Steroids to reduce the impact on delirium (STRIDE): a double-blind, randomised, placebo-controlled feasibility trial of pre-operative dexamethasone in people with hip fracture.

Neuro-inflammation may be important in the pathogenesis of postoperative delirium following hip fracture surgery. Studies have suggested a potential role for steroids in reducing postoperative delirium; however, the potential efficacy and safety of pre-operative high-dose dexamethasone in this specific population is largely unknown. Conducting such a study could be challenging, considering the multidisciplinary team involvement and the emergency nature of the surgery. The aim of this study was to assess feasibility and effectiveness of dexamethasone given as early as possible following hospital admission for hip fracture, to inform whether a full-scale trial is warranted. This single-centre, randomised, double-blind, placebo-controlled study randomly allocated 79 participants undergoing hip fracture surgery to dexamethasone 20 mg or placebo pre-operatively. Eligibility and recruitment rates, timing of the intervention and adverse events were recorded. Incidence and severity of postoperative delirium were assessed using the 4AT delirium screening tool and the Memorial Delirium Assessment Scale. Postoperative pain, length of stay and mortality were also assessed. The eligibility rate for inclusion was 178/527 (34%), and 57/178 (32%) of eligible patients presented to hospital when no researcher was available (e.g. after-hours, weekends, public holidays). Recruitment was limited mainly by ethical limitations (not including patients with impaired cognition) and lack of weekend staffing. Median (IQR [range]) time from emergency department admission to drug administration was 13.3 (5.9-17.6 [1.8-139.6]) hours. There was a significant difference in delirium severity scores, favouring the dexamethasone group: median (IQR [range]) 5 (3-6 [3-7]) vs. 9 (6-13 [5-14]) in the placebo group, with the probability of superiority effect size being 0.89, p = 0.010. Delirium incidence did not differ between groups: 6/40 (15%) in the dexamethasone group vs. 9/39 (23%) in the placebo group, relative risk (95%CI) 0.65 (0.22-1.65), p = 0.360). A larger randomised controlled trial is feasible and ideally this should include people with existing cognitive impairment, seven days-a-week cover and a multicentre design.

Study protocol: older people in retirement villages. A survey and randomised trial of a multi-disciplinary invention designed to avoid adverse outcomes.

BACKGROUND: There is increasing interest among older people in moving into retirement villages (RVs), an attractive option for those seeking a supportive community as they age, while still maintaining independence. Currently in New Zealand there is limited knowledge of the medical, service supports, social status and needs of RV residents. The objective of this study is to explore RV facilities and services, the health and functional status of RV residents, prospectively study their healthcare trajectories and to implement a multidisciplinary team intervention to potentially decrease dependency and impact healthcare utilization. METHODS: All RVs located in two large district health boards in Auckland, New Zealand were eligible to participate. This three-year project comprised three phases: The survey phase provided a description of RVs, residents' characteristics and health and functional status. RV managers completed a survey of size, facilities and recreational and healthcare services provided in the village. Residents were surveyed to establish reasons for entry to the village and underwent a Gerontology Nurse Specialist (GNS) assessment providing details of demographics, social engagement, health and functional status. The cohort study phase examines residents' healthcare trajectories and adverse outcomes, over three years. The final phase is a randomised controlled trial of a multidisciplinary team intervention aimed to improve health outcomes for more vulnerable residents. Residents who triggered potential unmet health needs during the assessment in the survey phase were randomised to intervention or usual care groups. Multidisciplinary team meetings included the resident and support person, a geriatrician or gerontology nurse practitioner, GNS, pharmacist and General Practitioner. The primary outcome of the randomised controlled trial will be first acute hospitalization. Secondary outcomes include all acute hospitalizations, long-term care admissions, and all-cause mortality. DISCUSSION: This paper describes the study protocol of this complex study. The study aims to inform policies and practices around health care services for residents in retirement villages. The results of this trial are expected early 2020 with publication subsequently. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry: ACTRN12616000685415 . Registered 25.5.2016. Universal Trial Number (UTN): U111-1173-6083.

Diverticular disease epidemiology: acute hospitalisations are growing fastest in young men.

