Very low birth weight survivors have reduced peak bone mass and reduced insulin sensitivity

CONTEXT

Increasing numbers of very low birth weight (VLBW) infants are surviving into adulthood because of improvements in neonatal intensive care. Adverse events in early life can have long-term effects through reprogramming of metabolic systems.

OBJECTIVE

To determine whether young adult VLBW survivors have abnormalities of skeletal development or endocrine function.

DESIGN

Cross-sectional, observational, case-control study.

PARTICIPANTS

Thirty-seven VLBW subjects and 27 healthy controls at peak bone mass (mean age 23).

MEASUREMENTS

Differences between cases and controls in body size, body composition, bone mass and bone geometry [assessed by dual-energy X-ray absorptiometry (DXA), hip structure analysis and peripheral quantitative computed tomography (pQCT)], bone turnover [urine N-terminal telopeptide of type I collagen (NTX), serum C-terminal telopeptide of type I collagen (CTX)], aminoterminal propeptide of type I procollagen (PINP) and bone alkaline phosphatase), hormones (sex steroids, IGF-1, PTH and 25-OH vitamin D) and insulin sensitivity (HOMA-IR and oral glucose tolerance testing).

RESULTS

VLBW subjects had lower bone density at the lumbar spine (5.7%) and femoral neck (8.6%), which persisted after correction for bone size by the estimation of volumetric density (bone mineral apparent density). Urine NTX was higher in VLBW subjects than in controls, but there were no significant differences in other bone turnover markers. VLBW survivors had lower insulin sensitivity (mean INS-30 controls = 57.0, VLBW subjects = 94.3, P < 0.01), but there were no differences in whole body fat mass or truncal fat mass between VLBW subjects and controls.

CONCLUSIONS

Young adult VLBW survivors have reduced bone density for their bone size and reduced insulin sensitivity, which may have significant implications for their risk of fracture and diabetes in later life.

Use of home oxygen for children in England and Wales

BACKGROUND

With the introduction of a standardised ordering system in February 2006, the opportunity arose to collect data on children requiring home oxygen in England and Wales. The authors' aim was to determine the incidence and patterns of home oxygen prescribing.

METHODS

A paediatric home oxygen clinical network and the Children's Home Oxygen Record Database were established. During a 3-year period (February 2006 to January 2009), prescribers were requested to submit copies of the Home Oxygen Order Forms. In addition, anonymised point prevalence data on all patients currently receiving home oxygen in June 2007 were obtained from the four provider companies.

RESULTS

Children's Home Oxygen Record Database--Forms were analysed for 888 children <16 years (58% boys) with a median age of 4.1 months; 656 (74%) were <1 year. 541 (68%) had a diagnosis of chronic neonatal lung disease; 53 (7%), neurodisability; and 49 (6%), cardiac disease. Order forms were often incomplete, and prescribing practice was variable. Provider's cross-sectional survey--There were 3338 children <16 years, representing 4% of all patients on home oxygen. Median age was 3.1 years with a peak at 6 months. The prevalence for paediatric home oxygen use in England and Wales was 0.33 per 1000, with a peak of 1.08 per 1000 for those <1 year. Marked regional variation was noted.

CONCLUSIONS

This is the first national dataset available for children prescribed home oxygen in England and Wales. The study emphasises the need for a coordinated approach to home oxygen prescribing and justifies the recent publication of evidence-based guidelines.

Methacholine challenge in pre-school children--which outcome measure?

The aim of our study was to evaluate the utility of interrupter resistance (R(int)), transcutaneous oximetry and auscultation as outcome measures for a recently suggested tripling-dose methacholine (Mch) challenge in pre-school children. We studied 57 children aged 3-6 years. R(int) was measured at baseline and after each Mch dose. Oxygen saturation (SaO(2)) and transcutaneous oxygen pressure (tcpO(2)) were monitored during the challenge. Mch concentrations of 0.22, 0.66, 2.0, 6.0 and 18.0 mg/ml were nebulised during tidal breathing. The challenge was terminated if there was wheeze, SaO(2) below 91% or persistent cough; this final Mch dose was considered as PCW. Nine healthy children, 17 with cough and 25 with wheeze performed the study up to the point of PCW or all five Mch inhalations. If a change of 20% of predicted R(int) or termination by wheeze, desaturation or cough is taken as a completed test, then 39 out of 51 children (78%) had adequate R(int) measurements on each occasions from start to completion. The success rate for tcpO(2) measurements was similar: 38 out of 51 (76%) had complete tcpO(2) data until a 15% fall of tcpO(2) or clinical endpoint was reached. Using the above-mentioned cut-off levels significant change in R(int) or tcpO(2) preceded PCW in most of the cases. Both R(int) and tcpO(2) measurements may allow detection of bronchial hyper-responsiveness at lower Mch doses and also provide a less subjective measure, but will not be feasible in all children.

Aerosolized diuretics for preterm infants with (or developing) chronic lung disease

BACKGROUND

Lung disease in preterm infants is often complicated with lung edema.

OBJECTIVES

The aim of this review is to assess the risks and benefits of aerosolized diuretic administration in preterm infants with or developing chronic lung disease (CLD). Primary objectives are to assess effects on short term outcome (changes in need for oxygen or ventilatory support) and effects on long-term outcome. Secondary objectives are to assess changes in pulmonary mechanics and potential complications of therapy.

SEARCH STRATEGY

We used the standard search method of the Cochrane Neonatal Review Group. We used the following keywords: {<bronchopulmonary dysplasia> or <chronic lung disease>} and <explode diuretics>, limited to <human> and limited to <infant, newborn> or <infant>. We searched MEDLINE (1966 - 1998), EMBASE (1974 - 1998) and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006). In addition, we hand searched several abstract books of national and international American and European Societies. The search of MEDLINE and of CENTRAL was last updated in March 2006.

SELECTION CRITERIA

For the purpose of this analysis, we included trials in which preterm infants with or developing chronic lung disease and at least five days of age were all randomly allocated to receive an aerosolized loop diuretic. Eligible studies needed to assess at least one of the outcome variables defined a priori for this systematic review. Primary outcome variables included need for ventilator support, chronic lung disease, mortality and other important clinical outcomes. Secondary outcome variables included pulmonary mechanics and potential complications of therapy.

