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Biomedical subjects

C Gaultier

Publications and source records attributed to C Gaultier.

At least 109 records · Page 6Linked to original sources
PubMed1991

Radionuclide evaluation of cardiac function during sleep in children with bronchopulmonary dysplasia.

The influence of sleep on cardiac function in severe bronchopulmonary dysplasia was assessed in five children 1.5 to 5 years of age. Left and right ventricular ejection fractions (LVEF and RVEF) were investigated by equilibrium radionuclide ventriculography in five children undergoing polygraphic monitoring during the different states of alertness: wakefulness, nonrapid eye movement sleep, and rapid eye movement sleep. Intraobserver and interobserver LVEF and RVEF measurement reproducibility was high. During quiet, supine wakefulness, LVEF was normal, but RVEF was low. During sleep, a decrease in both LVEF and RVEF, expressed as a percentage of the awake value, was marked in the two children with the most nocturnal desaturation and longest duration of paradoxic rib cage motion during inspiration. It is concluded that radionuclide ventriculography can be easily performed during sleep in children and can provide useful information regarding right ventricular function during sleep in children with severe bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗
PubMed1991

[Nocturnal continuous measurement of blood pressure in sleep apnea syndromes. Comparison between normotensive and hypertensive patients].

Sleep apnea syndrome and systemic hypertension are frequently associated but their causal relationship is unclear. We compared the oscillations of systemic blood pressure and heart rate during polysomnography in 8 normotensive subjects (2 females) and 5 hypertensive (supine awake blood pressure: 165 +/- 7/96 +/- 5 mmHg) without treatment. Their ages (normotensive: 52.1 +/- 11.0 yrs, hypertensive: 51.2 +/- 6.4 yrs) and body mass indices (32.6 +/- 9.6 kg/m2 vs 33.2 +/- 5.2 kg/m2 respectively) were not statistically different. Systemic blood pressure was continuously monitored by a non invasive digital plethysmography (Finapres). Both groups had similar respiratory events indices (normotensive: 45.2 +/- 18.1/hr, hypertensive: 48.4 +/- 20.5/hr) and minimal oxygen saturations (79.4 +/- 9.1% vs 82.4 +/- 7.0% respectively). During apneas in slow-wave sleep were observed the minimal values for systolic and diastolic pressures which were significantly higher in hypertensive than in normotensive (138.2 +/- 9.6/83.2 +/- 16.1 mmHg vs 105.9 +/- 11.1/60.5 +/- 10.9 mmHg respectively). During resumption of ventilation maximal blood values were recorded which were also higher in hypertensive than in normotensive (185.0 +/- 13.8/113.2 +/- 21.5 mmHg vs 155.9 +/- 19.8/88.7 +/- 17.1 mmHg respectively) (p less than 0.05). Although absolute variations of blood pressure were similar, relative changes in systolic pressure were significantly higher in normotensive (p less than 0.05). Maximal heart rate was 76.8 +/- 6.2 bpm in normotensive and 76.6 +/- 3.9 bpm in hypertensive during resumption of ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Pulmonary function in infancy and in childhood following mechanical ventilation in the neonatal period.

Pulmonary function was evaluated in both infancy and childhood in the same 19 prematurely born infants, who required mechanical ventilation (MV) during the neonatal period. Results of our patients were compared with those of control subjects. Upon first evaluation, we found that lung resistance (RL) was significantly elevated (24.85 +/- 6.06 vs. 17.77 +/- 2.39 cmH2O/L/s; P less than 0.01). The mean value of dynamic lung compliance (CLdyn) was low, but the difference compared to controls did not reach significance. From infancy to childhood, elevated RL persisted (9.33 +/- 2.51 vs. 6.52 +/- 1.52 cm H2O/L/s; P less than 0.01), and the decrease of CLdyn became significant (46.86 +/- 12.84 vs. 59.34 +/- 15.68 mL/cmH2O; P less than 0.05). In addition, maximum flow at functional residual capacity was significantly decreased (0.824 +/- 0.284 vs. 1.215 +/- 0.358 L/s; P less than 0.01); whereas pulmonary diffusing capacity for carbon monoxide was similar in the patients (7.62 +/- 2.16 mL/min/mm Hg) and in the controls (8.38 +/- 1.6). Pulmonary dysfunction following premature birth, respiratory distress, and prolonged MV may not resolve from infancy to childhood.

