Comparative analysis of predictive methods for early assessment of compliance with continuous positive airway pressure therapy

Background: Patients suffering obstructive sleep apnea are mainly treated with continuous positive airway pressure (CPAP). Although it is a highly effective treatment, compliance with this therapy is problematic to achieve with serious consequences for the patients’ health. Unfortunately, there is a clear lack of clinical analytical tools to support the early prediction of compliant patients. Methods: This work intends to take a further step in this direction by building compliance classifiers with CPAP therapy at three different moments of the patient follow-up, before the therapy starts (baseline) and at months 1 and 3 after the baseline. Results: Results of the clinical trial shows that month 3 was the time-point with the most accurate classifier reaching an f1-score of 87% and 84% in cross-validation and test. At month 1, performances were almost as high as in month 3 with 82% and 84% of f1-score. At baseline, where no information of patients’ CPAP use was given yet, the best classifier achieved 73% and 76% of f1-score in cross-validation and test set respectively. Subsequent analyzes carried out with the best classifiers of each time point revealed baseline factors (i.e. headaches, psychological symptoms, arterial hypertension and EuroQol visual analog scale) closely related to the prediction of compliance independently of the time-point. In addition, among the variables taken only during the follow-up of the patients, Epworth and the average nighttime hours were the most important to predict compliance with CPAP. Conclusions: Best classifiers reported high performances after one month of treatment, being the third month when significant differences were achieved with respect to the baseline. Four baseline variables were reported relevant for the prediction of compliance with CPAP at each time-point. Two characteristics more were also highlighted for the prediction of compliance at months 1 and 3.This work is part of the myOSA project (RTC-2014-3138-1), funded by the Spanish Ministry of Economy and Competitiveness (Ministerio de Economía y Competitividad) under the framework “Retos-Colaboración”, State Scientific and Technical Research and Innovation Plan 2013-2016. The study was also partially funded by the European Community under “H2020-EU.3.1. – Societal Challenges – Health, demographic change and well-being” programme, project grant agreement number 689802 (CONNECARE)

An investigation into the effects of commencing haemodialysis in the critically ill

<b>Introduction:</b> We have aimed to describe haemodynamic changes when haemodialysis is instituted in the critically ill. 3 hypotheses are tested: 1)The initial session is associated with cardiovascular instability, 2)The initial session is associated with more cardiovascular instability compared to subsequent sessions, and 3)Looking at unstable sessions alone, there will be a greater proportion of potentially harmful changes in the initial sessions compared to subsequent ones. <b>Methods:</b> Data was collected for 209 patients, identifying 1605 dialysis sessions. Analysis was performed on hourly records, classifying sessions as stable/unstable by a cutoff of >+/-20% change in baseline physiology (HR/MAP). Data from 3 hours prior, and 4 hours after dialysis was included, and average and minimum values derived. 3 time comparisons were made (pre-HD:during, during HD:post, pre-HD:post). Initial sessions were analysed separately from subsequent sessions to derive 2 groups. If a session was identified as being unstable, then the nature of instability was examined by recording whether changes crossed defined physiological ranges. The changes seen in unstable sessions could be described as to their effects: being harmful/potentially harmful, or beneficial/potentially beneficial. <b>Results:</b> Discarding incomplete data, 181 initial and 1382 subsequent sessions were analysed. A session was deemed to be stable if there was no significant change (>+/-20%) in the time-averaged or minimum MAP/HR across time comparisons. By this definition 85/181 initial sessions were unstable (47%, 95% CI SEM 39.8-54.2). Therefore Hypothesis 1 is accepted. This compares to 44% of subsequent sessions (95% CI 41.1-46.3). Comparing these proportions and their respective CI gives a 95% CI for the standard error of the difference of -4% to 10%. Therefore Hypothesis 2 is rejected. In initial sessions there were 92/1020 harmful changes. This gives a proportion of 9.0% (95% CI SEM 7.4-10.9). In the subsequent sessions there were 712/7248 harmful changes. This gives a proportion of 9.8% (95% CI SEM 9.1-10.5). Comparing the two unpaired proportions gives a difference of -0.08% with a 95% CI of the SE of the difference of -2.5 to +1.2. Hypothesis 3 is rejected. Fisher’s exact test gives a result of p=0.68, reinforcing the lack of significant variance. <b>Conclusions:</b> Our results reject the claims that using haemodialysis is an inherently unstable choice of therapy. Although proportionally more of the initial sessions are classed as unstable, the majority of MAP and HR changes are beneficial in nature

Enhancing the Diagnosis and Management of Obstructive Sleep Apnoea in Atrial Fibrillation Patients

