Cerebral perfusion is not impaired in persons with moderate obstructive sleep apnoea when awake.

PURPOSE: It is well established that, together with a multitude of other adverse effects on health, severe obstructive sleep apnoea causes reduced cerebral perfusion and, in turn, reduced cerebral function. Less clear is the impact of moderate obstructive sleep apnoea (OSA). Our aim was to determine if cerebral blood flow is impaired in people diagnosed with moderate OSA. METHODS: Twenty-four patients diagnosed with moderate OSA (15 ≤ apnoea-hypopnea index (AHI) < 30) were recruited (aged 32-72, median 59 years, 10 female). Seven controls (aged 42-73 years, median 62 years, 4 female) with an AHI < 5 were also recruited. The OSA status of all participants was confirmed at baseline by unattended polysomnography and they had an MRI arterial-spin-labelling scan of cerebral perfusion. RESULTS: Neither global perfusion nor voxel-wise perfusion differed significantly between the moderate-OSA and control groups. We also compared the average perfusion across three regional clusters, which had been found in a previous study to have significant perfusion differences with moderate-severe OSA versus control, and found no significant difference in perfusion between the two groups. The perfusions were also very close, with means of 50.2 and 51.8 mL/100 g/min for the moderate-OSAs and controls, respectively, with a negligible effect size (Cohen's d = 0.10). CONCLUSION: We conclude that cerebral perfusion is not impaired in people with moderate OSA and that cerebral flow regulatory mechanisms can cope with the adverse effects which occur in moderate OSA. This is an important factor in clinical decisions for prescription of continuous positive airway pressure therapy (CPAP).

Reasons for why Medical Students Prefer Specific Sleep Management Strategies.

OBJECTIVES: Insomnia symptoms are common among medical students. This study explored the perspectives of medical students about which sleep management strategies to use. METHODS: Medical students responded to an online survey on their thoughts about the use of various sleep management strategies. RESULTS: Of the 828 respondents, 568 (69%) provided responses to questions about the most preferred strategies and 450 (54%) provided responses about their least preferred strategies. About 48.5% felt their insomnia symptoms were too mild to see a clinician and 23.9% did not think their symptoms warranted sleep medication. Over 40% of students could not avoid work before sleep, have consistent sleep/wake times, or engage in regular exercise because of their busy and inconsistent schedules. Approximately 40-60% could not improve their sleep environment (e.g. better heating and bed) because of the associated costs. Over 80% reported an inability to change their pre-sleep habits (e.g. using electronics close to bedtime, using bed for activities other than sleep or sex). Half of the students disliked relaxation techniques or felt they would not help. Around 30-50% did not believe that changing caffeine and/or alcohol intake would affect their sleep. CONCLUSIONS: Medical students may benefit from additional sleep education. Clinicians may need to discuss which strategies individual students prefer and modify their recommendations accordingly.

Symptom persistence and recovery among COVID-19 survivors during a limited outbreak in Canterbury, New Zealand: a prospective cohort study.

BACKGROUND: In Canterbury, near complete identification of coronavirus disease 2019 (COVID-19) cases during a limited outbreak provides unique insights into sequelae. AIMS: The current study aimed to measure symptom persistence, time to return to normal activity, generalised anxiety and health-related quality of life (HrQoL) among COVID-19 survivors compared with uninfected participants. METHODS: The authors conducted a prospective cohort study of people tested for COVID-19 by reverse transcriptase polymerase chain reaction of nasopharyngeal swabs from 1 March to 30 June 2020. They enrolled participants who tested positive and negative at a 1:2 ratio, and administered community-acquired pneumonia, 7-item generalised anxiety disorder (GAD-7) and HrQoL (RAND-36) questionnaires. RESULTS: The authors recruited 145 participants, 48 with COVID-19 and 97 without COVID-19. The mean time from COVID-19 testing to completing the health questionnaire was 306 days. The mean age of patients was 46.7 years, and 70% were women. Four (8%) COVID-19-positive and eight (8%) COVID-19-negative participants required hospitalisation. Fatigue (30/48 [63%] vs 13/97 [13%]; P < 0.001), dyspnoea (13/48 [27%] vs 6/97 [6%]; P < 0.001) and chest pain (10/48 [21%] vs 1/97 [1%]; P < 0.001) were persistent in those with COVID-19. Fewer COVID-19-positive participants returned to normal activity levels (35/48 [73%] vs 94/97 97%; P < 0.001), with longer times taken (median 21 vs 14 days; P = 0.007). The GAD-7 and RAND-36 scores of both groups were similar across all anxiety and HrQoL subscales. CONCLUSIONS: Persistent symptoms and longer recovery times were found in COVID-19 survivors, but not impaired generalised anxiety levels or HrQoL compared with COVID-19-uninfected participants.