DATA COLLECTION AND ANALYSIS

We used the standard method for the Cochrane Collaboration which is described in the Cochrane Collaboration Handbook. Two investigators extracted, assessed and coded separately all data for each study, using a form that was designed specifically for this review. Any disagreement was resolved by discussion. We combined parallel and cross-over trials and, whenever possible, transformed baseline and final outcome data measured on a continuous scale into change scores using Follmann's formula.

MAIN RESULTS

We identified eight studies that met selection criteria. Most studies focused on pathophysiological parameters and did not assess effects on important clinical outcomes defined in this review or the potential complications of diuretic therapy. No study assessed the amount of diuretic effectively delivered to the patient. Furosemide was the only diuretic used in the eight studies included in this review. Among preterm infants < 3 weeks of age developing CLD, not enough information is available to assess the effect of aerosolized furosemide on outcome or lung function. Among infants > 3 weeks with CLD, a single aerosolized dose of 1 mg/kg of furosemide may transiently improve pulmonary mechanics. Not enough information is available to assess the effect of chronic administration of aerosolized furosemide on oxygenation and pulmonary mechanics.

AUTHORS' CONCLUSIONS

In preterm infants > 3 weeks with CLD administration of a single dose of aerosolized furosemide improves pulmonary mechanics. In view of the lack of data from randomized trials concerning effects on important clinical outcomes, routine or sustained use of aerosolized loop diuretics in infants with (or developing) CLD cannot be recommended based on current evidence.More double-blinded randomized trials are needed (1) to analyze factors likely to affect the response to aerosolized furosemide, e.g., washout period and delivery of furosemide to distal airways, and (2) to assess the effects of chronic administration of aerosolized furosemide on mortality, O2 dependency, ventilator dependency, length of hospital stay and long-term outcome.

Asthma severity and atopy: how clear is the relationship?

BACKGROUND

The relationship between asthma severity and atopy is complex. Many studies have failed to show significant relationships between clinical severity or lung function and markers of atopic sensitisation.

AIM

To determine whether increasing asthma severity is related to atopic sensitisation in a population of children with asthma.

METHODS

A total of 400 children (7-18 years) with asthma were recruited as part of a multicentre study of the genetics of asthma. Detailed phenotypic data were collected on all participants. Associations between measures of asthma severity and atopic sensitisation were sought using multilevel models allowing variation at the individual and family level.

RESULTS

Children recruited to the study had a range of asthma severities, with just over a third having mild persistent asthma. The logarithm of total serum IgE was associated with increased asthma severity score, decreased FEV1, increased airways obstruction, risk of hospital admission, and inhaled steroid use. Increasing skin prick test reactivity to a panel of seven aeroallergens was associated with increased risk of hospital admission, use of an inhaled steroid, and airways obstruction. The results remained highly significant after corrections for age, gender, and birth order.

CONCLUSIONS

In children with asthma, increasing atopy is associated with increasing asthma severity. However, the relationships between asthma severity and skin prick tests, and asthma severity and total serum IgE values, appear subtly different.

Feasibility of shortened methacholine challenge in preschool children

The aim of our study was to assess the feasibility and safety of a recently suggested tripling-dose methacholine (Mch) challenge in preschool children. Fifty-seven children aged 3-6 years were studied. Mch challenge was carried out using a tidal breathing method, with concentrations of 0.22, 0.66, 2.0, 6.0, and 18.0 mg/ml, at 5-min intervals, given by a Pari Turbo Boy compressor and Pari LC Plus nebulizer, for 1 min only. Oxygen saturation (SaO(2)) was monitored during the challenge. The challenge was terminated if there was wheeze, SaO(2) below 91%, or persistent cough. This final Mch dose was considered the provocative concentration inducing audible wheeze (PCW). Nine healthy children, 17 with cough and 25 with wheeze, completed the study. Mean output from nebulizers (SD) in these 51 children was 0.30 (0.05) ml/min. Geometric means for PCW in these groups were 2.88, 2.58, and 1.28 mg/ml Mch, respectively. The wheezing children were significantly more hyperresponsive than the coughing children (P < 0.05). A tripling-dose Mch protocol is safe and practicable in children over 3 years of age. A further reduction in nebulized dose may be needed for a more discriminatory test.

Effects of glutathione S-transferase M1, T1 and P1 on lung function in asthmatic families

RATIONALE

Previous data have suggested that glutathione-S-transferase (GST) genotypes are important in determining the rate of lung function growth in childhood. This effect was most marked in Caucasian children with asthma.

OBJECTIVES

We investigated the association of lung function with GSTM1, GSTP1 and GSTT1 genotypes in Caucasian families with asthma.

METHODS

Four hundred and eighteen children and 316 parents from 224 Caucasian families were recruited via a child with asthma, the proband. Associations between lung function and GST genotype were determined using multilevel models.

RESULTS

There were no observed associations between lung function and GST genotype in parents. However, in the children, the GSTP1 val(105)/val(105) and GSTM1 null genotypes were associated with significantly higher forced expiratory volume in 1 s (FEV(1)) and FVC values as percentage of predicted. This effect was not statistically significant in the probands but was marked in their siblings in whom GSTP1 val(105)/val(105) was associated with 9.4% higher FEV(1) and 10.7% higher FVC (P=0.005 and 0.001, respectively). The GSTM1 null genotype was associated with a 6.7% higher FEV(1) and 4.1% higher FVC (P=0.003 and 0.063, respectively). These effects remained significant after correcting for the confounders of individual atopic status, tobacco smoke exposure and familial aggregation of lung function values.

CONCLUSIONS

GSTM1 and GSTP1 genotypes are important determinants of lung function in childhood. The smaller differences seen in probands are predicted by a simple model in which more rapid decline in lung function is seen in these individuals.

Regional variation of airway hyperresponsiveness in children with asthma

Families with asthmatic children were recruited to take part in a multi-centre collaborative study into the genetics of asthma. Detailed phenotypic information was collected on all family members including: lung function, anthropomorphic measurements, response to methacholine challenge, skin prick testing, serum IgE measurements and a detailed nurse-administered questionnaire. Families were eligible for entry into the study if they had two children with a doctor-diagnosis of asthma. Bennett/Twin nebulisers were supplied to each centre from a single source and these were calibrated to determine gravimetric nebuliser output prior to use. Asthmatic probands from each centre had similar degrees of asthma severity and atopy. There was no significant difference in the sex ratios or ages of the probands or numbers of parents with a history of smoking in the families recruited at each centre. However, there was a significant difference in the number of children with airway hyperresponsiveness, with 90% of the North Staffordshire group but only 60% of the Sheffield group having a PC20 of <8 mg/ml for methacholine. This difference highlights the difficulty of using families from different centres in genetic and epidemiological studies.

