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Allan L Coates

Publications and source records attributed to Allan L Coates.

10 recordsLinked to original sources
PubMed2005

Long-term pulmonary morbidity in survivors of congenital diaphragmatic hernia.

Our objective was to study long-term respiratory outcomes of congenital diaphragmatic hernia (CDH) treated in the perinatal period. This was a cohort study with 26 adolescent survivors and age- and gender-matched controls. Medical histories were retrieved from hospital charts and questionnaires. Pulmonary function testing included measurement of maximum inspiratory and expiratory pressures (MIPS and MEPS) and maximum voluntary ventilation (MVV). Unpaired two-tailed t-test and nonlinear regression were used for statistical analysis. Significant differences were found in forced expiratory volume in one second (FEV(1)) (79% +/- 16% vs. 94% +/- 10%, P < 0.001), FEF(25-75) (62% +/- 24% vs. 84% +/- 15%, P < 0.001), FRC (114% +/- 20% vs. 95% +/- 13%, P < 0.001), RV/TLC (31% +/- 10% vs. 22% +/- 6%, P < 0.001), MVV (74% +/- 16% vs. 90% +/- 13%, P < 0.001), and MIPS (69% +/- 19% vs. 84% +/- 16%, P < 0.01), with numbers indicating percent predicted of reference values +/- SD. Reduction of MVV was not independent from FEV1 (r = 0.83). Forty-eight percent of patients vs. 4% of controls showed significant improvement of FEV1 after bronchodilators (86% +/- 15 vs. 98% +/- 10, P < 0.01). Forty-six percent of patients had abnormalities of the chest wall or spinal column such as pectus excavatum, pectus carinatum, and scoliosis, mostly mild or moderate. In conclusion, long-term respiratory outcome in adolescent CDH is associated with mild to moderate airway obstruction, a high prevalence of response to bronchodilators, and decreased inspiratory muscle strength. This should guide follow-up scheduling and should be taken into account for perioperative and critical care management.

Adolescent↗
PubMed2005

Bronchial constriction and inhaled colistin in cystic fibrosis.

STUDY OBJECTIVE: Inhaled colistin is used for the treatment of Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients despite reports of chest tightness and bronchospasm. The main objective of the study was to assess whether bronchospasm occurred in pediatric CF patients with or without clinical evidence of airway hyperreactivity. DESIGN AND METHODS: A prospective placebo-controlled clinical trial with crossover design was devised using challenge tests with 75 mg colistin in 4 mL saline solution and a placebo solution of the same osmolarity using a breath-enhanced nebulizer for administration. Subjects were recruited as follows: high risk (HR) for bronchospasm due to a personal history of recurrent wheezing, a family history of asthma and/or atopy, or bronchial lability, as demonstrated in pulmonary function tests; or low risk (LR) without these characteristics. RESULTS: The mean FEV(1) (expressed as the mean [+/- SD] fall from baseline) of the HR group (n = 12) fell 12 +/- 9% after placebo was administered, and fell 17 +/- 10% after colistin was administered. For the LR group (n = 8), the mean FEV(1) fell 9 +/- 4% following placebo administration and 13 +/- 8% following colistin administration. There was a greater number of subjects in the HR group compared to the LR group, which had a mean fall in FEV(1) of >/= 15% (p < 0.01) after inhaling colistin. The differences between placebo and colistin therapy in the LR group were not significant. CONCLUSION: The results demonstrated that colistin can cause bronchospasm, particularly in those patients with coexisting CF and asthma.

Administration, Inhalation↗
PubMed2004

Disease severity in siblings with cystic fibrosis.

Since cross-infection occurs between cystic fibrosis (CF) siblings, we hypothesized that subsequent siblings may acquire respiratory pathogens at an earlier age and have a more severe course of pulmonary disease. We studied a retrospective cohort of 31 sibling pairs from the CF database at the Hospital for Sick Children. Kaplan-Meier curves and modified log-rank tests were used to test sibling differences in age of acquisition of Pseudomonas aeruginosa (PA), Staphylococcus aureus (SA), or any positive culture. Differences in disease severity outcomes were explored. Older siblings were more likely to have both SA and any CF pathogen first isolated from respiratory culture at an older age than younger siblings (P = 0.0050 and P = 0.0008, respectively, by modified log-rank tests). However, more of the older siblings were positive on first culture at time of diagnosis, introducing an age-of-diagnosis bias. Hospitalization rates, courses of oral antibiotics, FEV(1) % predicted, and weight and height measurements were not better in the older children. No differences in clinical parameters were found between older and younger siblings. The apparent finding of younger age at first isolation of pathogens from respiratory cultures in younger siblings is likely because many older siblings were already infected with these organisms at time of diagnosis.

