Lung Ultrasound Reproducibly Outperforms Computed Tomography in the Detection of Extravascular Lung Water in Patients Undergoing Haemodialysis.

BACKGROUND: Lung ultrasound (LUS) is increasingly used as an extension of physical examination, informing clinical diagnosis, and decision making. There is particular interest in the assessment of patients with pulmonary congestion and extravascular lung water, although gaps remain in the evidence base underpinning this practice as a result of the limited evaluation of its inter-rater reliability and comparison with more established radiologic tests. METHODS: 30 patients undergoing haemodialysis were prospectively recruited to an observational cohort study (NCT01949402). Patients underwent standardised LUS assessment before, during and after haemodialysis; their total LUS B-line score was generated, alongside a binary label of whether appearances were consistent with an interstitial syndrome. LUS video clips were recorded and independently scored by two blinded expert clinician sonographers. Low-dose non-contrast thoracic CT, pre- and post dialysis, was used as a "gold standard" radiologic comparison. RESULTS: LUS detected a progressive reduction in B-line scores in almost all patients undergoing haemodialysis, correlating with the volume of fluid removed once individuals with no or minimal B-lines upon pre-dialysis examination were discounted. When comparing CT scans pre- and post dialysis, radiologic evidence of the change in fluid status was only identified in a single patient. CONCLUSIONS: This is the first study to demonstrate that LUS detects changes in extravascular lung water caused by changing fluid status during haemodialysis using a blinded outcome assessment and that LUS appears to be more sensitive than CT for this purpose. Further research is needed to better understand the role of LUS in this and similar patient populations, with the aim of improving clinical care and outcomes.

How clinicians make decisions for patient management plans in telehealth.

AIM: This systematic integrative literature review explores how clinicians make decisions for patient management plans in telehealth. BACKGROUND: Telehealth is a modality of care that has gained popularity due to the development of digital technology and the COVID-19 pandemic. It is recognized that telehealth, compared to traditional clinical settings, carries a higher risk to patients due to its virtual characteristics. Even though the landscape of healthcare service is increasingly moving towards virtual systems, the decision-making process in telehealth remains not fully understood. DESIGN: A systematic integrative review. DATA SOURCES: Databases include CINAHL, APA PsycInfo, Academic Search Complete, PubMed, Web of Science and Google Scholar. REVIEW METHODS: This systematic integrative review method was informed by Whittemore and Knafl (2005). The databases were initially searched with keywords in November 2022 and then repeated in October 2023. Thematic synthesis was conducted to analyse and synthesize the data. RESULTS: The search identified 382 articles. After screening, only 10 articles met the eligibility criteria and were included. Five studies were qualitative, one quantitative and four were mixed methods. Five main themes relevant to decision-making processes in telehealth were identified: characteristics of decision-making in telehealth, patient factor, clinician factor, CDSS factor and external influencing factor. CONCLUSIONS: The decision-making process in telehealth is a complicated cognitive process influenced by multi-faceted components, including patient factors, clinician factors, external influencing factors and technological factors. IMPACT: Telehealth carries higher risk and uncertainty than face-to-face encounters. CDSS, rather than bringing unification and clarity, seems to bring more divergence and ambiguity. Some of the clinical reasoning processes in telehealth remain unknown and need to be verbalized and made transparent, to prepare junior clinicians with skills to minimize risks associated with telehealth. PATIENT OR PUBLIC CONTRIBUTION: Not applicable.

'You see the empty bed which means it's either a transplant or a death': a qualitative study exploring the impact of death in the haemodialysis community.

OBJECTIVE: To explore the impact of the death of a patient in the haemodialysis unit on fellow patients. METHODS: We interviewed patients on dialysis in a tertiary dialysis centre using semistructured interviews. We purposively sampled patients who had experienced the death of a fellow patient. After interviews were transcribed, they were thematically analysed by independent members of the research team using inductive analysis. Input from the team during analysis ensured the rigour and quality of the findings. RESULTS: 10 participants completed the interviews (6 females and 4 males with an age range of 42-88 years). The four core themes that emerged from the interviews included: (1) patients' relationship to haemodialysis, (2) how patients define the haemodialysis community, (3) patients' views on death and bereavement and (4) patients' expectations around death in the dialysis community. Patients noticed avoidance behaviour by staff in relation to discussing death in the unit and would prefer a culture of open acknowledgement. CONCLUSION: Staff acknowledgement of death is of central importance to patients on haemodialysis who feel that the staff are part of their community. This should guide the development of appropriate bereavement support services and a framework that promotes the provision of guidance for staff and patients in this unique clinical setting. However, the authors acknowledge the homogenous sample recruited in a single setting may limit the transferability of the study. Further work is needed to understand diverse patient and nurse experiences and perceptions when sharing the knowledge of a patient's death and how they react to loss.

Accelerometer-measured physical activity and functional behaviours among people on dialysis.

