Chronic respiratory morbidity following premature delivery--prediction by prolonged respiratory support requirement?

Neonatal chronic lung disease (CLD) is usually diagnosed if an infant remains oxygen dependent beyond 36 weeks postconceptional age (PCA). Our aim was to determine whether a shorter duration of respiratory support accurately predicted subsequent respiratory morbidity. A total of 103 infants, median gestational age 29 weeks (range 23-35), were followed prospectively for 5 years. They had a birth weight of < 1500 g or, if a birth weight of between 1500 and 2000 g, had required neonatal ventilatory support. Parents completed diary cards; their child had positive symptom status if, in any one year, they coughed and/or wheezed on at least 3 days per week for a 4-week period or for at least 3 days following each upper respiratory tract infection. Subsequent respiratory morbidity, positive symptom status in years 1 and 2 or all 5 pre-school years, was related to various definitions of prolonged respiratory support: intermittent positive pressure ventilation dependence > 7 days; oxygen dependence > 28 days and oxygen dependence > 36 weeks PCA. In years 1 and 2, 25 children were symptomatic and 22 in all 5 years. The patients with subsequent respiratory morbidity were distinguished from those without by requiring longer respiratory support (P < 0.05). Logistic regression analysis demonstrated only oxygen dependence beyond 28 days was independently related to subsequent respiratory morbidity (P < 0.01). The positive predictive values and likelihood ratios (95% confidence intervals) for positive symptom status in all 5 years were for intermittent positive pressure ventilation > 7 days 35% (16-53) and 19.5 (1.01-3.76), for oxygen dependency > 28 days 42% (23-61) and 2.20 (1.45-5.02) and for oxygen dependency >36 weeks PCA 35% (13-58) and 1.67 (0.65-4.31).

CONCLUSION

Oxygen dependency at 28 days of age remains a useful criterion on which to diagnose "neonatal" chronic lung disease.

Perinatal lung function measurements and prediction of respiratory problems in infancy

The aim of this study was to determine which lung function test employed in the perinatal period gave the results most significantly associated with respiratory problems in infancy. The ratio of the proportion of time to reach peak tidal expiratory flow to total expiratory time (tPTEF:tE), thoracic gas volume (TGV) and airway resistance (R(aw)) (from which specific conductance (SG(aw)) was calculated) measurements were examined from 85 infants born at or near term. The infants were followed until at least one year of age and described as symptomatic if they wheezed for at least 24 hours. Twenty-three infants were symptomatic in the first year. The symptomatic group, compared to the asymptomatic, had a higher median FRC (p < 0.01) and R(aw) (p < 0.001); their median SG(aw) was lower (p < 0.001). It was possible to obtain tPTEF:tE results from only 61 infants; the median tPTEF:tE did not differ significantly between symptomatic and asymptomatic infants. Logistic regression analysis demonstrated a high R(aw) and FRC, but not a low tPTEF:tE, independently related to positive symptom status. A high R(aw) (>26 cm H2O (1 s(-1))(-1)) was the most sensitive (83%) predictor of subsequent respiratory problems, but all the tests examined had low positive predictive values.

Assessment of prematurely born children at follow-up using a tidal breathing parameter

Prematurely born children frequently have respiratory problems at follow-up. A non-invasive and easily performed lung function test would greatly facilitate their evaluation and appropriate treatment. We have, therefore, assessed whether the shape of the tidal breathing expiratory flow curve would give useful information in such a population. One hundred and twenty traces were randomly selected from plethysmographic measurements of thoracic gas volume and airway resistance made during a follow-up study of a prematurely born population. The children had a median gestational age of 29 (range 23-35, interquartile range 27-31) weeks and postnatal age at the time of measurement of 11 (range 6-24, interquartile range 7-13) months. From the flow and volume signals, the mean time to reach peak tidal expiratory flow as a proportion of the total expiratory time (tPTEF : tE) was determined for each child. The median tPTEF : tE differed significantly between children who, in the neonatal period, had or had not required mechanical ventilation (p < 0.001) and had or had not had an increased inspired oxygen requirement (p < 0.01), and who were or were not symptomatic at follow-up (p < 0.001). Logistic regression analysis demonstrated that a low tPTEF : tE ratio was independently associated with symptom status. These results suggest that assessment of a tidal breathing parameter during follow-up of prematurely born children may be useful. As tPTEF : tE can be measured without sedation, relatively quickly and with simple equipment, potentially large study populations could be investigated, and this technique should now be evaluated in a non-sedated group of young prematurely born children.

