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Biomedical subjects

I M Balfour-Lynn

Publications and source records attributed to I M Balfour-Lynn.

At least 19 recordsLinked to original sources
PubMed2006

A comparison of the prevalence of urinary incontinence in girls with cystic fibrosis, asthma, and healthy controls.

Urinary incontinence (UI) is recognized as a significant problem in adult females with cystic fibrosis and can often have a marked impact on day-to-day activities. The prevalence and severity of UI in the pediatric cystic fibrosis (CF) female population is less clear and there are no comparative data with healthy children or children with other respiratory disorders. An anonymous self-completed semi-structured questionnaire was used to study the prevalence rates of UI in girls with CF aged between 11 and 17 and compared it to age-matched asthmatic and healthy girls. The prevalence of UI in girls with CF was significantly higher (17/51, 33%) than the asthmatic (4/25, 16%) and healthy girls (2/27, 7%) (P = 0.02). It may manifest as early as 11 years of age and is associated with increasing lung disease. Surprisingly it is perceived as a relatively minor problem in terms of the distress it causes. Pediatric CF clinics should be routinely addressing UI as a potential problem in all girls from the age of 11 years.

Adolescent↗
PubMed2006

Cystic fibrosis presenting with haematological abnormalities.

Although cystic fibrosis (CF) is common, the diagnosis (and subsequent treatment) may be delayed if the presentation is atypical. We present three cases of children with CF who presented with haematological abnormalities. In all cases, they underwent extensive and invasive investigations prior to the diagnosis.

Anemia↗
PubMed2005

Thrombophilia in children with cystic fibrosis.

In some children with cystic fibrosis (CF), percutaneous long lines occlude sooner than expected (due to thrombophlebitis or thrombosis), and many have a totally implantable venous access device (TIVAD), a recognized complication of which is thrombosis. This complication is more likely if the child has an underlying thrombotic tendency, which may be enhanced in the presence of inflammatory lung disease. There are no reports of an identified association of heritable thrombophilia with CF, although individual cases have been recognized. Our aim was to determine the incidence of thrombophilia in children with CF. In a tertiary pediatric CF center, blood was screened for thrombophilia at annual review, and retested if abnormal. A thrombotic abnormality was found in 41/204 (20%) patients. These included activated protein C resistance (10/204, 5%) with a prevalence similar to that expected, but the following abnormalities had an increased prevalence: antithrombin deficiency (2/204, 1%), protein S deficiency (11/204, 5%), protein C deficiency (8/204, 4%), and lupus anticoagulant (18/204, 9%). There were no differences found in those with thrombophilia for the following parameters: age, gender, genotype, lung function, presence of Pseudomonas aeruginosa, prothrombin time, serum IgE, aspergillus-specific IgE, liver function, and blood inflammatory markers. Fifteen children had TIVADs, 4 of whom had evidence of thrombophilia. In conclusion, a significant proportion of patients had a thrombophilic abnormality. We recommend that thrombophilia screening be performed prior to insertion of a TIVAD, and also in those with a history of venous thrombosis, blocked TIVADs, or recurring problems with long lines.

Activated Protein C Resistance↗
PubMed2005

Growth and lung function in Asian patients with cystic fibrosis.

BACKGROUND: The incidence of cystic fibrosis (CF) in Asians is rare. How these patients fare in terms of morbidity and mortality in the UK compared to their non-Asian peers is not well documented. AIMS: To retrospectively study annual reviews of 31 Asian CF patients from three London paediatric CF centres. METHODS: Disease severity was assessed by lung function, age at first infection with Pseudomonas aeruginosa, and body mass index (BMI). The Asian children were compared with 143 matched non-Asian patients with CF. Matching criteria used were same sex and treatment centre as the Asian index patient. In addition, the controls were matched so that their date of birth, date of diagnosis, and date at annual review were within 12 months of the index patient. RESULTS: There was no significant difference in age at diagnosis or age at annual review between the Asian and non-Asian children. Mean Z-scores for FEV1 and FVC were significantly lower for the Asian girls. There was no significant difference in Z-scores for BMI between the Asian children and their controls. Age at first isolation of Pseudomonas aeruginosa in Asian girls was significantly later than for their controls (8.3 years compared to 5.6 years for non-Asian girls). CONCLUSIONS: While the Asian boys' lung function seems comparable with that of their non-Asian peers, the Asian girls emerge as a potentially vulnerable group and more work is required to discover why this is the case.