Background: Atrial fibrillation (AF), is the most common sustained cardiac arrhythmia, and significantly increases the risk of stroke and cardiovascular mortality. It is strongly associated with obstructive sleep apnoea (OSA). Aims: 1. Examine the epidemiology of OSA in a hospital cohort with AF. 2. Compare the diagnostic accuracy of clinical screening tools for OSA in patients with AF. 3. Compare cardiac autonomic function in AF patients with and without OSA. 4. Conduct a pilot study of mandibular advancement splint (MAS) therapy for OSA in AF patients. Methods: 107 AF patients were recruited. The diagnostic accuracy of screening tools including a level 3 (portable) sleep study device as compared to polysomnography in AF patients was assessed. Cardiac autonomic function as a potential mechanistic link between OSA and AF was assessed using Heart Rate Variability (HRV). A pilot study of OSA treatment in AF patients using MAS therapy was conducted. Results: 62.6% of patients were newly diagnosed with OSA. Patients with moderate to severe OSA showed an increased BMI, neck circumference and Mallampati score, but were not significantly different in terms of daytime somnolence. Oxygen desaturation index (ODI) derived from a Level 3 portable sleep study device performed best for the diagnosis of moderate to severe and severe OSA, with excellent diagnostic accuracy (AUC 0.899, 95% CI 0.838 – 0.960 and AUC 0.925, 95% CI 0.859 – 0.991 respectively). We found a chronic increase in parasympathetic nervous activity in paroxysmal AF patients with OSA. MAS therapy showed high rates of acceptance, compliance and efficacy in AF patients. Conclusions: This thesis contributes to our understanding of the association between AF and OSA across a spectrum o

Acute lung injury in paediatric intensive care: course and outcome

Introduction: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) carry a high morbidity and mortality (10-90%). ALI is characterised by non-cardiogenic pulmonary oedema and refractory hypoxaemia of multifactorial aetiology [1]. There is limited data about outcome particularly in children. Methods This retrospective cohort study of 85 randomly selected patients with respiratory failure recruited from a prospectively collected database represents 7.1% of 1187 admissions. They include those treated with High Frequency Oscillation Ventilation (HFOV). The patients were admitted between 1 November 1998 and 31 October 2000. Results: Of the 85, 49 developed acute lung injury and 47 had ARDS. There were 26 males and 23 females with a median age and weight of 7.7 months (range 1 day-12.8 years) and 8 kg (range 0.8-40 kg). There were 7 deaths giving a crude mortality of 14.3%, all of which fulfilled the Consensus I [1] criteria for ARDS. Pulmonary occlusion pressures were not routinely measured. The A-a gradient and PaO2/FiO2 ratio (median + [95% CI]) were 37.46 [31.82-43.1] kPa and 19.12 [15.26-22.98] kPa respectively. The non-survivors had a significantly lower PaO2/FiO2 ratio (13 [6.07-19.93] kPa) compared to survivors (23.85 [19.57-28.13] kPa) (P = 0.03) and had a higher A-a gradient (51.05 [35.68-66.42] kPa) compared to survivors (36.07 [30.2-41.94]) kPa though not significant (P = 0.06). Twenty-nine patients (59.2%) were oscillated (Sensormedics 3100A) including all 7 non-survivors. There was no difference in ventilation requirements for CMV prior to oscillation. Seventeen of the 49 (34.7%) were treated with Nitric Oxide including 5 out of 7 non-survivors (71.4%). The median (95% CI) number of failed organs was 3 (1.96-4.04) for non-survivors compared to 1 (0.62-1.62) for survivors (P = 0.03). There were 27 patients with isolated respiratory failure all of whom survived. Six (85.7%) of the non-survivors also required cardiovascular support.Conclusion: A crude mortality of 14.3% compares favourably to published data. The A-a gradient and PaO2/FiO2 ratio may be of help in morbidity scoring in paediatric ARDS. Use of Nitric Oxide and HFOV is associated with increased mortality, which probably relates to the severity of disease. Multiple organ failure particularly respiratory and cardiac disease is associated with increased mortality. ARDS with isolated respiratory failure carries a good prognosis in children

