Hormone replacement therapy: management of common problems

OBJECTIVE

To describe common pitfalls associated with hormone replacement therapy (HRT) and recommendations to prevent or ameliorate them.

DESIGN

After pertinent articles and texts were reviewed, we outlined the available regimens of HRT, the commonly encountered side effects, and the management options.

RESULTS

HRT is frequently prescribed for elderly women. Vaginal bleeding, nausea, breast tenderness, migraine headaches, mood alterations, and abdominal bloating are common occurrences with HRT. These problems often can be managed by changing the dose, using another preparation or regimen, or altering the route of administration. For example, transdermal administration of estradiol may be tolerated better than oral therapy in patients with nausea. Irregular bleeding warrants endometrial biopsy to rule out hyperplasia.

CONCLUSION

With simple measures, common side effects of HRT can easily be managed by primary-care physicians. Gynecologic referral is recommended when endometrial biopsy is necessary or when symptoms fail to respond to adjustments in hormone therapy.

Symposium on geriatrics--Part I: Drug prescribing for elderly patients

OBJECTIVE

To describe the pharmacokinetic and pharmacodynamic changes that occur with aging and to discuss common problems noted with the use of medications often prescribed for elderly patients.

DESIGN

We searched the medical literature, reviewed pertinent articles, and summarized drug-related information applicable to geriatric patients.

RESULTS

Use of medications is common in the elderly population; most elderly persons take two or more different medications each day. Aging is associated with anatomic and physiologic changes that can have an effect on how medications are handled. Such changes include alterations in various volumes of drug distribution and in drug absorption, metabolism, and clearance. Elderly patients may also have increased or decreased drug effects because of alteration in receptor response. These changes in pharmacokinetics and pharmacodynamics may result in a prolonged drug half-life, an increased potential for drug toxicity, and a greater likelihood for adverse drug reactions.

CONCLUSION

Medications for elderly patients should be prescribed only after the anatomic and physiologic changes of aging are understood and with increased surveillance for potential drug toxicity or adverse drug reactions.

Topical non-steroidal anti-inflammatory drugs and admission to hospital for upper gastrointestinal bleeding and perforation: a record linkage case-control study

OBJECTIVE

To evaluate the relation between topically applied non-steroidal anti-inflammatory drugs and upper gastrointestinal bleeding and perforation.

DESIGN

A case-control study with 1103 patients admitted to hospital for upper gastrointestinal bleeding or perforation between January 1990 and December 1992 (cases). Two different control groups were used, with six community controls and with two hospital controls for each case. Previous exposure to topical and oral non-steroidal anti-inflammatory drugs and ulcer healing drugs was assessed.

STUDY POPULATION

The population of 319,465 people who were resident in Tayside and were registered with a Tayside general practitioner between January 1989 and October 1994. A record linkage database containing all data on hospital events and dispensed drugs between 1989 and 1992 was used for this population.

MAIN OUTCOME MEASURES

Unadjusted and adjusted odds ratios of exposure in those admitted to hospital compared with controls.

RESULTS

Significant unadjusted associations were detected between all three classes of drug and upper gastrointestinal complications. The significant association detected for topical non-steroidal anti-inflammatory drugs was no longer evident in analyses which adjusted for the confounding effect of concomitant exposure to oral anti-inflammatories and ulcer healing drugs (odds ratio = 1.45; 95% confidence interval 0.84 to 2.50 with community controls; 1.06; 0.60 to 1.88 with hospital controls).

CONCLUSION

In this study topical non-steroidal anti-inflammatory drugs were not significantly associated with upper gastrointestinal bleeding and perforation after adjustment for the confounding effects of concomitant use of oral anti-inflammatories and ulcer healing drugs.

Medical care of nursing home residents

OBJECTIVE

To present an overview of the special challenges of providing medical care for nursing home residents.

DESIGN

After researching the current medical literature, we summarized information on nursing home demographics, government regulations, and specific care issues for medical practice in nursing homes.

RESULTS

Almost 2 million Americans currently live in more than 20,000 nursing homes nationwide, and these nursing home residents are increasingly older and more frail than in the past. Most nursing home residents receive multiple prescription medications, and many are cognitively and functionally impaired. Nursing home-acquired infections are a frequent occurrence, as are falls and fall-related injuries. Recent federal laws have had a major effect on medical care in the nursing home and have made physicians more accountable for the care provided. The use of physical restraints and psychotropic drugs has been severely restricted.