BACKGROUND: Older age has long been linked to risk of diverticulitis, but the epidemiology is seldom described for a national population. The aim of this study was to investigate age- and gender differences in incidence, temporal trends, lifetime risk and prevalence related to acute diverticulitis hospitalisations in New Zealand. METHODS: Records of all hospitalisations with diverticulitis the primary diagnosis were obtained from the Ministry of Health for the period 2000-2015. The first acute diverticulitis admission recorded for an individual was taken as an incident event; all others were classified as recurrent. Trends in age- and sex-specific and age-standardised incidence rates are described, and lifetime risk and prevalence estimated. RESULTS: Over the 16 years from 2000 to 2015, 37,234 acute hospitalisations for diverticulitis were recorded in 28,329 people aged 30 + years (median = 66 years). Rates of incident hospitalisations rose with age, from 5/10,000 person-years at age 50-54 years to 19/10,000py by age 80-84 years. Rates for women were lower than men before age 55 years, but higher thereafter. Age-standardised rates rose 0.2/10,000py annually, but approximately doubled among men aged < 50 years. Lifetime risk was estimated at over 5%, with the prevalence pool rising to over 1.5% of the population aged 30+ in 2030. CONCLUSIONS: Rapid increases in diverticulitis admissions among young men since 2000 correspond with increases reported elsewhere but remain unexplained; notably young women follow similar trends 5-10 years later. Increasing incidence, combined with population ageing, adds urgency to explain diverticular formation, to understand factors that trigger or provoke their inflammation/infection, and to clarify treatment and (self-)management pathways.

Modification to a testing assembly to enable strain-life measurements in pressurized hydrogen gas.

Strain-controlled fully reversed fatigue testing, or strain-life testing, provides critical information on material lifetime and damage response. Strain-life data in hydrogen gas environments is missing in the literature and could provide valuable insights into hydrogen effects on the mechanical response of metals such as steel. We adapted existing hydrogen-gas-environment mechanical-testing equipment, which had been designed only for tensile loads, to accommodate the large compressive loads needed to perform strain-life testing. The considerations of these adaptations are discussed. Successful strain-life testing data were acquired from a 4130 pressure vessel steel.

Sleep fragmentation and decreased REM sleep in a primate model of diurnal cortical seizures.

Many people with epilepsy suffer from comorbid sleep disorders and sleep fragmentation. While the disruptive nature of seizures on sleep is well documented, it is unclear how diurnal seizures impact sleep quality and for how long these changes persist during the following nights. To better understand this relationship, the sleep architecture of two rhesus macaques were studied before and several nights after penicillin-induced diurnal seizures. These focal seizures stopped naturally, and none occurred at night. We scored sleep-stage during the nights immediately following the seizures, as well as several nights after seizure induction. We noted a significant increase in movement along with a decrease in sleep efficiency, both limited to the night of seizure induction. For both animals, we observed a significant decrease in the number of REM periods that manifested as a decrease in total REM sleep duration, and this phenomenon persisted up to 2 nights after the seizures. We also found a significant increase in the probability to transition from stage N2 to stage N1 on the night of the seizures. This study shows for the first time that the NHP model of penicillin-induced cortical seizures exhibits significant changes in sleep architecture, including an increase in nocturnal movement, change in sleep architecture and a prolonged decrease in REM activity. The prolonged decrease in REM periods compared to the temporary enhanced movement and reduction of sleep efficiency suggest that these seizures may affect two neural circuits, one controlling REM sleep entry and the other controlling nocturnal wakefulness.

Polymorphisms in IL13 pathway genes in asthma and chronic obstructive pulmonary disease.