Age of Onset↗
PubMed2004

Comparison of spirometric reference values.

Lung-function reference values play a vital role in the management of respiratory disorders. There are many proposed reference equations for pediatric spirometry. Recently, spirometric reference equations were proposed, using data from people aged 8-80 years living in the US compiled by the third National Health and Nutrition Examination Survey. Our objective was to compare the predictive value of wider age-range reference equations to established pediatric reference equations for the pediatric population. Spirometry, height, and weight were obtained from 70 normal children aged 6-18 years. The difference between measured and predicted values as suggested by different reference equations was compared. Predicted values from general equations significantly differed from those generated from pediatric equations and from measured values in this population. The difference between measured and predicted values from the wider age-range equations varied between 7-16% for forced expired volume in 1 sec (FEV1) and forced vital capacity (FVC). The difference between measured and predicted values for the pediatric equations varied between 1-4%. Although wider age-range equations provide continuity through age ranges, their predictive accuracy may be low in the pediatric age group, especially for the youngest, smallest children. Extrapolating reference equations beyond the age range of subjects used to generate then is not recommended.

Adolescent↗
PubMed2004

Comparison of breath-enhanced to breath-actuated nebulizers for rate, consistency, and efficiency.

OBJECTIVES: To evaluate differences between three new-generation nebulizers-Pari LC Star (Pari Respiratory Equipment; Mississauga, ON, Canada), AeroEclipse (Trudell Medical International, London, ON, Canada), and Halolite (Medic-Aid Limited, West Sussex, UK)-in terms of rate and amount of expected deposition as well as the consistency of the doses delivered. METHODS: The in vitro performance characteristics were determined and then coupled to the respiratory pattern of seven patients with cystic fibrosis (age range, 4 to 18 years) in order to calculate expected deposition. The Pari LC Star and AeroEclipse were characterized while being driven by the Pari ProNeb Ultra compressor (Pari Respiratory Equipment) for home use, and by a 50-psi medical air hospital source. The Halolite has its own self-contained compressor. Algorithms for the rate of output for the inspiratory flow were developed for each device. Patient flow patterns were divided into 5-ms epochs, and the expected deposition for each epoch was calculated from the algorithms. Summed over a breath, this allowed the calculation of the estimated deposition for each patient's particular pattern of breathing. RESULTS: The rate of deposition was highest for the Pari LC Star and lowest for the Halolite. Rate of deposition was independent of respiratory pattern for the Pari LC Star and AeroEclipse, but proportional to respiratory rate for the Halolite. The differences between the Pari LC Star and AeroEclipse were less when driven by the 50-psi source. The AeroEclipse had the least amount of drug wastage. As designed, the Halolite delivered a predetermined amount of drug very accurately, whereas expected deposition when run to dryness of the other two devices had significant variations. CONCLUSIONS: To minimize treatment time, the Pari LC Star would be best. To minimize drug wastage, the AeroEclipse would be best. To accurately deliver a specific drug dose, the Halolite would be best.

Cystic Fibrosis↗
PubMed2002

Do in-line respiratory filters protect patients? Comparing bacterial removal efficiency of six filters.

With all pulmonary function diagnostic and respiratory therapy equipment, cross-infection has always been a concern, especially in the cystic fibrosis population, in whom pulmonary function tests are done routinely. The aim of this study was to identify and compare the bacterial removal efficiency (BRE, ability of a filter to remove microorganisms) of six different filters used in hospital settings: Microgard (MG), Spirobac (SB), PALL (PL), and KOKO (KK), used in the pulmonary function laboratory; and Clear-Guard (CG) and Respigard (RG), used in ventilator circuits. Filters were tested in both saturated and nonsaturated conditions. A Pseudomonas aeruginosa suspension of 1 x 10(4) to 1 x 10(8) CFU/mL was nebulized onto each filter. A blood agar plate was held immediately downstream from the filter. Colony-forming units (CFU) were then counted after 24 hr of incubation. A peak flow was applied across the spirometry filters. Bacterial thresholds of the filters were also identified (concentration of bacteria at which a filter no longer has 100% BRE). There was a significant difference in BRE among the six filters in saturated states when challenged with 1 x 10(4) CFU/mL (MG, KK, CG, and RG, 100%; SB, 98.8%; PL, 42.7%; P = 0.003). There was no significant difference between saturated and nonsaturated states, or after application of a peak flow. Filter thresholds were significantly different (KK 1 x 10(8), MG 1 x 10(7), CG 1 x 10(6), RG 1 x 10(5), and SB and PL <1 x 10(4) CFU/mL). In conclusion, when all filters are exposed to the same extreme challenges, significant differences exist in their ability to remove bacteria.