Overview and implications of obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a leading public health problem both in the developed and developing nations. However, awareness regarding diagnostic options, management and consequences of untreated OSA remains inadequate. In developing nations, the resources for adequate sleep medicine facilities are scarce. Therefore, there is a need for low cost, simple and accurate diagnostic and therapeutic modalities exists. Untreated OSA leads to excessive daytime sleepiness, diminished performance and an overall poor quality of life. The role of OSA in promoting insulin resistance, atherosclerosis, hypertension and a procoagulant state has now been established. Newer insights into the biochemical and genetic mediators of OSA have raised hopes regarding the development of a "cure". However, as of now, continuous positive airway pressure (CPAP) therapy remains the first-line treatment. Though its use improves the quality of life as well as metabolic derangements observed in OSA, patients' acceptance remains low. Its high cost and long-term use are also cumbersome. Newer modes of delivering CPAP, oral appliances and upper airway surgery are the other options available. It is hoped that their appropriate use to increase patients' compliance may improve the quality of life as well as provide a survival benefit

Mastering Treatment for Sleep Apnoea: The Grounded Theory of Bargaining and Balancing Life With Continuous Positive Airway Pressure (CPAP), in the Context of Decisional Conflict and Change Theories

Continuous positive airway pressure (CPAP) treatment for sleep apnoea can be challenging for patients to master. Given limited evidence on this topic, we used constructionist grounded theory methodology to explore experiences of living with CPAP from participants' perspectives. Adults (n=16) were recruited through a main-center respiratory service in New Zealand and participated in semi-structured interviews. Data were analyzed until theoretical saturation was achieved.In this article, we present the newly constructed grounded theory of bargaining and balancing life with CPAP, which explains how participants made a series of personal decisions about whether to use and how to master CPAP. To situate, support and provide explanatory power the new theory is discussed in the context of change and decision theories to illustrate the varying phases of readiness experienced by persons preparing to engage with CPAP and the decision-making process required for effective management of CPAP at home.This study provides valuable CPAP-user centered information for the development of interventions to optimize CPAP use. Acknowledging individuals' abilities to make reasoned healthcare decisions and providing clinical environments that support the active process of bargaining and balancing may increase uptake of CPAP, and potentially other long-term therapies.Im Fall von Schlafapnoe kann das Umgehen mit Continuous Positive Airway Pressure (CPAP) für Patient/innen herausfordernd sein. Da hierzu wenig Forschung erfolgt ist, haben wir die konstruktivistische Grounded-Theory-Methodologie genutzt, um die Erfahrungen aus der Perspektive der Patient/innen zu explorieren. Sechzehn Erwachsene wurden in einem neuseeländischen Gesundheitszentrum für teilstrukturierte Interviews rekrutiert. Die Daten wurden analysiert, bis eine theoretische Sättigung erreicht war. In diesem Beitrag stellen wir unsere Grounded Theory des Aushandelns und Balancierens von CPAP-Beatmung vor, mit deren Hilfe wir erklären, welche individuellen Entscheidungen bei dem Umgang und der Nutzung von CPAP getroffen werden. Um die erklärende Kraft der Theorie zu situieren und zu stützen, diskutieren wir unsere Ergebnisse im Kontext von Entscheidungskonflikt- und Veränderungstheorien. So kann veranschaulicht werden, welche unterschiedlichen Phasen Patient/innen durchlaufen in ihrer Bereitschaft, sich mit CPAP zu befassen bzw. Entscheidungen für einen effektiven Einsatz in ihrer häuslichen Umgebung zu treffen. Mittels unserer Studie werden wichtige Nutzungsinformationen für die Optimierung von CPAP-bezogenen Interventionen verfügbar. Die Anerkennung individuell vernünftigen Gesundheitshandelns und die Bereitstellung klinischer Settings, die den Prozess des aktiven Aushandelns und Balancierens unterstützen, können die Akzeptanz von CPAP und potenziell auch anderer Langzeittherapien verbessern

Perioperative interventions for prevention of postoperative pulmonary complications: systematic review and meta-analysis