Sleep Management Strategies Among Medical Students At the University of Otago.

OBJECTIVES: We aim to investigate factors which might affect the sleep of medical students, and how they currently manage their sleep. METHODS: An online survey was sent to medical students at the University of Otago. RESULTS: After adjusting for gender, ethnicity and age, depressive symptoms (Mild: odds ratio (OR) = 6.3; Moderate: OR = 18.1; Severe: OR = 15.6), and sleep hygiene (OR = 1.07) were associated with insomnia symptoms. Commonly endorsed strategies for sleep management by students were undertaking regular exercise (80.1%), having consistent sleep-wake time (71.3%), and limiting caffeine intake (70.3%). Few were willing to see a clinician (23.4%) or take medication (22.3%). Participants with insomnia symptoms were more likely to prefer limiting their alcohol intake (OR = 1.8), limiting daytime naps (OR = 1.5), seeing clinicians (OR = 1.9), and taking sleep medication (OR = 4.0), but less likely to prefer avoiding intense work (OR = .71) or minimizing using electronics (OR = .60) close to bedtime than those without insomnia symptoms. High sleep self-efficacy was associated with lower odds for having insomnia symptoms (OR = .74 (.70, .77)). CONCLUSIONS: Increased awareness and greater resources are needed to support the sleep health of medical students.

'People that suffer or have been through it know the answers': stakeholders' perspectives on improving healthcare systems for end-of-life care in chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a progressive and disabling lung condition with a high mortality. Our research has shown that health care for end-of-life COPD is poorly integrated. The aim of this study was to involve people with end-of-life COPD, their support people and health professionals in the design of healthcare services to help improve the delivery of care for advanced COPD, including informing system-level quality improvement. DESIGN: We conducted a focus group study involving stakeholders of healthcare services: people with end-of life COPD, support people, bereaved support people, and community- and hospital-based health care professionals. METHODS: We conducted qualitative analysis using deductive structural coding, and then inductive descriptive and pattern coding. Analyses were triangulated by investigators. The research positioned people with end-of-life COPD, their support people and health professionals as experts in healthcare services. Critical theory and Actor-Network theory informed the analysis. RESULTS: Seven focus groups involving 74 participants reported their experiences of end-of-life care for COPD. Five themes related to healthcare systems responses to improving care quality were identified: governance, system integration, resource design and development, standardisation of processes, and communication. CONCLUSION: Stakeholders provided multiple healthcare system-level responses to end-of-life care in COPD that could inform healthcare service design and clinical quality improvement.

Evaluation of pleural fluid cytology for the diagnosis of malignant pleural effusion: a retrospective cohort study.