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are chronic respiratory diseases involving an interaction between genetic and environmental factors. Interleukin-13 (IL13) has been suggested to have a role in both asthma and COPD. We investigated whether single nucleotide polymorphisms (SNPs) in the IL13 pathway may contribute to the susceptibility and severity of asthma and COPD in adults. METHODS: Twelve SNPs in IL13 pathway genes -IL4, IL13, IL4RA, IL13RA1, IL13RA2 and STAT6- were genotyped in subjects with asthma (n = 299) and in subjects with COPD or healthy smokers (n = 992). Genetic association was evaluated using genotype and allele models for asthma severity, atopy phenotypes and COPD susceptibility. Linear regression was used to determine the effects of polymorphism on baseline lung function (FEV(1), FEV(1)/FVC). RESULTS: In asthmatics, three IL13 SNPs - rs1881457(-1512), rs1800925(-1111) and rs20541(R130Q) - were associated with atopy risk. One SNP in IL4RA1 [rs1805010(I75V)] was associated with asthma severity, and several IL13 SNPs showed borderline significance. IL13 SNPs rs1881457(-1512) and rs1800925(-1111) were associated with better FEV(1) and FEV(1)/FVC in asthmatics. IL13 SNPs rs2066960(intron 1), rs20541(R130Q) and rs1295685(exon 4) were associated with COPD risk and lower baseline lung function in the recessive model. In females, but not in males, rs2250747 of the IL13RA1 gene was associated with COPD and lower FEV(1). CONCLUSION: These data suggest that IL13 SNPs (promoter and coding region) and, to a lesser extent, IL4RA SNPs may contribute to atopy and asthma. We also provide tentative evidence that IL13 SNPs in the coding region may be of significance in COPD susceptibility.

Depression and anxiety in chronic heart failure and chronic obstructive pulmonary disease: prevalence, relevance, clinical implications and management principles.

OBJECTIVE: To review evidence regarding the prevalence, causation, clinical implications, aspects of healthcare utilisation and management of depression and anxiety in chronic heart failure and chronic obstructive pulmonary disease. DESIGN: A critical review of the literature (1994-2009). FINDINGS: The prevalence of depression and anxiety is high in both chronic obstructive pulmonary disease (8-80% depression; 6-74% anxiety) and chronic heart failure (10-60% depression; 11-45% anxiety). However, methodological weaknesses and the use of a wide range of diagnostic tools make it difficult to reach a consensus on rates of prevalence. Co-morbid depression and anxiety are associated with increased mortality and healthcare utilisation and impact upon functional disability and quality of life. Despite these negative consequences, the identification and management of co-morbid depression and anxiety in these two diseases is inadequate. There is some evidence for the positive role of pulmonary/cardiac rehabilitation and psychotherapy in the management of co-morbid depression and anxiety, however, this is insufficient to guide recommendations. CONCLUSIONS: The high prevalence and associated increase in morbidity and mortality justifies future research regarding the management of anxiety and depression in both chronic heart failure and chronic obstructive pulmonary disease. Current evidence suggests that multi-faceted interventions such as pulmonary and cardiac rehabilitation may offer the best hope for improving outcomes for depression and anxiety.

Head mounted telemetry system for seizures monitoring and sleep scoring on non-human primate.

Radio telemetry systems are a useful way to continuously monitor broad electrical neuronal activity in behaving animals. It can also be used to study sleep disturbances or monitor seizure activity. Many different telemeter styles are available, but the more versatile and cost-efficient ones are the head mounted systems. They permit long-term recordings and allow more flexibility in the recordings. However, there are currently no such system available for non-human primate (NHP). In fact, the choices for NHP telemetry solutions are very limited. Here, we present a chronically implantable 3D printed chamber specifically designed to accommodate a rodent head-mounted system (RodentPACK) onto a NHP's head. We recorded EEG signal for more than a year, confirmed quality of the signal, and the ability to use the data to monitor sleep activity. We also used two of our epileptic animals to validate the embedded alarm system for real time seizure monitoring. While initially not designed for NHP, but with a minimum number of adaptions, this telemeter is in fact perfectly suitable for NHP experiments. Since early medical intervention during seizures is critical to avoid status epilepticus and to save the animal's life, real time seizures monitoring is becoming a safety requirement in many NHP studies. This method refines the current seizure monitoring methods for NHP and creates a flexible telemetry solution.

Prevalence of depression and anxiety symptoms in elderly patients admitted in post-acute intermediate care.