A case of ambiguous genitalia with unilateral amelia and unilateral peromelia of the upper limbs

A 7-year-old patient is reported with a 46,XY karyotype, ambiguous genitalia and unilateral amelia and unilateral peromelia of the upper limbs. The external genitalia had essentially a female configuration with labia majora, large clitoris, and narrow vaginal opening. Gonadal tissue was not palpable on either side. The levels of 17-OH progesterone dehydroepiandrosterone sulfate (DHEA-S), androstenedione and luteinizing hormone (LH) were normal, but the level of follicle stimulating hormone (FSH) was elevated minimally. Abdominal ultrasonography (USG) was normal. On pelvic USG, neither uterus nor ovaries were seen. Genitography showed a blind vagina. Gonads, Müllerian and/or Wolffian structures were not observed at laparotomy. Clitoral recession and cut-back vaginoplasty were performed. The occurrence of these findings suggests embryonic testicular regression syndrome with bilateral transverse defect of the upper limbs. The case has been presented because the pattern of the birth defects, including both ambiguous genitalia and unilateral amelia on one side of the upper limbs and unilateral peromelia on the other, have not been described previously.

Perinatal lung function and invasive antenatal procedures

BACKGROUND

Second trimester amniocentesis has been associated with an excess of perinatal lung function abnormalities. Early amniocentesis might have a similar adverse effect, as could other invasive investigations carried out in the first trimester.

METHODS

Plethysmographic measurements of thoracic gas volume (TGV) and airway resistance (Raw), from which specific conductance (sGaw) was calculated, were made in the perinatal period in non-sedated infants. In addition, functional residual capacity (FRC) was measured using a helium gas dilution technique. Measurements were made in 47 infants whose mothers had undergone early amniocentesis, 19 whose mothers had undergone chorion villus sampling, and 25 controls whose mothers had undergone no invasive antenatal procedures.

RESULTS

The infants of mothers who had undergone early amniocentesis had higher TGV (95% CI -6.3 to 1.1 ml/kg) and Raw values (95% CI -10.68 to -5.23 cm H2O/l/s) and lower sGaw (0.11 to 0.84 l/cm H2O.s) and FRC (-5.17 to - 0.87 ml/kg) values than the controls. Infants whose mothers had undergone chorion villus sampling also differed significantly from the controls with higher Raw (-7.59 to -1.99 cm H2O/l/s) and lower sGaw values (0.11 to 0.24 l/cm H2O.s), and had lower Raw values than those in the early amniocentesis group (not significant). Logistic regression analysis, taking into account possible risk factors for abnormal lung function, showed that the procedures performed in the first trimester were independently associated with a high airways resistance.

CONCLUSION

These results suggest that invasive procedures performed in the first trimester of pregnancy have an adverse effect on perinatal lung function.

Inhaled nedocromil sodium in symptomatic young children born prematurely

The efficacy of a non-steroidal anti-inflammatory agent (nedocromil sodium, NS) has been assessed in young children born prematurely who had recurrent respiratory symptoms at follow-up. In a randomized, double-blind cross-over trial, either two puffs of NS (2 mg puff-1) or placebo were administered three times a day via a spacer device and face mask. Fifteen children, median gestational age 27 weeks, birthweight 1100 g and postnatal age 12 months were studied. The symptom score was lower in the last 2 weeks of the active period (median score 26) compared to the run-in period (median score 55) and the last 2 weeks of the placebo period (median score 50), P < 0.01. The maximum possible symptom score for a 2-week period was 210. Compared to the run-in period, children required fewer days of bronchodilator therapy in the last 2 weeks of the active treatment (P < 0.01), but not in the placebo period. Although results of functional residual capacity (FRC) measurements were available on only 13 of the 15 children, these did demonstrate a significant change in FRC over the active, but not the placebo, period. These data suggest that NS is a useful prophylactic agent for children born prematurely and who are symptomatic at follow-up.