Adolescent↗
PubMed2005

Tumour necrosis factor gene polymorphisms and childhood wheezing.

Tumour necrosis factor (TNF)-alpha is associated with childhood wheezing. A genetic predisposition to increased TNF-alpha production, influenced by single nucleotide gene polymorphisms, may be important. Frequencies of TNF-alpha-308G/A and lymphotoxin (LT)-alpha+252G/A polymorphisms were compared in 115 asthmatic children, 55 wheezy infants and 156 control school children from the UK. Genotype frequencies for the TNF-alpha-308 and LT-alpha+252 polymorphisms were significantly different from controls. Haplotype analysis showed that TNF-alpha-308G, LT-alpha+252A/TNF-alpha-308A, LT-alpha+252A was associated with a markedly increased risk for both asthma and infant wheezing. The TNF-alpha-308G, LT-alpha+252G/TNF-alpha-308G, LT-alpha+252A combination was protective for asthma and infant wheezing. These findings were confirmed by analysis of Caucasian data. Nasal TNF-alpha levels were measured in the infants during acute wheezing episodes and higher, but nonsignificant levels were produced in those with one or two LT-alpha+252A alleles. Unexpectedly, significantly lower nasal TNF-alpha levels were found in the presence of one or two TNF-alpha-308A alleles. TNF-alpha-308/LT-alpha+252 genotype combinations had a significant influence on nasal TNF-alpha levels. In conclusion, these findings may have implications for future early intervention studies by helping to identify infants at increased risk for wheezing and childhood asthma.

Adolescent↗
PubMed2004

Intravenous immunoglobulin for cystic fibrosis lung disease: a case series of 16 children.

BACKGROUND AND OBJECTIVE: Some children with severe cystic fibrosis (CF) lung disease develop chest tightness, recurrent dry cough, and intractable wheeze, often accompanied by deteriorating lung function and failure to expectorate sputum. In an attempt to reduce the use of regular oral corticosteroids, we treated a group of such children with monthly courses of intravenous immunoglobulin (IVIG). METHODS: This is a retrospective case note review of 16 children, aged 3-16 years (median 13.0 years) who received 1-66 (median 7.5) courses of monthly IVIG, at a dose of 1 g/kg on two successive days for the first dose, followed by 1 g/kg monthly as a 12 hour infusion, with corticosteroid and antihistamine cover. RESULTS: FEV1 improved from a median (95% confidence interval (CI)) of 50% (39 to 61%) to 54% (48 to 66%), with a median (95% CI) difference of +7.5% (-1.5 to 14.5%; NS). FVC improved from 65% (60 to 77%) to 83% (70 to 89%), with a difference of +13% (4 to 22%, p = 0.01). The total daily dose/kg body weight of oral prednisolone was reduced from 0.6 (0.3 to 1.0) to 0 (0 to 0.1) mg/kg/day, with a reduction of -0.6 (-1.0 to -0.1, p = 0.006) mg/kg/day. The total daily dose of inhaled corticosteroid (budesonide equivalent) was a median (range) of 2000 microg (800-6000 microg), which was reduced to 1500 microg (0-3200 microg). The median (95% CI) difference was -400 microg (-1600 to 0 microg), p<0.05. IVIG was well tolerated and the regimen acceptable to all but one of the children. The following transient adverse reactions were seen in only one patient each: headache, fever, hypotension, aseptic meningitis, and chest tightness. CONCLUSION: We suggest that an n = 1 trial of IVIG in carefully selected patients with severe obstructive CF lung disease is worth considering, as for some it may lead to significant benefit.

Adolescent↗
PubMed2003

Three-minute step test to assess exercise capacity in children with cystic fibrosis with mild lung disease.

The information obtained from a simple submaximal test (the 3-min step test) was compared with that from a maximal cycle ergometry study, in a group of children with CF with relatively mild abnormalities of lung function (FEV(1) > 50% predicted). Nineteen subjects with CF undertook both exercise tests on the same day. Measurements included heart rate (HR), oxygen saturations (SaO(2)), visual analogue score of perceived breathlessness (VAS), 15-count breathlessness score (15c), and peak oxygen consumption (VO(2)). There were significant differences in the median changes in HR and VAS during the cycle test compared to the step test, 78 vs. 46 beats per minute (P < 0.05) and 51 mm vs. 42 mm (P < 0.05), respectively. There were no differences between median changes in 15c and SaO(2), but 3 subjects had significant desaturations (>4%) during the cycle test only. Significant exercise desaturations may occur in mild CF lung disease and will not be detected by a 3-min step test. The 15c did not discriminate between a maximal and a submaximal test, and was less useful than VAS. Important information may be missed by the step test which is detected by more complex exercise tests.