OBJECTIVES: Depression and anxiety symptoms are common in medically ill older patients. We investigated the prevalence and predictors of depression and anxiety symptoms in older patients admitted for further rehabilitation in post acute intermediate care. DESIGN: Observational cohort study. SETTING: An intermediate care unit, North West of England. PARTICIPANTS: One hundred and seventy-three older patients (60 male), aged mean (SD) 80 (8.1) years, referred for further rehabilitation to intermediate care. MEASUREMENTS: Depression and anxiety symptoms were assessed by the Hospital Anxiety and Depression Scale, and severity of depression examined by the Montgomery Asberg Depression Rating Scale. Physical disability was assessed by the Nottingham Extended ADL Scale and quality of life by the SF-36. RESULTS: Sixty-five patients (38%) were identified with depressive symptoms, 29 (17%) with clinical depression, 73 (43%) with anxiety symptoms, and 43 (25%) with clinical anxiety. 15 (35%) of the latter did not have elevated depression scores (9% of the sample). Of those with clinical depression, 14 (48%) were mildly depressed and 15 (52%) moderately depressed. Longer stay in the unit was predicted by severity of depression, physical disability, low cognition and living alone (total adjusted R2 = 0.24). CONCLUSIONS: Clinical depression and anxiety are common in older patients admitted in intermediate care. Anxiety is often but not invariably secondary to depression and both should be screened for. Depression is an important modifiable factor affecting length of stay. The benefits of structured management programmes for anxiety and depression in patients admitted in intermediate care are worthy of evaluation.

Reducing emergency presentations from long-term care: A before-and-after study of a multidisciplinary team intervention.

INTRODUCTION: The complexity of care required by many older people living in long-term care (LTC) facilities poses challenges that can lead to potentially avoidable referrals to a hospital emergency department (ED). The Aged Residential Care Intervention Project (ARCHIP) ran an implementation study to evaluate a multidisciplinary team (MDT) intervention supporting LTC facility staff to decrease potentially avoidable ED presentations by residents. METHODS: ARCHIP (conducted in 21 facilities [1,296 beds] with previously noted high ED referral rates) comprised clinical coaching for LTC facility staff by a gerontology nurse specialist (GNS) and an MDT (facility senior nurse, resident's general practitioner, GNS, geriatrician, pharmacist) review of selected high-risk residents' care-plans. A before-after repeated measures analysis was conducted for 9 months before and 9 months after intervention commencement (a 29-month period because of staggered facility enrolment). Modelling was adjusted for time trend, seasonality, facility size, and cluster effect. RESULTS: ED admission rate ratio post- versus pre-intervention was 0.75 (95% C.I. 0.63, 0.89, p-value = 0.0008), a 25% reduction in ED presentations post-intervention. A sensitivity model used a shorter, staggered time period centred on intervention start (9 months pre-intervention and 9 months post-intervention) for each facility, and a four-level categorical intervention variable testing intervention effect over time. The sensitivity test showed a 24% reduction in ED presentations in months 1-3 post-intervention (p-value = 0.07), a 34% reduction in months 4-6 (p-value = 0.01), and a 32% reduction in ED presentations in months 7-9 (p-value = 0.03). However, when the higher ED referral rates for 3 months immediately pre-intervention were modelled, the impact of the intervention on ED presentation rates reverted almost to previous levels. KEY CONCLUSIONS: A GNS-led MDT outreach intervention, targeted at selected conditions, decreases avoidable ED admissions of high-risk residents from selected facilities.

The impact of depression in older patients with chronic obstructive pulmonary disease and asthma.

Respiratory diseases are common in older people. However, the impact of comorbid depression in older patients with chronic obstructive pulmonary disease (COPD) and asthma has not been fully explored. This narrative review examines the impact of comorbid depression and its management in COPD and asthma in older adults. The causes of depression in patients with COPD and asthma are multifactorial and include physical, physiological and behavioural factors. Depression is associated with hospital readmission in older adults with asthma and COPD. We focus on the most current literature that has examined the efficacy of pulmonary rehabilitation (PR), cognitive behavioural therapy (CBT) and antidepressant drug therapy for patients with depression in the context of COPD and asthma. Our findings indicate that PR and CBT are beneficial in improving depressive symptoms and quality of life in short-term intervention studies. However, the long-term efficacy of CBT and PR is unknown. To date, the efficacy of antidepressant drug therapy for depression in patients with COPD and asthma is inconclusive. In addition, there has been no clear evidence that antidepressants can induce remission of depression or ameliorate dyspnoea or physiological indices of COPD. Factors that contribute to 'inadequate' assessment and treatment of depression in patients with COPD and asthma may include misconception of the disease by patients and their caregivers and stigma attached to depression. Thus, well-controlled randomized controlled trials are needed.

