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3.
Sci Rep ; 11(1): 4200, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33603086

RESUMO

Since its emergence in late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic with more than 55 million reported cases and 1.3 million estimated deaths worldwide. While epidemiological and clinical characteristics of COVID-19 have been reported, risk factors underlying the transition from mild to severe disease among patients remain poorly understood. In this retrospective study, we analysed data of 879 confirmed SARS-CoV-2 positive patients admitted to a two-site NHS Trust hospital in London, England, between January 1st and May 26th, 2020, with a majority of cases occurring in March and April. We extracted anonymised demographic data, physiological clinical variables and laboratory results from electronic healthcare records (EHR) and applied multivariate logistic regression, random forest and extreme gradient boosted trees. To evaluate the potential for early risk assessment, we used data available during patients' initial presentation at the emergency department (ED) to predict deterioration to one of three clinical endpoints in the remainder of the hospital stay: admission to intensive care, need for invasive mechanical ventilation and in-hospital mortality. Based on the trained models, we extracted the most informative clinical features in determining these patient trajectories. Considering our inclusion criteria, we have identified 129 of 879 (15%) patients that required intensive care, 62 of 878 (7%) patients needing mechanical ventilation, and 193 of 619 (31%) cases of in-hospital mortality. Our models learned successfully from early clinical data and predicted clinical endpoints with high accuracy, the best model achieving area under the receiver operating characteristic (AUC-ROC) scores of 0.76 to 0.87 (F1 scores of 0.42-0.60). Younger patient age was associated with an increased risk of receiving intensive care and ventilation, but lower risk of mortality. Clinical indicators of a patient's oxygen supply and selected laboratory results, such as blood lactate and creatinine levels, were most predictive of COVID-19 patient trajectories. Among COVID-19 patients machine learning can aid in the early identification of those with a poor prognosis, using EHR data collected during a patient's first presentation at ED. Patient age and measures of oxygenation status during ED stay are primary indicators of poor patient outcomes.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33525997

RESUMO

RATIONALE: Late recognition of patient deterioration in hospital is associated with worse outcomes, including higher mortality. Despite the widespread introduction of early warning score systems and electronic health records, deterioration still goes unrecognised. OBJECTIVES: To develop and externally validate a Hospital-wide Alerting Via Electronic Noticeboard (HAVEN) system to identify hospitalised patients at risk of reversible deterioration. METHODS: A retrospective cohort study of patients 16 years of age or above admitted to four UK hospitals. The primary outcome was cardiac arrest or unplanned admission to the intensive care unit (ICU). We used patient data (vital signs, laboratory tests, comorbidities, frailty) from one hospital to train a machine learning model (gradient boosting trees). We internally and externally validated the model and compared its performance to existing scoring systems (including NEWS, LAPS-2 and eCART). MEASUREMENTS AND MAIN RESULTS: We developed the HAVEN model using 230,415 patient admissions to a single hospital. We validated HAVEN on 266,295 admissions to four hospitals. HAVEN showed substantially higher discrimination (c-statistic 0.901 [95% CI 0.898-0.903]) for the primary outcome within 24 h of each measurement than other published scoring systems (which range from 0.700 [0.696-0.704] to 0.863 [0.860-0.865]). With a precision of 10%, HAVEN was able to identify 42% of cardiac arrests or unplanned ICU admissions with a lead time of up to 48 h in advance, compared to 22% by the next best system. CONCLUSION: The HAVEN machine learning algorithm for early identification of in-hospital deterioration significantly outperforms other published scores such as NEWS.

