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Ian Mitchell

Publications and source records attributed to Ian Mitchell.

12 recordsLinked to original sources
PubMed2006

Spinal muscular atrophy type 1: what are the ethics and practicality of respiratory support?

Spinal Muscular Atrophy Type I (SMA I) is the most severe form of SMA. It presents in infancy and without treatment death occurs by 2 years. Treatments in use address respiratory and nutritional issues but even with aggressive treatment death is still likely in childhood. Thus their use is not obligatory. However, pediatric respirologists must be willing and comfortable at presenting all treatment options, including the option of palliative care, to families and then supporting the family's choice. Whatever the chosen treatment regimen, decision making is difficult for families. Support and help must be provided from the time of presentation till death by a knowledgeable and compassionate team.

Child↗
PubMed2006

Beyond randomized controlled trials: a "real life" experience of respiratory syncytial virus infection prevention in infancy with and without palivizumab.

A population-based study of the impact of palivizumab on confirmed Respiratory Syncytial Virus (RSV) hospitalizations over a 7-year period within and between two similar health regions . Clinicians in Calgary implemented palivizumab prophylaxis for high-risk infants during the last four RSV seasons; clinicians in Edmonton did not. The two cities are part of a unified health care system and similar sociodemographics. Infants <36 weeks (wk) of gestational age (GA) were identified. RSV prophylaxis data and RSV-hospitalizations for high-risk infants eligible for prophylaxis were reviewed, as well as that of moderate-risk infants (33-35 weeks GA) for whom RSV prophylaxis was not given a high priority in the recommendations published by the Canadian Paediatric Society (CPS). Prevalence of RSV hospitalization before and after palivizumab was determined (1995-1998 and 1999-2002, respectively). There were 411 high-risk infants eligible for palivizumab prior to its provision (Pre) and 496 during the prophylaxis program (Post) in Calgary. There were 401 Pre and 425 Post in Edmonton, where no such prophylaxis program was implemented. In Calgary where palivizumab was offered (Post), RSV hospitalization was significantly reduced: 7.3% Pre versus 3.0% Post (OR, 2.53, 95% CI, 1.34, 4.76). No reduction was observed in Edmonton where palivizumab was not offered: 5.0% Pre versus 7.1% Post (OR, 1.45, 95% CI, 0.81, 2.59; P = 0.212). RSV hospitalizations did not change for moderate-risk infants not receiving palivizumab in Calgary (OR, 1.26, 95% CI, 0.75, 2.12; P = 0.389). An RSV prevention program with palivizumab for high-risk infants reduced RSV hospitalizations, providing "real life" evidence of the benefits of this prophylaxis strategy. Further research is required to determine if specific sub-sets of moderate-risk infants would also benefit from an RSV prophylaxis program with palivizumab.

Alberta↗
PubMed2006

Patients' opinions on privacy, consent and the disclosure of health information for medical research.

A structured survey of patients in three illness groups (acquired immune deficiency syndrome, multiple sclerosis and mental disorders) was undertaken to describe patients' perspectives on privacy, consent and the use of their health information for medical research. The survey was distributed by mail to subjects in the AIDS and MS groups and was completed in a clinic waiting room by people in the mental disorders group. Of the 478 patients approached for participation, 235 returned completed surveys (response rate 49.2 percent). Most subjects were concerned about privacy and they valued opportunities to provide consent for the use of their personal health information for research. Contextual factors, such as identification, type of illness and who was conducting the research, were important to individuals' preferences in granting consent. When health information was used specifically for research, the majority of subjects wanted to be asked for their consent unless anonymity was assured. Privacy and control over personal health information were important to patients in these groups. Patients prefer to be asked for research access to their health information.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Colorectal cancer metastasis: in the surgeon's hands?

BACKGROUND: Lymphovascular ligation before tumour manipulation during colorectal cancer resection is termed the 'no-touch isolation' technique. It aims to reduce the intra-operative dissemination of colorectal cancer cells. Recently, the detection of circulating tumour cells has been enhanced by molecular biology techniques. This paper reviews the evidence for the no-touch isolation technique in light of the recent developments in circulating tumour cell detection. METHODS: Studies investigating the effect of colorectal cancer surgery on circulating tumour cells were identified by a Medline search using the subject headings colorectal neoplasms and neoplasm circulating cells together with the map term 'no-touch isolation technique'. Further references were obtained from key articles. RESULTS: Molecular biological techniques have improved the detection of circulating colorectal cancer cells. There is a trend towards reduced tumour cell dissemination with the no-touch technique compared with the conventional method. However the benefit in terms of improved patient survival remains unproven. CONCLUSION: The no-touch isolation technique reduces circulating tumour cell dissemination but further work is needed to determine the significance of this with regards to patient survival.

Journal Article↗
PubMed2004

The Pediatric Investigators Collaborative Network on Infections in Canada study of predictors of hospitalization for respiratory syncytial virus infection for infants born at 33 through 35 completed weeks of gestation.