Child↗
PubMed1990

Respiratory adaptation during sleep in infants.

Respiratory adaptation during sleep improves with growth. The most vulnerable period for respiratory adaptation to sleep is from birth to 3 months of age. Factors that favor vulnerability are immaturity in ventilatory control and high rib cage compliance which impairs its effectiveness for ventilation. Improvement in respiratory adaptation during sleep is rapid during the first year of life. Sleep, and especially active (REM) sleep, is a risk period for respiratory disturbances in infants. Numerous factors may trigger apparent life threatening events. Respiratory disorders such as bronchiolitis, upper airway obstruction, and bronchopulmonary dysplasia impair respiratory adaptation during sleep. Treatment of respiratory disorders in infants must take into account the exacerbation of respiratory disturbances during sleep.

Humans↗
PubMed1990

Neonatal patterns of breathing after cesarean section with or without epidural fentanyl.

The pattern of breathing and lung mechanics were evaluated during the first 7 h of life in full-term healthy newborns delivered by cesarean section with bupivacaine epidural anesthesia, without (group 1) or with the addition of 100 micrograms of fentanyl (group 2). Respiration and oxyhemoglobin saturation (SpO2) were measured with calibrated inductive plethysmography and pulse oximetry, respectively, and recorded from 60-420 min following birth. Compliance of respiratory system (CRS) was measured using a multiple occlusion technique at 60 and 420 min. Pattern of breathing was compared during period I (60-240 min) and II (240-420 min) with the following results: 1) the number of apnea spells was similar in both groups during both periods; 2) in both groups, from period I to period II a significant decrease in apnea duration was observed (7.6 +/- 0.7 s-4.1 +/- 0.5 s in group 1 and 6.7 +/- 1.2 s-5.1 +/- 1.0 s in group 2, respectively (P less than 0.05); 3) respiratory rate (RR) and minute ventilation (VE) were similar in both groups during both study periods; and 4) both RR and VE significantly decreased in the two groups from period I to period II (i.e., 59 +/- 5-46 +/- 2 breath per min-1 and 313 +/- 60-248 +/- 24 ml.kg-1.min-1 in group 1, and 60 +/- 2-51 +/- 1 breath.min-1 and 318 +/- 12-290 +/- 12 ml.kg-1.min-1 in group 2, respectively; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Esophageal reflux in symptomatic and asymptomatic infants: postprandial and circadian variations.

Twenty-two full-term infants, nine asymptomatic and 13 symptomatic for chronic digestive problems, had long-term (mean = 21 h) esophageal pH monitoring. All children were observed in strictly standardized conditions including meals and body position. Symptomatic infants presented significantly more esophageal refluxes, spent a greater percentage of time with a pH below 4, had a longer reflux duration (longer clearing time) and presented more refluxes lasting more than 5 min. We performed a determination of the circadian variations of parameters associated with esophageal reflux. Asymptomatic and symptomatic infants presented significant circadian variations of the percentage of time below pH 4 and of the longest duration of reflux. However, symptomatic infants had significantly higher mean values and increased amplitudes of circadian rhythms. Moderate phase lag existed for certain variables between symptomatic and asymptomatic infants. These findings can be helpful when interpreting the results of long-term esophageal pH monitoring.

Analysis of Variance↗
PubMed1990

Interaction between tracheal sound and flow rate: a comparison of some different flow evaluations from lung sounds.

