Declan Lyons

A Review of Approaches to Mobility Telemonitoring of the Elderly in Their Living Environment

Rapid technological advances have prompted the development of a wide range of telemonitoring systems to enable the prevention, early diagnosis and management, of chronic conditions. Remote monitoring can reduce the amount of recurring admissions to hospital, facilitate more efficient clinical visits with objective results, and may reduce the length of a hospital stay for individuals who are living at home. Telemonitoring can also be applied on a long-term basis to elderly persons to detect gradual deterioration in their health status, which may imply a reduction in their ability to live independently. Mobility is a good indicator of health status and thus by monitoring mobility, clinicians may assess the health status of elderly persons. This article reviews the architecture of health smart home, wearable, and combination systems for the remote monitoring of the mobility of elderly persons as a mechanism of assessing the health status of elderly persons while in their own living environment.

A review of postural orthostatic tachycardia syndrome.

A 21-year-old female reports an 18-month history of light-headedness on standing. This is often associated with palpitations and a feeling of intense anxiety. She has had two black-outs in the past 12 months. She is not taking any regular medications. Her supine blood pressure was 126/84 mmHg with a heart rate of 76 bpm, and her upright blood pressure was 122/80 mmHg with a heart rate of 114 bpm. A full system examination was otherwise normal. She had a 12-lead electrocardiogram performed which was unremarkable. She was referred for head-up tilt testing. She was symptomatic during the test and lost consciousness at 16 min. Figure 1 summarizes her blood pressure and heart rate response to tilting. A diagnosis of postural orthostatic tachycardia syndrome with overlapping vasovagal syncope was made.

Impaired endothelial nitric oxide bioavailability: a common link between aging, hypertension, and atherogenesis?

Endothelial‐derived nitric oxide (NO) is responsible for maintaining continuous vasodilator tone and for regulating local perfusion and systemic blood pressure. It also has significant antiproliferative effects on vascular smooth muscle and platelet anti‐aggregatory effects. Impaired endothelial‐dependent (NO mediated) vasorelaxation is observed in most animal and human models of healthy aging. It also occurs in age‐associated conditions such as atherosclerosis and hypertension. Such “endotheliopathy” increases vascular risk in older adults. Studies have indicated that pharmacotherapeutic intervention with angiotensin‐converting enzyme inhibitors and 3‐hydroxy‐3‐methyl‐glutaryl coenzyme‐A reductase inhibitors may improve NO‐mediated vasomotor function. This review, evaluates the association between impaired endothelial NO bioavailability, accelerated vascular aging, and the age‐associated conditions hypertension and atherogenesis. This is important, because pharmacotherapy aimed at improving endothelial NO bioavailability could modify age‐related vascular disease and transform age into a potentially modifiable vascular risk factor, at least in a subpopulation of older adults.

Sitting and standing blood pressure measurements are not accurate for the diagnosis of orthostatic hypotension

INTRODUCTION Orthostatic hypotension (OH) is associated with troublesome symptoms and increased mortality. It is treatable and deserving of accurate diagnosis. This can be time consuming. The current reference standard for its diagnosis is head-up tilt (HUT) testing with continuous beat-to-beat plethysmography. Our objective was to assess the accuracy of sit-stand testing with semi-automatic sphygmomanometry for the diagnosis of OH. DESIGN Retrospective test of diagnostic accuracy. METHODS This was a retrospective study performed using a database maintained by a busy syncope unit. HUT testing was performed using an automated tilt table with Finometer monitoring. A 3 min 70 degrees HUT was performed following 5 min supine. Sitting blood pressure (BP) was measured following 3 min rest. Standing BP was measured within 30 s of assuming the upright posture. The results of sit-stand testing were compared with HUT testing as a reference standard. Both tests happened within 5 min of each other and patients underwent no intervention between tests. RESULTS From a total of 1452 consecutive HUTs, we identified 730 with pre-test measures of sitting and standing BP. The mean age of this group was 70.57 years (SD = 15.1), 62% were female. The sensitivity of sit-stand testing was calculated as 15.5%, specificity as 89.9%, positive predictive value as 61.7%, negative predictive value as 50.2% and the likelihood ratio as 1.6. The area under the Receiver Operator Curve was 0.564. CONCLUSION We have demonstrated that sit-stand testing for OH has very low diagnostic accuracy. We recommend that the more time-consuming reference standard method of diagnosis be used if the condition is suspected.