BACKGROUND: Infants born at 33 through 35 completed weeks of gestation (33-35GA) are at risk for severe respiratory syncytial virus (RSV) infection, and palivizumab prophylaxis lowers hospitalizations for RSV infection by as much as 80%. The 33-35GA cohort comprises 3-5% of annual births; thus expert panels recommend limiting prophylaxis to situations in which frequency or health care impact of RSV infection is high. This study sought to identify independent risk factors for hospitalization for RSV infection. METHODS: This was a multicenter, prospective, observational cohort study of 33-35GA infants followed through their first RSV season (2001/2002 or 2002/2003). Baseline data were collected by interview with parents and review of medical records. Respiratory tract illnesses were identified by monthly phone calls, and medical records were reviewed for emergency room visits or hospitalizations. Risk factors were determined by stepwise logistic regression. RESULTS: Of 1,860 enrolled subjects, 1,832 (98.5%) were followed for at least 1 month, and 1,760 (94.6%) completed all follow-ups. Of 140 (7.6%) subjects hospitalized for respiratory tract illnesses, 66 infants had proven RSV infection. Independent predictors for hospitalization for RSV infection were: day-care attendance (odds ratio, 12.32; 95% confidence interval, 2.56, 59.34); November through January birth (odds ratio, 4.89; 95% confidence interval, 2.57, 9.29); preschool age sibling(s) (odds ratio, 2.76; 95% confidence interval, 1.51, 5.03); birth weight <10th percentile (odds ratio, 2.19; 95% confidence interval, 1.14, 4.22); male gender (odds ratio, 1.91; 95% confidence interval, 1.10, 3.31); > or = 2 smokers in the home (odds ratio, 1.87; 95% confidence interval, 1.07, 3.26); and households with >5 people, counting the subject (odds ratio, 1.79; 95% confidence interval, 1.02, 3.16). Family history of eczema (odds ratio, 0.42; 95% confidence interval, 0.18, 0.996) was protective. CONCLUSIONS: Specific host/environmental factors can be used to identify which 33-35GA infants are at greatest risk of hospitalization for RSV infection and likely to benefit from palivizumab prophylaxis.

Antibodies, Monoclonal↗
PubMed2003

Evaluation of the safety of palivizumab in the second season of exposure in young children at risk for severe respiratory syncytial virus infection.

BACKGROUND: Palivizumab reduces respiratory syncytial virus (RSV) hospitalisations in high-risk infants. Those with severe bronchopulmonary dysplasia may require two seasons of prophylaxis. There is concern that this humanised antibody might cause an adverse immune response in a second season of use. OBJECTIVE: To evaluate and compare the occurrence of anti-palivizumab antibodies and clinical adverse events in subjects receiving monthly palivizumab injections for a first and second season, and to assess frequency and severity of RSV disease in the two groups. DESIGN AND PATIENTS: Subjects aged or=1 : 80). Serum palivizumab concentrations were similar for the two groups. Nine (12.7%) first season and 8 (12.7%) second season subjects experienced one or more serious adverse events; most were respiratory and all were considered to be not or probably not related to palivizumab. No deaths occurred during the study. CONCLUSIONS: Monthly palivizumab injections were not associated with adverse immune responses or adverse events in young children receiving palivizumab for one or two seasons. Children receiving palivizumab for a second season did not experience more severe adverse events than those receiving it for the first time.

Antibodies, Monoclonal↗
PubMed2002

Pseudomonas aeruginosa quorum-sensing systems may control virulence factor expression in the lungs of patients with cystic fibrosis.

Individuals with cystic fibrosis (CF) are commonly colonized with Pseudomonas aeruginosa. The chronic infections caused by P. aeruginosa are punctuated by acute exacerbations of the lung disease, which lead to significant morbidity and mortality. As regulators of virulence determinants, P. aeruginosa quorum-sensing systems may be active in the chronic lung infections associated with CF. We have examined the levels of autoinducer molecules and transcript accumulation from the bacterial populations found in the lungs of patients with CF. We detected biologically active levels of N-(3-oxododecanoyl)-L-homoserine (3-oxo-C12-HSL) and N-butyryl-L-homoserine lactone (C4-HSL) in sputum from CF patients. Interestingly, it appears that C4-HSL is less frequently detected than 3-oxo-C12-HSL in the lungs of patients with CF. We also examined the transcription of the autoinducer synthase gene lasI and showed that it is frequently expressed in the lungs of patients with CF. We observed a significant correlation between the expression of lasI and four target genes of the Las quorum-sensing system. Taken together, our results indicate that quorum-sensing systems are active and may control virulence factor expression in the lungs of patients with CF.

Bacterial Proteins↗
PubMed2002

Near-fatal asthma: a population-based study of risk factors.

