal position and referenced to the left mastoid. Th e electrooculogram was recorded from eye electrodes referenced to the right ear. Oxygen saturations and ECG were used to monitor the infant' s well-being but not as an end point of this study. Sleep state was monitored according to previous criteria (4). All variables were recorded on a polygraph (model 4221, Nihon Kohden , Tokyo, Japan ).Procedure . Infants were studied on the Ohio Neonatal Intensive Care Unit (Ohio Medical Products, Madison , WI) in a neut ral thermal environment with skin abdominal temperature at 36.5 ± 0.03°C. After appropriate placement of the various electrodes and the nosepiece, infant s were allowed to sleep. Once they had been in quiet sleep breathi ng 21% O 2 for 2 min, 100% O 2 was given for I min. Minute ventilation, tidal volume, frequency, alveolar Po 2 , alveolar Pco-, inspiratory drive, and the "duty cycle" were measured breath by breath during 2 1% O2 (I S ± 5 s) and during 100% O 2 ( I min ).Data collection and analysis. We analyzed the records by hand and transferred the data to a com puter for appropriate treatment. Control values were taken from the last eight breaths preceding the adm inistration of O 2 • The speed of the response was measured from the initiation of inspiration imm ediately after the increase in fraction of inspired O2• We used a paired t test to assess the significance of the differences between control values and those obtained in response to 100% O 2 • To find the 1st breath after 100% O 2 showing hypoventilation, we used a variation of the 226 ABSTRACf. To measure the response time of the peripheral chemoreceptors, we studied 13 preterm infants [birth weight 1602 ± 230 g (mean ± SEM); gestational age 31 ± 1 wk; postnatal age 15 ± 1 d) dur...

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Section: Discussionsupporting

confidence: 88%

“…Oxygen saturations and ECG were used to monitor the infant' s well-being but not as an end point of this study. Sleep state was monitored according to previous criteria (4). All variables were recorded on a polygraph (model 4221, Nihon Kohden , Tokyo, Japan ).…”

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confidence: 99%

Speed and Profile of the Arterial Peripheral Chemoreceptors as Measured by Ventilatory Changes in Preterm Infants

et al. 1992

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“…Neonates showed a pronounced decline inV E (Ϫ25%) in response to the hyperoxic test, as reported elsewhere (27,28). The ventilation decrease is detected at the RT, allowing measurement of the effectiveness of the peripheral chemoreceptors (22,23).…”

Section: Discussionsupporting

confidence: 75%

Ventilatory Response to a Hyperoxic Test Is Related to the Frequency of Short Apneic Episodes in Late Preterm Neonates

et al. 2007

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ABSTRACT:Chemoreception is frequently involved in the processes underlying apnea in premature infants. Apnea could result from a decrease in carotid body effectiveness. However, increased carotid body activity could also initiate apnea through hypocapnia following hyperventilation when the receptors are stimulated. The aim of this study was to analyze the relationship between carotid body effectiveness and short apneic episodes in older preterm neonates. Carotid body effectiveness was assessed at thermoneutrality in 36 premature neonates (2.07 Ϯ 0.26 kg) by performing a 30-s hyperoxic test during sleep, the oxygen inhalation involving a ventilation decrease. Blood O 2 saturation (Sp O2 ) and ventilatory parameters were monitored before and during the hyperoxic test. Short episodes of apnea (frequency and mean duration) were recorded during the morning's 3-h interfeeding interval. Pretest Sp O2 was not related to any of the measured respiratory parameters. A higher frequency of short apneic episodes was linked to a greater ventilation decrease in response to the hyperoxic test ( ϭ Ϫ0.32; p ϭ 0.01). Increased carotid body response is correlated with greater apneic episodes frequency, even in the absence of concomitant oxygen desaturation. Fetal or early postnatal hypoxemia could have increased peripheral chemoreceptor activity, which could initiate a "overshoot/ undershoot" situation, which in turn could induce a critical P O2 /P CO2 combination and apnea. (Pediatr Res 62: 591-596, 2007) S hort apneic episodes [defined as a respiratory pause of at least 3 s (1,2)] are common respiratory events in premature neonates, with an incidence of 25% in infants weighing Ͻ2500 g at birth and 84% in those weighing Ͻ1000 g (3).After birth, apnea frequency decreases progressively once chemoreception control is sufficiently developed to initiate the appropriate ventilatory responses to changes in arterial blood gas status (3-6). Chemoreception control is carried out by central and peripheral chemoreceptors that differ in their anatomical location and type of stimulation: peripheral chemoreceptors (mainly carotid bodies) are sensitive to variations in the levels of O 2 and (to a lesser extent) CO 2 , whereas central chemoreceptors are especially sensitive to variations in CO 2 and pH.It is accepted that abnormal functioning of the peripheral chemoreceptors can promote apnea even though the mechanism underlying this altered chemoreceptor activity is still subject to much debate. Provision of oxygen to infants suffering from bronchopulmonary dysplasia delays the peripheral chemoreceptor response and might induce more apnea (7). In preterm neonates, an increase in the chemoreceptor gain during the postnatal period has also been suggested. The latter can initiate an "overshoot/undershoot" situation: the apnea results from a central depression in inspiratory motor drive, which is mainly due to hypocapnia. This concept has been described in adult dogs to explain periodic breathing (8) and extended to the newborn lamb (9), but physiolog...

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“…These infants can become apneic when their inspired oxygen is increased sufficiently to produce a physiologic denervation of peripheral chemoreceptors. 10,11 Adults show a sustained increase in ventilation in response to hypoxia. N-methyl D-aspartate glutamate receptors in the nucleus of the solitary tract have a pivotal role in the hypoxic ventilatory response.…”

Section: Peripheral Chemoreceptors and Impaired Hypoxic Ventilatory Rmentioning

confidence: 99%

Apnea of prematurity: pathogenesis and management strategies

Mathew

2010

J Perinatol

105

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Apnea of prematurity (AOP) is a significant clinical problem manifested by an unstable respiratory rhythm reflecting the immaturity of respiratory control systems. This review will address the pathogenesis of and treatment strategies for AOP. Although the neuronal mechanisms leading to apnea are still not well understood, recent decades have provided better insight into the generation of the respiratory rhythm and its modulation in the neonate. Ventilatory responses to hypoxia and hypercarbia are impaired and inhibitory reflexes are exaggerated in the neonate. These unique vulnerabilities predispose the neonate to the development of apnea. Treatment strategies attempt to stabilize the respiratory rhythm. Caffeine remains the primary pharmacological treatment modality and is presumed to work through blockade of adenosine receptors A 1 and A 2 . Recent evidences suggest that A 2A receptors may have a greater role than previously thought. AOP typically resolves with maturation suggesting increased myelination of the brainstem.

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Ventilatory response to 100% and 15% O2 during wakefulness and sleep in preterm infants

Cited by 76 publications

References 15 publications

Speed and Profile of the Arterial Peripheral Chemoreceptors as Measured by Ventilatory Changes in Preterm Infants

Speed and Profile of the Arterial Peripheral Chemoreceptors as Measured by Ventilatory Changes in Preterm Infants

Ventilatory Response to a Hyperoxic Test Is Related to the Frequency of Short Apneic Episodes in Late Preterm Neonates

Apnea of prematurity: pathogenesis and management strategies

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