We simultaneously recorded tracheal sound and air flow from nine normal subjects (seven males and two females). Sound was picked up at the supra sternal notch with an air-coupled sensitive microphone held in a small airtight probe. Flow was measured at the mouth using a pneumotachograph Fleisch n degrees 2. Both sound and flow were directly digitized at a sampling rate of 5120 Hz and then divided in 128-sample blocks. For each sound block the frequency spectrum was computed using the fast Fourier transform. In order to evaluate instantaneous flow-rate from tracheal sounds we investigated eight methods divided in two groups of four. In the first group (i.e., reference curves methods), we assumed that a relationship existed between sound and flow and was thus reflected by the variations of certain parameters. We chose to use simple straightforward relationships, already known and published. We tested four different parameters. During a calibration phase, we built for each parameter P a reference curve representing the variations of P versus flow and being specific to each subject. Then, an unknown flow was evaluated in calculating P on a 128-sample block, and the reference curve gave the corresponding flow. In the second group, we made a hierarchial clustering analysis of sound spectra for revealing the frequency modifications, induced by the flow. We tested two kinds of spectra as well as two ways of associating a flow to a given cluster. This led us to four other methods for calculating the flow. All the eight methods but one gave a mean uncertainty in the measure of flow of about 15%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Cardiac and respiratory responses to esophageal dilatation during REM sleep in human infants.

Forty-one preterm and fullterm infants (26.5-40.5 weeks gestational age and 31.5-50 weeks postconceptional age) free from neurologic and cardiopulmonary disease at the time of testing underwent a standardized esophageal dilatation test (EDT) during polygraphically controlled REM sleep. RR interval and total duration of the respiratory cycle (TTOT) were measured (1) during the 60 s preceding the EDT, i.e. mean control RR and mean control TTOT; (2) during EDT. Percent RR (%RR) was defined as the longest RR interval in milliseconds during EDT divided by mean control RR in milliseconds multiplied by 100, and percent TTOT (%TTOT) as the longest TTOT in seconds during EDT divided by mean control TTOT in seconds multiplied by 100. EDT provoked prolongation of both RR interval and TTOT. %RR decreased significantly with advancing gestational age (p less than 0.003), and %TTOT with advancing postconceptional age (p less than 0.003), indicating that both cardiac and respiratory responses to an EDT challenge are blunted with maturation.

Electrocardiography↗
PubMed1990

Trigeminal airstream stimulation. Maturation-related cardiac and respiratory responses during REM sleep in human infants.

Thirty-three premature and full-term infants (PCA, 31.5 to 50 weeks) who were free from neurologic and cardiopulmonary disease at the time of testing underwent a standardized TAS test during polygraphically controlled REM sleep. The R-R interval and the TTOT were measured before and during TAS. The R-R interval and TTOT changes during TAS were compared to the preceding 60-second mean R-R interval and TTOT in each infant and expressed as a percentage of mean control values (ie, % RR and % TTOT). During TAS, there was a significant negative correlation between cardiac and respiratory responses and postconceptional age (p less than 0.001 and p less than 0.0001, respectively). Prolongation of both the R-R interval and the TTOT elicited by TAS was significantly blunted by maturation.

Electrocardiography↗
PubMed1990

Systemic hypertension in sleep apnea syndrome. Relationship with sleep architecture and breathing abnormalities.

To examine the possible relationship between systemic HT and SAS we compared 21 hypertensive (HT+) and 29 normotensive (HT-) patients for morphologic characteristics, sleep disturbances and respiratory events monitored during a full night polysomnography. There was no significant difference between HT+ and HT- patients with respect to age, weight, BMI, sleep stage distribution and disorganization, apnea-hypopnea index (number of episodes per hour of sleep) and duration (minutes per hour of sleep) nor O2 saturation indices: mean nocturnal and minimum O2 saturation. We conclude therefore that HT in SAS patients is not directly related to morphologic characteristics, sleep disturbances and breathing abnormalities.

Adult↗
PubMed1990

[Passive compliance of the total respiratory system in newborn infants born by cesarean section].