Respiratory morbidity in young school children born prematurely--chronic lung disease is not a risk factor?

Children born prematurely and recruited into a prospective follow up study were examined at 5 years of age. Our aim was to determine aetiological associations of respiratory symptoms in such children and, in particular, to determine the importance of severe chronic lung disease (CLD, oxygen dependence beyond 36 weeks post conceptional age). Respiratory status was documented from parental history in 103 children of median gestational age 29 weeks (range 23-35), 17 of whom had suffered from severe CLD. In 90 of the 103 children lung function had been assessed at 1 year of age. Regression analysis revealed that neither severe CLD nor other perinatal variables, but only a family history of atopy, significantly related to a positive symptom status. A high airways resistance at 1 year also significantly related to positive symptom status.

CONCLUSION

Reduction in severe CLD (oxygen dependence beyond 36 weeks postconceptional age) may make relatively little impact on respiratory morbidity in young school children born prematurely.

Respiratory morbidity in preschool children born prematurely. Relationship to adverse neonatal events

Respiratory morbidity, recurrent cough and/or wheeze and lung function abnormalities are common even outside infancy in preschool children born prematurely. Throughout the first 5 years of life, adverse neonatal events such as immaturity at birth and a requirement for prolonged respiratory support are significantly associated with positive symptom status. In the older preschool child, however, there is some evidence to suggest that other factors, such as a family history of atopy, may be equally important. The development of recurrent symptoms even at 4 years of age can be predicted accurately from the results of lung function measurements made in infancy, and hopefully such data will facilitate the introduction of effective intervention strategies. Lung function abnormalities are more marked in symptomatic patients and, in older children, seem to reflect increased airway responsiveness rather than having a significant relationship to adverse neonatal events. The hospital readmission rate for respiratory disorders, however, is certainly adversely affected by extremely low birthweight and neonatal chronic lung disease, as well as current symptom status. These data highlight that strategies to reduce extremely premature delivery and its consequences should favourably influence respiratory morbidity in preschool children.

Differential expression of Fc receptors for IgG by monocytes and granulocytes from neonates and adults

The immature neonatal immune system is thought to result in increased risk of infection. Receptors for the Fc moiety of IgG (Fc gamma R) are important in antibody-mediated clearance of microbes by granulocytes and monocytes/macrophages. As an approach to understanding their role in neonatal life, we have compared the constitutive expression of the three Fc receptors--Fc gamma RI (CD64), Fc gamma RII (CD32) and Fc gamma RIII (CD16)--by neonatal and adult blood monocytes and granulocytes using quantitative immunofluorescence by flow cytometry. Our results confirm that there is a small subpopulation of Fc gamma RIII-positive monocytes in adult blood, and furthermore show that this is absent or at a low percentage in cord blood samples. However, the main population of cord blood monocytes expresses low, but significantly higher levels of Fc gamma RIII than adult monocytes. No differences were seen in the quantitative expression of Fc gamma RI and Fc gamma RII. Neonatal granulocytes expressed significantly higher levels of both Fc gamma RI and Fc gamma RII but significantly lower levels of Fc gamma RIII. The data are discussed in terms of the possible role of cytokines and susceptibility to infection.

Advanced maternal age and smoking: risk factors for admission to a neonatal intensive care unit

The aim of this study was to assess if advanced maternal age and cigarette smoking increased the requirement for admission to the neonatal intensive care unit (NICU) and if those factors acted synergistically. Retrospective analysis was made of 3518 singleton pregnancies receiving antenatal care and delivering at King's College Hospital from 1 January 1992 to 31 December 1992. The maternal age was greater than 35 years in 356 women (10.1% of the total) and 49 (13.8%) of those were cigarette smokers. There was an inverse relationship between maternal age and smoking. Two hundred and fifty-nine infants were admitted to the NICU. Logistic regression analysis revealed a significant relationship between maternal age and admission (p < 0.05), but no independent effect of maternal smoking. The proportion of infants from smoking mothers of advanced age (> 35 years) admitted to the NICU, however, was greater than that from young (< or = 35 years) smoking mothers (p < 0.05). Advanced maternal age does increase the requirement for NICU admission and this effect is enhanced by smoking.

Do parental smoking and history of allergy influence cord-serum IgE?