5.
Obstet Gynecol ; 137(2): 295-304, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33417320

RESUMO

OBJECTIVE: To estimate normal ranges for postpartum maternal vital signs. METHODS: We conducted a multicenter prospective longitudinal cohort study in the United Kingdom. We recruited women before 20 weeks of gestation without significant comorbidities and with accurately dated singleton pregnancies. Women recorded their own blood pressure, heart rate, oxygen saturation and temperature daily for 2 weeks postpartum. Trained midwives measured participants' vital signs including respiratory rate around postpartum days 1, 7, and 14. RESULTS: From August 2012 to September 2016, we screened 4,279 pregnant women; 1,054 met eligibility criteria and chose to take part. Postpartum vital sign data were available for 909 women (86.2%). Median, or 50th centile (3rd-97th centile), systolic and diastolic blood pressures increased from the day of birth: 116 mm Hg (88-147) and 74 mm Hg (59-93) to a maximum median of 121 mm Hg (102-143) and 79 mm Hg (63-94) on days 5 and 6 postpartum, respectively, an increase of 5 mm Hg (95% CI 3-7) and 5 mm Hg (95% CI 4-6), respectively. Median (3rd-97th centile) systolic and diastolic blood pressure returned to 116 mm Hg (98-137) and 75 mm Hg (61-91) by day 14 postpartum. The median (3rd-97th centile) heart rate was highest on the day of birth, 84 beats per minute (bpm) (59-110) decreasing to a minimum of 75 bpm (55-101) 14 days postpartum. Oxygen saturation, respiratory rate, and temperature did not change in the 2 weeks postbirth. Median (3rd-97th centile) day-of-birth oxygen saturation was 96% (93-98). Median (3rd-97th centile) day-of-birth respiratory rate was 15 breaths per minute (10-22). Median (3rd-97th centile) day-of-birth temperature was 36.7°C (35.6-37.6). CONCLUSION: We present widely relevant, postpartum, day-specific reference ranges which may facilitate early detection of abnormal blood pressure, heart rate, respiratory rate, oxygen saturation and temperature during the puerperium. Our findings could inform construction of an evidence-based modified obstetric early warning system to better identify unwell postpartum women. CLINICAL TRIAL REGISTRATION: ISRCTN, 10838017.

6.
Appl Ergon ; 90: 103149, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32866689

RESUMO

BACKGROUND: Infra-red and thermal imaging enable wireless systems to monitor patients' vital signs and absence of wires may improve patient experiences. No studies have explored staff perceptions of the concept of this specific type of technology in the adult population. Understanding existing working systems before introducing technology could improve adoption. METHODS: We conducted semi-structured interviews with Intensive Care Unit (ICU) staff exploring perceptions of wireless patient monitoring. We used the Systems Engineering Initiative for Patient Safety (SEIPS) model to guide thematic analysis. RESULTS: We identified usability themes relating to staff perceptions of current patient monitoring experiences, staff perceptions of patient/relative expectations of ICU care, troubleshooting, hierarchy of monitoring, and consensus of trust. CONCLUSION: The concept of wireless monitoring has perceived benefits for patients and staff. The Systems Engineering Initiative for Patient Safety model guided a systems-based exploratory evaluation. Results highlight the social and environmental factors which may influence usability, adoption, or abandonment of wireless technology in the ICU.

7.
JMIR Mhealth Uhealth ; 8(12): e20214, 2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33325827

RESUMO

BACKGROUND: Timely recognition of patient deterioration remains challenging. Ambulatory monitoring systems (AMSs) may provide support to current monitoring practices; however, they need to be thoroughly tested before implementation in the clinical environment for early detection of deterioration. OBJECTIVE: The objective of this study was to assess the wearability of a selection of commercially available AMSs to inform a future prospective study of ambulatory vital sign monitors in an acute hospital ward. METHODS: Five pulse oximeters (4 with finger probes and 1 wrist-worn only, collecting pulse rates and oxygen saturation) and 2 chest patches (collecting heart rates and respiratory rates) were selected to be part of this study: The 2 chest-worn patches were VitalPatch (VitalConnect) and Peerbridge Cor (Peerbridge); the 4 wrist-worn devices with finger probe were Nonin WristOx2 3150 (Nonin), Checkme O2+ (Viatom Technology), PC-68B, and AP-20 (both from Creative Medical); and the 1 solely wrist-worn device was Wavelet (Wavelet Health). Adult participants wore each device for up to 72 hours while performing usual "activities of daily living" and were asked to score the perceived exertion and perception of pain or discomfort by using the Borg CR-10 scale; thoughts and feelings caused by the AMS using the Comfort Rating Scale (CRS); and to provide general free text feedback. Median and IQRs were reported and nonparametric tests were used to assess differences between the devices' CRS scores. RESULTS: Quantitative scores and feedback were collected in 70 completed questionnaires from 20 healthy volunteers, with each device tested approximately 10 times. The Wavelet seemed to be the most wearable device (P<.001) with an overall median (IQR) CRS score of 1.00 (0.88). There were no statistically significant differences in wearability between the chest patches in the CRS total score; however, the VitalPatch was superior in the Attachment section (P=.04) with a median (IQR) score of 3.00 (1.00). General pain and discomfort scores and total percentage of time worn are also reflective of this. CONCLUSIONS: Our results suggest that adult participants prefer to wear wrist-worn pulse oximeters without a probe compressing the fingertip and they prefer to wear a smaller chest patch. A compromise between wearability, reliability, and accuracy should be made for successful and practical integration of AMSs within the hospital environment.