Orthostatic tolerance in older patients with vitamin B12 deficiency before and after vitamin B12 replacement

Orthostatic hypotension (OH) and vitamin B12 deficiency are common disorders in older people. Several case series have reported an association between vitamin B12 deficiency and OH. The effect of vitamin B12 replacement on this dysfunction has not been studied. We prospectively studied responses to head up tilt in patients over 70 years with vitamin B12 deficiency (intervention group) and compared their responses after replacement to those of matched patients with idiopathic OH and normal serum vitamin B12 concentrations (control group). Blood pressure (BP), heart rate (HR) and systemic vascular resistance (SVR) changes during orthostatic stress were evaluated using digital artery photoplethysmography. Eight patients and eight controls were studied. Initial head up tilt produced a mean BP decrease of 44/29 mmHg (s. e. m. 4/4 mmHg) in the intervention group and 33/12 mmHg (s. e. m. 3/2 mmHg) in the control group. Repeat head up tilt 6 months after vitamin B12 replacement produced a mean BP decrease of 15/9 mmHg (s. e. m. 5/2 mmHg) in the intervention group. The mean decrease in the control group was 30/12 mmHg (s. e. m. 2/2 mmHg). The difference in BP decreases between groups was statistically significant for both systolic and diastolic BP (p < 0.001 for both systolic BP and diastolic BP). Mean SVR in the intervention group decreased by 658 dynes/cm5/ sec (s. e. m. 74 dynes/cm5/sec) during initial head up tilt. Mean SVR during repeat head up tilt decreased by 79 dynes/cm5/sec (s. e. m. 12 dynes/cm5/sec). Mean SVR in the control group decreased by 158 dynes/cm5/sec (s. e. m. 10 dynes/cm5/sec) during initial head up tilt and by 258 dynes/cm5/sec (s. e. m. 31 dynes/cm5/sec). The difference in SVR changes between groups was statistically significant (p = 0.02). We conclude that replacing vitamin B12 in older patients with vitamin B12 deficiency is associated with improved orthostatic tolerance to head up tilt.

Specialist medication review does not benefit short-term outcomes and net costs in continuing-care patients

OBJECTIVES to evaluate specialist geriatric input and medication review in patients in high-dependency continuing care. DESIGN prospective, randomised, controlled trial. SETTING two residential continuing care hospitals. PARTICIPANTS two hundred and twenty-five permanent patients. INTERVENTION patients were randomised to either specialist geriatric input or regular input. The specialist group had a medical assessment by a geriatrician and medication review by a multidisciplinary expert panel. Regular input consisted of review as required by a medical officer attached to each ward. Reassessment occurred after 6 months. RESULTS one hundred and ten patients were randomised to specialist input and 115 to regular input. These were comparable for age, gender, dependency levels and cognition. After 6 months, the total number of medications per patient per day fell from 11.64 to 11.09 in the specialist group (P = 0.0364) and increased from 11.07 to 11.5 in the regular group (P = 0.094). There was no significant difference in mortality or frequency of acute hospital transfers (11 versus 6 in the specialist versus regular group, P = 0.213). CONCLUSION specialist geriatric assessment and medication review in hospital continuing care resulted in a reduction in medication use, but at a significant cost. No benefits in hard clinical outcomes were demonstrated. However, qualitative benefits and lower costs may become evident over longer periods.

Cerebral autoregulation in the vertebral and middle cerebral arteries during combine head upright tilt and lower body negative pressure in healthy humans

The majority of cerebral autoregulation research has focused on the middle cerebral artery. However, many symptoms of presyncope indicate posterior cerebral hypoperfusion. To address this issue, we measured cerebrovascular reactivity, cerebral blood flow velocity and dynamic cerebral autoregulation in the middle cerebral artery and vertebral arteries during orthostatic stress to presyncope in 9 healthy subjects. There was no significant difference in either the decline in cerebral blood flow velocity or indices of dynamic cerebral autoregulation between the middle cerebral and vertebral arteries prior to or during presyncope. In conclusion, there is no significant difference in regulation of blood flow between the vertebral artery and middle cerebral artery in healthy subjects. Further study is required to determine whether or not a difference exists in syncopal patient populations.

