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Biomedical subjects

Paul Aurora

Publications and source records attributed to Paul Aurora.

9 recordsLinked to original sources
PubMed2006

Multiple-breath washout in preschool children--FRC and ventilation inhomogeneity.

The open-circuit multiple-breath inert gas washout method is used to measure functional residual capacity and also to quantify ventilation distribution. The technique is readily applicable in preschool children as it requires quiet tidal breathing. Guidelines for data collection and interpretation in this age group will shortly be published by the European Respiratory Society and the American Thoracic Society.

Breath Tests↗
PubMed2005

Spirometry in the pre-school age group.

Spirometry is a widely used lung-function test in school-aged children and adults. It can also be used to test lung function in the pre-school population, provided that they are tested in a child-friendly setting, by experienced paediatric-orientated personnel and in a way that is congruent with their development. Accurate results can be obtained provided care and attention are paid to applying quality-control criteria suitable for this age group. The biggest challenge is to make the testing fun.

Child, Preschool↗
PubMed2005

Gas mixing efficiency from birth to adulthood measured by multiple-breath washout.

Efficient mixing of inspired gas with the resident gas of the lung is an essential requirement of effective respiration. This review focuses on one method for quantifying ventilation inhomogeneity: the multiple-breath inert gas washout (MBW). MBW has been employed as a research tool in adults and school age children for more than 50 years. Modifications allowing data collection in infants and preschoolers have been described recently. Indices of overall ventilation inhomogeneity, such as the lung clearance index and moment ratios, are raised in many infants with lung disease of prematurity, and in young children with cystic fibrosis. These indices may be more sensitive than other lung function measures for the early detection of airway disease. We describe, for the first time, a development of the MBW analysis that allows calculation of acinar and conductive zone inhomogeneity indices in spontaneously breathing children. Although methodological and analytical issues remain, the future clinical and research applications of MBW justify accelerated research in this field.

Age Factors↗
PubMed2005

Monitoring of Epstein-Barr viral load in pediatric heart and lung transplant recipients by real-time polymerase chain reaction.

BACKGROUND: Elevation in Epstein-Barr virus (EBV) load measured in peripheral blood has been proposed as a marker for development of post-transplant lymphoproliferative disease (PTLD), but there are few published data examining this relationship. We report the longitudinal surveillance of EBV for all recipients of heart (HTx), heart-lung (HLTx) and lung (LTx) transplants at our institution. METHODS: The study population included all patients transplanted between January 2003 and July 2004. EBV load was serially measured in peripheral blood by real-time polymerase chain reaction (PCR). Results were correlated with recipient pre-transplant EBV status and development of PTLD. RESULTS: Forty-four transplant operations were performed, including 33 HTx, 6 HLTx and 5 LTx. Thirty-two (73%) of the patients were EBV seropositive pre-transplant. Nineteen (44%) pediatric recipients developed EB viremia, including 17 HTx, 1 HLTx and 1 LTx. Eleven (58%) of these patients were EBV seropositive pre-transplant. EBV was first detected at a median of 30.5 days (range 2 to 81) post-transplant. The median peak EBV load in that group was 10,099 copies/ml (range 5,935 to 255,466) whole blood. One patient with cystic fibrosis post-LTx developed PTLD localized in the colon. This patient was EBV seronegative pre-transplant; peak EBV load was 14,513 copies/ml. Acute infectious mononucleosis was seen in 1 case. Positive pre-transplant EBV status did not predict post-transplant EB viremia (positive predictive value 0.03). CONCLUSIONS: Contrary to earlier reports, our data demonstrate that a high EBV load does not lead to PTLD early post-transplant. These results do not support the practice of pre-emptively reducing immunosuppression in patients with raised EBV load.

Adolescent↗
PubMed2005

High prevalence of gastroesophageal reflux in children after lung transplantation.

Bronchiolitis obliterans and its clinical correlate bronchiolitis obliterans syndrome (BOS) are a major cause of morbidity and mortality following lung transplantation. Gastroesophageal reflux disease (GERD) may be a contributing factor for the development of BOS. Since 2002, all recipients of lung and heart-lung transplantation at our institution have been routinely investigated for GERD. In this observational study, we report on the prevalence of GERD in this population, including all pediatric patients undergoing single (SLTx) or double (DLTx) lung transplantation or heart-lung (HLTx) transplantation from January 2003-May 2004. GERD was assessed 3-6 months after transplantation by 24-hr pH testing. The fraction time (Ft) with a pH < 4 within a 24-hr period was recorded. Spirometry data, episodes of confirmed acute rejection, and demographic data were also collected. Ten transplant operations were performed: 4 DLTx, 1 SLTx, and 5 HLTx. Nine patients had cystic fibrosis. One patient had end-stage pulmonary disease secondary to chronic aspiration pneumonia and postadenovirus lung damage. Of 10 patients tested, 2 had severe GERD (Ft > 20%), 5 had moderate GERD (Ft 10-20%), 2 had mild GERD (Ft 5-10%), and 1 had no GERD. The only patient in this group with no GERD had a Nissen fundoplication pretransplant. All study patients were asymptomatic for GERD. All patients with episodes of rejection had moderate to severe GERD posttransplant. There was no association between severity of GERD and peak spirometry results posttransplant. Moderate to severe GERD is common following lung transplantation in children.