8.
Health Expect ; 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33316120

RESUMO

BACKGROUND: Having a stroke or transient ischaemic attack increases the risk of a subsequent one, especially with high blood pressure (BP). Home-based BP management can be effective at maintaining optimal BP. OBJECTIVE: To describe the optimization of a digital intervention for stroke patients and the value of participant diversity, using the person-based approach (PBA) and integral patient and public involvement (PPI). SETTING AND PARTICIPANTS: Stroke patients recruited from primary care and community settings, and health-care professionals in primary care, in England and Ireland. DESIGN: Three linked qualitative studies conducted iteratively to develop an intervention using the PBA, with integral PPI. INTERVENTION: The BP: Together intervention, adapted from existing BP self-monitoring interventions, is delivered via mobile phone or web interface to support self-monitoring of BP at home. It alerts patients and their clinicians when a change in antihypertensive medication is needed. FINDINGS: Feedback from a diverse range of participants identified potential barriers, which were addressed to improve the intervention accessibility, feasibility and persuasiveness. Easy-to-read materials were developed to improve usability for patients with aphasia and lower literacy. The importance of including family members who support patient care was also highlighted. Feedback messages regarding medication change were refined to ensure usefulness for patients and clinicians. DISCUSSION: Input from PPI alongside qualitative research with a diverse study sample allowed the creation of a simple and equitable BP management intervention for stroke patients. PATIENT INVOLVEMENT: Two PPI co-investigators contributed to design, conduct of study, data interpretation and manuscript preparation; community PPI sessions informed early planning. Study participants were stroke patients and family members.

9.
Sci Rep ; 10(1): 18529, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33116150

RESUMO

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.

10.
Resuscitation ; 156: 99-106, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32918984

RESUMO

BACKGROUND: The global pandemic of coronavirus disease 2019 (COVID-19) has placed a huge strain on UK hospitals. Early studies suggest that patients can deteriorate quickly after admission to hospital. The aim of this study was to model changes in vital signs for patients hospitalised with COVID-19. METHODS: This was a retrospective observational study of adult patients with COVID-19 admitted to one acute hospital trust in the UK (CV) and a cohort of patients admitted to the same hospital between 2013-2017 with viral pneumonia (VI). The primary outcome was the start of continuous positive airway pressure/non-invasive positive pressure ventilation, ICU admission or death in hospital. We used non-linear mixed-effects models to compare changes in vital sign observations prior to the primary outcome. Using observations and FiO2 measured at discharge in the VI cohort as the model of normality, we also combined individual vital signs into a single novelty score. RESULTS: There were 497 cases of COVID-19, of whom 373 had been discharged from hospital. 135 (36.2%) of patients experienced the primary outcome, of whom 99 died in hospital. In-hospital mortality was over 4-times higher in the CV than the VI cohort (26.5% vs 6%). For those patients who experienced the primary outcome, CV patients became increasingly hypoxaemic, with a median estimated FiO2 (0.75) higher than that of the VI cohort (estimated FiO2 of 0.35). Prior to the primary outcome, blood pressure remained within normal range, and there was only a small rise in heart rate. The novelty score showed that patients with COVID-19 deteriorated more rapidly that patients with viral pneumonia. CONCLUSIONS: Patients with COVID-19 who deteriorate in hospital experience rapidly-worsening respiratory failure, with low SpO2 and high FiO2, but only minor abnormalities in other vital signs. This has potential implications for the ability of early warning scores to identify deteriorating patients.