Ageing, late-onset asthma and the beta-adrenoceptor.

Late-onset asthma in old age is a common clinical problem. There are similarities between receptor and post-receptor beta 2-adrenoceptor abnormalities reported in young asthmatics and in elderly normal subjects. Recent evidence lends some support to the idea of the 'aging' beta 2-adrenoceptor as a contributory factor in the development of late-onset asthma, although questions of the validity of the peripheral mononuclear cell model and of receptor tachyphylaxis to intrinsic and extrinsic beta-adrenoceptor agonists remain unresolved. Further work should focus on in vivo studies of airway receptor function and on beta 2-adrenoceptor-mediated pathways other than smooth muscle-related bronchoconstriction.

Plasma beta-endorphin levels in silent myocardial ischemia induced by exercise.

Although silent myocardial ischemia is a well recognized phenomenon, the reasons for the lack of symptoms in patients with coronary artery disease (CAD) is unclear. Because the endogenous opioid beta-endorphin has been related to pain modulation, plasma beta-endorphin levels were studied before, during and after exercise-induced ischemia in symptomatic and asymptomatic men. Because beta-endorphin responses have been closely linked to adrenocorticotropic hormone (ACTH) and cortisol responses, these hormones also were measured. Nine symptomatic and 12 asymptomatic patients with a high probability (at least 95%) of CAD and 8 apparently healthy men completed a Bruce protocol treadmill test. Blood samples were drawn before, during and 10 minutes after exercise. During exercise the measured hormones showed no significant increases from basal levels. However, plasma beta-endorphin, ACTH and cortisol levels were significantly elevated (p less than or equal to 0.01) 10 minutes after exercise in all 3 groups. There was no significant difference in plasma beta-endorphin levels during or after exercise between the symptomatic and asymptomatic patients with CAD. Thus, differences in circulating levels of beta-endorphin, ACTH and cortisol are not associated with the presence or absence of pain during exercise-induced myocardial ischemia.

The relationship between age and bronchial responsiveness: evidence from a population survey.

OBJECTIVES: Increased bronchial responsiveness is a feature of symptomatic asthma, and it predicts the onset of wheezing. We have investigated the relationship between bronchial responsiveness and age in a population sample with an age range of 45 to 86 years. DESIGN: Cross-sectional population survey. SETTING: Population of Central Manchester, UK. PARTICIPANTS: An age-stratified random sample of white adults aged > or = 45 years old and living in Central Manchester. They were recruited from their primary care physician (general practitioner) lists. Patients with confusion and patients who were housebound were excluded. MEASUREMENTS: Respondents to a mail questionnaire were invited to attend a methacholine bronchial challenge performed using the Newcastle dosimeter method. Respondents with ischemic heart disease or respondents taking oral steroids, beta-blockers, or anticholinergic medication were excluded. RESULTS: Of the 783 subjects contacted, 92.3% of the subjects responded, and 508 subjects returned enough information for us to deduce their suitability for the bronchial challenge. Of the 395 suitable subjects, 247 subjects participated (62.5% of those invited; 31.5% of the study population), and 208 participants completed the bronchial challenge. Participants were slightly younger than nonparticipants, but they were otherwise representative of the population. Increased bronchial responsiveness (provocative dose of methacholine causing a 20% fall in FEV1 < or = 200 microg) was present in 71 (34.1%) participants. Stepwise multiple regression analysis showed weak, independent, positive associations between bronchial responsiveness and age, and between bronchial responsiveness and the total immunoglobulin E level. There was an independent negative relationship between bronchial responsiveness and the airways caliber (expressed as standardized residuals; R2 = 0.29). CONCLUSIONS: We have found a high prevalence of increased bronchial responsiveness in this inner-city population of older adults. Bronchial responsiveness showed a weak independent positive association with age.

