Laryngeal chemoreflexes induced by acid, water, and saline in nonsedated newborn lambs during quiet sleep

2005 ◽  
Vol 98 (6) ◽  
pp. 2197-2203 ◽  
Author(s):  
Marie St-Hilaire ◽  
Élise Nsegbe ◽  
Karine Gagnon-Gervais ◽  
Nathalie Samson ◽  
François Moreau-Bussière ◽  
...  
Keyword(s):  
Heart Rate ◽  
Random Order ◽  
Systemic Arterial Pressure ◽  
Full Term ◽  
Lower Airway ◽  
Distilled Water ◽  
Acid Solutions ◽  
Quiet Sleep ◽  
Laryngeal Mucosa ◽  
Life Threatening

Laryngeal chemoreflexes (LCR) are triggered by the contact of assorted liquids with the laryngeal mucosa. In the neonatal period, the immature LCR consist primarily of apnea and bradycardia, which at times can be life threatening. The aim of this study was to assess LCR induction in nonsedated, newborn full-term lambs by several acid solutions, compared with distilled water and saline. Twelve lambs were instrumented for recording of glottal adductor and diaphragm EMG, EEG, eye movements, heart rate, systemic arterial pressure, and respiratory movements. LCR were induced during quiet sleep by the injection (0.5 ml) of saline, distilled water or two acid solutions (HCl and citric acid, pH 2, diluted in either water or saline). A chronic supraglottal catheter was used to inject the solutions in a random order. Distilled water and acid solutions did not induce any significant decrease in heart rate or respiratory rate. However, significant lower airway protective responses (swallowing, cough, and arousal) were observed after distilled water and especially acid solution administration. In conclusion, LCR in full-term lambs, particularly with acid solutions, are merely characterized by lower airway protective responses resembling mature LCR reported in adult mammals.

scholarly journals Postnatal maturation of laryngeal chemoreflexes in the preterm lamb

2007 ◽  
Vol 102 (4) ◽  
pp. 1429-1438 ◽  
Author(s):  
Marie St-Hilaire ◽  
Nathalie Samson ◽  
Elise Nsegbe ◽  
Charles Duvareille ◽  
François Moreau-Bussière ◽  
...  
Keyword(s):  
Heart Rate ◽  
Lower Airway ◽  
Distilled Water ◽  
Active Sleep ◽  
Sleep State ◽  
Quiet Sleep ◽  
General Belief ◽  
Postnatal Maturation ◽  
Laryngeal Mucosa ◽  
Life Threatening

Laryngeal chemoreflexes (LCR) are triggered by the contact of liquids with the laryngeal mucosa. In the mature organism, LCR trigger lower airway protective responses (coughing, effective swallowing, and arousal) to prevent aspiration. General belief holds that LCR are responsible for apnea and bradycardia in the newborn mammal, including humans. Our laboratory has recently shown that LCR in full-term lambs are consistently analogous to the mature LCR reported in adult mammals, without significant apneas and bradycardias (St-Hilaire M, Nsegbe E, Gagnon-Gervais K, Samson N, Moreau-Bussiere F, Fortier PH, and Praud J-P. J Appl Physiol 98: 2197–2203, 2005). The aim of the present study was to assess LCR in nonsedated, newborn preterm lambs born at 132 days of gestation (term = 147 days). The preterm lambs were instrumented for recording glottal adductor electromyogram, electroencephalogram, eye movements, heart rate, respiration, and oximetry. A chronic supraglottal catheter was used for injecting 0.5 ml of saline, distilled water, and HCl (pH 2) during quiet sleep, active sleep, and wakefulness on postnatal days 7 (D7) and 14 (D14). Laryngeal stimulation by water or HCl on D7 induced significant apneas, bradycardia, and desaturation, which, at times, appeared potentially life-threatening. No significant apneas, bradycardias, or desaturation were observed on D14. No consistent effects of sleep state could be shown in the present study. In conclusion, laryngeal stimulation by liquids triggers potentially dangerous LCR in preterm lambs on D7, but not on D14. It is proposed that maturation of the LCR between D7 and D14 is partly involved in the disappearance of apneas/bradycardias of prematurity with postnatal age.