Assuntos
Betacoronavirus , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Triagem/métodos , Sinais Vitais , Idoso , Idoso de 80 Anos ou mais , Infecções por Coronavirus/epidemiologia , Feminino , Mortalidade Hospitalar/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Reino Unido/epidemiologia
11.
IEEE Trans Biomed Eng ; PP2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32746016

RESUMO

Skin temperature has long been used as a natural indicator of vascular diseases in the extremities. Considerable correlation between oscillations in skin surface temperature and oscillations of skin blood flow has previously been demonstrated. We hypothesised that the impairment of blood flow in stenotic (subcutaneous) peripheral arteries would influence cutaneous temperature such that, by measuring gradients in the temperature distribution over skin surfaces, one may be able to diagnose or quantify the progression of vascular conditions in whose pathogenesis a reduction in subcutaneous blood perfusion plays a critical role (e.g. peripheral artery disease). As proof of principle, this study investigates the local changes in the skin temperature of healthy humans (15 male, 30.0 ± 5.2 years old, BMI 25.1 ± 2.2 kg/m 2) undergoing two physical challenges designed to vary their haemodynamic status. Skin temperature was measured in four central regions (forehead, neck, chest, and left shoulder) and four peripheral regions (left upper arm, forearm, wrist, and hand) using an infrared thermal camera. We compare inter-region patterns. Median temperature over the peripheral regions decreased from baseline after both challenges (maximum decrease: -2.09 ± 0.41 °C at 60 s after exercise; p = 0.0001 and -0.58 ± 0.14 °C at 180 s of cold-water immersion; p = 0.0013). Median temperature over the central regions showed no significant changes. Our results show that the non-contact measurement of perfusion-related changes in peripheral temperature from infrared video data is feasible. Further research will be directed towards the thermographic study of patients with symptomatic peripheral vascular disease.

12.
Artigo em Inglês | MEDLINE | ID: mdl-32477588

RESUMO

Background: Hip fracture is common, affecting 20% of women and 10% of men during their lifetime. The trajectory of patients' recovery as they transition from the acute hospital setting to their usual residence is poorly understood. Recently, the use of activity trackers to monitor physical activity during recovery has been investigated as a way to explore this trajectory. Methods: This prospective observational cohort study followed patients from hospital to home as they recovered from a hip fracture. Participants were recruited from a single centre and provided with a 3-axis logging accelerometer worn as a pendant, for 16 weeks from recruitment. Participants received monthly follow-up visits which included questions about wearing the monitor. Monthly activity monitor data were also downloaded. Participant activity was estimated from the monitor data using the calibrated "Euclidean Norm Minus One" (ENMO) metric. Polynomial mixed-effects modelling was used to evaluate the difference between the weekly activity trends of 2 groups of participants: those with and without independent mobility at 16 weeks (defined by whether aids or personal assistance were required to mobilise). Results: Twenty-nine participants from 125 eligible patients were recruited. Of these, 19 (66%) reported being aware of wearing the monitor at least some of the time. Fourteen (48%) participants withdrew before study completion. Data for thirteen (45%) participants were of sufficient quantity to be included in the activity modelling procedure. Of these, 8 reported independent mobility at 16 weeks post-surgery, and 5 did not. By week 7, the weekly predicted mean ENMO ( ENMO ¯ W ) values were significantly different between the two participant groups, demonstrating feasibility of the model's ability to predict which patients will report independent mobility at 16 weeks. Conclusions: This is the first study to our knowledge to investigate acceptability and feasibility of a pendant-worn activity monitor in this patient cohort. Acceptability of wearing the monitor and feasibility of recruitment and retention of participants were limited. Future research into the use of activity monitors in this population should use minimally intrusive devices which are acceptable to this population. Study registration: MoHIP is a sub-study of the World Hip Trauma Evaluation (WHiTE) Study (ISRCTN 63982700).