The associations between parental smoking habits during pregnancy, family history of allergy, and IgE levels in cord-serum IgE (cIgE) were investigated prospectively in 1251 infants. Mean cIgE levels were similar in infants with positive and negative family history of allergy (0.50 and 0.54 kU/l, respectively). In infants with a positive family history of allergy whose mothers smoked more than 10 cigarettes a day, however, the mean cIgE level was significantly higher (0.78 kU/l) than that in infants of nonsmoking mothers (p = 0.011). Similarly, the mean cIgE level was significantly higher in boys (0.61 kU/l) than in girls (0.51 kU/l) of nonsmoking parents (p = 0.03). However, in infants of smoking parents, there was no significant difference in the mean cIgE level between boys and girls. A total of 178 (14%) mothers and 477 (38%) fathers were current smokers, and in 128 (10%) cases, both parents were active smokers. The mean cIgE level tended to be slightly higher in infants of smoking mothers, especially when the mother consumed more than 10 cigarettes a day (0.63 vs 0.54 kU/l) (p > 0.05). Thus, cIgE levels were higher only in genetically prone babies whose mothers consumed more than 10 cigarettes a day.

Epidemiology of meningococcal infections in children in mid-southern part of Turkey

59 patients were treated for meningococcal infections in Cukurova University Faculty of Medicine, Division of Pediatric Infectious Diseases. 50.8% of patients were male, 33.9% were under two years of age and 61% were under five. 78% of patients were admitted to hospital in winter and spring time. Meningococcal meningitis (MM) was present in 39% of patients on admission, however, meningococcemia in 27.1% and meningococcemia and meningococcic meningitis (Meningococcemia + MM) in 33.9%. Fatality rate was 18.6% and no association was found between mortality and clinical type of disease (p > 0.05), but mortality ratio decreased with an increasing age (p < 0.01). No deaths occurred among the 12 patients who received i.v. penicillin treatment shortly before admitting to hospital, on the other hand 11 of 47 patients (23.4%) without such a previous treatment died.

Ethnic origin and lung function of infants born prematurely

BACKGROUND

Ethnic origin has an important influence on the lung function of adults and young children but its effect during infancy, particularly following premature delivery, is unclear.

METHODS

The results from infants of pure Afro-Caribbean (subjects) and pure Caucasian (controls) descent, all of whom were born prematurely (median gestational age 28 weeks), were compared. Fifty subjects were each retrospectively matched with a control for gestational age, sex, and requirement for neonatal ventilation. Lung function measurements were performed at similar postnatal ages in each pair. The median postnatal ages of the two groups at the time of study was seven and eight months, respectively. Lung function was assessed by measurement of functional residual capacity (FRC) by a helium gas dilution technique and plethysmographic measurement of thoracic gas volume (TGV) and airways resistance (Raw), from which specific conductance (sGaw) was calculated.

RESULTS

No differences were found between the subjects and controls regarding FRC or TGV, but Raw was higher and sGaw lower in the subjects. The mean Raw of the subjects was 50.3 cm H2O/1/s and of the controls was 44.1 cm H2O/1/s (95% confidence intervals of the difference 1.5 to 10.9).

CONCLUSIONS

Prematurely born infants of Afro-Caribbean origin have more severe lung function abnormalities at approximately 7-8 months of age than those of Caucasian origin. This merits further investigation.

Functional residual capacity to thoracic gas volume (FRC:TGV) ratio in healthy neonates

Gas trapping has been suggested to be common in healthy newborns in the immediate postnatal period. To determine the veracity of that finding, functional residual capacity (FRC) and thoracic gas volume (TGV) were measured in such a population and the FRC:TGV ratios were related to measurements of airway resistance (RAW). FRC was assessed by a helium gas dilution technique, TGV and RAW by plethysmography. Twenty-four healthy infants born at term were studied at a median age of 2 days (range 1-5 days). None had respiratory problems, nor had their mothers undergone invasive antenatal procedures. Their median FRC, which was 27.1 (range 23.8-32.0) ml kg-1, was significantly lower than their TGV (median 29.8, range 26-33 ml kg-1, P < 0.01). The mean 'within subject' difference between FRC and TGV was 2.5 (range 0.3-5.5) ml kg-1. The median FRC:TGV ratio was 0.93 (range 0.82-0.99). Eight infants had an FRC:TGV ratio less than 0.9, two of whom were studied on the first postnatal day. No infant with a low (< 0.9) FRC:TGV ratio had an abnormal RAW. The differences between FRC and TGV demonstrated in this study were smaller than documented in earlier series, suggesting the degree of gas trapping may previously have been over-estimated.