Heart Rate and Respiratory Rate Differences Between Preterm and Full-Term Infants During Quiet Sleep: Possible Implications for Sudden Infant Death Syndrome

PEDIATRICS ◽  
1978 ◽  
Vol 62 (1) ◽  
pp. 91-95 ◽  
Author(s):  
Peter G. Katona ◽  
John R. Egbert
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Sudden Infant Death Syndrome ◽  
Infant Death ◽  
Sudden Infant Death ◽  
Full Term ◽  
Sudden Infant ◽  
Quiet Sleep ◽  
Term Infants ◽  
The Difference

The heart rate and respiratory rate of eight preterm (average gestational age, 33.3 ± 2.2 weeks) and 13 full-term infants were determined during quiet sleep at home during the first year of life. Both heart rate and respiratory rate were greater in preterm infants throughout the first six months. The difference was maximum at age 10 weeks (21.1 beats per minute and 13.7 breaths per minute), with the difference being statistically significant, at least at the P < .01 level at ages 10, 12, and 14 weeks, while P ≥.01 at all other ages. The 10-to 14-week period is precisely the same period during which the incidence of sudden infant death syndrome (SIDS) has been reported to be maximum. These results support the concept that SIDS is linked to a vulnerable phase of cardiorespiratory maturation.

Influence of sleep and myometrial activity on systemic and uteroplacental hemodynamics in pregnant ewes

1995 ◽  
Vol 268 (4) ◽  
pp. H1734-H1739
Author(s):  
J. E. Fewell
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Uterine Artery ◽  
Systemic Arterial Pressure ◽  
Uterine Horn ◽  
Artery Blood Flow ◽  
Active Sleep ◽  
Quiet Sleep ◽  
Quiet Wakefulness ◽  
Uteroplacental Blood Flow

Little is known about the influence of sleep on systemic and uteroplacental hemodynamics during pregnancy. Experiments were therefore carried out on six chronically instrumented pregnant ewes (125–133 days of gestation) to investigate the influence of sleep on systemic and uteroplacental hemodynamics. Because nonlabor myometrial activity influences uteroplacental hemodynamics, we made measurements during quiet wakefulness, quiet sleep, and active sleep in the presence and absence of myometrial activity. Cardiac output, heart rate, and systemic arterial pressure were decreased in active sleep compared with quiet wakefulness; these variables were not significantly altered by myometrial activity. The interaction between sleep and myometrial activity was such that the lowest values of uteroplacental blood flow, as estimated from middle uterine artery blood flow to the pregnant uterine horn and, hence, uteroplacental oxygen delivery occurred during active sleep in the presence of myometrial activity (i.e., decreased approximately 19% compared with quiet wakefulness and the absence of myometrial activity). Further investigation is required to determine the possible fetal consequences of a reduced uteroplacental perfusion in the presence of myometrial activity during sleep.

Respiratory Reflex Responses of the Larynx Differ between Sevoflurane and Propofol in Pediatric Patients

2005 ◽  
Vol 103 (6) ◽  
pp. 1142-1148 ◽  
Author(s):  
Christine Oberer ◽  
Britta S. von Ungern-Sternberg ◽  
Franz J. Frei ◽  
Thomas O. Erb
Keyword(s):  
Pediatric Patients ◽  
Elective Surgery ◽  
Random Order ◽  
Group Differences ◽  
Distilled Water ◽  
Sevoflurane Anesthesia ◽  
Reflex Responses ◽  
Laryngeal Mucosa ◽  
Respiratory Responses ◽  
Respiratory Reflex

Background The effects of anesthetics on airway protective reflexes have not been extensively characterized in children. The aim of this study was to compare the laryngeal reflex responses in children anesthetized with either sevoflurane or propofol under two levels of hypnosis using the Bispectral Index score (BIS). The authors hypothesized that the incidence of apnea with laryngospasm evoked by laryngeal stimulation would not differ between sevoflurane and propofol when used in equipotent doses and that laryngeal responsiveness would be diminished with increased levels of hypnosis. Methods Seventy children, aged 2-6 yr, scheduled to undergo elective surgery were randomly allocated to undergo propofol or sevoflurane anesthesia while breathing spontaneously through a laryngeal mask airway. Anesthesia was titrated to achieve the assigned level of hypnosis (BIS 40 +/- 5 or BIS 60 +/- 5) in random order. Laryngeal and respiratory responses were elicited by spraying distilled water on the laryngeal mucosa, and a blinded reviewer assessed evoked responses. Results Apnea with laryngospasm occurred more often during anesthesia with sevoflurane compared with propofol independent of the level of hypnosis: episodes lasting longer than 5 s, 34% versus 19% at BIS 40 and 34% versus 16% at BIS 60; episodes lasting longer than 10 s, 26% versus 10% at BIS 40 and 26% versus 6% at BIS 60 (group differences P < 0.04 and P < 0.01, respectively). In contrast, cough and expiration reflex occurred significantly more frequently in children anesthetized with propofol. Conclusion Laryngeal and respiratory reflex responses in children aged 2-6 yr were different between sevoflurane and propofol independent of the levels of hypnosis examined in this study.

