191 research outputs found
Hering-Breuer reflex, lung volume and position in prematurely born infants
No full textOBJECTIVES: To investigate the effect of position on the strength of the Hering-Breuer reflex in prematurely born infants and determine whether any differences seen were related to differences in lung or tidal volume between positions. WORKING HYPOTHESIS: Position related differences in the strength of the Hering-Breuer reflex relate to differences in lung or tidal volume. STUDY DESIGN: Prospective observational study. PATIENT/SUBJECT SELECTION: Eighteen infants, median gestational age 30 (range 25-32) weeks were studied. METHODOLOGY: Infants were examined in the supine and prone position, each position was maintained for 2 hr. At the end of each 2-hr period, the strength of the Hering-Breuer reflex was assessed by determining the prolongation of expiration following an end inspiratory occlusion. In addition, tidal volume and functional residual capacity (FRC) were assessed in each position. RESULTS: The strength of the Hering-Breuer reflex was greater (P = 0.01) and the mean FRC was higher (P < 0.0001) in the prone compared to the supine position. The position related differences in the strength of the reflex correlated significantly with position related differences in FRC (P = 0.05). CONCLUSIONS: The Hering-Breuer reflex is stronger in the prone compared to the supine position. Our results suggest this is explained by position related differences in lung volume
End-tidal carbon monoxide levels in prematurely born infants developing bronchopulmonary dysplasia
No full textBronchopulmonary dysplasia (BPD) is associated with an early inflammatory response that persists after the first week of life. Inflammatory mediators can induce hemoxygenase-1 with a consequent increase in carbon monoxide (CO) production. End-tidal CO (ETCO) levels would be elevated in infants developing BPD. Serial measurements of ETCO levels were attempted on d 3, 5, 7, 14, 21, and 28 in 50 prematurely born infants (median gestational age 29 wk). Fourteen infants developed BPD [oxygen dependent beyond 36 wk post-menstrual age (PMA)] and had higher ETCO levels compared with the rest of the cohort on d 7, 14, 21, and 28. On d 14, the mean (SD) ETCO levels of the BPD group were 3.19 (1.11) ppm and 1.43 (0.61) ppm in the non-BPD group (p 2.15 ppm had a sensitivity of 80% and specificity of 92% in predicting oxygen dependency at 36 wk PMA. Measurement of ETCO levels in prematurely born infants may be useful in the prediction of BP
Effect of prone and supine position on sleep, apneas, and arousal in preterm infants
No full textOBJECTIVE. Prematurely born compared with term born infants are at increased risk of sudden infant death syndrome, particularly if slept prone. The purpose of this work was to test the hypothesis that preterm infants with or without bronchopulmonary dysplasia being prepared for neonatal unit discharge would sleep longer and have less arousals and more central apneas in the prone position.METHODS. This was a prospective observational study in a tertiary NICU. Twenty-four infants (14 with bronchopulmonary dysplasia) with a median gestational age of 27 weeks were studied at a median postconceptional age of 37 weeks. Video polysomnographic recordings of 2-channel electroencephalogram, 2-channel electro-oculogram, nasal airflow, chest and abdominal wall movements, limb movements, electrocardiogram, and oxygen saturation were made in the supine and prone positions, each position maintained for 3 hours. The duration of sleep, sleep efficiency (total sleep time/total recording time), and number and type of apneas, arousals, and awakenings were recorded.RESULTS. Overall, in the prone position, infants slept