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PubMed2005

Cognitive impairment as determinant for sub-optimal control of oral anticoagulation treatment in elderly patients with atrial fibrillation.

BACKGROUND AND OBJECTIVE: Atrial fibrillation is an indication for oral anticoagulation treatment. Maintaining the International Normalized Ratio (INR) within the therapeutic range minimises thromboembolic and bleeding complications. We have investigated whether cognitive capacity affects control of anticoagulation in elderly patients with atrial fibrillation. PATIENTS AND METHODS: A retrospective study was conducted to investigate the association between cognitive impairment and control of anticoagulation. Patients > or =70 years of age with atrial fibrillation using acenocoumarol (nicoumalone) as anticoagulant were included. All patients were monitored by the Anticoagulation Clinic in the Midden-Brabant region in the Netherlands. The cognitive function of all patients was assessed using the Mini-Mental State Examination (MMSE) on the index date. INR values were obtained from the year preceding the index date. Patients with an MMSE score <23 were defined as cognitively impaired. The primary outcome of the study was the incidence of an INR value within the therapeutic range of 2.0-3.4 during < or =70% of treatment time in the year prior to the cognitive function assessment. The secondary endpoint was the number of patients with an INR <2.0 or > or =6.0 at least once during this year. Logistic regression analysis was used to evaluate the association between cognitive function and control of anticoagulation. RESULTS: A total of 152 patients were included in the study. An MMSE score <23 was associated with an inadequate INR control (odds ratio [OR] 2.77; 95% CI 1.13, 6.74). After correction for hospital admission and change of possibly interacting medication (both also associated with inadequate INR control), this association remained statistically significant. Significantly more patients with an MMSE score <23 had one or more INR values of six or higher (OR 3.06; 95% CI 1.14, 8.18). CONCLUSION: In elderly people with atrial fibrillation using oral anticoagulation, an MMSE score <23 is independently associated with an inadequate INR control, mainly because of an increased number of supratherapeutic INR values. This finding should be taken into account when making decisions about use of oral anticoagulants in the elderly.

Administration, Oral↗
PubMed2007

Management of gout in older adults: barriers to optimal control.

Gout, a common inflammatory arthritis, can be diagnosed with absolute certainty. Gout results from the body's reaction to urate crystals deposited in tissues, and this pathophysiology is well understood. If used appropriately, available therapies can be entirely effective in not only treating the symptoms of gout, but also in eliminating the excess urate from the body, thereby eradicating the disease. Because of these facts, management of patients with gout should be successful. However, management of gout is particularly challenging in the elderly, even though the principles of management are the same for all age groups. The purpose of this article is to review these principles and discuss them as they pertain to the elderly. The classic gout attack is acute in onset, extremely painful and associated with marked swelling, warmth, erythema and tenderness of a single joint. However, the diagnosis of gout may be challenging in the elderly because atypical presentations are more common in this group. Treatment of acute gout involves the use of NSAIDs, colchicine, corticosteroids or corticotropin (adrenocorticotropic hormone). Unfortunately, co-morbid conditions such as chronic kidney disease, peptic ulcer disease and congestive heart failure may make the use of these agents dangerous or contraindicated. Thus, it is important to try to treat an acute flare of gout at the earliest sign, because the sooner treatment is initiated, the faster the inflammation will resolve. Urate-lowering agents include allopurinol and uricosuric agents. These also must be used judiciously in the elderly. However, if used at the lowest dose that maintains the serum urate level below 5.0-6.0 mg/dL, the excess urate in the body will be eliminated, acute flares will no longer occur and tophi will resolve. Gout is often seen in association with hypertension, excessive alcohol consumption, obesity and hypertriglyceridaemia. These conditions and the medications used to treat them may contribute to the hyperuricaemia. Treating these conditions and using medications that do not promote hyperuricaemia will aid in the management of gout. Despite the challenges that often complicate the management of gout in the elderly, an understanding of the pathophysiology of the disease and both the indications and limitations of the medications used should allow successful treatment.