13.
BMJ Open ; 10(6): e036235, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32532774

RESUMO

INTRODUCTION: Skin perfusion varies in response to changes in the circulatory status. Blood flow to skin is reduced during haemodynamic collapse secondary to peripheral vasoconstriction, whereas increased skin perfusion is frequently observed when haemodynamics improve with resuscitation. These changes in perfusion may be monitored using non-contact image-based methods. Previous camera-derived physiological measurements have focused on accurate vital signs monitoring and extraction of physiological signals from environmental noise. One of the biggest challenges of camera-derived monitoring is artefacts from motion, which limits our understanding of what parameters may be derived from skin. In this study, we use phenylephrine and glyceryl trinitrate (GTN) to cause vasoconstriction and vasodilation in stationary healthy volunteers to describe directional changes in skin perfusion pattern. METHODS AND ANALYSIS: We aim to recruit 30 healthy volunteers who will undergo protocolised infusions of phenylephrine and GTN, followed by the monitored and timed release of a thigh tourniquet. The experimental timeline will be identical for all participants. Measurements of traditionally used haemodynamic markers (heart rate, blood pressure and stroke volume) and camera-derived measurements will be taken concurrently throughout the experimental period. The parameters of interest from the image data are skin colour and pattern, skin surface temperature, pulsatile signal detected at the skin surface and skin perfusion index. ETHICS AND DISSEMINATION: This study was reviewed and approved by the Oxford University Research and Ethics Committee and Clinical Trials and Research Governance teams (R63796/RE001). The results of this study will be presented at scientific conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN10417167.

14.
Heart ; 106(20): 1573-1578, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32580977

RESUMO

OBJECTIVES: We aimed to investigate whether digital home monitoring with centralised specialist support for remote management of heart failure (HF) is more effective in improving medical therapy and patients' quality of life than digital home monitoring alone. METHODS: In a two-armed partially blinded parallel randomised controlled trial, seven sites in the UK recruited a total of 202 high-risk patients with HF (71.3 years SD 11.1; left ventricular ejection fraction 32.9% SD 15.4). Participants in both study arms were given a tablet computer, Bluetooth-enabled blood pressure monitor and weighing scales for health monitoring. Participants randomised to intervention received additional regular feedback to support self-management and their primary care doctors received instructions on blood investigations and pharmacological treatment. The primary outcome was the use of guideline-recommended medical therapy for chronic HF and major comorbidities, measured as a composite opportunity score (total number of recommended treatment given divided by the total number of opportunities the treatment should have been given, with a score 1 indicating 100% adherence to recommendations). Co-primary outcome was change in physical score of Minnesota Living with Heart Failure questionnaire. RESULTS: 101 patients were randomised to 'enhanced self-management' and 101 to 'supported medical management'. At the end of follow-up, the opportunity score was 0.54 (95% CI 0.46 to 0.62) in the control arm and 0.61 (95% CI 0.52 to 0.70) in the intervention arm (p=0.25). Physical well-being of participants also did not differ significantly between the groups (17.4 (12.4) mean (SD) for control arm vs 16.5 (12.1) in treatment arm; p for change=0.84). CONCLUSIONS: Central provision of tailored specialist management in a multi-morbid HF population was feasible. However, there was no strong evidence for improvement in use of evidence-based treatment nor health-related quality of life. TRIAL REGISTRATION NUMBER: ISRCTN86212709.

16.
Open Heart ; 7(1): e001099, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32153787

RESUMO

Objective: The impact of heart failure (HF) on perceived and objectively measured levels of physical activity (PA) can inform risk stratification and treatment recommendation. We aimed to compare self-reported and objectively measured PA levels in a large sample of participants with and without HF. Methods: A validated PA questionnaire was used to estimate self-reported weekly PA among 1600 participants with HF and 387 580 participants without HF. Accelerometer data were studied in 596 participants with HF and 96 105 participants without HF for a period of 7 days. Using multivariable linear regression models, we compared the PA levels between participants with HF and without HF, focusing on both the average daily PA levels and the intensity of PAs throughout the day. Results: PA levels were significantly lower in participants with HF using both self-report (excess metabolic equivalent of task hours per week of 26.5 (95% CI 24.7 to 28.4) vs 34.7 (95% CI 34.5 to 34.9), respectively (p<0.001)) and accelerometer measures (mean accelerations of 23.7 milligravity (95% CI 23.1 to 24.4) vs 28.1 milligravity (95% CI 28.0 to 28.1), respectively (p<0.001)). Findings were consistent across different PA intensities. Hour-by-hour comparisons showed that accelerometer-derived PA levels of patients with HF were reduced throughout the day. Conclusion: Perceived and objectively recorded PA levels of patients with chronic HF are significantly lower than those of individuals without HF. This difference is continuous throughout the different hours of the day, with individuals with HF being on average 16% less active than individuals without HF. In patients with HF, increases in everyday activity may be a potential alternative to structured exercise programmes.