BACKGROUND: Cytological examination of pleural fluid has good specificity, but imperfect sensitivity for the diagnosis of malignant pleural effusion (MPE). Published estimates of sensitivity vary and predictors of false negative cytology are not well established. AIMS: To estimate pleural fluid cytology sensitivity and identify risk factors for false negative cytology. METHODS: We conducted a retrospective cohort study of patients who had cytology testing of pleural fluid at Christchurch Hospital, New Zealand, from July 2017 to October 2019. Data on clinical and pleural fluid characteristics were collected. MPE was defined by positive pleural fluid cytology, tissue histology or multidisciplinary meeting consensus. We estimated sensitivity of the first pleural cytology assessment. We performed multivariate logistic regression to ascertain patient groups at greatest risk of false negative results. RESULTS: Initial pleural fluid cytology was diagnostic in 117 of 156 patients, providing a sensitivity (95% confidence interval (CI)) of 75.0% (67.4-81.6%). The sensitivity was 79.0% (66.8-88.3%) for lung cancer, 91.3% (72.0-98.9%) for breast cancer and 33.3% (95% CI 11.8-61.6%) for mesothelioma. Cloudy appearance of pleural fluid (odds ratio (OR) 0.12; 95% CI 0.03-0.54) and yellow/gold pleural fluid (OR 0.24; 95% CI 0.06-0.96) reduced the odds of false negative pleural cytology. Pleural thickening on computed tomography scan (OR 3.3; 95% CI 1.2-9.4) was a risk factor for false negative cytology. CONCLUSION: Sensitivity of pleural fluid cytology was greatest in primary lung and breast cancer, and lowest in mesothelioma. Clinicians should be alert to false negative results when suspecting mesothelioma or if pleural thickening is present.

Long-term outcomes in patients with pulmonary embolism: results from a longitudinal cohort study.

BACKGROUND: Patients with pulmonary embolism (PE) have increased mortality in short-term; however, long-term prognosis is not well defined. AIM: In this long-term cohort study, we aimed to determine if PE was associated with increased risk of mortality or serious clinical events (SCE). Secondary aims were to ascertain predictors of mortality and SCE. METHODS: Patients admitted with clinical suspicion of PE were prospectively recruited from July 2002 to May 2003 and followed up until March 2015. Clinical outcomes in patients with PE were compared to those without PE. SCE was defined as composite of mortality, malignancy, cardiovascular events, recurrent venous thromboembolism and chronic thromboembolic pulmonary hypertension. RESULTS: A total of 501 patients with median follow up of 11.9 years (interquartile range 3.91-12.28) was included. PE was diagnosed in 104 (20.7%) patients. Overall, 45.9% died and 57.1% developed SCE during follow up, with no significant difference in PE and no-PE groups (both P > 0.5). Major determinants of mortality were age (hazard ratio (HR) 1.06 per year, 95% confidence interval (CI) 1.05-1.08), malignancy (HR 2.19, 95% CI 1.64-2.91) and congestive heart failure (HR 1.72, 95% CI 1.23-2.42). Factors associated with increased risk of SCE were age (HR 1.05 per year, 95% CI 1.04-1.06), malignancy (HR 1.93, 95% CI 1.48-2.52) and congestive heart failure (HR 1.77, 95% CI 1.29-2.43). In patients without PE, elevated D-dimer concentration was not found to be associated with diagnosis of malignancy during follow up (HR 1.31, 95% CI 0.55-3.12). CONCLUSIONS: In this prospective study, we did not find association between PE and risk of all-cause mortality or SCE. Major determinants of poor clinical outcomes were advancing age and underlying comorbidities.

Reported sources of health inequities in Indigenous Peoples with chronic kidney disease: a systematic review of quantitative studies.

BACKGROUND: To summarise the evidentiary basis related to causes of inequities in chronic kidney disease among Indigenous Peoples. METHODS: We conducted a Kaupapa Maori meta-synthesis evaluating the epidemiology of chronic kidney diseases in Indigenous Peoples. Systematic searching of MEDLINE, Google Scholar, OVID Nursing, CENTRAL and Embase was conducted to 31 December 2019. Eligible studies were quantitative analyses (case series, case-control, cross-sectional or cohort study) including the following Indigenous Peoples: Maori, Aboriginal and Torres Strait Islander, Métis, First Nations Peoples of Canada, First Nations Peoples of the United States of America, Native Hawaiian and Indigenous Peoples of Taiwan. In the first cycle of coding, a descriptive synthesis of the study research aims, methods and outcomes was used to categorise findings inductively based on similarity in meaning using the David R Williams framework headings and subheadings. In the second cycle of analysis, the numbers of studies contributing to each category were summarised by frequency analysis. Completeness of reporting related to health research involving Indigenous Peoples was evaluated using the CONSIDER checklist. RESULTS: Four thousand three hundred seventy-two unique study reports were screened and 180 studies proved eligible. The key finding was that epidemiological investigators most frequently reported biological processes of chronic kidney disease, particularly type 2 diabetes and cardiovascular disease as the principal causes of inequities in the burden of chronic kidney disease for colonised Indigenous Peoples. Social and basic causes of unequal health including the influences of economic, political and legal structures on chronic kidney disease burden were infrequently reported or absent in existing literature. CONCLUSIONS: In this systematic review with meta-synthesis, a Kaupapa Maori methodology and the David R Williams framework was used to evaluate reported causes of health differences in chronic kidney disease in Indigenous Peoples. Current epidemiological practice is focussed on biological processes and surface causes of inequity, with limited reporting of the basic and social causes of disparities such as racism, economic and political/legal structures and socioeconomic status as sources of inequities.