Home oxygen for children: who, how and when?

A review of the specific requirements of home oxygen therapy in children which attempts to offer guidance to clinicians and service providers.

Discharge and aftercare in chronic lung disease of the newborn

This article deals with the discharge planning and continuing care of babies with chronic lung disease of the newborn (CLD), especially those with a continuing oxygen requirement, with some reference to longer term outcome. The pattern of CLD has changed since early descriptions, and the most useful definition for persisting morbidity in a baby with lung disease is a continuing oxygen requirement beyond 36 weeks post-menstrual age. Long-term oxygen therapy to maintain oxygen saturation at a mean of 95% or more and prevent levels below 90% is the cornerstone of management, and with adequate oxygen therapy the excess mortality previously reported in CLD can largely be avoided. Care must be given to the method of assessing oxygen saturation: overnight monitoring using appropriate recording devices is recommended. Exposure to respiratory viruses should be minimized where possible. Metabolic requirements are increased, but if efforts are made to maintain adequate energy input the long-term outlook for catch-up growth in height is good. Respiratory morbidity is increased in early life, but this improves in later childhood, along with lung function and exercise tolerance. Although respiratory symptoms should be treated as they arise, there is no evidence for long-term benefit from any pharmacological intervention in CLD.

Neonatal lungs: maturational changes in lung resistivity spectra

The electrical resistivity of lung tissue can be related to the structure and composition of the tissue and also to the air content. Electrical impedance tomographic measurements have been used on 155 normal children over the first three years of life and 25 pre-term infants, to determine the absolute resistivity of lung tissue as a function of frequency. The results show consistent changes with increasing age in both lung tissue resistivity (5.8 ohm m at birth to 20.9 ohm m at 3 years of age) and in the changes of resistivity with frequency (Cole parameter ratio R/S=0.41 at birth and 0.84 at 3 years of age). Comparison with a lung model showed that the measurements are consistent with maturational changes in the number and size of alveoli, the extracapillary blood volume and the size of the extracapillary vessels. However, the results show that the process of maturation is not complete at the age of three years.

Diagnostic and treatment behaviour in children with chronic respiratory symptoms: relationship with socioeconomic factors

BACKGROUND

The prevalence and severity of asthma is believed to increase with increasing socioeconomic deprivation. The relationship between asthma diagnosis, symptoms, diagnostic accuracy, and socioeconomic deprivation as determined by Townsend scores was determined in Sheffield schoolchildren.

METHODS

All 6021 schoolchildren aged 8-9 years in one school year in Sheffield were given a parent respondent survey based on International Survey of Asthma and Allergies in Childhood (ISAAC) questions.

RESULTS

5011/6021 (83.2%) questionnaires were returned. Postcode data were available in 4131 replies (82.4%) and were used to assign a composite deprivation score (Townsend score). Scores were divided into five quintiles, with group 1 being least and group 5 being most deprived. A positive trend was observed from group 1 to group 5 for the prevalence of wheeze in the previous 12 months, wheeze attacks >or=4/year, nocturnal wheeze and cough (all p<0.001), cough and/or wheeze "most times" with exertion (p<0.03), current asthma (p<0.001), and significant asthma symptoms (p<0.001). No significant trend was observed for lifetime wheeze or attacks of speech limiting wheeze. There were no significant trends in the prevalence of current asthmatic children without significant symptoms (overdiagnosis) or children with significant asthma symptoms but no current asthma diagnosis (underdiagnosis) across the social groups. There was a significant negative trend in the ratio of asthma medication to asthma diagnosis from least to most deprived groups (p<0.001).

CONCLUSIONS

Asthma morbidity and severity increase according to the level of socioeconomic deprivation. This may be due to differences in environment, asthma management, and/or symptom reporting. Diagnostic accuracy does not vary significantly across deprivation groups but children living in areas of least deprivation and taking asthma medication are less likely to be labelled as having asthma, suggesting diagnostic labelling bias.

Neonatal lungs--can absolute lung resistivity be determined non-invasively?

The electrical resistivity of lung tissue can be related to the structure and composition of the tissue and also to the air content. Conditions such as pulmonary oedema and emphysema have been shown to change lung resistivity. However, direct access to the lungs to enable resistivity to be measured is very difficult. We have developed a new method of using electrical impedance tomographic (EIT) measurements on a group of 142 normal neonates to determine the absolute resistivity of lung tissue. The methodology involves comparing the measured EIT data with that from a finite difference model of the thorax in which lung tissue resistivity can be changed. A mean value of 5.7 +/- 1.7 omega(m) was found over the frequency range 4 kHz to 813 kHz. This value is lower than that usually given for adult lung tissue but consistent with the literature on the composition of the neonatal lung and with structural modelling.

Diuretics acting on the distal renal tubule for preterm infants with (or developing) chronic lung disease

OBJECTIVES

The aim of this review is to assess the risks and benefits of diuretics acting on distal segments of the renal tubule (distal diuretics) in preterm infants with or developing chronic lung disease (CLD). Primary objectives are to assess changes in need for oxygen or ventilatory support and effects on long-term outcome, and secondary objectives are to assess changes in pulmonary mechanics and potential complications of therapy.

SEARCH STRATEGY

We used the standard method of the Cochrane Neonatal Review Group. We searched MEDLINE (1966-November 2001), EMBASE (1974-November 2001) and the Cochrane Controlled Trials Register (CCTR) (Cochrane Library Issue 4, 2001). In addition, we hand searched several abstract books of national and international American and European Societies.

SELECTION CRITERIA

We included in this analysis trials in which preterm infants with or developing CLD and at least five days of age were all randomly allocated to receive a distal diuretic (i.e., a diuretic acting on the distal renal tubule). Eligible studies needed to assess at least one of the outcome variables defined a priori for this systematic review. Primary outcome variables included changes in need for respiratory support and oxygen supplementation, mortality, bronchopulmonary dysplasia (BPD), death or BPD, chronic lung disease at 36 weeks of postconceptional age (gestational age + postnatal age), length of stay, and number of rehospitalizations during the first year of life. Secondary outcome variables included pulmonary mechanics and potential complications of therapy.