CONCLUSION

The medical care of nursing home residents presents many challenges to primary-care physicians. Nevertheless, nursing home residents are among those patients in greatest need of competent, compassionate care. Despite numerous disincentives, provision of medical care for nursing home residents can be gratifying.

Spectral indices of cardiovascular adaptations to short-term simulated microgravity exposure

We investigated the effects of exposure to microgravity on the baseline autonomic balance in cardiovascular regulation using spectral analysis of cardiovascular variables measured during supine rest. Heart rate, arterial pressure, radial flow, thoracic fluid impedance and central venous pressure were recorded from nine volunteers before and after simulated microgravity, produced by 20 hours of 6 degrees head down bedrest plus furosemide. Spectral powers increased after simulated microgravity in the low frequency region (centered at about 0.03 Hz) in arterial pressure, heart rate and radial flow, and decreased in the respiratory frequency region (centered at about 0.25 Hz) in heart rate. Reduced heart rate power in the respiratory frequency region indicates reduced parasympathetic influence on the heart. A concurrent increase in the low frequency power in arterial pressure, heart rate, and radial flow indicates increased sympathetic influence. These results suggest that the baseline autonomic balance in cardiovascular regulation is shifted towards increased sympathetic and decreased parasympathetic influence after exposure to short-term simulated microgravity.

Nonsteroidal antiinflammatory drugs and dyspepsia in the elderly

Upper gastrointestinal tract symptoms are common in the elderly and, despite a paucity of data, nonsteroidal antiinflammatory drugs (NSAIDs) are believed to be important risk factors. We aimed to evaluate the association of NSAIDs with dyspepsia and heartburn in a population-based study. An age- and gender-stratified random sample of Olmsted County, Minnesota, Caucasian residents aged 65 years and older was mailed a valid self-report questionnaire; 74% responded (N = 1375). Age- and gender-adjusted (to 1980 US Caucasian population) prevalence rates for NSAID use, dyspepsia (defined as pain located in the upper abdomen or nausea), and heartburn (defined as retrosternal burning pain) were calculated. Logistic regression analysis was used to estimate the association of dyspepsia and heartburn with potential risk factors adjusting for age and gender. The age- and gender-adjusted annual prevalences (per 100) of aspirin and nonaspirin NSAID use were 60.0 (95% CI 57.2, 62.7) and 26.1 (95% CI 23.6, 28.7), respectively. The annual prevalences of dyspepsia and heartburn were 15.0 (95% CI 12.9, 17.0) and 12.9 (95% CI 10.9, 14.8), respectively. Aspirin was associated with dyspepsia and/or heartburn (OR = 1.6, 95% CI 1.2, 2.2) as were nonaspirin NSAIDs (OR = 1.8, 95% CI 1.3, 2.6), but smoking and alcohol were not significant risk factors. Aspirin and nonaspirin NSAIDs are associated with almost a twofold risk of upper gastrointestinal tract symptoms in elderly community subjects.

Voluntary control of breathing does not alter vagal modulation of heart rate

Variations in respiratory pattern influence the heart rate spectrum. It has been suggested, hence, that metronomic respiration should be used to correctly assess vagal modulation of heart rate by using spectral analysis. On the other hand, breathing to a metronome has been reported to increase heart rate spectral power in the high- or respiratory frequency region; this finding has led to the suggestion that metronomic respiration enhances vagal tone or alters vagal modulation of heart rate. To investigate whether metronomic breathing complicates the interpretation of heart rate spectra by altering vagal modulation, we recorded the electrocardiogram and respiration from eight volunteers during three breathing trials of 10 min each: 1) spontaneous breathing (mean rate of 14.4 breaths/min); 2) breathing to a metronome at the rate of 15, 18, and 21 breaths/min for 2, 6, and 2 min, respectively; and 3) breathing to a metronome at the rate of 18 breaths/min for 10 min. Data were also collected from eight volunteers who breathed spontaneously for 20 min and breathed metronomically at each subject's mean spontaneous breathing frequency for 20 min. Results from the three 10-min breathing trials showed that heart rate power in the respiratory frequency region was smaller during metronomic breathing than during spontaneous breathing. This decrease could be explained fully by the higher breathing frequencies used during trials 2 and 3 of metronomic breathing. When the subjects breathed metronomically at each subject's mean breathing frequency, the heart rate powers during metronomic breathing were similar to those during spontaneous breathing. Our results suggest that vagal modulation of heart rate is not altered and vagal tone is not enhanced during metronomic breathing.