Aged↗
PubMed1999

Optimal control of blood pressure can reverse left ventricular hypertrophy in uremic hypertensive hemodialysis patients.

We investigated the effects of antihypertensive treatment on left ventricular hypertrophy (LVH) of long-term hemodialysis patients. In uremic patients, it is still controversial in antihypertensive effect to the regression of LVH. The left ventricular size and function of 39 uremic hypertensive long-term hemodialysis patients (27 men, 12 women, mean age 58.3) was evaluated with M-mode, 2-dimensional and Doppler echocardiography before, and 12 months after, the start of combined antihypertensive therapy. This therapy included angiotensin II converting enzyme inhibitors, beta-blockers and calcium antagonists. Patients were classified as responders or nonresponders, depending upon whether their systolic blood pressure (SBP) decreased by more than 10 mmHg after antihypertensive treatment for 12 months. Before treatment, 36 (92%) patients had LVH and diastolic dysfunction and three (8%) had systolic dysfunction. At the end of 12 months, only 25 (64%) patients had LVH, 30 (77%) had diastolic dysfunction and 2 (5%) had systolic dysfunction. Left ventricular mass index (LVMI) also decreased from 203.63 +/- 70.47 g/m2 to 178.57 +/- 67.31 g/m2. LVMI correlated with systolic blood pressure (SBP) but did not correlate with diastolic blood pressure (DBP). There were 26 responders and 13 non-responders. Among responders, both the SBP (153.91 +/- 13.24 mmHg vs 134.43 +/- 14.21 mmHg, p < 0.01) and DBP (90.39 +/- 7.89 mmHg vs 79.98 +/- 7.35 mmHg, p < 0.01) decreased significantly after antihypertensive therapy. Responders also exhibited progressive regression of LVH (LVMI decreased significantly from 208.52 +/- 72.03 g/m2 to 168.52 +/- 55.53 g/m2, p < 0.05). However, LVH regression was not found in nonresponders (LVMI showed 194.84 +/- 64.36 g/m2 vs 193.66 +/- 77.67 g/m2). We conclude that good control of blood pressure can reverse LVH in hypertensive hemodialysis patients.

Adult↗
PubMed2004

The stabilometric evaluation of the erect stance. Energy-based optimal control in a numerical model.

AIM: This paper proposes an anthropomorphic model developed in a virtual context, useful to simulate the maintenance of the erect stance. Such a model can be built through a suitable software which can identify the geometry of the articular parts and place mechanical constraints (e.g. joints, spherical links, etc.) between the single elements. METHODS: Our approach can be described as the assembly of rigid parts linked at the joints. The control is given by internal torques at the joints and driven by strategy for the balance aimed to the least amount of total muscular energy spent. The anthropomorphic model proposed underlines and solves the typical problems of a system characterized by a multiple number of degree of freedom placed in erect stance and perturbed by phenomena of endogenous and exogenous nature. This model is developed via the coupling of 2 separate bi-dimensional models, one representing the sagittal plane and the other the frontal plane. The numerical tests were validated through experimental tests in a group of healthy volunteers. For this purpose we employed a stabilometric platform (force-plate) to record the statokinesigram (SKG) on the rest surface. RESULTS: The shapes of the stabilometric plots show a good spatial similarity between the experimental and simulated SKG. Both SKGs present a good range in the frontal plane with concentration of points in some areas (or attractors) in the experimental SKG, but not in the simulated one. The tests also showed a postural oscillation at low frequency (= 0.02Hz), probably due to the differential tiredness of groups of muscles or because of a delayed action of the neurological control. CONCLUSIONS: On the numerical simulations, we claim the suitability of the antropomorphic model for a general description of the maintenance of the erect stance. Despite the simplification, with our approach it is possible to simulate some of the main characteristics of the postural act. In particular, the length and the areas of the simulated SKG's are comparable with those of the experimental tests.

Journal Article↗
PubMed1990

[Optimal control of the microflora environment in suppurative foci].