longer, had greater sleep efficiency (89.5% vs 72.5%), and had more central apneas (median: 5.6 vs 2.2), but fewer obstructive apneas (0.5 vs 0.9). The infants had more awakenings (9.7 vs 3.5) and arousals per hour (13.6 vs 9.0) when supine. There were similar findings in the bronchopulmonary dysplasia infants.CONCLUSIONS. Very prematurely born infants studied before neonatal unit discharge sleep more efficiently with fewer arousals and more central apneas in the prone position, emphasizing the importance of recommending supine sleeping after neonatal unit discharge for prematurely born infants
Very prematurely born infants wheezing at follow-up: lung function and risk factors
No full textOBJECTIVES: To determine whether abnormalities of lung volume and/or airway function were associated with wheeze at follow-up in infants born very prematurely and to identify risk factors for wheeze. DESIGN: Lung function data obtained at 1 year of age were collated from two cohorts of infants recruited into the UKOS and an RSV study, respectively. SETTING: Infant pulmonary function laboratory. PATIENTS: 111 infants (mean gestational age 26.3 (SD 1.6) weeks). INTERVENTIONS: Lung function measurements at 1 year of age corrected for gestational age at birth. Diary cards and respiratory questionnaires were completed to document wheeze. MAIN OUTCOME MEASURES: Functional residual capacity (FRC(pleth) and FRC(He)), airways resistance (R(aw)), FRC(He):FRC(pleth) and tidal breathing parameters (T(PTEF):T(E)). RESULTS: The 60 infants who wheezed at follow-up had significantly lower mean FRC(He), FRC(He):FRC(pleth) and T(PTEF):T(E), but higher mean R(aw) than the 51 without wheeze. Regression analysis demonstrated that gestational age, length at assessment, family history of atopy and a low FRC(He):FRC(pleth) were significantly associated with wheeze. CONCLUSIONS: Wheeze at follow-up in very prematurely born infants is associated with gas trapping, suggesting abnormalities of the small airway
Randomised sham-controlled trial of transcutaneous electrical stimulation in obstructive sleep apnoea
No full textIntroduction Obstructive sleep apnoea (OSA) is characterised by a loss of neuromuscular tone of the upper airway dilator muscles while asleep. This study investigated the effectiveness of transcutaneous electrical stimulation in patients with OSA.
Patients and methods This was a randomised, sham-controlled crossover trial using transcutaneous electrical stimulation of the upper airway dilator muscles in patients with confirmed OSA. Patients were randomly assigned to one night of sham stimulation and one night of active treatment. The primary outcome was the 4% oxygen desaturation index, responders were defined as patients with a reduction >25% in the oxygen desaturation index when compared with sham stimulation and/or with an index <5/hour in the active treatment night.
Results In 36 patients (age mean 50.8 (SD 11.2) years, male/female 30/6, body mass index median 29.6 (IQR 26.9–34.9) kg/m2, Epworth Sleepiness Scale 10.5 (4.6) points, oxygen desaturation index median 25.7 (16.0–49.1)/hour, apnoea-hypopnoea index median 28.1 (19.0–57.0)/hour) the primary outcome measure improved when comparing sham stimulation (median 26.9 (17.5–39.5)/hour) with active treatment (median 19.5 (11.6–40.0)/hour; p=0.026), a modest reduction of the mean by 4.1 (95% CI −0.6 to 8.9)/hour. Secondary outcome parameters of patients' perception indicated that stimulation was well tolerated. Responders (47.2%) were predominantly from the mild-to-moderate OSA category. In this subgroup, the oxygen desaturation index was reduced by 10.0 (95% CI 3.9 to 16.0)/hour (p<0.001) and the apnoea-hypopnoea index was reduced by 9.1 (95% CI 2.0 to 16.2)/hour (p=0.004).
