Biomedical subjects

Allan L Coates

Publications and source records attributed to Allan L Coates.

21 records · Page 2Linked to original sources

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↗