Hypertension in the elderly

Residents living near a polyurethane foam manufacturing facility expressed concern to health officials over chemical emissions from the plant. Environmental monitoring of ambient air near the plant indicated the presence of toluene diisocyanate (TDI), which was used in foam production. Health officials collected blood samples from 113 residents and analyzed the blood sera for antibodies to TDI and related diisocyanates. Ten of the 113 residents (9%) had elevated levels of IgG or IgE antibodies specific for one or more diisocyanates. Exposure histories were taken from antibody-positive individuals to identify possible occupational exposure to TDI or the use of diisocyanate-containing consumer products. Exposure to TDI in ambient air may be responsible for the positive antibody responses detected in some residents of the community.     

Hypertension in the elderly: don't treat too quickly!

In the asymptomatic patient without target organ damage who is seen with severely elevated BP, pseudohypertension is more often than not the cause. Rapid lowering of arterial pressure is unnecessary and even contraindicated. Nurses play an important role in the evaluation and the treatment of elderly patients with hypertension. Both research-based practice and thorough evaluation and monitoring are requisite for safe and effective treatment. Given the seriousness of the adverse effects and the lack of outcome data, the use of sublingual nifedipine capsules in hypertensive emergencies and pseudohypertension should be abandoned.     

Hypertension in the elderly: age- and disease-related complications and therapeutic implications

Effective treatment of hypertension in the elderly requires an understanding of both the progressive course of the disease and the impact of aging on the cardiovascular system, including physiological, genetic, lifestyle, and environmental factors. Review of the literature that has attempted to define the impact of an "aging process" on cardiovascular structure and function reveals a diversity of findings and interpretations. However, in general, normotensive elderly subjects exhibit the heart and vascular characteristics of "muted" hypertension, including many features of younger hypertensive patients: cardiac hypertrophy, diminution in resting left ventricular early diastolic filling rate, increased arterial stiffness and aortic impedance, diminution in the baroreceptor reflex, a diminished response to catecholamines and diminished renal blood flow, and an increase in peripheral vascular resistance (PVR). Treatment of elderly hypertensives is more challenging because of the greater likelihood of the presence of concomitant diseases, most importantly, coronary and peripheral atherosclerosis, renal dysfunction, and diabetes mellitus. Isolated systolic hypertension (ISH), the most common form of hypertension in the elderly, has also been clearly shown to be an important predictor of cardiovascular morbidity and mortality, including coronary artery disease, congestive heart failure, and stroke. Treatment of ISH has been shown to lower systolic pressure safely and effectively in the elderly. By reducing PVR, and possibly the arterial stiffness, and thus the early reflected pulse waves, vasodilators, including calcium antagonists, may lower these three components of arterial impedance, and hence lower the arterial load on the heart. The cardiac hypertrophy and reduced left ventricular filling rate associated with hypertension in older individuals can also be ameliorated, to some extent, by calcium channel blockers.     

Hypertension in the elderly: attitudes of British patients and general practitioners

The question of why vancomycin-resistant enterococci (VRE) became epidemic in the United States can be answered on at least three basic levels: (1) molecular and genetic, (2) factors affecting host-microbe interactions, and (3) epidemiological. This article will address the epidemiological issues and seek to defend the assertion that, once VRE had evolved, its spread throughout hospitals in the United States was all but assured. Nosocomial VRE outbreaks were reported first in the mid- and late-1980s. Since that time, scientific reports of VRE have increased over 20-fold. Among hospitals participating in the National Nosocomial Infection Surveillance System from 1989 to 1997, the percentage of enterococci reported as resistant to vancomycin increased from 0.4% to 23.2% in intensive-care settings and from 0.3% to 15.4% in non-intensive-care settings. Factors leading to the spread of VRE in US hospitals include (1) antimicrobial pressure, (2) sub-optimal clinical laboratory recognition and reporting, (3) unrecognized "silent" carriage and prolonged fecal carriage, (4) environmental contamination and survival, (5) intrahospital and interhospital transfer of colonized patients, (6) introduction of unrecognized carriers from community settings such as nursing homes, and (7) inadequate compliance with hand washing and barrier precautions. Guidelines developed by the Centers for Disease Control and Prevention's Hospital Infection Control Practices Advisory Committee address each of these factors. The impact of these guidelines on the spread of VRE within individual institutions has been variable, and the overall impact of the guidelines nationally is unknown.     