DATA COLLECTION AND ANALYSIS

We used the standard method for the Cochrane Collaboration which is described in the Cochrane Collaboration Handbook. Two investigators extracted, assessed and coded separately all data for each study, using a form that was designed specifically for this review. Any disagreement was resolved by discussion. We combined parallel and cross-over trials and, whenever possible, transformed baseline and final outcome data measured on a continuous scale into change scores using Follmann's formula.

MAIN RESULTS

Of six studies fulfilling entry criteria, most focused on pathophysiological parameters and did not assess effects on important clinical outcomes defined in this review, or the potential complications of diuretic therapy. In preterm infants > 3 weeks of age with CLD, a four-week treatment with thiazide and spironolactone improved lung compliance and reduced the need for furosemide. Thiazide and spironolactone decreased the risk of death and tended to decrease the risk for lack of extubation after 8 weeks in intubated infants who did not have access to corticosteroids, bronchodilators or aminophylline. However, there is little or no evidence to support any benefit of diuretic administration on need for ventilatory support, length of hospital stay, or long-term outcome in patients receiving current therapy. There is no evidence to support the hypothesis that adding spironolactone to thiazide or that adding metolazone to furosemide improves the outcome of preterm infants with CLD.

REVIEWER'S CONCLUSIONS

In preterm infants > 3 weeks of age with CLD, acute and chronic administration of distal diuretics improve pulmonary mechanics. Studies are needed to assess (1) whether thiazide administration improves mortality, duration of oxygen dependency, ventilator dependency, length of hospital stay and long-term outcome in patients exposed to corticosteroids and bronchodilators (2) whether adding spironolactone to thiazides or adding metolazone to furosemide has any beneficial effect.

Intravenous or enteral loop diuretics for preterm infants with (or developing) chronic lung disease

BACKGROUND

Lung disease in preterm infants is often complicated with lung edema.

OBJECTIVES

The aim of this review was to assess the risks and benefits of administration of a diuretic acting on the loop of Henle (loop diuretic) in preterm infants with or developing chronic lung disease (CLD). Primary objectives were to assess changes in need for oxygen or ventilatory support and effects on long-term outcome, and secondary objectives were to assess changes in pulmonary mechanics and potential complications of therapy.

SEARCH STRATEGY

We used the standard search method of the Cochrane Neonatal Review Group. We searched MEDLINE (1966-October 2001), EMBASE (1974-November 2001) and the Cochrane Controlled Trials Register (CCTR) (Cochrane Library, Issue 4, 2001). In addition, we hand searched several abstract books of national and international American and European Societies.

SELECTION CRITERIA

We included in this analysis trials in which preterm infants with or developing chronic lung disease and at least 5 days of age were all randomly allocated to receive a loop diuretic either enterally or intravenously. Eligible studies needed to assess at least one of the outcome variables defined a priori for this systematic review. Primary outcome variables included important clinical outcomes, and secondary outcome variables included toxicity and pulmonary mechanics (e.g., lung compliance and airway resistance).

DATA COLLECTION AND ANALYSIS

We used the standard method for the Cochrane Collaboration which is described in the Cochrane Collaboration Handbook. Two investigators extracted, assessed and coded separately all data for each study, using a form that was designed specifically for this review. Any disagreement was resolved by discussion. We combined parallel and cross-over trials and, whenever possible, transformed baseline and final outcome data measured on a continuous scale into change scores using Follmann's formula.

MAIN RESULTS

The only loop diuretic used in the studies which met the selection criteria was furosemide. Most studies focused on pathophysiological parameters and did not assess effects on important clinical outcomes defined in this review, or the potential complications of diuretic therapy. In preterm infants < 3 weeks of age developing CLD, furosemide administration has either inconsistent effects or no detectable effect. In infants > 3 weeks of age with CLD, a single intravenous dose of 1 mg/kg of furosemide improves lung compliance and airway resistance for 1 hour. Chronic administration of furosemide improves both oxygenation and lung compliance.

REVIEWER'S CONCLUSIONS

In preterm infants > 3 weeks of age with CLD, acute and chronic administration of furosemide improve lung compliance. Chronic administration of intravenous or enteral furosemide improves oxygenation. In view of the lack of data from randomized trials concerning effects on important clinical outcomes, routine or sustained use of systemic loop diuretics in infants with (or developing) CLD cannot be recommended based on current evidence. Randomized trials are needed to assess the effects of furosemide administration on survival, duration of ventilatory support and oxygen administration, length of hospital stay, potential complications and long-term outcome.

Training the ideal hospital doctor: the specialist registrars' perspective

BACKGROUND

When training for junior doctors is being planned, little discussion is focused on what outcomes hospitals are trying to achieve with regard to education/training, i.e. on what makes the ideal hospital doctor. Instead, the primary focus is on the requirements of the syllabi of the Royal Colleges (credentialing) and the requirements of service delivery (job description). Current literature has no qualitative studies of any longitude in which middle-grade doctors are asked about their vision of the ideal hospital doctor, what they feel can be done to help realize this vision, and how they feel about their own training.

METHODS

This study examined data principally collected through a series of semistructured interviews conducted with eight specialist registrars (SpRs), four each from the North Trent and South Thames rotations over a period of 18 months. Additional information was taken from focus groups, interviews with programme directors, and questionnaires.

FINDINGS

A model was created of the SpRs' perceptions of the key attributes of an ideal hospital doctor and of how these may be achieved in training. Eight broad areas were identified: clinical knowledge and skills; key clinically related generic/non-clinical skills; self-directed learning and medical education; implementing change management; applying strategic and organizational skills in career planning; consultation skills; research; and key personal attributes.

CONCLUSIONS

SpRs are articulate in expressing their own expectations of their training and have considerable insight into the components of good training. Further improvement could be made and will require significant commitment from both trainees and trainers.

Survey of respiratory sounds in infants

BACKGROUND

Over the last decade there has been an apparent increase in childhood wheeze. We speculated that much of the reported increase may be attributed to the term wheeze being adopted by parents to describe a variety of other forms of noisy breathing.

AIMS

To investigate terminology used by parents to describe their children's breath sounds.