Cross Infection↗
PubMed2002

Efficacy of oral dexamethasone in outpatients with acute bronchiolitis.

OBJECTIVE: To examine the efficacy of oral dexamethasone in acute bronchiolitis. STUDY DESIGN: A double-blind randomized, placebo-controlled trial involving 70 children < 24 months old in the emergency department with Respiratory Disease Assessment Instrument > or = 6. Each patient received either 1 dose of 1 mg/kg of oral dexamethasone or placebo and was assessed hourly for a 4-hour period. Repeated measures regression analysis evaluated a change in the Respiratory Assessment Change Score (RACS). RESULTS: The 2 groups had similar baseline characteristics with Respiratory Disease Assessment Inventory of 9.4 +/- 2.3 in the dexamethasone group (n = 36) and 10.0 +/- 2.7 in the placebo group (n = 34). The RACS was -5.0 +/- 3.1 in the dexamethasone group and -3.2 +/- 3.7 in the placebo group (P =.029). Poor RACS occurred in 41% and 17% of the placebo and dexamethasone groups, respectively (P =.034). Of the children treated with dexamethasone, 19% were hospitalized compared with 44% in the placebo group (P =.039). There was no difference in RACS between the groups on day 7 (P =.75). CONCLUSION: Outpatients with moderate-to-severe acute bronchiolitis derive significant clinical and hospitalization benefit from oral dexamethasone treatment in the initial 4 hours of therapy.

Acute Disease↗
PubMed2002

Evaluation of bronchial constriction in children with cystic fibrosis after inhaling two different preparations of tobramycin.

OBJECTIVES: This randomized, double-blind, cross-over study evaluated the risk of bronchoconstriction with two preparations of inhaled tobramycin in children with cystic fibrosis (CF) infected with Pseudomonas aeruginosa with and without airway hyperreactivity. DESIGN: Of 19 children with CF (age range, 7 to 16 years) with mild-to-moderate pulmonary disease, 10 children were at high risk (HR) for bronchospasm (family history of asthma and previous response to bronchodilators) and 9 children were at low risk (LR) for bronchospasm (no family history of asthma or previous response to bronchodilators). Two solutions of tobramycin were administered: (1) 80 mg in a 2-mL vial diluted with 2 mL of saline solution containing the preservatives phenol and bisulfites (IV preparation); and (2) 300 mg in a preservative-free preparation in a 5-mL solution. Following a bronchodilator-free period of 12 h, the patients inhaled either one or the other preparation in random order on two different occasions, 2 weeks apart. RESULTS: Prechallenge and postchallenge results for the LR group showed a percentage of fall in FEV(1) (DeltaFEV(1)) of 12 +/- 9% (mean +/- SD) for the IV preparation, compared to 4 +/- 5% for the preservative-free preparation (p = 0.046). An DeltaFEV(1) of > 10% was seen in six of nine patients for the IV preparation and in one of nine patients for preservative-free preparation. For the HR group, the DeltaFEV(1) was 17 +/- 13% for the IV-preparation group, compared to 16 +/- 12% for the preservative-free group (p = 0.4). In this group, equal numbers of patients (8 of 10 patients) had an DeltaFEV(1) > 10% after inhaling each preparation. The largest DeltaFEV(1) was 44% (HR group with the preservative-free preparation that forced the early termination of inhalation). CONCLUSIONS: Both preparations caused significant bronchoconstriction in the HR group, and the preservative-containing IV preparation caused more bronchospasm in LR group than the preservative-free solution. Heightened airway reactivity in children with CF places them at risk of bronchospasm from inhalation therapy.

Administration, Inhalation↗