Verapamil SR/trandolapril combination therapy for the elderly hypertensive patient. German VeraTran Hypertension Study Group

There are conflicting reports in the literature concerning the neuroprotective effect of ascorbic acid on excitotoxic processes in which excessive glutamate release and nitric oxide are supposed to be major factors. To study the influence of ascorbate on the nitric oxide modulated glutamate release rat striatal slices, preloaded with the tritiated glutamate analog D-aspartate, were used. The high potassium-induced efflux of D-[3H]aspartate was concentration dependently stimulated by the nitric oxide donors sodium nitroprusside, S-nitroso-N-acetylpenicillamine (SNAP) or 5-amino 3-morpholinyl-1,2,3-oxadiazolium chloride (SIN-1), as well as by solutions of gaseous nitric oxide and, interestingly, by cyanide. Only the stimulation of D-[3H]aspartate release by SNAP and nitroprusside was affected by ascorbate in terms of a highly significant potentiation. Ascorbate was shown to exert its effect primarily by influencing the decomposition of these nitric oxide donors rather than by a direct interaction of ascorbate with nitric monoxide on glutamate release.     

Hypertension and the obstetrician-gynecologist

Hypertension is a major risk factor for cardiovascular-related morbidity and death. Antihypertensive therapy markedly reduces the risk caused by elevated blood pressure. Earlier treatment of hypertensive patients should reduce deaths and morbidity even further. The obstetrician-gynecologist has the opportunity and responsibility to identify hypertensive patients early in the course of their disease. He must also confront the problem of elevated blood pressure associated with the use of oral contraceptives. In addition to its impact on the general population, chronic hypertension presents special problems during pregnancy. Pregnant women with elevated blood pressure have an increased fetal mortality rate and develop pre-eclampsia more frequently and earlier than nonhypertensive women. Antihypertensive treatment possibly increases fetal survival; when used appropriately, it definitely does not decrease fetal salvage. The appropriate use of antihypertensive therapy during pregnancy requires an understanding of the mechanism of action of these agents and recognition of side effects, especially those important during pregnancy.     

Hypertension

We have investigated the mechanism and the evolutionary pathway of protein dimerization through analysis of experimental structures of dimers. We propose that the evolution of dimers may have multiple pathways, including (1) formation of a functional dimer directly without going through an ancestor monomer, (2) formation of a stable monomer as an intermediate followed by mutations of its surface residues, and (3), a domain swapping mechanism, replacing one segment in a monomer by an equivalent segment from an identical chain in the dimer. Some of the dimers which are governed by a domain swapping mechanism may have evolved at an earlier stage of evolution via the second mechanism. Here, we follow the theory that the kinetic pathway reflects the evolutionary pathway. We analyze the structure-kinetics-evolution relationship for a collection of symmetric homodimers classified into three groups: (1) 14 dimers, which were referred to as domain swapping dimers in the literature; (2) nine 2-state dimers, which have no measurable intermediates in equilibrium denaturation; and (3), eight 3-state dimers, which have stable intermediates in equilibrium denaturation. The analysis consists of the following stages: (i) The dimer is divided into two structural units, which have twofold symmetry. Each unit contains a contiguous segment from one polypeptide chain of the dimer, and its complementary contiguous segment from the other chain. (ii) The division is repeated progressively, with different combinations of the two segments in each unit. (iii) The coefficient of compactness is calculated for the units in all divisions. The coefficients obtained for different cuttings of a dimer form a compactness profile. The profile probes the structural organization of the two chains in a dimer and the stability of the monomeric state. We describe the features of the compactness profiles in each of the three dimer groups. The profiles identify the swapping segments in domain swapping dimers, and can usually predict whether a dimer has domain swapping. The kinetics of dimerization indicates that some dimers which have been assigned in the literature as domain swapping cases, dimerize through the 2-state kinetics, rather than through swapping segments of performed monomers. The compactness profiles indicate a wide spectrum in the kinetics of dimerization: dimers having no intermediate stable monomers; dimers having an intermediate with a stable monomer structure; and dimers having an intermediate with a stable structure in part of the monomer. These correspond to the multiple evolutionary pathways for dimer formation. The evolutionary mechanisms proposed here for dimers are applicable to other oligomers as well.     

Arthroscopy in the elderly

The uptake rate of oxygen and nitrous oxide were studied during low flow anaesthesia with enflurane or isoflurane in nitrous oxide with either spontaneous or controlled ventilation. The excess gas flow and composition were analysed. The nitrous oxide uptake rate was in agreement with Severinghaus' formula VN20 1000.t-0.5. The composition of excess gas was predictable and the following formula for oxygen uptake could be derived: VO2 = VfgO2-0.45 (VfgN2(0)-(kg: 70.1000.t-0.5)) where oxygen uptake rate (VO2, ml.min-1) equals oxygen fresh gas flow (VfgO2) minus 0.45 times the difference between the fresh gas flow of nitrous oxide (VfgN2O), ml.min-1 and estimated uptake of nitrous oxide. The equation assumes constant inspired gas concentrations of 30% oxygen and 65-70% nitrous oxide. The oxygen uptake rates calculated from this formula were in good agreement with measured uptake rates. Thus, continuous monitoring of oxygen uptake rates is possible by using only reliable flowmeters and analysis of inspired oxygen concentration.     