A Clinical Evaluation of a Remote Mobility Monitoring System based on SMS Messaging

The objective of this work was to evaluate the accuracy and viability of a mobility telemonitoring system, based on the short message service (SMS), to monitor the functional mobility of elderly subjects in an unsupervised environment A clinical trial was conducted consisting of 6 elderly subjects; 3 male, 3 female (mean: 81.7, SD: 5.09). Mobility was monitored using an accelerometer based portable unit worn by each monitored subject for eleven hours. Every 15 minutes the mobility of the subject was summarized and transmitted as an SMS message from the portable unit to a remote server for long term analysis. The activPALtrade Trio Professional physical activity logger was simultaneously used for comparison with the portable unit. On conclusion of the trial each subject completed a questionnaire detailing their satisfaction with the portable unit and any recommendations for improvements. Overall a percentage difference of 2.31% was found between the activPALtrade Trio and the portable unit for the detection of sitting. For the combined postures of standing and walking the percentage difference was calculated as 2.9%. A bivariate correlation and regression analysis was performed on the entire data set of one subject. Strong positive correlations were found for the detection of sitting (r = 0.996) and for the combined postures of standing and walking (r = 0.994). Subjects suggested that a lighter, smaller and wireless unit would be more effective.

The changing face of orthostatic and neurocardiogenic syncope with age

AIM Reports of the outcomes of syncope assessment across a broad spectrum of ages in a single population are scarce. It is our objective to chart the varying prevalence of orthostatic and neurocardiogenic syncope (NCS) as a patient ages. METHODS This was a retrospective study. All consecutive patients referred to a tertiary referral syncope unit over a decade were included. Patients were referred with recurrent falls or orthostatic intolerance. Tilt tests and carotid sinus massage (CSM) were performed in accordance with best practice guidelines. RESULTS A total of 3002 patients were included (1451 short tilt, 127 active stand, 1042 CSM and 382 prolonged tilt). Ages ranged from 11 to 91 years with a median (IQR) of 75 (62-81) years. There were 1914 females; 1088 males. Orthostatic hypotension (OH) was the most commonly observed abnormality (test positivity of 60.3%). Those with OH had a median (IQR) age of 78 (71-83) years. Symptomatic patients were significantly younger than asymptomatic (P = 0.03). NCS demonstrated a bimodal age distribution. Of 194 patients with carotid sinus hypersensitivity, the median age (IQR) was 77 (68-82) years. Those with vasovagal syncope (n = 80) had a median (IQR) age of 30 (19-44) years. There were 57 patients with isolated postural orthostatic tachycardia syndrome. Of the total patients, 75% were female. They had a median (IQR) age of 23 (17-29) years. CONCLUSION We have confirmed, in a single population, a changing pattern in the aetiology of syncope as a person ages. The burden of disease is greatest in the elderly.

Development and evaluation of new blood pressure and heart rate signal analysis techniques to assess orthostatic hypotension and its subtypes.

Orthostatic hypotension (OH) is a clinical condition, which frequently results in symptoms such as syncope, dizziness during standing, weakness, blurred vision and fatigue. It is defined as a sustained drop in blood pressure exceeding 20 mmHg systolic or 10 mmHg diastolic occurring within 3 min of assuming upright posture, and is a common causal factor for falls in the elderly. Since 1986, tilt-table testing has become widely used in the diagnosis of OH. The Finometer provides non-invasive monitoring of haemodynamic changes during tilt-table testing. In this study, new algorithms for parameter extraction from Finometer data were developed, with specific reference to the diagnosis of OH. Algorithms were developed to assess the rates of change of haemodynamic variables in response to head-up tilt testing, a previously unexamined aspect of tilt-table testing. These algorithms were applied to the Finometer measurements of 20 patients, who underwent tilt-table testing in the Mid-Western Regional Hospital, Limerick. The data extraction algorithms were shown to accurately record changes in haemodynamic variables for further analysis. It was also demonstrated that the rate of change of blood pressure during the head-up tilt-table testing could have prognostic significance for OH.