BACKGROUND: The feasibility of wrist-worn accelerometers, and the patterns and determinants of physical activity, among people on dialysis are uncertain. METHODS: People on maintenance dialysis were fitted with a wrist-worn AxivityAX3 accelerometer. Subsets also wore a 14-day electrocardiograph patch (Zio®PatchXT) and wearable cameras. Age-, sex- and season-matched UK Biobank control groups were derived for comparison. RESULTS: Median (interquartile range) accelerometer wear time for the 101 recruits was 12.5 (10.4-13.5) days, of which 73 participants (mean age 66.5 years) had excellent wear on both dialysis and non-dialysis days. Mean (standard error) overall physical activity levels were 15.5 (0.7) milligravity units (mg), 14.8 (0.7) mg on dialysis days versus 16.2 (0.8) mg on non-dialysis days. This compared with 28.1 (0.5) mg for apparently healthy controls, 23.4 (0.4) mg for controls with prior cardiovascular disease (CVD) and/or diabetes mellitus and 22.9 (0.6) mg for heart failure controls. Each day, we estimated that those on dialysis spent an average of about 1 hour (h/day) walking, 0.6 h/day engaging in moderate-intensity activity, 0.7 h/day on light tasks, 13.2 h/day sedentary and 8.6 h/day asleep. Older age and self-reported leg weakness were associated with decreased levels of physical activity, but the presence of prior CVD, arrhythmias and listing for transplantation were not. CONCLUSIONS: Wrist-worn accelerometers are an acceptable and reliable method to measure physical activity in people on dialysis and may also be used to estimate functional behaviours. Among people on dialysis, who are broadly half as active as general population controls, age and leg weakness appear to be more important determinants of low activity levels than CVD.

A cross-sectional study exploring levels of physical activity and motivators and barriers towards physical activity in haemodialysis patients to inform intervention development.

PURPOSE: To describe physical activity (PA) levels and motivators and barriers to PA amongst haemodialysis (HD) patients and to identify an appropriate approach to increasing their PA. METHODS: A cross-sectional mixed methods study conducted in a tertiary and satellite HD unit. One hundred and one participants aged 18 years and over, receiving regular HD for at least four months, were recruited. Patients with recent hospital admission or acute cardiac event were excluded. Participants completed health status (EQ-5D-3L™) and activity (Human Activity Profile (HAP)) questionnaires. A subgroup was invited to wear accelerometers and wearable cameras to measure PA levels and capture PA episodes, to inform subsequent semi-structured interviews on motivators and barriers. Semi-structured interviews were analysed using the framework method informed by constructs of the Health Belief Model. RESULTS: 98/101 completed the study (66 males, 32 females). For 68/98 participants, adjusted activity scores from the HAP indicated "impaired" levels of PA; for 67/98 participants, the EQ-5D-3L indicated problems with mobility. Semi-structured interviews identified general (fear of falls, pain) and disease specific barriers (fatigue) to PA. Motivators included tailored exercise programmes and educational support from health care professionals. CONCLUSIONS: Participants indicated a need for co-development with healthcare professionals of differentiated, targeted exercise interventions.Implications for rehabilitationHealthcare professionals should encourage and motivate haemodialysis patients to participate in physical activity (PA).As part of this approach, there is a need to increase patient knowledge of safe beneficial exercise activities and help individuals identify and overcome barriers.To allow for individualised approaches, clinical interventions should focus on other community activities that patients can do outside the dialysis clinic setting and utilise existing networks such as the British Renal Society Rehabilitation Network.The dialysis clinic provides professionals the opportunity to monitor and motivate patients.Relevant education is needed for staff about the benefits of PA and how to engage patients and their carers in safe and effective approaches.

Non-contact vital-sign monitoring of patients undergoing haemodialysis treatment.

A clinical study was designed to record a wide range of physiological values from patients undergoing haemodialysis treatment in the Renal Unit of the Churchill Hospital in Oxford. Video was recorded for a total of 84 dialysis sessions from 40 patients during the course of 1 year, comprising an overall video recording time of approximately 304.1 h. Reference values were provided by two devices in regular clinical use. The mean absolute error between the heart rate estimates from the camera and the average from two reference pulse oximeters (positioned at the finger and earlobe) was 2.8 beats/min for over 65% of the time the patient was stable. The mean absolute error between the respiratory rate estimates from the camera and the reference values (computed from the Electrocardiogram and a thoracic expansion sensor-chest belt) was 2.1 breaths/min for over 69% of the time for which the reference signals were valid. To increase the robustness of the algorithms, novel methods were devised for cancelling out aliased frequency components caused by the artificial light sources in the hospital, using auto-regressive modelling and pole cancellation. Maps of the spatial distribution of heart rate and respiratory rate information were developed from the coefficients of the auto-regressive models. Most of the periods for which the camera could not produce a reliable heart rate estimate lasted under 3 min, thus opening the possibility to monitor heart rate continuously in a clinical environment.

Validation of Modelflow Estimates of Cardiac Output in Hemodialysis Patients.