The informative capacity of various statistic parameters characterizing the ecology of pathogens of purulent processes was studied. Many-years' results of the routine bacteriological tests of the materials from purulent wounds in patients from surgical, traumatological and burn departments served as the study subjects. The frequency, persistence and contamination capacity of the pathogens were investigated. Data on the changes in the frequency parameter with respect to the main pathogens of wound infections in various contingents of patients were collected. In relation to the observation period and contingent of the patients, various microorganisms were found to be permanent, supplementary and casual. The use of the ecological parameters was shown to provide integrated information on the etiological role of the pathogens in the development of purulent processes. The information characterized the microbial properties which should be considered in planning the use of antibacterial drugs and estimating the efficacy of the epidemiological control.

Abscess↗
PubMedDate not supplied

[The use of radiobiometry with computerized information processing in optimizing control over the efficacy of therapeutic loading regimens].

The data presented support the significance of radiobiometry in combined functional control of coronary patients on sanatorium treatment. Muscular loading was graded walking (terrain cure) up to registration of submaximal pulse. The criteria were similar to those at bicycle ergometry. Ischemic changes on telecardiograms were correlated with the degree of angina pectoris and arrhythmia. Episodes of painless myocardial ischemia had no independent prognostic value. Telecardiogram is considered usefull as a functional test for control of the adequacy and effectiveness of sanatorium treatment.

Adult↗
PubMed1986

[Mathematical model of brain edema and optimal control of intracranial pressure].

It is necessary to analyse various parameters responding to hypertonic solutions such as mannitol or glycerol, in order to achieve the best therapeutic results for patients having increased intracranial pressure (ICP). The responding model system for the ICP composing of multi-compartments of blood and brain tissue was mathematically introduced. By analysing the changes of the ICP under administration of glycerol using this system, the mathematical model for brain edema was developed. The cause of water transfer in this model system was indicated as the difference of the osmotic pressure and determined as ICP increasing factor, V. It was demonstrated that this theoretical model responded quite similarly to human ICP monitored by sumulating this system for clinical cases. The ICP controller was further developed. The automatic control of ICP was clinically achieved by using this controller. The minimal effective dose of glycerol can be automatically administered by presetting a desirable ICP for each patient.

Aged↗
PubMed1986

Factors controlling optimal bone ingrowth of total hip replacement components.

The major factors dealing with optimization of bony ingrowth for total hip replacement have been shown by experimental and limited clinical experience to be apposition, pore size, rigid initial fixation, the type of bone surface, weight bearing, biocompatibility, remodeling, bone grafting, other forms of stimuli, and the distinctions between the human response and the response of the experimental animals.

Animals↗
PubMed1985

A mathematical model to predict the optimal control mode for a pusher-plate total artificial heart (TAH).

Table I lists the physiological criteria for ranking each control mode (hemodynamic conditions assumed are listed in Figure 4). For each criteria, each mode was given a ranking of 0 to 3, with 3 the best. At the bottom of the table is the total of all criteria grades. The ranking from best to worst mode is in order: IND, LMA/LMS, Low FR/High FR, RMA/RMS. A discussion of Table I follows: FR is a reliable control mode and has been used extensively clinically, including the recent TAH human implants. The advantage of this mode is its simplicity: if the venous return is below pump capacity, then all incoming blood can be pumped out without any sophisticated controller. However, when the flow demand exceeds the pump capacity, HR must be increased. The ideal situation would be to set FR at one HR and %S, and leave these settings over the life of the recipient. However, a high HR like this would result in relatively high atrial pressures and low flow rates with respect to IND (as shown theoretically, in vitro, and in vivo). Although the patient would have a high maximum COR, the daily COR would be low, resulting in a relatively high AVO2 difference. Finally, FR lacks afterload sensitivity. RMA and RMS received the lowest grade of all modes. Because of the L-L shunt, the stroke length of these modes are smallest, and thus the CO curves and FPS are poorer than any other mode.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