Mechanisms of airway protection after pharyngeal fluid infusion in healthy sleeping piglets

1995 ◽  
Vol 78 (5) ◽  
pp. 1942-1949 ◽  
Author(s):  
M. Page ◽  
H. E. Jeffery ◽  
V. Marks ◽  
E. J. Post ◽  
A. K. Wood
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Test Fluid ◽  
Distilled Water ◽  
Airway Protection ◽  
Quiet Sleep ◽  
Protective Mechanisms ◽  
Fluid Infusion ◽  
Significant Difference ◽  
Common Response

The airway protective mechanisms evoked after infusion of fluids into the pharynx were examined in the intact and healthy newborn piglet during sleep. Thirteen healthy normothermic piglets (3–6 days of age) were examined on 4 consecutive days during sleep. The fluids infused (0.05–1.5 ml) were 0.9% saline, distilled water, and HCl (pH 3 and pH 2). Respiratory rate, heart rate, oxygen saturation (SaO2), swallowing, and arousal were compared pre- and postinfusion during active (AS) and quiet sleep (QS) for each test fluid. The most common response in AS and QS was swallowing (90%) and then arousal (24%); however, no apnea occurred, and respiratory rate and SaO2 were always maintained. A significant difference occurred between HCl infusions of pH 2 and pH 3; at pH 2, the frequency of swallows and latency to the first swallow were reduced (P < 0.05) and the frequency of arousal was reduced in AS compared with that in QS (P < 0.01). Airway protection after pharyngeal fluid stimulation is achieved primarily by swallowing and arousal, without any effect on respiratory rate and SaO2. Attenuation of protective mechanisms occurred, however, when the infusate was at pH 2.

scholarly journals Wireless Fetal Heart Rate Monitoring in Inpatient Full-Term Pregnant Women: Testing Functionality and Acceptability

PLoS ONE ◽  
2015 ◽  
Vol 10 (1) ◽  
pp. e0117043 ◽  
Author(s):  
Adeline A. Boatin ◽  
Blair Wylie ◽  
Ilona Goldfarb ◽  
Robin Azevedo ◽  
Elena Pittel ◽  
...  
Keyword(s):  
Heart Rate ◽  
Pregnant Women ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Full Term ◽  
Heart Rate Monitoring ◽  
Fetal Heart Rate Monitoring

Coordination of the EEG and the heart rate of preterm neonates during quiet sleep

2009 ◽  
Vol 465 (3) ◽  
pp. 252-256 ◽  
Author(s):  
K. Schwab ◽  
H. Skupin ◽  
M. Eiselt ◽  
M. Walther ◽  
A. Voss ◽  
...  
Keyword(s):  
Heart Rate ◽  
Preterm Neonates ◽  
Quiet Sleep

Nocturnal headache: systemic arterial pressure and heart rate during sleep

Cephalalgia ◽  
1983 ◽  
Vol 3 (1_suppl) ◽  
pp. 54-57 ◽  
Author(s):  
Fabio Cirignotta ◽  
Giorgio Coccagna ◽  
Tommaso Sacquegna ◽  
Emiliana Sforza ◽  
Giuseppe Lamontanara ◽  
...  
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Rem Sleep ◽  
Continuous Monitoring ◽  
Systemic Arterial Pressure ◽  
Fréquence Cardiaque ◽  
The Awakening ◽  
Sono Stati ◽  
Autonomic Instability ◽  
Polygraphic Recording