Adolescent↗
PubMed2004

Multiple-breath washout as a marker of lung disease in preschool children with cystic fibrosis.

Sensitive measures of lung function applicable to young subjects are needed to detect early cystic fibrosis (CF) lung disease. Forty children with CF aged 2 to 5 years and 37 age-matched healthy control subjects performed multiple-breath inert gas washout, plethysmography, and spirometry. Thirty children in each group successfully completed all measures, with success on first visit being between 68 and 86% for all three measures. Children with CF had significantly higher lung clearance index (mean [95% CI] difference for CF control 2.7 [1.9, 3.6], p < 0.001) and specific airway resistance (1.65 z-scores [0.96, 2.33], p < 0.001), and significantly lower forced expired volume in 0.5 seconds (-0.49 z-scores [-0.95, -0.03], p < 0.05). Abnormal lung function results were identified in 22 (73%) of 30 children with CF by multiple-breath washout, compared with 14 (47%) of 30 by plethysmography, and 4 (13%) of 30 by spirometry. Children with CF who were infected with Pseudomonas aeruginosa had significantly higher lung clearance index, but no significant difference in other lung function measures, when compared with noninfected children. Most preschool children can perform multiple-breath washout, plethysmography, and spirometry at first attempt. Multiple-breath washout detects abnormal lung function in children with CF more readily than plethysmography or spirometry.

Age Factors↗
PubMed2004

Quality control for spirometry in preschool children with and without lung disease.

The reliability of spirometry is dependent on strict quality control. We examined whether quality control criteria recommended for adults could be applied to children aged 2-5 years. Forty-two children with cystic fibrosis and 37 healthy children attempted spirometry during their first visit to our laboratory. Whereas 59 children (75%) were able to produce a technically satisfactory forced expiration lasting 0.5 second, only 46 (58%) could produce an expiration lasting 1 second, with the youngest children having the most difficulty. Start of test criteria for adults were inappropriate for this age group, with only 16 of 59 children producing a volume of back extrapolation as a proportion of forced vital capacity of less than 5%, whereas all but 4 could produce a volume of back extrapolation of 80 ml or less. More than 90% of children were able to produce a second forced vital capacity and a second forced expired volume in 0.75 second within 10% of their highest. Errors in the spirometry software resulted in inaccurate reporting of expiratory duration and inappropriate timed expired volumes in some children. We describe recommendations for modified start of test and repeatability criteria for this age group, and for improvements in software to facilitate better quality control.

Case-Control Studies↗
PubMed2003

Variability in standard care for cytomegalovirus prevention and detection in pediatric lung transplantation: survey of eight pediatric lung transplant programs.

Cytomegalovirus (CMV) infection after pediatric lung transplantation is a significant risk factor for morbidity and mortality in the first year after transplantation. Multiple strategies have been reported for CMV prevention among adult lung transplant programs. In contrast, little information has been reported regarding protocols for prevention and detection of CMV from pediatric programs. We conducted a survey to better understand the range of practice patterns for CMV prevention and detection at pediatric lung transplant centers. A self-administered questionnaire was distributed to 11 pediatric lung transplant centers identified through the International Pediatric Lung Transplant Collaborative in September 2002. A member of the lung transplant team from each institution was asked to provide the methods of CMV prevention and surveillance. Eight of 11 centers surveyed responded to the questionnaire accounting for 45.6% (26 of 57) and 100% (three of three) of the pediatric lung transplants performed in the US and UK in 2001, respectively. All centers used prophylactic therapy against CMV with either ganciclovir or valganciclovir with duration ranging from 3.5 wk to indefinitely. Most centers (six of eight) prescribed a prophylactic regimen based on donor and recipient CMV serostatus. Half (four of eight) of the centers report using CMV hyperimmune globulin in addition to an antiviral agent. Method for CMV detection varied widely, including use of conventional viral culture (n = 1), antigenemia (n = 7), and polymerase chain reaction (n = 2). A wide range of strategies is used to prevent and detect CMV in pediatric lung transplant recipients with little empiric evidence demonstrating the optimal approach. A retrospective analysis among these centers is being conducted to evaluate the efficacy of these approaches.

Antiviral Agents↗