Conclusion Transcutaneous electrical stimulation of the pharyngeal dilators during a single night in patients with OSA improves upper airway obstruction and is well tolerated
Estudio descriptivo del cuestionario proyectivo de Sacks. (Frases incompletas).. Anales del Instituto Nacional de Antropología e Historia. Num. 50 Tomo II (1969) Séptima Época (1967-1976)
No full textGaltung, J. 1966 Teorías y métodos de la investigación social. EUDEBA. (Ediciones previas). Buenos Aires.Garza Cantú, F. 1966 Selección psicológica en la Armada de México. Revista Médica, vol. XII, No. 46, pp. 239-83. México.Gulljksen, H. 1950 Theory of mental tests. Wiley. New York.Guttman, L. 1945 A basis for scaling qualitative data. Psychometrika, No. 10, pp. 255-82.Hayakawa, S. 1967 El lenguaje en el pensamiento y en la acción. UTEHA. México.Kahn, L., Bodine, A. y Guttman, L. 1951 Scale Analysis by means IBM equipment. Educ. Psychol. Measmt., No. 11, pp. 288-314.Likert, R. A. 1932 Technique for the measurement of attitudes. Arch. Psychol., No. 140.Rotter, J. B. 1963 Métodos de asociaciones de palabras y frases incompletas, en Anderson y Anderson. Técnicas Proyectivas del Diagnóstico Psicológico, pp. 328-63. Ed. Rialp. Madrid.Rotter, J. B., Rafferty, J. E. y Schachtitz, E. 1949 Validation of the Rotter Incomplete Sentence Blank for college screening. J. Consult. Psychol., No. 13, pp. 348-56
Three-dimensional ultrasound fetal lung volumes and infant respiratory outcome: A prospective observational study
No full textObjective: To determine if fetal lung volumes (FLVs), determined by three-dimensional rotational ultrasound and virtual organ computer-aided analysis software (vocal), correlated with neonatal respiratory outcomes in surviving infants who had a high risk [fetuses with congenital diaphragmatic hernia (CDH)], lower risk [fetuses with anterior wall defects (AWDs)] and no risk (controls) of abnormal antenatal lung growth. Design: Prospective observational study. Setting: Tertiary fetal medicine and neonatal intensive care units. Population: Sixty fetuses (25 with CDH, 25 with AWDs and ten controls). Methods: FLVs were measured and expressed as the percentage of the observed compared with the expected for gestational age. Main outcome measures: Neonatal respiratory outcome was determined by the duration of supplemental oxygen, mechanical ventilation and dependencies, and assessment of lung volume using a gas dilution technique to measure functional residual capacity (FRC). Results: The infants with CDH had lower FLV results than both the infants with AWDs (P = 0.05) and the controls (P < 0.05). The infants with CDH had longer durations of mechanical ventilation (P < 0.001) and supplementary oxygen (P < 0.001) dependence, compared with infants with AWDs. The infants with CDH had a lower median FRC than both the infants with AWDs (P < 0.001) and the controls (P < 0.001). FLV results correlated significantly with the durations of dependency on ventilation (r = )0.744, P < 0.01) and oxygen (r = )0.788, P < 0.001), and with FRC results (r = 0.429, P = 0.001). Conclusions: These results suggest that FLVs obtained using three-dimensional rotational ultrasound might be useful in predicting neonatal respiratory outcome in surviving infants who had varying risks of abnormal lung growth. Larger and more comprehensive studies are needed to clarify the role that lung volume measurements have in assessing lung function and growth. © 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe
Measurement of maximal inspiratory pressure in ventilated children
No full textMaximal inspiratory pressure (PIMAX), the maximum negative pressure generated during temporary occlusion of the airway, is commonly used to measure inspiratory muscle strength in mechanically ventilated infants and children. There are, however, no guidelines as to how the PIMAX measurement should be made. We compared the maximum inspiratory pressure generated during airway occlusion (PIMAX(OCC)) to that when a unidirectional valve (PIMAX(UNI)), which allowed expiration, but not inspiration was used. Twenty-two mechanically ventilated children (mean (SD) age 4.8 (4.5) years) were studied. Three sets of end expiratory occlusions were performed for each method in random order. The expired volume during PIMAX(UNI) was assessed and related to the functional residual capacity (FRC) measured using a helium dilution technique.The mean (SD) PIMAX(UNI) (45.5 (15.2) cmH(2)O) was significantly greater than mean (SD) PIMAX(OCC) (30.9 (9.0) cmH(2)O) (P <0.0001). The mean (SD) expired volume during PIMAX(UNI), was 98 ml (62.3), a mean reduction in FRC of 33.1% (SD 13.9). There were no significant differences between techniques in the baseline respiratory drive, the number of efforts required and the time to reach PIMAX. Regardless of technique, PIMAX was reached in 10 inspiratory efforts or 15 sec of airway occlusion.A unidirectional valve allowing expiration, but not inspiration yields greater PIMAX values in children. Occlusions should be maintained for 12 sec or eight breaths (99% CI of mean)
- …