Antiviral therapy in neonatal chronic lung disease

Infants born prematurely who develop chronic lung disease frequently suffer acute respiratory deteriorations. In a randomized trial, we assessed if treatment of such relapses with the antiviral agent Ribavirin increased the speed of recovery and improved lung function at follow-up. During the acute deterioration and its treatment, respiratory rate and requirement for respiratory support were recorded. Once discharged from hospital, respiratory symptoms and admissions for chest-related illnesses were documented. Infants were recalled at 6 months of age for lung function measurements. Forty-four infants (23 given Ribavirin), median gestational age of 26 weeks, completed the trial and had lung function measurements at 6 months. Although viral infections were identified in relatively few patients, the interim analysis demonstrated Ribavirin administration for 3 days was associated with a greater reduction in respiratory rate and inspired oxygen concentration (P < 0.02). At follow-up, there was no significant difference between groups in the proportion of infants who were symptomatic or required re-admission to hospital for chest-related illnesses; the Ribavirin group, however, had lower airways resistance (P < 0.01) and higher specific conductance (P < 0.02). We conclude that antiviral therapy seems to speed the rate of recovery from acute respiratory deteriorations seen in preterm infants with chronic lung disease; this is associated with improved lung function, but not lower respiratory morbidity, at follow-up.

Clinical features of Bardet-Biedl syndrome

Six patients with Bardet-Biedl syndrome who have been followed in our clinics for the last 5 years are reported in this study. Of the five classic features of this syndrome; obesity and mental retardation were present in all cases, retinal disturbances were present in five, polydactyly in three and hypogenitalism was observed in all four male patients. Renal involvement, often suggested as a cardinal feature of this syndrome, was described in two patients. Iron deficiency anemia occurred in three patients, two patients were of short stature, one patient presented with an empty sella, and in two patients clinodactyly was detected. The results are compared to previously published literature and discussed.

Growth and development of 280 hypothyroidic patients at diagnosis

The growth and development of 280 hypothyroidic patients who were diagnosed from 1979 to 1991, has been evaluated by standardized anthropometric criteria. According to the chronologic age during the diagnosis, the patients were divided into five groups of 0-6, 7-12, 13-24, 25-60 and 61-144 months. In these groups, the rates of the patients' weights and heights which were found below the 5th percentile, were as follows; for height 44%, 69%, 71%, 85%, 80% and for weight 38%, 68%, 70%, 55%, 60% respectively. Height age, weight age, head circumference age, and bone age were found to be significantly lower than chronologic age in all the groups, with the exception of the head circumference age in the 0-6 months group. The bone age was found to be significantly retarded compared to the height age in all the groups.

Measurement of thoracic gas volume in patients born prematurely: should occlusion be made at end-inspiration or end-expiration?

It has been suggested that in infants born at term thoracic gas volume (TGV) may be more accurately estimated in a plethysmograph if end-inspiratory (TGVl) rather than end-expiratory (TGVE) occlusions are used. The aim of this study was to assess whether the timing of occlusion affected TGV results in patients born very prematurely. Fifteen children with a median gestational age of 28 weeks (range 23-34) and postnatal age of 10 months (range 6-24) were studied. Measurements of TGV and airway resistance (R(aw)) were made in a whole body plethysmograph after sedation with chloral hydrate. End-expiratory and end-inspiratory occlusions were performed randomly in each subject. Overall, TGVl was significantly lower than TGVE (median, TGVl 233 mL; range, 130-498. Median TGVE 250 mL; range, 132-604; P < 0.05; 95% confidence intervals for the difference, 4-50 mL). In 13 infants, TGVl was lower than TGVE; the remaining two patients did not differ significantly from the rest of the group and neither had neonatal chronic lung disease. In only five infants did TGVl lie below the 95% confidence intervals of TGVE, however, two-way analysis of variance with replicated measurements showed a significant difference between TGVE and TGVl (P < 0.05). The median R(aw) was 55 cmH2O/L/s (range, 36-71). A significant positive correlation was found between R(aw) and TGVE-TGVl (r2 = 0.5, P < 0.01). We conclude that in children born very prematurely and with high R(aw) occlusion at end-expiration rather than end-inspiration yields higher TGV results at follow-up.