METHODS

An interview was carried out with the parents of 92 infants with noisy breathing, beginning with an open question and then directed towards a more detailed description. Finally, the parents were asked to choose from a wheeze, ruttle, and stridor on imitation by the investigator and video clips of children.

RESULTS

Wheeze was the most commonly chosen word on initial questioning (59%). Only 36% were still using this term at the end of the interview, representing a decrease of one third, whereas the use of the word ruttles doubled.

CONCLUSIONS

Our results reflect the degree of inaccuracy involved in the use of the term wheeze in clinical practice, which may be leading to over diagnosis. Imprecise use of this term has potentially important implications for therapy and clinical trials.

Use of diclofenac in children with asthma

This study investigated the effect of diclofenac on the lung function of 70 children aged 6-15 years with a diagnosis of asthma, recruited from a hospital respiratory clinic. Peak flow and a forced expiratory flow-volume loop were measured and the patients were then given 1-1.5 mg.kg-1 effervescent diclofenac orally. Spirometry was repeated at 10, 20 and 30 min, a 15% decrease in results being considered a significant reduction in lung function. No patient demonstrated a consistent reduction in lung function of > 15% during the study and there were no reports of wheezing or increased bronchodilator use after completion of the spirometry. In conclusion, we studied a group of genuine asthmatics and found no clinically significant incidence of bronchospasm with the use of a single therapeutic dose of diclofenac.

Aerosolized diuretics for preterm infants with (or developing) chronic lung disease

BACKGROUND

Lung disease in preterm infants is often complicated with lung edema.

OBJECTIVES

The aim of this review is to assess the risks and benefits of aerosolized diuretic administration in preterm infants with or developing chronic lung disease (CLD). Primary objectives are to assess effects on short term outcome (changes in need for oxygen or ventilatory support) and effects on long-term outcome. Secondary objectives are to assess changes in pulmonary mechanics and potential complications of therapy.

SEARCH STRATEGY

We used the standard search method of the Cochrane Neonatal Review Group. We used the following keywords: ¿<bronchopulmonary dysplasia> or <chronic lung disease>¿ and <explode diuretics>, limited to <human> and limited to <infant, newborn> or <infant>. We searched Medline (1966-1998), Embase (1974-1998) and the Cochrane Controlled Trials Register (CCTR) from the Cochrane Library (1998, Issue 4). In addition, we hand searched several abstract books of national and international American and European Societies.

SELECTION CRITERIA

We included in this analysis trials in which preterm infants with or developing chronic lung disease and at least five days of age were all randomly allocated to receive an aerosolized loop diuretic. Eligible studies needed to assess at least one of the outcome variables defined a priori for this systematic review. Primary outcome variables included important clinical outcomes, and secondary outcome variables included pulmonary mechanics and potential complications of therapy.

DATA COLLECTION AND ANALYSIS

We used the standard method for the Cochrane Collaboration which is described in the Cochrane Collaboration Handbook. Two investigators extracted, assessed and coded separately all data for each study, using a form that was designed specifically for this review. Any disagreement was resolved by discussion. We combined parallel and cross-over trials and, whenever possible, transformed baseline and final outcome data measured on a continuous scale into change scores using Follmann's formula.

MAIN RESULTS

We identified eight studies which met selection criteria. Most studies focused on pathophysiological parameters and did not assess effects on important clinical outcomes defined in this review or the potential complications of diuretic therapy. No study assessed the amount of diuretic effectively delivered to the patient. Furosemide was the only diuretic used in the eight studies included in this review. Among preterm infants < 3 weeks of age developing CLD, not enough information is available to assess the effect of aerosolized furosemide on outcome or lung function. Among infants > 3 weeks with CLD, a single aerosolized dose of 1 mg/kg of furosemide may transiently improve pulmonary mechanics. Not enough information is available to assess the effect of chronic administration of aerosolized furosemide on oxygenation and pulmonary mechanics.

REVIEWER'S CONCLUSIONS

In preterm infants > 3 weeks with CLD administration of a single dose of aerosolized furosemide improves pulmonary mechanics. In view of the lack of data from randomized trials concerning effects on important clinical outcomes, routine or sustained use of aerosolized loop diuretics in infants with (or developing) CLD cannot be recommended based on current evidence. More double-blinded randomized trials are needed (1) to analyze factors likely to affect the response to aerosolized furosemide, e.g. , washout period and delivery of furosemide to distal airways, and (2) to assess the effects of chronic administration of aerosolized furosemide on mortality, O2 dependency, ventilator dependency, length of hospital stay and long-term outcome.

A comparison of neonatal and adult lung impedances derived from EIT images

An objective method of extracting respiratory data from lung images is presented, together with a technique for automatically generating regions of interest delineating the anterior and posterior regions of the lungs. The method is used to extract data on the change in lung impedance with frequency, and on calculated Cole parameters, from 19 normal neonates (gestational age 32 to 42 weeks) and 8 normal adults (age 21 to 82 years). A comparison of the impedance properties of neonatal and adult lungs was made. The variation of lung impedance with frequency in neonates, as derived from EIT images, is significantly different from that found for adults. The implications for a model of the electrical impedance of lung tissue are discussed.

Methacholine challenge in preschool children: methacholine-induced wheeze versus transcutaneous oximetry

Tracheal/chest auscultation for wheeze and transcutaneous oximetry have both been suggested as measures of outcome in bronchial provocation tests in young children. This study aimed to compare the sensitivity and safety of these two techniques as end-points for methacholine challenge in children aged <4 yrs. Seventy-two methacholine challenges were performed in 39 children aged <4 yrs with recurrent wheeze. Arterial oxygen saturation (Sa,O2) and transcutaneous oxygen pressure tcPO2 continuously, and the test was terminated when wheeze was heard or at Sa,O2 <91%. tcPO2 was not used as an end-point. Wheeze or desaturation occurred at < or =8 mg x mL(-1) methacholine in every test. One child had transient clinical cyanosis, but no other ill-effects were seen. Fifty-six tests (78%) were terminated for wheeze, seven (10%) for fall in Sa,O2 and nine (12%) showed simultaneous responses in both parameters. Twenty-eight tests (39%) contained a fall in tcPO2 >3 kPa but six of these also showed a significant rise. Fifty-three tests (75%) contained a fall in tcPO2 >15%, but 20 of these also showed a significant rise. Tracheal/chest auscultation with Sa,O2 monitoring is a sensitive and relatively safe end-point for bronchial challenges in preschool children. The erratic pattern of transcutaneous oxygen pressure response in some children casts doubt on its reliability as a proxy measure of bronchial obstruction.

