Effect of Obstructive Sleep Apnea Treatment on Renal Function in Patients with Cardiovascular Disease.

RATIONALE: Obstructive sleep apnea (OSA) is associated with impaired renal function, but uncertainty exists over whether OSA treatment can influence renal outcomes. OBJECTIVES: To determine the effects of continuous positive airway pressure (CPAP) on renal function in subjects with coexisting OSA and cardiovascular disease. METHODS: This was a substudy of the international SAVE (Sleep Apnea Cardiovascular Endpoints) trial, in which 2,717 patients with moderate to severe OSA and established coronary or cerebrovascular disease were randomized to receive either CPAP plus usual care or usual care alone. Renal function and adverse renal events were compared between the CPAP (n = 102) and usual care (n = 98) groups. Glomerular filtration rate was estimated at randomization and at the end of follow-up, and the urinary albumin-to-creatinine ratio was measured at study exit. MEASUREMENTS AND MAIN RESULTS: In 200 substudy participants (mean age, 64 yr; median, 4% oxygen desaturation index; 20 events/h; mean estimated glomerular filtration rate at baseline, 82 ml/min/1.73 m2), the median (interquartile range) changes in estimated glomerular filtration rate (ml/min/1.73 m2/yr) were -1.64 (-3.45 to -0.740) in the CPAP group and -2.30 (-4.53 to -0.71) in the usual care group (P = 0.21) after a median of 4.4 years. There were no between-group differences in end-of-study urinary albumin-to-creatinine ratio or in the occurrence of serious renal or urinary adverse events during the trial. The level of CPAP adherence did not influence the findings. CONCLUSIONS: CPAP treatment of OSA in patients with cardiovascular disease does not alter renal function or the occurrence of renal adverse events. Clinical trial registered with www.clinicaltrials.gov (NCT00738179).

Use of respiratory function tests to predict survival in amyotrophic lateral sclerosis.

Respiratory function tests (RFTs) are commonly used as a measure of progression in ALS. This study assessed the ability of various RFTs to predict survival in ALS patients. Subjects with ALS had one or more measurements of seated and supine FVC, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). Kaplan-Meier (KM) analysis was used to determine whether patients with abnormal RFTs had shorter survival than those with normal RFTs. The sensitivity and specificity of RFTs as predictors of two-year survival were calculated from receiver operating characteristic (ROC) curves. With KM analysis, subjects with abnormal values of seated FVC, supine FVC, MIP and MEP had significantly reduced survival compared to subjects with normal values. With ROC curves, a normal supine FVC was highly predictive for two-year survival and had superior sensitivity over seated FVC. Slower rates of decline in seated or supine FVC were strong predictors of two-year survival. Our study demonstrates that respiratory function measurements are useful to predict survival in ALS patients. We show that measurements of FVC in the supine position are worth including in the assessment of respiratory function in ALS.

Confirmatory factor analysis of the Epworth Sleepiness Scale (ESS) in patients with obstructive sleep apnoea.

BACKGROUND: The Epworth Sleepiness Scale (ESS [Johns MW. A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep 1991;14(6):540-5]) has been used frequently to assess daytime sleepiness, particularly in the context of clinical sleep disorders. Its psychometric properties are still unclear, particularly when used to evaluate sleep propensity in patients with obstructive sleep apnoea. METHODS: The present study used confirmatory factor analysis (CFA) to investigate a potential single-factor structure of the ESS in a sample of 759 Australian patients with a diagnosis of obstructive sleep apnoea by the treating physicians. RESULTS: CFA results from showed that the original single-factor structure proposed by Johns [Johns MW. Reliability and factor analysis of the Epworth Sleepiness Scale. Sleep 1992;15(4):376-81] did not adequately fit the data. A re-specified single-factor solution provided a good fit for data, and this improved fit was confirmed on a second CFA. CONCLUSIONS: The findings suggest that standard scoring of the ESS should be interpreted cautiously for patients with obstructive sleep apnoea.

Developing a successful treatment for co-morbid insomnia and sleep apnoea.

Insomnia and sleep apnoea are the two most common sleep disorders, found in 6% and 23-50% of the general population respectively. These disorders also frequently co-occur, with 39-58% of sleep apnoea patients reporting symptoms indicative of co-morbid insomnia. When these disorders co-occur, clinicians are faced with difficult treatment decisions, patients experience the additive detrimental impacts of both disorders, and the effectiveness of discrete treatments for each disorder may be impaired. A common finding is that co-morbid insomnia and sleep apnoea (COMISA) is more difficult to treat than either disorder presenting alone. Co-morbid insomnia reduces the initial acceptance of, and later adherence to, continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea. This has resulted in recent recommendations that treatment approaches should initially target COMISA patients' insomnia to remove this barrier to CPAP treatment, and improve patient outcomes. However, no randomised controlled trial outcomes investigating this treatment approach currently exist. The current article aims to review and integrate recent research examining the prevalence, characteristics, and theoretical mechanistic relationships between co-occurring insomnia and OSA, and discuss previous treatment attempts.

Sleep assessment of hospitalised patients: a literature review.