Polytrauma in the elderly

As the elderly population grows, a concomitant increase in polytrauma in the geriatric sector is predicted. Diminished physiologic reserve and deficiencies in management contribute to higher rates of morbidity and mortality in the elderly patient with trauma as compared with the young patient with equivalent trauma. Currently, traditional trauma scoring systems are insufficient in directing triage and predicting survival for these elderly patients. This may be related to the effects of aging and associated comorbidities. Age, therefore, should be considered in contemporary scoring systems and treatment algorithms. The benefits of prompt identification and treatment of musculoskeletal, neurologic, abdominal, and cardiopulmonary trauma, and maintenance of adequate nutritional status are well established in the polytrauma setting, in general. For the elderly patient with polytrauma, early invasive hemodynamic and cardiac monitoring are advisable to identify occult shock, limit end organ hypoperfusion, prevent multiorgan failure, and ultimately improve survival.     

Constipation in the elderly

Constipation affects as many as 26 percent of elderly men and 34 percent of elderly women and is a problem that has been related to diminished perception of quality of life. Constipation may be the sign of a serious problem such as a mass lesion, the manifestation of a systemic disorder such as hypothyroidism or a side effect of medications such as narcotic analgesics. The patient with constipation should be questioned about fluid and food intake, medications, supplements and homeopathic remedies. The physical examination may reveal local masses or thrombosed hemorrhoids, which may be contributing to the constipation. Visual inspection of the colon is useful when no obvious cause of constipation can be determined. Treatment should address the underlying abnormality. The chronic use of certain treatments, such as laxatives, should be avoided. First-line therapy should include bowel retraining, increased dietary fiber and fluid intake, and exercise when possible. Laxatives, stool softeners and nonabsorbable solutions may be needed in some patients with chronic constipation.     

Stapedectomy in the elderly

Clinical records were reviewed to examine the effectiveness of stapedectomy in patients 70 years and older. A total of 154 patients was studied, including 11 with profound hearing loss with long-standing otosclerosis. Ages at the time of surgery ranged from 70 to 92 years (mean, 76.3 years). The mean pure-tone average (500, 1,000, 2,000, and 4,000 Hz) improved 30.6 dB after surgery for the 143 patients in the main otosclerotic group and 26.8 dB for the patients in the profound-hearing-loss group. The rate of successful stapedectomies for the 70(+)-year-old patients (90.9%) and the younger comparison group (90.0%) were similar. These findings extend the documented range of stapedectomy as a safe and effective procedure through the eighth decade of life.     

Cataracts in the elderly

Fraud and abuse risks in subacute care concern three major areas: (1) inadequate treatment and quality of care; (2) underutilization of services; and (3) misrepresentation of service capabilities. Strategies on how to manage these risks and guide changes are given.     

ECT in the elderly

Depression is a common clinical problem in the elderly. Risk factors in this population include genetic vulnerability, psychosocial losses, medical comorbidity, cerebrovascular disease, and neurodegenerative disorders. Depression in the elderly may have severe consequences, including high rates of suicide, malnutrition or dehydration, high utilization of medical services, impaired recovery from medical illnesses, and inappropriate placement in residential care facilities. A significant number of older depressed patients may not respond to anti-depressant medications, suffer intolerable medication side effects, or have illnesses with symptoms or consequences so severe that it is not feasible to wait the time required for one or more antidepressant trials to work. For many of these patients ECT can be a dramatically effective treatment. With appropriate evaluation and monitoring, ECT can be performed with relative safety even for patients with serious concurrent medical illnesses. Serious adverse effects are rare, and cognitive consequences of ECT are generally circumscribed and of limited duration; there is no evidence of "brain damage" or permanent change in cognitive ability from ECT. After a recovery period memory function is often better than it was during the episode of depression. For patients who have been refractory to or intolerant of medication, maintenance ECT can be an effective strategy for preventing early relapse. Further research is needed, however, to clarify the optimum use of MECT schedules and pharmacotherapy combinations to most effectively and safely prevent relapse of depression in different elderly populations and to help predict who will best respond to which treatment modalities.