The bronchoprotective effect of inhaled salmeterol in preschool children: a dose-ranging study

The optimal dose of salmeterol in infants and preschool children is not known. The aim of this study was to assess the bronchoprotective effect of different doses of salmeterol using methacholine-induced wheeze in children aged <4 yrs. Children <4 yrs old with a history of recurrent wheeze underwent two methacholine challenges within 7 days. One hour before each challenge they were pretreated in double-blind fashion using a metered-dose inhaler and Babyhaler spacer. Placebo was given before one challenge, and either 25, 50 or 100 microg of salmeterol before the other. Both the dose and treatment order were random. The provocative concentration of methacholine causing wheeze (PCwheeze) was measured on each occasion. Studies were terminated when wheeze occurred or arterial oxygen saturation (Sa,o2) fell below 91%. Of the 42 children enrolled, 33 completed the study. Two subjects refused the challenge test, two failed to return and five developed upper respiratory tract infections or wheeze between the two tests. The mean (range) age of the population was 27 (8-46) months. Ratios of PCwheeze between treatment and placebo challenges were calculated for each dosage group. The treatment/placebo ratios (95% confidence intervals) were 1.2 (0.6-2.4) for 25 microg, 2.5 (1.4-4.6) for 50 microg (p<0.01), and 4.0 (2.1-7.4) (p<0.001) for 100 microg doses. In recurrently wheezy children aged <4 yrs a single dose of salmeterol between 25 and 100 microg has a dose-dependent effect on methacholine-induced wheeze, and this is significantly different from placebo at 50 and 100 microg. This study suggests that the Babyhaler effectively delivers salmeterol to children <4 yrs of age and that doses between 50-100 microg are efficacious.

Arterial oxygen saturation profiles in healthy preterm infants

AIM

To construct a reference range of SpO2 values in healthy preterm infants using a simple data logging device.

METHODS

Thirty three healthy preterm infants were monitored for a continuous period of 4 hours at rest using an Ohmeda Biox 3700 E Pulse Oximeter and an electronic data logger (Rustrack Ranger). Stored data were downloaded and saved as individual files on a personal computer.

RESULTS

The study group median and 5th and 95th percentiles were used to construct a cumulative frequency curve of time against SpO2 value, representing the normal reference range of SpO2 profiles in healthy preterm infants.

CONCLUSION

Comparison of an infant's SpO2 profile against this curve may be more helpful in guiding supplemental oxygen treatment in that individual than a figure for a mean SPO2 and its standard deviation.

Variable phenotype in Kaufman-McKusick syndrome: report of an inbred Muslim family and review of the literature

Multiple congenital anomalies (MCA) in two siblings and digit abnormalities in four related individuals from a large highly inbred Muslim family are described. The pattern of MCA is consistent with the autosomal recessive Kaufman-McKusick syndrome [MIM 236700]. The present report reviews the previously published reports on this uncommon MCA dysmorphic syndrome and draws attention to the marked variation in the phenotype.

Pulmonary function, exercise performance, and growth in survivors of congenital diaphragmatic hernia

A cohort of survivors of congenital diaphragmatic hernia (CDH), with matched controls, was studied to assess growth, respiratory function, and exercise performance. Nineteen of 24 survivors from an 11 year period (79%) were compared with 19 matched controls. Subjects had detailed auxology, performed spirometry and cycle ergometry, and completed questionnaires about respiratory symptoms and exercise. There were no significant differences between the groups for height, weight, sitting height, head circumference, or body mass index expressed as SD scores. The mean (95% confidence interval) percentage predicted forced vital capacity (FVC) was 84.7% (79.1 to 90.3) in index cases and 96.5% (91.4 to 101.6) in controls (p < 0.01). There was no significant difference in total lung capacity. Expiratory flow rates corrected for FVC were also similar between groups, suggesting normal airway function relative to lung size. Mean maximum oxygen consumption in ml/kg/min was 40.1 (36.8 to 43.4) and 42.2 (38.5 to 45.8) in index and control cases. These differences were not significant. Index cases achieved a similar minute ventilation to controls by more rapid and shallower breathing. Index cases had lower perception of their own fitness and lower enjoyment of exercise, although habitual activity levels were similar. Survivors of CDH repair have reduced functional lung volumes, but normal airway function compared with matched controls. They have no growth impairment nor significant impairment of exercise performance, although they have more negative perceptions of their own fitness. They should be encouraged and expected to participate fully in sport and exercise.

Neonatal respiratory distress in near-term infants--consider surfactant protein B deficiency

Two infants presenting with respiratory distress in the first 24 h of life are described. Both patients underwent extensive investigation before the diagnosis of surfactant protein B-deficiency was reached. Both children died within 2 months of birth. Parental consanguinity was known to be a feature in the first case, who proved to have a previously unrecognized mutation of the surfactant protein B gene. In the second case, a history of parental consanguinity was not sought from the Caucasian family, but was later volunteered by the parents themselves. Case 2 proved to have the "common" surfactant protein B-deficient genotype. The key to diagnosis is having a high index of suspicion in any term or near-term newborn with severe respiratory distress; parental consanguinity must be excluded. Surfactant protein B-deficiency can be readily diagnosed from bronchoalveolar lavage specimens; a simple, inexpensive procedure which is well tolerated in newborns.

Reproducibility of electrical impedance tomographic spectroscopy (EITS) parametric images of neonatal lungs

The reproducibility of electrical impedance tomographic spectroscopy (EITS) images of neonatal lungs have been investigated in 11 clinically stable babies. We have used the Sheffield Mark IIIa EITS system. An average inspiration frame was generated from the data frames associated with maximum inspiration. Frequency images were reconstructed from these frames. The frequency images were analysed to locate the pixel with the maximum change in the right lung field. The change was defined as the 614 kHz measurement relative to 9.6 kHz. A 3 x 3 pixel region of interest was centred at this point. The changes in impedance with frequency for this region of interest show good overall reproducibility between electrode applications for eight frequencies (95% limits of agreement +/- 28%). This reproducibility is improved (95% limits of agreement +/- 13%) by omitting the highest frequency (1.2 MHz) which is most subject to system noise. The parameters for the Cole model derived from data with the highest frequency omitted are less reproducible between electrode applications (95% limits of agreement, R/S +/- 0.83, fc +/- 81.6, RC +/- 0.52, SC +/- 0.39). We suspect that the parametric model used may have an effect on this. The signals recorded at the highest frequency (1.2 MHz) are a major source of variability. The reproducibility results are improved by omitting this frequency from the analysis.

