Exclusion of venous thromboembolism: evaluation of D-Dimer PLUS for the quantitative determination of D-dimer

The objective of this study was to evaluate if D-Dimer PLUS (Dade Behring, USA), a rapid fully automated assay, could be used as an initial screening test in the diagnosis of venous thromboembolism (VTE). Samples from 274 consecutive symptomatic patients with suspected pulmonary embolism (n=229; 79% outpatients, 21% inpatients), deep venous thrombosis (n=37; 84% outpatients, 16% inpatients) or suspected for both complications (n=8) were tested with this D-dimer assay with a Sysmex CA-1500 Coagulation Analyzer. Clinical probability for pulmonary embolism (PE) or deep venous thrombosis (DVT) was staged according to a pretest risk score proposed by Wells. Final diagnosis of PE and/or DVT was established by spiral-computed tomography of the pulmonary arteries or compression ultrasonography, respectively. PE was diagnosed in 13.5% of the patients, whereas DVT was confirmed in 17.7% of the patients. The optimal cut-off value for exclusion of venous thromboembolism was 130 mug/l, and sensitivity, specificity and negative predictive value (NPV) were 95.0% (95% CI: 92.4-97.6), 30.4% (95% CI: 25.0-35.8) and 97.2% (95% CI: 95.2-99.2), respectively. In fact, two patient with PE were missed using D-Dimer PLUS; both cases were outpatients. In conclusion, this assay appears to be safe when implemented in an algorithm based on clinical assessment, D-dimer concentration, and radiological diagnostic techniques to stratify the risk for PE or DVT. However, higher sensitivities and negative predictive values were claimed in the scarce published reports for the D-Dimer PLUS assay than found in this study.

Effect of levodopa on orthostatic and postprandial hypotension in elderly Parkinsonian patients

BACKGROUND

This study describes orthostatic and postprandial hypotension in elderly Parkinsonian patients and evaluates the effect of levodopa therapy on orthostatic and postprandial hypotension in these patients.

METHODS

Seventeen elderly patients with a clinical diagnosis of Parkinson's disease or Parkinsonism based on the U.K. Parkinson's Disease Society Brain Bank criteria (age range, 66-84 years) participated in the study. Blood pressure was continuously monitored during standardized standing and meal tests, after starting 125-mg b.i.d. doses of levodopa/benserazide (Madopar) or placebo, in a double-blind, randomized, cross-over design. Seventeen age- and sex-matched healthy subjects served as controls.

RESULTS

Orthostatic hypotension was infrequently found in Parkinsonian patients (13%) and healthy subjects (6%; p =.58, between groups), whereas postprandial hypotension was more frequent in Parkinsonian patients (82%) than in healthy subjects (41%; p <.05, between groups). Doses of levodopa/benserazide, administered 2 times per day, did not result in significantly larger blood pressure decreases after standing or eating, or in higher frequencies of orthostatic or postprandial hypotension in the Parkinsonian group. Postprandial hypotension was related to disease severity (r = -.56, p <.05).

CONCLUSIONS

Postprandial hypotension, but not orthostatic hypotension, was more common in elderly Parkinsonian patients than in healthy subjects. Therapy with 125-mg b.i.d. doses of levodopa/benserazide did not significantly aggravate orthostatic or postprandial hypotension.

The influence of low-, normal-, and high-carbohydrate meals on blood pressure in elderly patients with postprandial hypotension

BACKGROUND

Postprandial hypotension (PPH) is a common and serious disorder of blood pressure (BP) regulation in elderly people. It has been suggested that primarily the carbohydrate (CH) content of a meal induces the BP decrease. Therefore, we examined the relationship between the CH content of meals and postprandial BP responses in elderly patients diagnosed with PPH.

METHODS

Twelve geriatric patients (aged 75 to 91 years; 6 men) who were previously diagnosed with PPH received standardized liquid meals with low- (25 g), normal- (65 g), and high- (125 g) CH content in random order on three separate days. Systolic BP (SBP), diastolic BP, and heart rate were measured every 5 minutes from 20 minutes before until 75 minutes after each meal. Postprandial symptoms were recorded every 15 minutes.

RESULTS

The maximum decrease in SBP was significantly smaller after the low-CH meal (-28 +/- 5 mm Hg) than after the normal- (-39 +/- 7 mm Hg) and high-CH meals (-40 +/- 5 mm Hg) (p <.050 between groups). In addition, the duration of PPH was significantly shorter (p <.010), and postprandial symptoms were less frequent and less severe after the low-CH meal.

CONCLUSIONS

Reducing the CH amount in meals induces significantly smaller decreases in SBP, shorter duration of PPH, and reduction of PPH-related symptoms. Therefore, limiting the CH content of an elderly patient's meal can be a clinically effective nonpharmacological treatment for PPH in elderly patients and can reduce the risk of developing symptomatic PPH.