Assuntos
Actigrafia/instrumentação , Exercício Físico , Monitores de Aptidão Física , Insuficiência Cardíaca/fisiopatologia , Comportamento Sedentário , Autorrelato , Adulto , Idoso , Estudos de Casos e Controles , Doença Crônica , Estudos Transversais , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Fatores de Tempo , Reino Unido/epidemiologia
17.
Obstet Gynecol ; 135(3): 653-664, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32028507

RESUMO

OBJECTIVE: To estimate normal ranges for maternal vital signs throughout pregnancy, which have not been well defined in a large contemporary population. METHODS: We conducted a three-center, prospective, longitudinal cohort study in the United Kingdom from August 2012 to September 2017. We recruited women at less than 20 weeks of gestation without significant comorbidities with accurately dated singleton pregnancies. We measured participants' blood pressure (BP), heart rate, respiratory rate, oxygen saturation and temperature following standardized operating procedures at 4-6 weekly intervals throughout pregnancy. RESULTS: We screened 4,279 pregnant women, 1,041 met eligibility criteria and chose to take part. Systolic and diastolic BP decreased slightly from 12 weeks of gestation: median or 50th centile (3rd-97th centile) 114 (95-138); 70 (56-87) mm Hg to reach minimums of 113 (95-136); 69 (55-86) mm Hg at 18.6 and 19.2 weeks of gestation, respectively, a change (95% CI) of -1.0 (-2 to 0); -1 (-2 to -1) mm Hg. Systolic and diastolic BP then rose to a maximum median (3rd-97th centile) of 121 (102-144); 78 (62-95) mm Hg at 40 weeks of gestation, a difference (95% CI) of 7 (6-9) and9 (8-10) mm Hg, respectively. The median (3rd-97th centile) heart rate was lowest at 12 weeks of gestation: 82 (63-105) beats per minute (bpm), rising progressively to a maximum of 91 (68-115) bpm at 34.1 weeks. SpO2 decreased from 12 weeks of gestation: median (3-97 centile) 98% (94-99%) to 97% (93-99%) at 40 weeks. The median (3-97 centile) respiratory rate at 12 weeks of gestation was 15 (9-22), which did not change with gestation. The median (3-97 centile) temperature at 12 weeks of gestation was 36.7 (35.6-37.5)°C, decreasing to a minimum of 36.5 (35.3-37.3)°C at 33.4 weeks. CONCLUSION: We present widely relevant, gestation-specific reference ranges for detecting abnormal BP, heart rate, respiratory rate, oxygen saturation and temperature during pregnancy. Our findings refute the existence of a clinically significant BP drop from 12 weeks of gestation. CLINICAL TRIAL REGISTRATION: ISRCTN, ISRCTN10838017.


Assuntos
Gravidez , Sinais Vitais , Feminino , Humanos , Estudos Longitudinais , Estudos Prospectivos , Valores de Referência
18.
BMJ Open ; 10(1): e034593, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31980512

RESUMO

INTRODUCTION: Self-monitoring of blood pressure (BP) in pregnancy could improve the detection and management of pregnancy hypertension, while also empowering and engaging women in their own care. Two linked trials aim to evaluate whether BP self-monitoring in pregnancy improves the detection of raised BP during higher risk pregnancies (BUMP 1) and whether self-monitoring reduces systolic BP during hypertensive pregnancy (BUMP 2). METHODS AND ANALYSES: Both are multicentre, non-masked, parallel group, randomised controlled trials. Participants will be randomised to self-monitoring with telemonitoring or usual care. BUMP 1 will recruit a minimum of 2262 pregnant women at higher risk of pregnancy hypertension and BUMP 2 will recruit a minimum of 512 pregnant women with either gestational or chronic hypertension. The BUMP 1 primary outcome is the time to the first recording of raised BP by a healthcare professional. The BUMP 2 primary outcome is mean systolic BP between baseline and delivery recorded by healthcare professionals. Other outcomes will include maternal and perinatal outcomes, quality of life and adverse events. An economic evaluation of BP self-monitoring in addition to usual care compared with usual care alone will be assessed across both study populations within trial and with modelling to estimate long-term cost-effectiveness. A linked process evaluation will combine quantitative and qualitative data to examine how BP self-monitoring in pregnancy is implemented and accepted in both daily life and routine clinical practice. ETHICS AND DISSEMINATION: The trials have been approved by a Research Ethics Committee (17/WM/0241) and relevant research authorities. They will be published in peer-reviewed journals and presented at national and international conferences. If shown to be effective, BP self-monitoring would be applicable to a large population of pregnant women. TRIAL REGISTRATION NUMBER: NCT03334149.