Stability of respiratory symptoms in unlabelled wheezy illness and nocturnal cough

OBJECTIVE

To assess the natural history of respiratory symptoms not labelled as asthma in primary schoolchildren.

DESIGN

Repeat questionnaire survey of subgroups identified from a previous questionnaire survey after a two year delay.

SUBJECTS

The original population of 5321 Sheffield children aged 8-9 years yielded 4406 completed questionnaires in 1991(82.8%). After excluding children with a label of asthma, there were 370 children with current wheeze, 129 children with frequent nocturnal cough, and a random sample of 222 children with minor cough symptoms and 124 asymptomatic children.

RESULTS

Response rates in the four groups were 233 (63.0%), 77 (59.7%), 160 (72.1%), and 90 (72.6%) respectively. Of those who initially wheezed, 114 (48.9%) had stopped wheezing and 42 (18.0%) had been labelled as having asthma. Those with more frequent wheezing episodes (p < 0.02) and a personal history of hay fever (p < 0.01) in 1991 were more likely to retain their wheezy symptoms. In the children with frequent nocturnal cough in 1991, 20.1% had developed wheezing, 42.9% had a reduced frequency of nocturnal coughing, and 14.2% had stopped coughing altogether two years later. One sixth had been labelled as having asthma. Children with nocturnal cough were more likely to develop wheezing if they had a family history of atopy (p = 0.02). Only 3.8% and 3.3% of those with minimal cough and no symptoms respectively in 1991 had developed wheeze by 1993 (1.9% and 1.0% labelled as asthma).

CONCLUSIONS

Most unlabelled recurrent respiratory symptoms in 8-10 year olds tend to improve. Unlabelled children who have persistent symptoms have other features such as frequent wheezing attacks and a family or personal history of atopy. If a screening questionnaire were to be used to identify such children, a combination of questions should be employed.

Longitudinal study of free running exercise challenge: reproducibility

The reproducibility of free running exercise challenge has been examined in an unselected population of 8-10 year olds. Using a standardised protocol, monthly exercise tests were performed on 143 children over one year. A positive test was defined using both a 15% and 20% fall in peak expiratory flow after exercise. The mean (95% confidence interval, CI) population frequency for a positive test at 15% fall was 14.9% (6.5 to 23.3) and coefficient of variation 24.6%. For a 20% fall, the mean (95% CI) population frequency was 7.9% (2.9 to 12.9) and coefficient of variation 27.8%. Seventy two (50.3%) of the children gave at least one positive response at 15% fall. Exercise testing is not reproducible in the community setting and should not be used as a screening test. Exercise data from epidemiological studies of asthma should be interpreted with caution.

Multifrequency and parametric EIT images of neonatal lungs

The aims of the study were to investigate the problems involved in making multifrequency EIT measurements on neonates and to compare the images obtained with the results from a group of normal adults. The Sheffield electrical impedance tomographic spectroscopy (EITS) system acquires multifrequency data using a set of eight drive and eight receive electrodes. EITS measurements were made on an inhomogeneous group of 10 neonates admitted to the special care baby unit for observation and feeding. R/S, characteristic frequency, RC and SC parameters were generated using the Cole equation. Comparisons of the parameters were made with data collected from normal adults in another study. We have shown that it is possible to obtain EITS parametric images of neonatal lungs and that there are some differences in Cole parameters between the adult and neonatal groups.

Asthma treatment, perceived respiratory disability, and morbidity

An entire school year of 8-9 year old schoolchildren in Sheffield were surveyed using the core questions of the international study of asthma and allergies in childhood in order to assess the morbidity associated with diagnosed asthma. Of 5321 children surveyed, replies were obtained from 4539 (85.3%). A current diagnosis of asthma was reported in 466 (10.3%), and a further 6.4% reported symptoms compatible with significant undiagnosed asthma. A validated questionnaire was used to assess symptoms and perceived disability in 336 (72.1%) of the children with diagnosed asthma. One third reported symptoms every day or most days, while 15.3% reported frequent nocturnal symptoms. There was no significant difference in reported symptoms between those receiving inhaled steroids, sodium cromoglycate, or no prophylaxis. Despite this, parents of children receiving inhaled steroids perceived more disability, and worried more about their children's health. It is concluded that perceived symptoms and morbidity are high in children with diagnosed asthma, and speculate that level of treatment is determined by parental tolerance of symptoms as much as by the symptoms themselves.

Early changes in lung function and response to surfactant replacement therapy

Dynamic respiratory system compliance (Cdyn) was measured in 44 preterm babies before, immediately after, and for 96 h following administration of artificial surfactant (Exosurf). There was no significant change in Cdyn for the whole group over the entire study period. Subdivision into three groups on the basis of Cdyn prior to surfactant revealed a significant and sustained deterioration in lung function in those babies with the highest starting compliance and a significant and sustained improvement in those with the lowest compliance. Inspired oxygen and alveolar/arterial oxygen gradient also exhibited significant differences with least improvement in the babies with the best initial lung function and most improvement in the babies with worst initial lung function and most improvement in the babies with worst initial lung function. Despite clear initial differences in clinical status, neither long-term oxygen requirements nor the incidence of chronic lung disease differed significantly between the three groups. We conclude that the response of an individual baby to the administration of surfactant is, in part, determined by the lung function before surfactant is administered. Babies with higher initial lung compliance are more likely to deteriorate after administration and caution should be used before selection of such babies for surfactant treatment.

Antioxidant status in asthma

Reduced levels of glutathione peroxidase (GSH-Px) have been observed in adults with asthma. This study examines the antioxidant status in children with asthma compared with a control group in a cross-sectional analysis. Red blood cell GSH-Px, superoxide dismutase (SOD), and plasma concentrations of retinol, vitamin C, alpha tocopherol, and cholesterol were measured in 37 subjects (26 males) with stable controlled asthma. Thirty-five subjects (20 males) without eczema, hayfever, or recurrent respiratory symptoms were used as a control group. Children with asthma had significantly reduced red blood cell GSH-Px activity compared with controls [median (inter-quartile range) for asthma group, 10.25 (9.25-11.91); for control group, 11.75 (10.34-12.26) IU/g Hb; P = 0.006]. There were no significant differences in activity of SOD or vitamin C, retinol, or alpha tocopherol/cholesterol ratio. The reduction in GSH-Px activity may have therapeutic and etiological implications for asthma. The effects of disease activity and treatment on antioxidant status needs for further study.