Impaired bronchodilator response to albuterol in healthy elderly men and women.

BACKGROUND: Lymphocytes of normal elderly subjects and young asthmatics display dysfunctional beta-adrenoceptors. If beta-adrenoceptor dysfunction were found in senescent airways, it might help explain the pathogenesis of late onset asthma. METHODS: The bronchodilatory effects of albuterol after methacholine-provoked bronchoconstriction were compared in 17 healthy young (age 20 to 36 years) and 17 healthy elderly (age 60 to 76 years) volunteer subjects. Albuterol was inhaled via dosimeter (initially 7.8 micrograms, doubling every 7.5 min) with forced expiratory flow at 50% vital capacity (FEF50) measured prior to each dose. Albuterol sensitivity was expressed as the cumulative logarithm of the area under the FEF50 recovery curve (AUC); a greater AUC meant lower sensitivity. On another study day, spontaneous recovery from methacholine was assessed similarly. RESULTS: There was no intergroup difference in spontaneous recovery. Despite lower methacholine doses provoking similar (35%) FEF50 falls in elderly subjects, albuterol AUC was greater in elderly subjects (6,552%.min.microgram) than young subjects (3,922%.min microgram; p = 0.03). Multiple regression showed that AUC and age were related (p = 0.02). CONCLUSION: Airway beta 2-adrenoceptor responsiveness is diminished in old age, suggesting that airway beta-adrenoceptor dysfunction may be implicated in late-onset asthma.

The Manchester Respiratory Activities of Daily Living questionnaire: development, reliability, validity, and responsiveness to pulmonary rehabilitation.

OBJECTIVES: Because there is no respiratory-specific activities of daily living (ADL) scale for use in older patients, our aim was to design and develop the Manchester Respiratory ADL questionnaire (MRADL) and to assess its validity in older patients with chronic obstructive pulmonary disease (COPD). DESIGN: The MRADL is a composite of the most discriminative questions from the Nottingham Extended ADL Questionnaire (NEADL) and the Breathing Problems Questionnaire (BPQ). SETTING: A University teaching hospital. PARTICIPANTS: Participants were 188 (104 men) COPD out-patients aged 60 to 93 (mean 77) years and 55 (23 men) normal controls (NCs) aged 70 to 90 (mean 78) years. Exclusions were confusion and acute respiratory exacerbation/use of oral corticosteroid within 6 weeks. INTERVENTION: A subgroup of COPD subjects completed a pulmonary rehabilitation program (PR) to assess responsiveness of the MRADL to intervention. MEASUREMENTS: All subjects completed MRADL and NEADL scales, and 15 COPD subjects (11 men) completed an 8-week PR program. RESULTS: Mean (SE) 1-second forced expiratory volume (FEV1) in COPD subjects was 0.94 (0.03) liters, and in NCs it was 1.96 (0.07) liters. MRADL discriminated better between COPDs and NCs than did the NEADL in terms of sensitivity (90% vs 76%; X2 = 4.8, P = .02) and negative predictive value (84% vs 69%; X2 = 4.5, P = .03). MRADL responded to changes during PR: pre versus post mean (SE) score 11.2 (1.1) vs 13.4 (1.1); (t = 3.09; P = .008), but NEADL was unchanged. MRADL showed high consistency (Cronbach alpha 0.91). 95% confidence limits of repeatability were -0.63 to +0.26 (P = .42) for MRADL and -0.53 to +0.26 (P = .50) for NEADL. CONCLUSIONS: MRADL is a reliable and valid self-report scale for assessment of physical disability in older COPD patients. It is responsive to pulmonary rehabilitation.

Do respiratory symptoms predict chronic airflow obstruction and bronchial hyperresponsiveness in older adults?