Adolescent↗
PubMed2002

Long term azithromycin in children with cystic fibrosis: a randomised, placebo-controlled crossover trial.

BACKGROUND: The macrolide antibiotic azithromycin has anti-inflammatory properties potentially beneficial in cystic fibrosis. Since findings of open pilot studies seemed to show clinical benefit, we undertook a formal trial. METHODS: 41 children with cystic fibrosis, aged 8-18 years, and with a median forced expiratory volume in 1 s (FEV1) of 61% (range 33-80%) participated in a 15-month randomised double-blind, placebo-controlled crossover trial. They received either azithromycin (bodyweight < or =40 kg: 250 mg daily, >40 kg: 500 mg daily) or placebo for 6 months. After 2 months of washout, the treatments were crossed over. The primary outcome was median relative difference in FEV1 between azithromycin and placebo treatment periods. Sputum cultures, sputum interleukin 8 and neutrophil elastase, exercise testing, quality of life, antibiotic use, and pulmonary exacerbation rates were secondary outcome measures. Side-effects were assessed by pure tone audiometry and liver function tests. Analysis was by intention-to-treat. FINDINGS: Median relative difference in FEV1 between azithromycin and placebo was 5.4% (95% CI 0.8-10.5). 13 of 41 patients improved by more than 13% and five of 41 deteriorated by more than 13% (p=0.059). Forced vital capacity and mid-expiratory flow did not significantly change overall. 17 of 41 patients had 24 fewer oral antibiotic courses when on azithromycin than when taking placebo, and five had six extra courses (p=0.005). Sputum bacterial densities, inflammatory markers, exercise tolerance, and subjective well-being did not change. There were no noticeable side-effects. INTERPRETATION: A 4-6-month trial of azithromycin is justified in children with cystic fibrosis who do not respond to conventional treatment. The mechanism of action remains unknown.

Adolescent↗
PubMed2002

Inflammatory endobronchial polyps in childhood: clinical spectrum and possible link to mechanical ventilation.

Inflammatory polyps of the airways are now regarded as histopathologically distinct nonneoplastic endobronchial lesions, which in adults are associated with a variety of chronic inflammatory insults. However, their clinical presentation in the pediatric population is extremely rare, with the etiology of such polyps poorly defined. The clinical and histopathological data from four pediatric patients, identified in the histopathology files of the Royal Brompton Hospital, were retrospectively reviewed. Three out of 4 patients had a history of mechanical ventilation in the neonatal period. In these 3 patients, the polyps were all situated in the proximal airways on the right side. These 3 patients presented at 6 weeks, 7 weeks, and 2 years, respectively, and were successfully treated by polypectomy at rigid bronchoscopy, with subsequent return to normality. One patient, presenting at 12 years of age without history of iatrogenic intervention, underwent a left lower lobectomy for a polyp sited in a segmental bronchus. Presentation in 3 of the 4 patients was with lobar collapse. The fourth patient presented with hyperinflation. We conclude that inflammatory endobronchial polyps may be associated with a history of mechanical ventilation in the neonatal period, polyp formation perhaps being secondary to airway trauma. The small caliber of the main airways in neonates may also be a contributory factor in presentation.

Bronchial Neoplasms↗
PubMed2002

Are annual blood tests in preschool cystic fibrosis patients worthwhile?

AIM: To investigate whether routine annual assessment blood tests in cystic fibrosis (CF) patients under 5 years influence management. METHODS: Retrospective review of the results of the first annual assessment blood tests of patients with CF less than 5 years of age during a four year period (1995-99). Management changes were identified from a follow up letter to the general practitioner or local paediatrician. RESULTS: A total of 169 patients (100 female), median age 2.2 years (range 0.3-4.9) were identified. Venepuncture was successful in 93% of patients. Of the 32 individual blood parameters measured, the overall success rate in obtaining a result was 81%. Eleven per cent of patients underwent subsequent management changes, including liver ultrasound, fasting glucose, and a short course of iron. Of particular importance, vitamin A and E concentrations were low in 9% of patients, which prompted an increase in prescribed dose. CONCLUSIONS: These results support the recommendations for routine blood tests at annual review in preschool CF children. The results may help to rationalise which tests are performed and thus reduce laboratory costs.

