Impaired cerebral autoregulation and elevation in plasma glial fibrillary acidic protein level during cardiopulmonary bypass surgery for CHD.

BACKGROUND: Cerebrovascular reactivity monitoring has been used to identify the lower limit of pressure autoregulation in adult patients with brain injury. We hypothesise that impaired cerebrovascular reactivity and time spent below the lower limit of autoregulation during cardiopulmonary bypass will result in hypoperfusion injuries to the brain detectable by elevation in serum glial fibrillary acidic protein level. METHODS: We designed a multicentre observational pilot study combining concurrent cerebrovascular reactivity and biomarker monitoring during cardiopulmonary bypass. All children undergoing bypass for CHD were eligible. Autoregulation was monitored with the haemoglobin volume index, a moving correlation coefficient between the mean arterial blood pressure and the near-infrared spectroscopy-based trend of cerebral blood volume. Both haemoglobin volume index and glial fibrillary acidic protein data were analysed by phases of bypass. Each patient's autoregulation curve was analysed to identify the lower limit of autoregulation and optimal arterial blood pressure. RESULTS: A total of 57 children had autoregulation and biomarker data for all phases of bypass. The mean baseline haemoglobin volume index was 0.084. Haemoglobin volume index increased with lowering of pressure with 82% demonstrating a lower limit of autoregulation (41±9 mmHg), whereas 100% demonstrated optimal blood pressure (48±11 mmHg). There was a significant association between an individual's peak autoregulation and biomarker values (p=0.01). CONCLUSIONS: Individual, dynamic non-invasive cerebrovascular reactivity monitoring demonstrated transient periods of impairment related to possible silent brain injury. The association between an impaired autoregulation burden and elevation in the serum brain biomarker may identify brain perfusion risk that could result in injury.

Trajectories of adherence to airway clearance therapy for patients with cystic fibrosis.

OBJECTIVE: Although cross-sectional studies have demonstrated poor adherence to airway clearance therapy (ACT) for patients with cystic fibrosis (CF), no studies have identified longitudinal patterns of adherence. The objective was to characterize and identify predictors of ACT adherence trajectories for individuals with CF. METHODS: Secondary data analyses were conducted for a randomized clinical trial examining differences in three ACTs. Participants (n = 153; M = 14.3 years, 55% male, 86% Caucasian, baseline FEV(1)% predicted: M = 86.7)/primary caregivers completed Daily Phone Diaries, an empirically supported adherence measure, every 4 months. RESULTS: Group-based trajectory modeling revealed the best-fitting solution was a three-group model: low-adherence (14%), medium-adherence (49%), and high-adherence (37%) groups. ACT type was the only significant predictor of adherence trajectories. DISCUSSION: Three trajectories of adherence to ACT for patients with CF were found. With the identification of trajectories, adherence interventions can be targeted for the subgroup at highest risk in order to prevent poor health outcomes.

Adherence to treatment among children with cardiac disease.

OBJECTIVE: Our purpose was to review the literature with respect to issues of adherence to treatment among children with congenital and acquired cardiac disease. MATERIALS AND METHODS: Databases used for this review included MEDLINE, Pub Med's Single Citation Manager, Cochrane Library, Cochrane Central Register of Controlled Trials, Scopus, and Google Scholar. We did not use any restrictions on date when locating peer-reviewed articles published worldwide through December of 2008. RESULTS: There exists a lack of published research regarding adherence to medical treatment for children with cardiac conditions. Of the few published studies, rates of adherence for children with congenital and acquired cardiac disease ranged from a high of 96% for an in-patient exercise programme, to a low of 33% among those who made all of their medical appointments. Risk factors for nonadherence included older age, one as opposed to two parents in the home, lack of emotional availability of parents, smoking, sedentary lifestyle, use of illicit drugs, presence of tattoos, and multiple body piercings. Clinical outcomes associated with non adherence in the population of children undergoing transplantation included mortality, acute episodes of rejection, lower levels of Cyclosporine A, and lower values for the International Normalised Ratio of prothrombin. CONCLUSIONS: For children with congenital and acquired heart disease, the challenges of adherence to treatment can often be overwhelming. Recommendations designed to maximize the impact and scientific rigour of future studies include obtaining quantitative and qualitative measures of adherence, identifying primary and secondary endpoints, emphasizing factors of interest, planning studies with sufficient power to impact on the adherence to treatment, and developing epidemiologic foundations.