BACKGROUND: The study of near-fatal asthma (NFA) may provide a means to further our understanding of fatal asthma. Studies of NFA often are derived from a single ICU rather than from a defined population. We therefore aimed to identify factors distinguishing NFA patients (cases) from those persons treated in an emergency department (ED) [ED control subjects] and in the community (community control subjects [CCs]). METHODS: This was a population-based case-control study conducted over 20 months of 45 NFA patients (age range, 5 to 50 years), 197 ED control subjects treated in an ED, and 303 CCs, all of whom were residents of Alberta. RESULTS: The age distribution was similar between NFA patients and control subjects, with the majority being < 22 years of age (NFA patients, 68.9%; ED control subjects, 71.3%; CCs, 60.7%). Those patients with NFA were significantly more likely to have received a diagnosis before 5 years of age (66.6%), compared to ED control subjects (39.6%) and CCs (28.7%). The NFA group was significantly more likely to report moderate-to-severe disease and more frequent symptoms than the other groups. Therapy with bronchodilators was used most frequently by the NFA group compared to the ED control subjects and CCs (p < 0.001), as was therapy with inhaled steroids (p < 0.001) and oral steroids (p < 0.001). NFA patients had higher scores for vulnerability and were most likely to admit to stress as an asthma trigger. All groups had high exposure to cigarette smoke and pets. CONCLUSION: NFA patients have many modifiable risk factors and many similarities to ED control subjects and CCs with asthma. General measures to improve asthma control and awareness of risks are required in all groups.

Adolescent↗
PubMed2002

Differences in admission rates of children with bronchiolitis by pediatric and general emergency departments.

OBJECTIVE: It is uncertain whether pediatric and general emergency departments have different admitting practices regarding children with bronchiolitis. The objective of this study was to quantify the differences in admission practices between pediatric and general emergency departments of children with bronchiolitis in 1 North American metropolitan area, controlling for various factors such as clinical severity, comorbid conditions, and socioeconomic status. DESIGN: Retrospective cohort review of emergency department visits from April 1992 to March 1997. SETTING: Five emergency departments (1 pediatric and 4 general) serving the Calgary Health Region, which encompasses approximately 850 000 people. PATIENTS: All children residing within the region who visited a regional emergency department and were diagnosed to have bronchiolitis (International Classification of Diseases, Ninth Revision code 466.1, primary or secondary diagnosis). MAIN OUTCOME MEASURE: Population-standardized estimates of admission rates. RESULTS: The medical charts of 3091 children diagnosed to have bronchiolitis during the study period were reviewed. Of this number, 2496 children were evaluated at the pediatric emergency department, and 629 (25%) were admitted. The remaining 595 (19%) were evaluated at the general emergency departments, and 221 (37%) were admitted. Controlling for age, gender, estimated family income based on postal code, medical comorbidity, and clinical severity estimated by presenting respiratory rate and room air oxygen saturation, population-standardized estimates for admission rates at the pediatric and general emergency departments were 24% (standard error: 1%) and 43% (standard error: 2%), respectively. CONCLUSION: Children diagnosed to have bronchiolitis at the Calgary Health Region's pediatric emergency department were about half as likely to be admitted to the hospital as children diagnosed at the region's general emergency departments.

Alberta↗
PubMedDate not supplied

Asthma in adolescents: a randomized, controlled trial of an asthma program for adolescents and young adults with severe asthma.

BACKGROUND: Asthma is common and is often poorly controlled in adolescent subjects. OBJECTIVE: To determine the impact of an age-specific asthma program on asthma control, particularly on exacerbations of asthma requiring emergency department treatment, and on the quality of life of adolescents with asthma. METHODS: The present randomized, controlled trial included patients who were 15 to 20 years of age and had visited emergency departments for management of their asthma. The interventional group attended an age-specific asthma program that included assessment, education and management by a team of asthma educators, respiratory therapists and respiratory physicians. In the control group, spirometry was performed, and the patients continued to receive usual care from their regular physicians. The outcomes were assessed by a questionnaire six months after entry into the study. RESULTS: Ninety-three subjects entered the study and were randomly assigned to the intervention or control group. Of these, only 62 patients were available for review after six months. Subjects in both the control and the intervention groups showed a marked improvement in their level of asthma control, reflected primarily by a 73% reduction in the rate of emergency department attendance for asthma. Other indexes of disease control, including disease-specific quality of life, as assessed by questionnaires, were improved. There was, however, no discernible difference between the subjects in the two groups, with the exception of an improvement in favour of the intervention group in the symptom (actual difference 0.7, P=0.048) and emotional (actual difference 0.8, P=0.028) domains of the asthma quality of life questionnaire. The overall quality of life score favoured the intervention group by a clinically relevant difference of 0.6, but this difference did not reach statistical significance (P=0.06). CONCLUSIONS: Although all subjects demonstrated a significant improvement in asthma control and quality of life, the improvement attributable to this intervention was limited to two domains in disease-specific quality of life.

Adolescent↗