Child, Preschool↗
PubMed2002

"CF asthma": what is it and what do we do about it?

The diagnosis of "CF asthma" is problematic and it is difficult to determine which patients have a combination of CF and asthma and which have asthma like symptoms caused by inflammation of the CF lung. This may not matter, however; the relevance lies in the possible approaches to treatment.

Adrenal Cortex Hormones↗
PubMed2001

Effect of intravenous antibiotics on exercise tolerance (3-min step test)) in cystic fibrosis.

Most children with cystic fibrosis (CF) feel better and display more energy after a course of intravenous antibiotics (IVABs), but this is not always reflected by a satisfactory improvement in lung function. We assessed the change in exercise tolerance after treatment with IVABs using the 3-min step test, and compared it with changes in spirometric lung function and arterial oxygen saturation (SaO(2)). Thirty-six children (mean age, 13.8 years) were enrolled from two tertiary CF centers during an inpatient stay for IVABs. After 10-14 days of treatment, there was a significant improvement in median FEV(1) from 43% to 57% of predicted values (P < 0.0001), and median FVC from 66% to 73% of predicted values (P < 0.0001), while median SaO(2) significantly increased from 95% to 96.5% (P < 0.05). This was accompanied by a reduction in resting heart rate (median 118 bpm to 109 bpm, P < 0.005) and subjective breathlessness at rest (median visual analogue score 2.2 to 0.8, P < 0.005). All outcomes of exercise tolerance were improved after IVABs. There was a reduction in maximum heart rate (median 156 bpm to 150 bpm, P < 0.05) and an increase in minimum SaO(2) (median 93.5% to 94.5%, P = 0.08) measured during the step test. There was also a reduction in subjective breathlessness (median visual analogue score of 5.5 to 4.2, P < 0.005) and objective breathlessness (median 15-count score of 3 to 2, P < 0.0001) measured immediately after the step test. Exercise testing was a useful outcome measure for monitoring effectiveness of inpatient therapy, and complemented spirometry and SaO(2) monitoring. The simple ward-based 3-min step test was found to be a particularly suitable method for measuring changes in exercise tolerance in children with CF.

Adolescent↗
PubMed2001

Children with difficult asthma: a practical approach.

Many open studies investigating the effects of innovative treatments for steroid-dependent asthma demonstrate some benefit. This is also true of the majority of placebo arms in placebo-controlled trials. This suggests that children with difficult asthma benefit from the high level of input that is typically provided in clinical trials, with or without additional medication. Such intensive management of patients, with the emphasis on establishing the diagnosis, improving adherence, and identifying provoking factors, is the key to optimizing asthma control for these children. For patients with genuinely severe asthma, despite high doses of conventional treatment, a greater understanding of the pathological basis of persistent symptoms is needed. Identification of different pathological subtypes of severe asthma should allow for more rational prescribing of asthma therapy, as well as the design of further trials of potential steroid-sparing treatments.

Administration, Inhalation↗
PubMed2001

Exercise tolerance in children with cystic fibrosis undergoing lung transplantation assessment.

The aim of this study was to compare the 6-min walk test against the recently developed 3-min step test, as measures of exercise tolerance in children with moderate to severe cystic fibrosis (CF) lung disease referred for lung transplantation assessment. Twenty-eight children with CF (16 girls, 12 boys), with a mean age of 13.7 yrs (range 7.2-17.8 yrs) and mean forced expiratory volume in one second of 34% predicted (range 17%-67%) were recruited. All subjects performed both the 6-min walk and 3-min step-tests. Outcome measures were maximum rise in heart rate (HR), and maximum fall in arterial oxygen saturation (Sa,O2). There was no significant difference in resting HR or Sa,O2 prior to starting the two tests. Both step and walk tests produced significant rises in median HR (from 114-149 min(-1), p<0.0005, and 119-138 min(-1), p<0.0005, respectively) and significant falls in Sa,O2 (both from 94-92%, p<0.0005). The step test produced a significantly greater percentage rise in HR (30% versus 18%, p<0.0005) and a significantly greater percentage fall in Sa,O2 (4% versus 2%, p=0.002). Bland-Altman analysis gave wide 95% limits of agreement (10.7-29.3% for rise in HR, -2.14.6% for fall in Sa,O2). The step test was well tolerated. The 3-min step test produced a greater fall in Sa,O2 and a greater rise in HR than the 6-min walk test in children with moderate to severe CF lung disease. It may be of value when assessing a child's suitability for lung transplantation.

Adolescent↗