Does vitamin C intake influence the rate of tyrosine catabolism in premature babies?

A study was conducted to investigate the relationship between vitamin C intake and the rate of tyrosine catabolism in premature babies. A 13C tyrosine breath test was developed for the measurement of tyrosine catabolism. Premature babies were randomly allocated to receive a daily intake of vitamin C which ranged from 8 to 100 mg/kg body weight, for 5 days. Tyrosine catabolism was measured at the beginning and the end of this period. Daily intakes of vitamin C of 20 mg/kg or more elicited a greater increase in tyrosine catabolism over 5 days than 8 mg/kg/day. The magnitude of the difference, in terms of percentage of tyrosine metabolised, was, however, small and of doubtful biological significance. Vitamin C intakes above 20 mg/kg/day had no further measurable effect on the catabolism of tyrosine.

Pneumococcal infection in the newborn

Two fatal cases of invasive pneumococcal disease in the newborn are reported, both acquired from the maternal vagina. The rarity of vaginal carriage of pneumococcus suggests that this organism has a higher invasion to colonisation ratio than group B streptococcus and maternal carriage or neonatal colonisation should be more aggressively treated.

Ethnic and environmental factors affecting fetal growth in Papua New Guinea

We studied 738 live singleton births in Papua New Guinea to examine the contribution of ethnic origin and environmental factors to birth weight and gestation. Maternal history, examination and post-partum anthropometry, infant anthropometry and clinical gestational assessment were performed, and placental blood slides and histology were examined. Mothers from Highlands provinces who delivered on the coast had larger babies (mean birthweight 3.34 SD 0.48 kg) than either indigenous coastal mothers (mean 3.10 SD 0.51 kg) or those migrating to Port Moresby from other coastal regions (mean 3.14 SD 0.51 kg). This was due to a combination of longer gestation and better intrauterine growth (assessed by birthweight standard deviation scores). Gestation was slightly longer in Highlands mothers delivering on the coast compared with those delivering in the Highlands, but birthweight standard deviation scores were unchanged. Malarial infection of the placenta was almost never found. Stepwise regression analysis showed that parity, maternal height, Highlands origin and maternal body mass index (weight/height2) were all significant predictors of birthweight standard deviation score, while maternal body mass index and Highlands origin were predictors of gestational length. We conclude that Highland mothers have a tendency to deliver heavier babies, and do not demonstrate the fetal growth-retarding effects of altitude seen in other races. Although the incidence of low birthweight was only 7.1% in our study, we found that indices of maternal nutrition were predictors of birth weight.

First day serum creatine kinase BB isoenzyme in high-risk infants

Serum creatine kinase BB (CK-BB) on the 1st day of life was measured by radioimmunoassay in 37 very low birth weight (VLBW) infants, 14 severely asphyxiated infants and 24 controls. The 31 survivors from the two high-risk groups were followed up for 12 months or more. VLBW non-survivors (n = 14) had significantly higher mean CK-BB levels than survivors (n = 23), (P less than 0.05). However, if only survivors were considered, CK-BB was a poor discriminator of outcome in either study group. First day serum CK-BB is not a useful predictor of neurodevelopmental outcome in surviving high-risk infants.

Isolated fructose malabsorption

A patient with isolated fructose malabsorption presented with diarrhoea and colic during the first year of life and subsequently responded to a fructose free diet. Fructose malabsorption has been implicated in some cases of irritable bowel syndrome in adults and may also be an infrequently recognised cause of gastrointestinal symptoms in children.

Simple maturity classification of the newborn infant

We set out to design a simple test, derived from the Dubowitz gestational assessment, to differentiate immature from mature newborn infants. An initial group of 196 infants of known gestation was studied to determine the two criteria with the most discriminant value. It was found that the clearest cut-off for most criteria occurred at 36 rather than at 37 weeks gestation, and that the best criteria were breast size and plantar creases. The usefulness of this pair of criteria was then assessed in a second group of 120 babies weighing 1750-2200 g where a full 21-point Dubowitz assessment had been used to estimate gestational age. Based on this assessment, babies were categorized as "true immature" (less than 36 weeks) or "true mature". In this low-birthweight group, if maturity (36 weeks or more) was diagnosed when both the breast nodule and the plantar creases scored 2 or more on Dubowitz rating, then 79% of "true immature" and 81% of "true mature" infants were correctly classified. Thus, in low-birthweight Melanesian infants, a baby with indentations on the sole (or red marks on the posterior half) and breast tissue of diameter 0.5 cm or more on one or both sides is likely to be mature. If one or both signs is absent, immaturity is likely. This simple assessment of maturity would be practical and easy to teach in primary health care in developing countries.

Trends in infant feeding in Port Moresby

A survey of infant feeding practices was conducted among children aged less than 1 year attending an urban health clinic and the main Children's Outpatients Department (COPD) in Port Moresby in 1986. A further survey was conducted in 1987 to assess the short-term trends. The use of artificial milk increased by 60%, from 9.4% in the first to 15.2% in the second survey. This increase was particularly marked in the COPD sample. Bottle feeding accounted for 95% of artificial feeding methods. In 67% of cases the reason given for using artificial feeding was that the mother was working. Legislation and an explicit government policy to foster the establishment of creches in the work place may be necessary to counter the worrying increase in artificial feeding.

Reduced vital capacity in insulin-dependent diabetes

Spirometry was performed on 88 children with insulin-dependent diabetes mellitus (IDDM) and 216 healthy controls living in Sheffield. Children with IDDM had significantly lower percentage predicted forced vital capacity (FVC) than did control children or reference norms. There was no evidence that the reduced FVC was confined to a subgroup of children, and there was no correlation with duration of IDDM or glycemic control. A longitudinal study of 27 children with IDDM did not show progressive deterioration in percentage predicted FVC with age. These findings suggest that a tendency toward reduced lung volumes exists in IDDM and may not be a direct result of the metabolic disturbances in the disease.