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Biomedical subjects

R Hagan

Publications and source records attributed to R Hagan.

29 records · Page 2Linked to original sources
PubMed1995

Neonatal chronic lung disease, oxygen dependency, and a family history of asthma.

We examined the relationship between a family history of asthma (FHA), neonatal chronic lung disease (CLD), and oxygen dependency in an inception cohort study of all 24- to 30-week gestation infants admitted to the sole tertiary perinatal center in Western Australia. One hundred and forty-four infants were admitted during the study period; 116 had data analyzed, 112 of whom survived to discharge. Respiratory morbidity was common and the prevalence increased with decreasing gestation. Hyaline membrane disease (HMD) occurred in 92 (79%) and CLD (oxygen dependency at 28 days) in 62 (53%); 35 (30%) were oxygen dependent at 36 weeks corrected age, and 16 (14%) were oxygen dependent at term. Thirty-two infants had an FHA which was equally distributed between those infants with and without CLD. Infants with an FHA were more likely to be oxygen dependent at term (relative risk 4.4; 95% Cl 1.7,11.1). Thirty-eight percent of mothers smoked; 68% of their infants developed HMD compared to 89% of those whose mothers did not smoke. Logistic regression identified GA<28 weeks (OR 7.3; 95% Cl 1.4,39), severe HMD (OR 4.8; 95% Cl 1.1,22), and FHA (OR 11.0; 95% Cl 2.3,53) as the only factors associated with an increased risk of being oxygen dependent at term. The duration of supplemental oxygen in infants with CLD was significantly related to decreasing gestation, greater degree of barotrauma, presence of HMD, pregnancy-induced hypertension in the mother, duration of patent ductus arteriosus, and an FHA. An FHA may worsen chronic lung disease in the neonate, but is not involved as a causal factor. Clinicians should be aware of its influence on duration of oxygen supplementation when counselling parents of very preterm infants.

Asthma↗
PubMed1995

Home oxygen management of neonatal chronic lung disease in Western Australia.

OBJECTIVE: To describe the course and management of infants with neonatal chronic lung disease who were discharged home on low-flow supplemental oxygen. METHODOLOGY: Retrospective case series in Western Australia. RESULTS: Fifty-six neonates born in the 6 year period 1987-92 inclusive were discharged home on supplemental oxygen. The median gestational age was 27 weeks (range 22-40), median birthweight 865 g (range 450-3350), median oxygen flow rates 125 mL/min (range 30-850). The median corrected age at discharge was 1 month (range term-9.5) and this had decreased throughout the study period. Acute hospital readmissions were common (36 of 56, 64%). The majority of these admissions were for wheezing illnesses. Three infants died. The median corrected age at weaning from day oxygen was 4 months (range term-33) and from night oxygen was 6 months (range 2-38). Monitoring of oxygen saturation in air, in low-flow oxygen and in the overnight sleep study were important non-invasive guides in deciding when patients were ready for discharge, reducing the oxygen flow rate and when oxygen could be ceased, respectively. CONCLUSIONS: The home oxygen programme enables infants with neonatal chronic lung disease to be discharged home earlier, is safe, and well accepted by parents and community health care workers.

Chronic Disease↗
PubMed1994

Erythropoietin in very preterm infants.

Three neonates (a male and two females of gestational ages 27, 27 and 29 weeks with birthweight 985, 660 and 1130 g), born to parents who are Jehovah's Witnesses, were admitted to our neonatal intensive care unit over a 2 month period in 1992. Human recombinant erythropoietin (rHuEpo, 200 u/kg sc. on alternate days for 6-8 weeks) was started early in conjunction with strict control of blood sampling in an attempt to avoid the need for blood transfusion. The lowest haemoglobin recorded was 95 g/L at 35 days of age in the first infant. The amount of blood withdrawn for sampling was 21.4 mL, 20.7 mL and 5.5 mL, respectively. All were discharged near their expected birthdate, never having received a blood transfusion in the Nursery. It is possible to manage sick, very preterm, very low birthweight neonates in a neonatal intensive care setting without the use of blood transfusions by the early use of rHuEpo in conjunction with strict control of blood sampling.

Anemia, Neonatal↗
PubMed1992

Individual differences in the selective processing of threatening information, and emotional responses to a stressful life event.