Increased incidence of aortic aneurysm and dissection in giant cell (temporal) arteritis. A population-based study

OBJECTIVE

To determine the frequency of aneurysm and dissection of the aorta in patients with giant cell arteritis and to assess the effects of these events on these patients.

DESIGN

Population-based cohort study.

SETTING

A multispecialty and a primary care clinic in southern Minnesota.

PATIENTS

96 residents of Olmsted County, Minnesota, who developed giant cell arteritis between 1950 and 1985. The presence of aortic aneurysm, dissection, or both was confirmed using computed tomography, ultrasonography, angiography, or autopsy.

RESULTS

11 of the 96 patients were found to have thoracic aortic aneurysms. In 2 of these patients, the aneurysms were detected when giant cell arteritis was diagnosed. In the remaining 9 patients, the aneurysms occurred a median of 5.8 years after giant cell arteritis was diagnosed. Six of the 11 died suddenly of acute thoracic aortic dissection. Five patients who did not have thoracic aortic aneurysms developed isolated abdominal aortic aneurysms a median of 2.5 years after giant cell arteritis was diagnosed. The incidence of thoracic aortic aneurysm in patients with giant cell arteritis was 999 per 100,000 person-years; the incidence of abdominal aortic aneurysm in these patients was 555 per 100,000 person-years. Compared with all persons of the same age and sex living in Olmsted County, patients with giant cell arteritis were 17.3 times (95% Cl, 7.9 to 33.0) more likely to develop thoracic aortic aneurysm and 2.4 times (Cl, 0.8 to 5.5) more likely to develop isolated abdominal aortic aneurysm.

CONCLUSIONS

Giant cell arteritis is associated with a markedly increased risk for the development of aortic aneurysm, which is often a late complication and may cause death.

Thoracic aortic aneurysm and rupture in giant cell arteritis. A descriptive study of 41 cases

OBJECTIVE

To determine the features and outcomes of patients with giant cell arteritis (GCA) who have aneurysms or rupture of the thoracic aorta.

METHODS

Patients with GCA seen over a 40-year period who had aneurysms and/or rupture of the thoracic aorta were identified by assistance of a computerized indexing system. The presence of thoracic aortic aneurysms (TAA), with or without aortic valve insufficiency (AI), was determined by radiographs, computed tomography scans, and ultrasound studies of the thorax, angiograms of the aorta, and postmortem examination.

RESULTS

Ten men and 31 women with GCA were found to have TAA and/or rupture. Three developed TAA before GCA was diagnosed, 5 developed aortic findings near the time of the diagnosis, and 33 after the diagnosis of GCA (median of 7 years after diagnosis). Sixteen patients developed acute aortic dissection, which caused death in 8. Nineteen patients also had AI due to aortic root dilation, 15 of whom developed congestive heart failure. Eighteen patients underwent 21 surgical procedures for TAA resection and/or aortic valve replacement or repair. Aortitis was documented histologically in 10 cases.

CONCLUSION

Thoracic aortic complications in GCA are associated with serious outcomes that have been underrecognized and may be fatal. Physicians should be alert to the development of these complications at any time in the course of GCA, even many years after usual symptoms have subsided.

Ethylene precursors and antagonists increase embryogenesis of Hordeum vulgare L. anther culture

The role of ethylene in microspore embryogenesis and regeneration was analyzed by studying the effects of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) and the ethylene antagonists silver nitrate and silver thiosulphate on the androgenic response of in vitro cultured anthers of seven genotypes of barley. Incorporation of either ACC or silver salts in the culture medium lead to a significant increase in callus induction for five of the seven genotypes tested. The treatment that increased callus induction depended upon genotype. Only anthers cultured on 1 mg l(-1) silver thiosulphate gave rise to fertile plants in all seven genotypes tested.