Volume-clamp technology (e.g. Finometer) has become a popular method of collecting continuous, non-invasive, hemodynamic information during hemodialysis. There is minimal data validating the technique in this patient group. A gold standard cardiac output measurement can be obtained using ultrasound dilution in patients with arterio-venous fistulae. Continuous cardiac output was measured in 124 hemodialysis sessions in 27 patients using a volume-clamp device (Finometer PRO). Ultrasound dilution measurement was first taken at baseline (Transonic HD03), then used to calibrate the Finometer. Ultrasound dilution measurement was repeated 2 h into hemodialysis to assess drift following calibration. Pearson's correlation and Bland-Altman statistics, modified for repeated measures, were used to assess agreement between methods. Linear mixed models were constructed to identify factors that could explain session-level and patient-level variation in agreement. For baseline cardiac output before calibration, agreement between volume-clamp and ultrasound dilution measurements was poor, at 25 ± 75% (correlation 0.26, P < 0.001). There was significant variation in agreement between patients, with age, peripheral vascular disease and hemodialysis vintage contributing to poorer agreement. For cardiac output 2 h after calibration, agreement was -5.2 ± 57.5% (correlation 0.6, P < 0.001). Dynamic changes in blood pressure and fluid balance during hemodialysis resulted in greater drift over time after calibration. There was a large error, both random and systematic, in volume-clamp estimates of absolute, pre-calibration cardiac output in this prevalent hemodialysis population. There was minimal bias and reasonable correlation for cardiac output 2 h post-calibration, but limits of agreement remained too wide to meet current clinical standards.

Relationship between Hypotension and Cerebral Ischemia during Hemodialysis.

The relationship between BP and downstream ischemia during hemodialysis has not been characterized. We studied the dynamic relationship between BP, real-time symptoms, and cerebral oxygenation during hemodialysis, using continuous BP and cerebral oxygenation measurements prospectively gathered from 635 real-world hemodialysis sessions in 58 prevalent patients. We examined the relationship between BP and cerebral ischemia (relative drop in cerebral saturation >15%) and explored the lower limit of cerebral autoregulation at patient and population levels. Furthermore, we estimated intradialytic exposure to cerebral ischemia and hypotension for each patient, and entered these values into multivariate models predicting change in cognitive function. In all, 23.5% of hemodialysis sessions featured cerebral ischemia; 31.9% of these events were symptomatic. Episodes of hypotension were common, with mean arterial pressure falling by a median of 22 mmHg (interquartile range, 14.3-31.9 mmHg) and dropping below 60 mmHg in 24% of sessions. Every 10 mmHg drop from baseline in mean arterial pressure associated with a 3% increase in ischemic events (P<0.001), and the incidence of ischemic events rose rapidly below an absolute mean arterial pressure of 60 mmHg. Overall, however, BP poorly predicted downstream ischemia. The lower limit of cerebral autoregulation varied substantially (mean 74.1 mmHg, SD 17.6 mmHg). Intradialytic cerebral ischemia, but not hypotension, correlated with decreased executive cognitive function at 12 months (P=0.03). This pilot study demonstrates that intradialytic cerebral ischemia occurs frequently, is not easily predicted from BP, and may be clinically significant.

The relationship between symptoms and blood pressure during maintenance hemodialysis.

Intradialytic hypotension (IDH) is a detrimental complication of maintenance hemodialysis, but how it is defined and reported varies widely in the literature. European Best Practice Guideline and Kidney Disease Outcomes Quality Initiative guidelines require symptoms and a mitigating intervention to fulfill the diagnosis, but morbidity and mortality outcomes are largely based on blood pressure alone. Furthermore, little is known about the incidence of asymptomatic hypotension, which may be an important cause of hypoperfusion injury and impaired outcome. Seventy-seven patients were studied over 456 dialysis sessions. Blood pressure was measured at 15-minute intervals throughout the session and compared with post-dialysis symptom questionnaire results using mixed modeling to adjust for repeated measures in the same patient. The frequency of asymptomatic hypotension was estimated by logistic regression using a variety of commonly cited blood pressure metrics that describe IDH. In 113 sessions (25%) where symptoms were recorded on the questionnaire, these appear not to have been reported to dialysis staff. When symptoms were reported (293 sessions [64%]), an intervention invariably followed. Dizziness and cramp were strongly associated with changes in systolic blood pressure (SBP), but not diastolic blood pressure. Nausea occurred more frequently in younger patients but was not associated with falls in blood pressure. Thresholds that maximized the probability of an intervention rather than a session remaining asymptomatic were SBP <100 mmHg or a 20% reduction in SBP from baseline. The probability of SBP falling to <100 mmHg in an asymptomatic session was 0.23. Symptoms are frequently not reported by patients who are hypotensive during hemodialysis, which leads to an underestimation of IDH if symptom-based definitions are used. A revised definition of IDH excluding patient-reported symptoms would be in line with literature reporting morbidity and mortality outcomes and include sessions in which potentially detrimental asymptomatic hypotension occurs.