Relationship between lung function results in the first year of life and respiratory morbidity in early childhood in patients born prematurely

The relationship between lung function results at 6 months and 1 year of age to respiratory symptoms in the first 3 years of life in prematurely born population has been determined. In 88 infants (median gestational age, 29 weeks) thoracic gas volume (TGV) and airway resistance (R(aw)) was measured and specific conductance (SGaw) calculated at 6 months and 1 year of age. During 3 years of prospective follow-up neither TGV measured at either 6 months or 1 year, nor R(aw) and SGaw at 6 months, differed significantly between infants who were asymptomatic or symptomatic. At 1 year, however, R(aw) and SGaw were significantly higher and lower respectively in patients who were symptomatic than in those who were asymptomatic in any of the 3 years. An elevated R(aw) (> or = 50 cmH2O/L/s) measured at 1 year, but not at 6 months, was associated with a significant relative risk of symptoms in the first, second, and third year of life. We conclude that in prematurely born patients an abnormal airway resistance at 1 year predicts symptoms in early childhood.

Tuberculous meningitis in children

Between May 1988 and November 1992 the data from 52 patients with tuberculous meningitis (TBM) were noted down for their symptoms and signs, BCG vaccines, PPD tests; clinical, laboratory, radiologic and microbiologic findings. These data were discussed by means of literature knowledge. Cranial computed tomography (CT) demonstrated hydrocephalus (HC) in 98% of the patients. There was a statistically significant difference among the clinical stages on admission in respect to prognosis (P < 0.05). In addition, there was also a significant relationship between prognosis and HC (P < 0.05). However, we did not find any significant relationship between parenchymal involvement, basilar meningitis and prognosis (P > 0.05).

Influence of lung function and postnatal age on the response to nebulized ipratropium bromide in children born prematurely

Nebulized ipratropium bromide reduces airways resistance in young children born prematurely, but that response is not invariable. We have assessed whether postnatal age or baseline lung function influences the effect of ipratropium bromide. Forty-five children, median gestational age 28 weeks (range 23-34) were studied at a postnatal age of 10 months (range 6-18). Twenty-four were symptomatic at follow-up. Airways resistance (Raw) was measured using a whole body plethysmograph before (baseline) and 20 min after nebulized ipratropium bromide. Sixteen patients had a significant improvement in Raw (a reduction in Raw greater than twice the coefficient of variation of the measurement). The baseline Raw of those 16 infants was significantly higher than the baseline Raw of the other 29 infants (P < 0.01). Multiple regression analysis, after taking into account baseline lung function and symptom status, demonstrated there was a significant relationship between the change in Raw following ipratropium bromide and postnatal age (P < 0.01). We conclude that both baseline lung function and postnatal age influence the response to nebulized ipratropium bromide in young children born prematurely.

Birth weight and hospital readmission of infants born prematurely

OBJECTIVE

To determine whether the hospital readmission rate of infants born prematurely was greatest in those whose birth weight was less than 750 g.

DESIGN

A prospective cohort study.

SETTING

Regional neonatal intensive care unit.

PATIENTS

Consecutive very-low-birth-weight (< 1500 g) infants admitted to the neonatal intensive care unit; infants with congenital abnormalities were excluded. Two-year follow-up was completed for 109 (90.8%) of these patients.

MEASUREMENTS/MAIN RESULTS

Following discharge from the neonatal intensive care unit, infants were seen at 6-month intervals at which time a detailed history was taken and examinations were performed. Hospital admissions were documented and confirmed from the medical records. Infants with birth weights of less than 750 g and those of very-low gestational age (< or = 28 weeks) made up the greatest number of admissions and had the longest hospital stays. In the first year of life, the duration of stay was inversely related to birth weight.

CONCLUSION

Increased survival of extremely low-birth-weight infants has important implications for resource allocation of pediatric beds.