Cardiovascular regulation in humans in response to oscillatory lower body negative pressure

The frequency response characteristics of human cardiovascular regulation during hypotensive stress have not been determined. We therefore exposed 10 male volunteers to seven frequencies (0.004-0.1 Hz) of oscillatory lower body negative pressure (OLBNP; 0-50 mmHg). Fourier spectra of arterial pressure (AP), central venous pressure (CVP), stroke volume (SV), cardiac output (CO), heart rate (HR), and total peripheral resistance (TPR) were determined and first harmonic mean, amplitude, and phase angles with respect to OLBNP are presented. AP was relatively well regulated as demonstrated by small oscillations in half amplitude (3.5 mmHg) that were independent of OLBNP frequency and similar to unstressed control spectra. Due to the biomechanics of the system, the magnitudes of oscillations in calf circumference (CC) and CVP decreased with increasing frequency; therefore, we normalized responses by these indexes of the fluid volume shifted. The ratios of oscillations in AP to oscillations in CC increased by an order of magnitude, whereas oscillations in CVP to oscillations in CC and oscillations in AP to oscillations in CVP both tripled between 0.004 and 0.1 Hz. Therefore, even though the amount of fluid shifted by OLBNP decreased with increasing frequency, the magnitude of both CVP and AP oscillations per volume of fluid shifted increased (peaking at 0.08 Hz). The phase relationships between variables, particularly the increasing lags in SV and TPR, but not CVP, indicated that efferent responses with lags of 5-6 s could account for the observed responses. We conclude that, at frequencies below 0.02 Hz, the neural system of humans functioned optimally in regulating AP; OLBNP-induced decreases in SV (by as much as 50%) were counteracted by appropriate oscillations in HR and TPR responses. As OLBNP frequency increased, SV, TPR, and HR oscillations increasingly lagged the input and became less optimally timed for AP regulation.

Bronchial responsiveness is not always increased after allergen challenge

Increased bronchial responsiveness has been reported at various time points following allergen challenge (AC), and may be related to the magnitude of the late response (LAR). We have studied 20 mild asthmatics, who were known to develop a late asthmatic response to inhalation of house dust mite extract (fall of > 15% from post-diluent baseline FEV1 from 2 to 7h after AC). The provocation concentration of methacholine causing a 20% fall in FEV1 (PC20 FEV1) was measured before and 24 h after challenge with house dust mite extract (HDM). The mean (SEM) change in log(PC20) was 0.08 (0.09) mg ml-1, and was not significant (P = 0.38; paired t-test). The change in PC20 for each subject was not significantly correlated with the size of LAR (r = -0.33; P > 0.05), but was significantly correlated with the absolute change from baseline FEV1 at 24 h (r = 0.67; P < 0.01). Our subjects had a high baseline responsiveness, when compared with previous studies. We suggest they may have been approaching a maximally responsive state prior to study, and allergen challenge may have had little effect in further increasing responsiveness. Exposure to allergen in late responders is not necessarily followed by an increase in non-specific bronchial responsiveness.

Gait-stance duration as a measure of injury and recovery in the rat sciatic nerve model

The rat sciatic nerve is a well-established animal model for the study of peripheral nerve crush injury. Footprint analysis is the most widely used non-invasive method of measuring functional recovery after injury in this model. However, this method has significant limitations due to inability to obtain clear reproducible prints, especially when the injury is severe, and variation of these prints with gait velocity. In the case of contracture or toe loss, footprint analysis is unreliable. We describe a new technique, gait-stance duration, which is capable of non-invasively quantitating functional recovery in the rat model. This method is not dependent on accurate foot positioning during gait. It utilizes video recording of the animal walking and measures the time each hind foot is in contact with the floor by counting the number of frames that pass. By pairing consecutive steps, it minimizes variation due to changes in velocity and, by calculating a ratio of injured/uninjured hind feet, comparisons to normal gait can be made. This method shows recovery patterns similar to footprint analysis with small inter-animal variability. We believe it has significant advantages over footprint analysis for the measurement of functional recovery in the crushed sciatic nerve rat model.

Enhancement of functional recovery following a crush lesion to the rat sciatic nerve by exposure to pulsed electromagnetic fields

Previous studies showed that exposure to pulsed electromagnetic fields (PEMF) produced a 22% increase in the axonal regeneration rate during the first 6 days after crush injury in the rat sciatic nerve. We used the same injury model to assess the effect on functional recovery. The animals were treated with whole body exposure to PEMF (0.3 mT, repetition rate 2 Hz) for 4 h/day during Days 1-5 while held in plastic restrainers. Functional recovery was serially assessed up to Postinjury Day 43 using recently described video imaging of the 1-5 toe spread and the gait-stance duration. Footprint analysis was also used with calculation of a sciatic function index. Those animals treated with PEMF had improved functional recovery, as compared to sham controls, using the tests for video 1-5 toe spread and gait-stance duration (P = 0.001 and P = 0.081, respectively). This effect was found throughout the 43-day recovery period. No effect was found using the sciatic function index. This study confirms that functional recovery after nerve crush lesion is accelerated by PEMF and has broad implications for the clinical use of these fields in the management of nerve injuries.