The compliance of the total respiratory system (CRS) was measured by the occlusion technique: a) at H1-H2, H6-H7 and D3-D4 in 8 full-term newborns after cesarean section; b) at H1-H2 and H6-H7 in 6 full-term newborns delivered vaginally and at D3-D4 in 10 full-term newborns delivered vaginally. At H1-H2 respiratory frequency measured by inductive plethysmography was not significantly different between newborns after cesarean section (60 +/- 6 c/min) and newborns delivered vaginally (53 +/- 16 c/min). CRS normalized for body weight was not significantly different between newborns after cesarean section and those delivered vaginally at H1-H2 (0.6 +/- 0.1 vs 0.7 +/- 0.1 ml/cmH2O/kg) and at H6-H7 (0.7 +/- 0.1 vs 0.8 +/- 0.3 ml/cmH2O/kg). At D3-D4, CRS was significantly greater than at H6-H7 in newborns after cesarean section (1.1 +/- 0.2 ml/cmH2O/kg, p less than 0.001) and in newborns delivered vaginally (1 +/- 0.1 ml/cmH2O/kg, p less than 0.02). We conclude that in newborns after cesarean section without tachypnea, the evolution in CRS is similar to that in newborns delivered vaginally.

Analysis of Variance↗
PubMed1990

Effects of increase in body temperature on the breathing pattern in premature infants.

This study was designed to determine the effects of a mild increase in body temperature within the physiological range (0.8 degrees C) in healthy premature infants. Seven unsedated premature infants (38.4 wk +/- 1.5 postconceptional age) were monitored polygraphically during "morning naps" in an incubator under two different environmental temperatures: (1) normothermia with the incubator temperature set at 25 degrees C and the rectal temperature equal to 36.9 degrees C +/- 0.1; (2) hyperthermia with the incubator temperature set at 35 degrees C and the rectal temperature equal to 37.7 degrees C +/- 0.15. Respiratory frequency and heart rate, respiratory events, i.e., central and obstructive apnea, and periodic breathing with and without apneic oscillations were tabulated. Results for respiratory events were expressed as (1) indices of the total number of respiratory events, and of specific respiratory events per hour of total, quiet and active sleep times; (2) duration of total and specific respiratory events expressed as a percentage of total sleep, quiet and active sleep times. Respiratory frequency and heart rate were significantly increased by hyperthermia (P less than 0.05). Hyperthermia did not significantly modify the indices or the duration of central and obstructive apnea. But the indices and the duration of periodic breathing with and without apneic oscillations were significantly increased by hyperthermia during active sleep (P less than 0.05) but not during quiet sleep. The present study shows that a mild increase in body temperature within the physiological range in premature infants enhances the instability of the breathing pattern during active sleep.

Body Temperature↗
PubMed1990

[Obstructive sleep apnea-hypopnea syndromes in children. Therapeutic results].

43 children with a clinical suspicion of obstructive sleep apnea-hypopnea were studied. All children underwent clinical examination and a standardised questionnaire was completed by their parents in order to investigate the principal nocturnal and diurnal symptoms present. A sleep study was performed. In addition to methods designed to identify the stage of sleep (EEG, EOG, EMG), this included recording of nasal and buccal airflow, thoracic and abdominal respiratory movements and blood gas analysis. 38 children has recordings during their afternoon nap, and 4 children during the night. Tonsillar hypertrophy was the principal etiology responsible for nocturnal respiratory disorders (33 cases). In addition, other etiologies were demonstrated: Pierre Robin syndrome, cranio-facial stenosis, laryngomalacia, Prader-Willi syndrome and Arnold Chiari malformation. Surgery was performed in 31 children: 22 tonsillectomies with or without adenoidectomy, 4 uvulo-palato-pharyngoplasties with tonsillectomy, 3 epiglottoplasties and 2 staphylorrhaphies. Long-term results were studied clinically and in 11 cases by polysomnographic recording.

Airway Obstruction↗