Electronic cigarettes: A position statement from the Thoracic Society of Australia and New Zealand.

The TSANZ develops position statements where insufficient data exist to write formal clinical guidelines. In 2018, the TSANZ addressed the question of potential benefits and health impacts of electronic cigarettes (EC). The working party included groups focused on health impacts, smoking cessation, youth issues and priority populations. The 2018 report on the Public Health Consequences of E-Cigarettes from the United States NASEM was accepted as reflective of evidence to mid-2017. A search for papers subsequently published in peer-reviewed journals was conducted in August 2018. A small number of robust and important papers published until March 2019 were also identified and included. Groups identified studies that extended, modified or contradicted the NASEM report. A total of 3793 papers were identified and reviewed, with summaries and draft position statements developed and presented to TSANZ membership in April 2019. After feedback from members and external reviewers, a collection of position statements was finalized in December 2019. EC have adverse lung effects and harmful effects of long-term use are unknown. EC are unsuitable consumer products for recreational use, part-substitution for smoking or long-term exclusive use by former smokers. Smokers who require support to quit smoking should be directed towards approved medication in conjunction with behavioural support as having the strongest evidence for efficacy and safety. No specific EC product can be recommended as effective and safe for smoking cessation. Smoking cessation claims in relation to EC should be assessed by established regulators.

A multicentre prospective observational study comparing arterial blood gas values to those obtained by pulse oximeters used in adult patients attending Australian and New Zealand hospitals.

BACKGROUND: Pulse oximetry is widely used in the clinical setting. The purpose of this validation study was to investigate the level of agreement between oxygen saturations measured by pulse oximeter (SpO2) and arterial blood gas (SaO2) in a range of oximeters in clinical use in Australia and New Zealand. METHODS: Paired SpO2 and SaO2 measurements were collected from 400 patients in one Australian and two New Zealand hospitals. The ages of the patients ranged from 18 to 95 years. Bias and limits of agreement were estimated. Sensitivity and specificity for detecting hypoxaemia, defined as SaO2 < 90%, were also estimated. RESULTS: The majority of participants were recruited from the Outpatient, Ward or High Dependency Unit setting. Bias, oximeter-measured minus arterial blood gas-measured oxygen saturation, was - 1.2%, with limits of agreement - 4.4 to 2.0%. SpO2 was at least 4% lower than SaO2 for 10 (2.5%) of the participants and SpO2 was at least 4% higher than the SaO2 in 3 (0.8%) of the participants. None of the participants with a SpO2 ≥ 92% were hypoxaemic, defined as SaO2 < 90%. There were no clinically significant differences in oximetry accuracy in relation to clinical characteristics or oximeter brand. CONCLUSIONS: In the majority of the participants, pulse oximetry was an accurate method to assess SaO2 and had good performance in detecting hypoxaemia. However, in a small proportion of participants, differences between SaO2 and SpO2 could have clinical relevance in terms of patient monitoring and management. A SpO2 ≥ 92% indicates that hypoxaemia, defined as a SaO2 < 90%, is not present. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ACTRN12614001257651). Date of registration: 2/12/2014.