19.
Physiol Meas ; 41(2): 025001, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-31978903

RESUMO

OBJECTIVE: Atrial fibrillation (AF) is the most common cardiac arrhythmia, with an estimated prevalence of around 1.6% in the adult population. The analysis of the electrocardiogram (ECG) data acquired in the UK Biobank represents an opportunity to screen for AF in a large sub-population in the UK. The main objective of this paper is to assess ten machine-learning methods for automated detection of subjects with AF in the UK Biobank dataset. APPROACH: Six classical machine-learning methods based on support vector machines are proposed and compared with state-of-the-art techniques (including a deep-learning algorithm), and finally a combination of a classical machine-learning and deep learning approaches. Evaluation is carried out on a subset of the UK Biobank dataset, manually annotated by human experts. MAIN RESULTS: The combined classical machine-learning and deep learning method achieved an F1 score of 84.8% on the test subset, and a Cohen's kappa coefficient of 0.83, which is similar to the inter-observer agreement of two human experts. SIGNIFICANCE: The level of performance indicates that the automated detection of AF in patients whose data have been stored in a large database, such as the UK Biobank, is possible. Such automated identification of AF patients would enable further investigations aimed at identifying the different phenotypes associated with AF.

20.
JMIR Mhealth Uhealth ; 8(1): e13756, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31899457

RESUMO

BACKGROUND: The 6-min walk test (6MWT) is a convenient method for assessing functional capacity in patients with cardiopulmonary conditions. It is usually performed in the context of a hospital clinic and thus requires the involvement of hospital staff and facilities, with their associated costs. OBJECTIVE: This study aimed to develop a mobile phone-based system that allows patients to perform the 6MWT in the community. METHODS: We developed 2 algorithms to compute the distance walked during a 6MWT using sensors embedded in a mobile phone. One algorithm makes use of the global positioning system to track the location of the phone when outdoors and hence computes the distance travelled. The other algorithm is meant to be used indoors and exploits the inertial sensors built into the phone to detect U-turns when patients walk back and forth along a corridor of fixed length. We included these algorithms in a mobile phone app, integrated with wireless pulse oximeters and a back-end server. We performed Bland-Altman analysis of the difference between the distances estimated by the phone and by a reference trundle wheel on 49 indoor tests and 30 outdoor tests, with 11 different mobile phones (both Apple iOS and Google Android operating systems). We also assessed usability aspects related to the app in a discussion group with patients and clinicians using a technology acceptance model to guide discussion. RESULTS: The mean difference between the mobile phone-estimated distances and the reference values was -2.013 m (SD 7.84 m) for the indoor algorithm and -0.80 m (SD 18.56 m) for the outdoor algorithm. The absolute maximum difference was, in both cases, below the clinically significant threshold. A total of 2 pulmonary hypertension patients, 1 cardiologist, 2 physiologists, and 1 nurse took part in the discussion group, where issues arising from the use of the 6MWT in hospital were identified. The app was demonstrated to be usable, and the 2 patients were keen to use it in the long term. CONCLUSIONS: The system described in this paper allows patients to perform the 6MWT at a place of their convenience. In addition, the use of pulse oximetry allows more information to be generated about the patient's health status and, possibly, be more relevant to the real-life impact of their condition. Preliminary assessment has shown that the developed 6MWT app is highly accurate and well accepted by its users. Further tests are needed to assess its clinical value.

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