Previous research has established that high levels of trait anxiety commonly are associated with an automatic pattern of encoding selectivity, operating to favour the processing of emotionally threatening information. It has been suggested that this processing bias may play a functional role in mediating emotional vulnerability by moderating affective responses to stressful real life events. The current experiment employs a longitudinal design, capable of addressing the central predictions arising from this theoretical position. Thirty-one women awaiting colposcopy investigation were screened on both traditional questionnaire measures of emotional vulnerability, and on a modified emotional Stroop task that provided objective indices of their automatic and strategic patterns of processing selectivity. Subsequently, those 15 women who later received a diagnosis of cervical pathology reported the degree to which this diagnosis had impaired their level of emotional functioning. The results confirm that, at the initial test time, trait anxiety was indeed associated with an apparently automatic tendency to selectively process threat related distractor information. Furthermore, an index of this initial pattern of automatic processing selectivity was consistently the best predictor of the intensity of emotional distress elicited by the subsequent diagnosis of cervical pathology. None of our conventional questionnaire measures were capable of significantly predicting this later emotional response. We suggest that these findings offer empirical support for the hypotheses that patterns of automatic processing selectivity may moderate individuals' emotional responses to stressful life events.

Adaptation, Psychological↗
PubMed1991

Observations of parent reactions to sex-stereotyped behaviors: age and sex effects.

To examine differential socialization of boys and girls by mothers and fathers, home observations were completed for families of 92 12-month-old children, 82 18-month-old children, and 172 5-year-old children. Mothers gave more instructions and directions than did fathers, while fathers spent more time in positive play interaction. Differences in parents' reactions to 12- and 18-month boys and girls were as expected, with the exception that boys received more negative comment for communication attempts than did girls. The suggestion in the literature that fathers would be more involved in sex typing than mothers was not confirmed in this study. The only 2 significant sex-of-parent x sex-of-child effects occurred at 18 months; fathers gave fewer positive reactions to boys engaging in female-typical toy play, and mothers gave more instruction to girls when they attempted to communicate. We argue that the second year of life is the time when children are learning many new skills and when parents are still experimenting with parenting styles and may well use stereotypical responses when unsure of themselves.

Child, Preschool↗
PubMed1985

Differential reactions to assertive and communicative acts of toddler boys and girls.

34 children were observed in infant play groups. 2 sets of infant behaviors were coded: assertive acts and attempts to communicate with adults. No sex differences were observed at 13 to 14 months in any of these behaviors. However, adults attended to girls' assertive behaviors far less of the time than to boys' assertive behaviors. They attended more to girls' less intense communication attempts and to boys' more intense attempts. When 29 of the same children were observed in toddler play groups no more than 11 months later, there were sex differences in behavior. Boys were more assertive; girls talked to teachers more. Teachers no longer differentiated their responses to boys and girls. Peers reacted more to boys' assertive behavior than to girls.' We hypothesized that caregivers may use stereotypes to guide their reactions to infants because infant behavior is ambiguous. For the toddlers, behavior had become more defined, and caregivers reacted to the behaviors. By using the sex stereotype to guide their reactions to younger children, the caregivers may have perpetuated the stereotype.

Assertiveness↗
PubMed1977

Neonatal chest wall afferents and regulation of respiration.

We have studied two groups of eight preterm infants, relating chest wall afferent information to respiratory timing. Rib cage and abdominal motion were monitored by magnetometers and flow and tidal volume via a face mask. In the first group, studies were done in REM sleep when spontaneously occurring distortion of the rib cage occurred and a significant linear relationship between the rate of distortion of the chest wall and shortening of the inspiratory time (Ti) was found in all infants. Reduction in this distortion by the use of continuous positive airway pressure (CPAP) or continuous negative pressure at the body surface (CNeg) was associated with a significant (P less than 0.01) lengthening of Ti. Absence of changes in Ti when pressure was applied in quiet sleep suggested that lung volume or chemical changes were not involved. In the second group of infants we artificially generated the afferent inflow by using vibratory stimuli applied in one intercostal interspace and produced a significant (P less than 0.05) shortening in Ti. We suggest that the distortion of the rib cage in REM sleep generates afferent information from intercostal muscle spindles that is related to the rate of distortion and this, via a supraspinal reflex, inhibits phrenic motoneuron discharge. It may then be of importance in the etiology of apneic episodes in these infants. Applied pressure may be of benefit because it reduces an inhibitory afferent inflow.

Afferent Pathways↗