Polymyalgia rheumatica and giant cell arteritis in emergency department patients

Elderly patients with undiagnosed polymyalgia rheumatica and giant cell arteritis are not uncommon, and they may present to the emergency department with nonspecific physical complaints. We describe the cases of two patients who had the "typical" constellation of symptoms. It is important that emergency physicians consider the diagnosis and provide appropriate testing, therapy, and follow-up.

Neonatal wellbeing after elective caesarean delivery with general, spinal, and epidural anaesthesia

A comparison was made of the acid-base and Apgar status of neonates following general (n = 34), spinal (n = 28) and epidural (n = 23) anaesthesia for elective caesarean section. Neonates delivered following spinal anaesthesia were more acidaemic (pH = 7.249) (P < 0.05) than those delivered following epidural (pH = 7.291) or general anaesthesia (pH = 7.296) despite measures taken to minimize hypotension. The percentage of neonates with a 1 min Apgar score > or = 7 was 96% after epidural anaesthesia, 93% after spinal anaesthesia and 75% after general anaesthesia. The difference between epidural and general anaesthesia was significant (P < 0.05). Using these two measures of neonatal wellbeing, epidural anaesthesia provided the most favourable outcome.

Theophylline--an immunomodulatory role in asthma?

Theophylline, a drug used for the treatment of asthma, is recognized as an immunomodulator affecting T-lymphocytes both in vitro and in vivo. The effect of slow-release theophylline (Uniphyllin Continus) on the late asthmatic response (LAR) has been compared with placebo before and after 5 wk of treatment in a double-blind, randomized, parallel group study. Nineteen volunteers with stable mild asthma successfully completed the study. All were dual responders with a documented late response to inhaled house dust mite extract. The LAR was assessed both in terms of changes in lung function and in peripheral blood T-lymphocyte subsets. The mean (SEM) maximal late fall in FEV1 before and after treatment was 28.8 (4.1)% and 7.8 (2.0)% with theophylline, versus 35.8 (5.1)% and 29.1 (5.0)% with placebo (p = 0.046; Cl, 0.3-26.9). Corresponding figures for specific airway conductance (SGaw) were 46.4 (8.4)% and 7.2 (8.0)% with theophylline versus 46.2 (7.2)% and 44.8 (7.7)% with placebo (p = 0.008; Cl, 11.2 to 64.1). This was achieved at a mean (SD) trough serum theophylline level of only 7.8 (3.5) micrograms/ml. Airway responsiveness to methacholine was not significantly changed 24 h after the initial allergen challenge. There was a trend towards a decrease in baseline responsiveness after treatment with theophylline compared with that after placebo (p = 0.07). Studies of peripheral blood lymphocytes showed a modifying effect of treatment on the allergen-induced changes in CD4 and CD8 counts 48 h after challenge. Previous studies have shown a protective effect of theophylline on the LAR at serum theophylline concentrations within the conventional range for bronchodilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Separation of the enantiomers of some potassium channel activators using an alpha 1-acid glycoprotein column

The separations of the enantiomers of some 3,4-dihydro-2,2'-dimethyl-2H-1-benzopyrans and a related tetrahydronaphthalene on alpha 1-acid glycoprotein (Chiral-AGP) are presented, together with the results from an investigation of the effects of organic modifier and pH on the separations achieved. The general utility of Chiral-AGP in separating the enantiomers of compounds from this class of antihypertensive agents is demonstrated in this paper.

A clinically relevant modification to existing inhaler therapy

A modified formulation of inhaled salbutamol and a new inhaler device were studied in a group of 11 moderate-to-severe asthmatic patients. Changes in airway calibre (FEV1, Vmax30) were measured before and after inhalation of the new formulation, and compared with changes following inhalation of conventional salbutamol. A standard Rotahaler was used as a reference for the new inhaler. The study was conducted as a two-part randomized, double-blind cross-over trial. We found a significantly greater bronchodilatation of the larger airways using the modified drug in the Rotahaler. The new inhaler did not show any superiority over the Rotahaler, contrary to expectations from in vitro work. A slightly shorter model may better reflect the in vitro results. The study has implications for inhalation therapy in general.