In order to evaluate autonomic nervous system changes occurring before nocturnal headache attacks, we studied three subjects (one male, two females) suffering from chronic migraine. All three patients underwent a nocturnal polygraphic recording including continuous monitoring of systemic arterial pressure and heart rate. Two subjects showed increases and irregularities of arterial pressure before awakening with headache. These changes began during N–REM sleep and lasted during REM sleep preceding the awakening with headache. Heart rate did not change before the attacks. These findings do not support the hypothesis that autonomic instability during REM sleep represents the precipitating factor of the attacks. On a étudié avec des méthodes polygrafiques trois sujets (1 homme et deux femmes) souffrant d'hémicranie chronique avec des crises nocturnes. Chez deux malades les crises étaient précédées d'augmentation et d'irrégularité de la tension artérielle. Ces modifications commençaient pendant le sommeil N-REM et contineaient pendant le sommeil REM qui précédait le réveil avec hémicranie. La fréquence cardiaque n'a pas subi de modification avant les crises. Les résultats obtenus ne confirment l'hypothèse selon laquelle le facteur causant les crises est l'instabilité anticronique à la fase REM. Sono stati studiati con metodiche poligrafiche 3 soggetti (1 maschio e 2 femmine) affetti da emicrania cronica con attacchi notturni. In 2 di essi gli attacchi erano preceduti da incrementi ed irregolarità della pressione arteriosa. Tali modificazioni iniziavano durante il sonno N-REM e perduravano nel corso del sonno REM che precedeva il risveglio con cefalea. La frequenza cardiaca non si modificava prima dell'attacco. I risultati ottenuti non confermano l'ipotesi che il fattore precipitante gli attacchi emicranici sia l'instabilità anticronica della fase REM.

Heart rate control in normal and aborted-SIDS infants

1993 ◽  
Vol 264 (3) ◽  
pp. R638-R646 ◽  
Author(s):  
S. M. Pincus ◽  
T. R. Cummins ◽  
G. G. Haddad
Keyword(s):  
Heart Rate ◽  
Rem Sleep ◽  
Rate Control ◽  
Approximate Entropy ◽  
Sudden Infant Death ◽  
Sudden Infant ◽  
Normal Infant ◽  
Quiet Sleep ◽  
Heart Rate Data ◽  
High Risk Subject

Approximate entropy (ApEn), a mathematical formula quantifying regularity in data, was applied to heart rate data from normal and aborted-sudden infant death syndrome (SIDS) infants. We distinguished quiet from rapid-eye-movement (REM) sleep via the following three criteria, refining the notion of REM as more "variable": 1) REM sleep has greater overall variability (0.0374 +/- 0.0138 vs. 0.0205 +/- 0.0090 s, P < 0.005); 2) REM sleep is less stationary (StatAv = 0.742 +/- 0.110) than quiet sleep (StatAv = 0.599 +/- 0.159, P < 0.03); 3) after normalization to overall variability, REM sleep is more regular (ApEnsub = 1.224 +/- 0.092) than quiet sleep (ApEnsub = 1.448 +/- 0.071, P < 0.0001). Fifty percent of aborted-SIDS infants showed greater ApEn instability across quiet sleep than any normal infant exhibited, suggesting that autonomic regulation of heart rate occasionally becomes abnormal in a high-risk subject. There was an association between low ApEn values and aborted-SIDS events; 5 of 14 aborted-SIDS infants had at least one quiet sleep epoch with an ApEn value below the minimum of 45 normal-infant ApEn values.

Role of NO in goat basal cerebral circulation and after vasodilatation to hypercapnia or brief ischemias

1993 ◽  
Vol 265 (6) ◽  
pp. R1410-R1415 ◽  
Author(s):  
G. Dieguez ◽  
J. L. Garcia ◽  
N. Fernandez ◽  
A. L. Garcia-Villalon ◽  
L. Monge ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heart Rate ◽  
Methyl Ester ◽  
Cerebral Circulation ◽  
Systemic Arterial Pressure ◽  
Nitric Oxide Production ◽  
Hemodynamic Effects ◽  
Arterial Pco2 ◽  
Different Levels

The role of nitric oxide (NO) in the cerebral circulation under basal conditions and after vasodilatation to hypercapnia or reactive hyperemias was studied in 17 anesthetized goats. The intravenous administration of NG-nitro-L-arginine methyl ester (L-NAME, 3-4 or 8-10 mg/kg), an inhibitor of nitric oxide production, reduced middle cerebral artery (MCA) flow (electromagnetically measured) by 19 and 30% and increased systemic arterial pressure by 21 and 26%, respectively, whereas heart rate did not significantly change; MCA resistance increased by 48 and 86%, respectively. These hemodynamic effects were reversed by L-arginine (200-300 mg/kg iv; 5 goats). Different levels of hypercapnia (PCO2 of 30-35, 40-45, and 55-65 mmHg) (12 goats) produced arterial PCO2-dependent increases in MCA flow that were similar under control and L-NAME treatment. Graded cerebral hyperemia occurred after 5, 10, and 20 s of MCA occlusion in 5 goats, but its magnitude was decreased during L-NAME treatment. It suggests that, in the cerebral circulation, nitric oxide 1) produces a basal vasodilator tone and 2) is probably not involved in the vasodilatation to hypercapnia but may mediate hyperemic responses after short brain ischemias.

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