Objective To identify, appraise, and synthesise the best available evidence on the efficacy of perioperative interventions to reduce postoperative pulmonary complications (PPCs) in adult patients undergoing non-cardiac surgery. Design Systematic review and meta-analysis of randomised controlled trials. Data sources Medline, Embase, CINHAL, and CENTRAL from January 1990 to December 2017. Eligibility criteria Randomised controlled trials investigating short term, protocolised medical interventions conducted before, during, or after non-cardiac surgery were included. Trials with clinical diagnostic criteria for PPC outcomes were included. Studies of surgical technique or physiological or biochemical outcomes were excluded. Data extraction and synthesis Reviewers independently identified studies, extracted data, and assessed the quality of evidence. Meta-analyses were conducted to calculate risk ratios with 95% confidence intervals. Quality of evidence was summarised in accordance with GRADE methods. The primary outcome was the incidence of PPCs. Secondary outcomes were respiratory infection, atelectasis, length of hospital stay, and mortality. Trial sequential analysis was used to investigate the reliability and conclusiveness of available evidence. Adverse effects of interventions were not measured or compared. Results 117 trials enrolled 21 940 participants, investigating 11 categories of intervention. 95 randomised controlled trials enrolling 18 062 participants were included in meta-analysis; 22 trials were excluded from meta-analysis because the interventions were not sufficiently similar to be pooled. No high quality evidence was found for interventions to reduce the primary outcome (incidence of PPCs). Seven interventions had low or moderate quality evidence with confidence intervals indicating a probable reduction in PPCs: enhanced recovery pathways (risk ratio 0.35, 95% confidence interval 0.21 to 0.58), prophylactic mucolytics (0.40, 0.23 to 0.67), postoperative continuous positive airway pressure ventilation (0.49, 0.24 to 0.99), lung protective intraoperative ventilation (0.52, 0.30 to 0.88), prophylactic respiratory physiotherapy (0.55, 0.32 to 0.93), epidural analgesia (0.77, 0.65 to 0.92), and goal directed haemodynamic therapy (0.87, 0.77 to 0.98). Moderate quality evidence showed no benefit for incentive spirometry in preventing PPCs. Trial sequential analysis adjustment confidently supported a relative risk reduction of 25% in PPCs for prophylactic respiratory physiotherapy, epidural analgesia, enhanced recovery pathways, and goal directed haemodynamic therapies. Insufficient data were available to support or refute equivalent relative risk reductions for other interventions. Conclusions Predominantly low quality evidence favours multiple perioperative PPC reduction strategies. Clinicians may choose to reassess their perioperative care pathways, but the results indicate that new trials with a low risk of bias are needed to obtain conclusive evidence of efficacy for many of these interventions. Study registration Prospero CRD42016035662

Incentive spirometry prescription and inspiratory capacity recovery guideline for the early period after open heart surgery

Incentive spirometry (IS) is often used as lung expansion therapy for increasing postoperative IS inspiratory capacity (ISIC) in open heart surgery (OHS) patients. However, currently there is a lack of guidelines and prescription on how this therapy should be administered for these patients. Although there is some information on several patient- and surgery- related factors associated with ISIC volumes after OHS, the role of IS performance variables such as IS inspiration volumes (ISv) and IS inspiration frequency (ISf) has not been investigated. In order to formulate evidence-based IS therapy guidelines and prescription, this study investigated factors, which included ISv and ISf, to identify predictors of ISIC recovery in a cohort of OHS patients in Hospital Sultanah Aminah, Johor Bahru (HSAJB). This study involved collection of objective and precise IS performance data of 95 OHS patients using a newly developed and validated multisensor data collection device (ISDCD) for five consecutive postoperative days (POD). Data analysis identified ISv as the sole predictor of ISIC recovery which explaines 23%, 24%, 17% and 25% of variances for ISIC recovery on POD2, POD3, POD4 and POD5 respectively. Three pathways for postoperative ISIC recovery were also identified, namely for patients following the fastest pathway having the highest ISIC recovery rate of 19% for each POD, followed by 16% for the middle pathway and 12% for slowest. The findings facilitated the formulation of evidence-based IS therapy prescription and ISIC recovery guidelines from POD1 to POD4. However, these findings need to be verified further through research involving comprehensive and objective evaluation of IS performance using appropriate technology devices

Resistant Hypertension

The most common causes of therapeutic failure in hypertensive control are undiscovered secondary causes of hypertension and lack of patient/doctor compliance. In about 10% of cases, it can be attributed to resistant hypertension caused by a hyperactivity of the sympathetic nervous system, condition with a high cardiovascular risk to the patient. Resistant hypertension is failure to diminish blood pressure values to <140/90 mmHg (<140/85 mmHg for diabetic patients) with a lifestyle method and prescription of least three antihypertensive drugs in optimal doses, including a diuretic, or when patients use four or more antihypertensive drugs regardless of blood pressure control. Patients with resistant hypertension are typically presented with a long-standing history of poorly controlled hypertension. Early diagnosis and adequate treatment are needed to avoid end organ damage and to prevent cardiorenovascular remodeling. Cardiorenovascular morbidity and mortality are significantly higher in resistant hypertensive population. The need for the individualization of therapy and the use of the management strategies are also given weight in the treatment of resistant hypertension patients, including optional, innovative therapies, like a renal denervation or baroreflex activation. New innovative device therapies create an additional novel pathway of blood pressure-lowering procedures and should be prescribed by a specialist hypertension clinic