BACKGROUND: Respiratory symptoms are common in older adults. In young populations the predictive value of such symptoms for chronic airflow obstruction and bronchial hyperresponsiveness is low. We investigated whether symptoms predict airflow obstruction and bronchial responsiveness in adults aged 45-86 years. METHODS: An age-stratified random sample of white adults aged 45 years and older was obtained from family doctor lists in Central Manchester, UK, and sent a respiratory symptoms questionnaire (exclusions: housebound, confused). Responders were invited to participate in a methacholine challenge (Newcastle dosimeter method; exclusions: ischemic heart disease, oral steroids, anticholinergic or beta-blocker medication). RESULTS: Of 783 eligible subjects, 723 responded (response rate 92.3%). Symptoms were reported by 53.8%. Methacholine challenge was completed by 208 subjects. Sixty-five (26.4%) had chronic airflow obstruction, of whom 76.6% reported respiratory symptoms. Bronchial hyperresponsiveness (PD20 < or = 100 micrograms) was present in 26.0% of subjects overall, and in 36.8% of symptomatic and 14.6% of asymptomatic subjects (p < .001). Of those with bronchial hyperresponsiveness, 26.4% were asymptomatic. Predictive values of symptoms for chronic airflow obstruction and bronchial hyperresponsiveness were low. CONCLUSIONS: Respiratory symptoms, chronic airflow obstruction, and bronchial hyperresponsiveness were all common in this adult population sample. However, the predictive value of symptoms for airflow obstruction/bronchial hyperresponsiveness was low. It was concluded that respiratory symptoms do not identify adults with airflow obstruction or bronchial hyperresponsiveness. Investigation by spirometry and peak flow monitoring is necessary to guide appropriate management.

The effect of body position on arterial oxygen saturation in acute stroke.

BACKGROUND: Evidence suggests that respiratory function is impaired poststroke. Body position is known to influence respiratory function in normal subjects and those with respiratory pathologies. Its effect on respiratory function after stroke has received little attention. However, one study suggests that some positions used in clinical practice may adversely influence respiratory function. This study therefore aimed to identify resting positions that maintain arterial oxygen saturation (SaO2) at optimal levels, changes in SaO2 during time spent in the test position, and differences in SaO2 among the positions investigated. METHOD: A within-subject, two-center clinical study was made. Patients in the first 72 hours following mild to moderately severe stroke were allocated a randomized sequence of four positions. One hour was spent in each position. SaO2 was recorded each minute by pulse oximetry with a finger probe. Mean values for the hour were calculated. RESULTS: Mean arterial oxygen saturation values for all patients were >90% for the hour spent in each test position for all patients. There were no changes in arterial oxygen saturation across the hour spent in the test positions (repeated-measures analysis of variance). No differences in arterial oxygen saturation were identified among positions (analysis of covariance). DISCUSSION: The saturation levels recorded corresponded to those observed in studies of normal elderly persons. The positions tested may be recommended for use in clinical practice to maintain arterial oxygen saturation in patients in the first 72 hours following mild to moderately severe stroke.

Baroreceptor-mediated compensation for hemodynamic effects of positive end-expiratory pressure.

The roles of the carotid arterial baroreceptor reflex and of vagally mediated mechanisms during positive end-expiratory pressure (PEEP) were determined in pentobarbital-anesthetized dogs with isolated carotid sinuses. Spontaneously breathing dogs were placed on PEEP (5-10 cmH2O) with the carotid sinus pressure set to the systemic arterial pressure (with feedback) or to a constant pressure (no feedback). Right atrial volume was measured with a conductance catheter. With carotid baroreceptor feedback before bilateral cervical vagotomy, total peripheral resistance increased (P < 0.01) and mean arterial pressure decreased (-9.8 +/- 4.3 mmHg) in response to PEEP. With no feedback after vagotomy, mean arterial pressure decreased to a greater extent (-45 +/- 6 mmHg, P < 0.01), and total peripheral resistance decreased (P < 0.05) in response to PEEP. In contrast, cardiac index decreased similarly during PEEP (P < 0.01) for all baroreceptor and vagal inputs. This response comprised a decrease in the passive phase of right ventricular filling (P < 0. 01) that was not matched by the estimated increase in active right atrial output. Although the carotid baroreceptor reflex and vagally mediated mechanisms elicit vasoconstriction to compensate for the effects of PEEP on the arterial pressure, these processes fail to defend cardiac output because of the profound effect of PEEP on the passive filling of the right ventricle.