BACKGROUND: Sleep is a dynamic and essential part of human life and health. In healthcare settings, nurses are strategically placed to promote sleep and sleep health. In this regard, nursing actions should be based upon effective methods of assessment of patient sleep. Standardised sleep assessment does not currently occur in the care of acute hospitalised patients. Use of an appropriate measurement tool would help evaluate inpatient sleep. An effective, efficient sleep assessment tool is needed to aid clinicians. Such assessment would enable specific nursing intervention to be tailored to individual patients. OBJECTIVE: The objective of this paper was to examine the literature on sleep measurement to identify subjective sleep assessment tools that may be suitable for routine use with hospitalised patients, and to evaluate their reliability and validity. METHOD: A review of existing literature was undertaken to identify and evaluate subjective sleep measurement tools. RESULTS: The initial literature searches identified 402 articles, of which ten met the criteria for review. These reported on three subjective sleep measurement scales: the Richards-Campbell Sleep Questionnaire; the St Mary's Hospital Sleep Questionnaire; and the Verran Snyder-Halpern Sleep Scale. The Richards-Campbell Sleep Questionnaire is brief and easy to use. In specific samples, its items correlate with domains reflecting sleep quality and has shown excellent internal consistency. Equivocal results and scoring challenges were found with the St Mary's Hospital Sleep Questionnaire. The Verran Snyder-Halpern Sleep Scale captured sleep disturbance and total sleep time, but time-to-complete is more burdensome than the Richards-Campbell Sleep Questionnaire. CONCLUSIONS: The current use of sleep assessment instruments in the acute hospital setting is restricted mainly to research activities. Of the three tools identified that could be used clinically to measure inpatient sleep, and although it was developed for use in the intensive care setting, the Richards-Campbell Sleep Questionnaire held greatest potential due to its ease and rapidity of use. However, it has yet to be validated for use with general hospital inpatients, and further research is required in this area.

Seasonal variation of biomass and bioactive alkaloid content of goldenseal, Hydrastis canadensis.

Seasonal variations in biomass and alkaloid contents of goldenseal (Hydrastis canadensis) were investigated. Five-year-old plants gave 5x the yield of roots and rhizomes of two-year-old plants, and summer growth gave significant increases in root biomass but not rhizomes. Berberine contents of roots plus rhizomes did not vary significantly and were >3.4% in all samples. Hydrastine contents of 5 y roots plus rhizomes showed significant seasonal variation. These variations were due to significant changes in the hydrastine contents of the roots (1.3-1.9%), but not the rhizomes (2.2-2.8%). Goldenseal leaves plus stems had lower contents of hydrastine (0.4-0.8%) and berberine (1.0-1.5%).

Intention to exercise in patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a common and serious health issue that is strongly associated with excess weight. Exercise may be an effective mechanism for reducing the severity of OSA both in association with, and independent of, reduction in body weight. As such, increased exercise has been suggested as a potential intervention for OSA, particularly for patients with mild to moderate clinical severity. However, it is unknown how ready to engage in exercise patients with OSA are. Self-reported exercise intention was assessed in 206 consecutive patients attending a large tertiary sleep disorders service in Australia. Classification of the patients by Stage of Change, a construct of the Transtheoretical Model of behavior change, was supported by differences between the groups in level of habitual self-reported exercise. Cluster analysis identified 4 potential patient types, with differing profiles in perceived costs and benefits of exercise, and exercise-related self-efficacy. The validity of these patient clusters was also supported by differences between the groups in current self-reported exercise levels. The results may help to identify patients who are more likely to engage in increased exercise, and to identify barriers to exercise in patients less inclined to increase their exercise.

Clinical presentation of metabolic alkalosis in an adult patient with cystic fibrosis.

In subtropical and tropical climates, dehydration is common in cystic fibrosis patients with respiratory exacerbations. This may lead to a clinical presentation of metabolic alkalosis with associated hyponatraemia and hypochloraemia. An adult cystic fibrosis patient who presented with a severe respiratory exacerbation accompanied by metabolic alkalosis is presented and the effects of volume correction are reported.

A new glucosyl feruloyl quinic acid as a potential marker for roots and rhizomes of goldenseal, Hydrastis canadensis.

A new compound, 5-O-(4'-[beta-d-glucopyranosyl]-trans-feruloyl)quinic acid (GPFQ, 10), is reported from the medicinal plant goldenseal (Hydrastis canadensis). A new HPLC method is described and used to show that GPFQ is a potential marker for goldenseal roots (1.0% w/w) and rhizomes (2.3%). GPFQ was found at much lower levels in stems (<0.1%) and could not be detected in leaves. Neochlorogenic acid (9), which has not previously been reported from goldenseal, and chlorogenic acid (6) reached their highest levels in leaves (0.9% 9 and 0.5% 6). The main alkaloids, hydrastine (1) and berberine (2), were highest in rhizomes (2.8% 1 and 4.6% 2), but palmatine (5) was not found in genuine goldenseal.

Sesquiterpene lactones in Arnica montana: a rapid analytical method and the effects of flower maturity and simulated mechanical harvesting on quality and yield.

A rapid extraction, clean-up and RPLC procedure suitable for routine quantitative analyses of sesquiterpene lactones (SLs) in Arnica montana is described. Seven SLs were isolated of which tigloyl and methacryloyl esters of helenalin made up over 50 % of the total. This method was applied to analyses of replicated samples of different flower parts, different stages of flower maturity, and herb from different harvest methods. The mean total SL levels were higher in the disk flowers (0.872 % w/w) than the ray flowers (0.712 %), lower in the flower receptacles (0.354 %) and lowest in stems (0.028 %). Relative levels of individual SLs varied significantly between flower parts, especially acetyldihydrohelenalin which had its highest concentration in stems. The total SL contents increased progressively as the flowers matured, from 0.512 % in buds to 0.943 % in withered flowers. Harvesting a range of flower maturities at one time in a simulated mechanical harvest, followed by mechanical separation of low quality stem material gave the same quality as hand harvested A. montana flowers (over 0.8 % total SLs) and the flower yields from the two processes were similar when adjusted for harvesting technique (320 kg dry matter/ha by hand, 295 kg/ha mechanical). Delaying flower harvest until the flower petals had withered greatly improved the SL concentration of the drug.