Reproducibility of orthostatic changes in cerebral oxygenation in healthy subjects aged 70 years or older

In the elderly, standing can frequently be accompanied by blood pressure (BP) changes and cerebral symptoms such as dizziness, fall, or even syncope, but this may vary from day-to-day. Therefore, we aimed to investigate the reproducibility of orthostatic responses of cerebral cortical oxygenation and systemic haemodynamics in elderly subjects. In 27 healthy elderly subjects (age 70-84 years), changes in systolic BP (SBP), diastolic BP (DBP), heart rate (HR) and stroke volume (SV) were continuously monitored by Finapres (Finger Arterial Pressure), and changes in oxyhaemoglobin ([O2Hb]) and deoxyhaemoglobin ([HHb]) concentrations were continuously measured over the right frontal cortex by near infrared spectroscopy (NIRS) during supine rest and 10 min of active standing on two separate occasions. SBP and DBP increased by 6.7 +/- 15.4 mmHg (P<0.05, mean +/- SD) and 8.2 +/- 6.4 mmHg (P<0.01), respectively, whereas HR increased by 9.5 +/- 5.0 bpm (P<0.01) and SV decreased by -8.3 +/- 7.4 ml (P<0.01) during standing on the first occasion. [O2Hb] decreased by -3.9 +/- 2.9 micromol l-1 (P<0.01), while [HHb] increased by 1.8 +/- 2.2 micromol l-1 (P<0.01). Group-averaged orthostatic changes in cortical oxygenation and systemic haemodynamics were very similar on the two occasions, although an intraindividual variation was found. Cortical oxygenation changes were not accompanied by severe cerebral symptoms. Active standing induced reproducible group-averaged frontal cortical oxygenation declines in healthy elderly subjects, although an intraindividual day-to-day variability was present, possibly related to the variability of orthostatic BP responses. These findings indicate that cerebral autoregulation fails to compensate completely for postural changes in elderly subjects, which might predispose elderly subjects to ischaemic cerebral symptoms.

Achieving haemodynamic baseline values with Finapres in elderly subjects during supine rest

BACKGROUND

Clear guidelines for the resting time necessary to achieve stable blood pressure (BP) levels are scant in gerontology research. Therefore, we aimed to determine the minimum period required for obtaining haemodynamic baseline values in elderly subjects during supine rest. In addition, we evaluated the effect of cardiovascular morbidity, such as diastolic heart failure, and the effect of complex comorbidity of geriatric patients, on haemodynamic changes during supine rest.

METHODS

A total of 17 healthy subjects, 18 heart failure patients with normal systolic function and 24 geriatric patients, aged 70 years and more, participated. After an overnight fast, changes in systolic BP (SBP), diastolic BP (DBP), heart rate (HR), and stroke volume (SV) were determined by Finapres beat-to-beat non-invasive BP monitoring during a 20-min supine rest. The procedure was repeated in the healthy subjects and geriatric patients on a second day.

RESULTS

Complete BP stabilization was reached in each group within 5 min of supine rest, as SBP remained essentially unchanged and DBP did not change significantly anymore after the fourth minute. In the heart failure patients, HR decreased and SV increased until the twelfth minute of rest. The SBP, DBP, HR, and SV changes during supine rest showed good reproducibility.

CONCLUSIONS

A span of 5 min of supine rest ensured achievement of reliable and reproducible baseline BP values by Finapres in elderly subjects. However, we recommend at least 12 min of rest to obtain full haemodynamic stability in elderly patients with diminished cardiac compliance and diastolic function.

Cerebral oxygenation declines in healthy elderly subjects in response to assuming the upright position

BACKGROUND AND PURPOSE

With increasing age, assuming the upright position is more often accompanied by symptoms such as dizziness and lightheadedness, possibly as a result of a diminished oxygen supply to the brain due to impaired cerebral autoregulation. We aimed to quantify postural changes in cerebral oxygenation and systemic hemodynamics in healthy elderly and young subjects.

METHODS

In 18 healthy elderly subjects (aged 70 to 83 years) and 10 healthy young subjects (aged 22 to 45 years), frontal cortical oxygenation and hemodynamic responses were continuously monitored by near infrared spectroscopy and Finapres, respectively, before and during 10 minutes of active standing.

RESULTS

-Cortical oxyhemoglobin concentration [O(2)Hb] decreased by -4.6+/-2.2 micromol/L (P<0.001) and cortical deoxyhemoglobin concentration increased by 1.5+/-2.4 micromol/L (P<0.05) in the elderly subjects after posture change, whereas these variables did not change significantly in the young subjects. The postural hemodynamic changes tended to be attenuated in the elderly subjects, except for the increases in systolic blood pressure (BP). Smaller postural increases in diastolic BP were related to larger [O(2)Hb] decreases (r=0.53, P<0.01, corrected for the age effect).

CONCLUSIONS

Assuming the upright position evokes an asymptomatic decrease in frontal cortical oxygenation in healthy elderly subjects but not in healthy young subjects. Cortical [O(2)Hb] changes are affected by diastolic BP changes. These findings may indicate that regulation of cerebral oxygenation alters with increasing age.

Furosemide withdrawal in elderly heart failure patients with preserved left ventricular systolic function

To explore the possibilities of furosemide withdrawal in elderly heart failure (HF) patients with intact left ventricular (LV) systolic function and assess its effects on functional status and orthostatic blood pressure homeostasis, we performed a placebo-controlled pilot trial of furosemide withdrawal with 3 months of follow-up in 32 HF patients (aged 75.1 +/- 0.7 years [mean +/- SEM]) with a LV ejection fraction of 60 +/- 2% and without overt congestion. Investigations included repeated clinical assessment, spirometry, standardized 6-minute walking test, and chest x-rays. Measurements of blood pressure response on active standing and Doppler echocardiography were performed before and 3 months after furosemide withdrawal. Recurrent congestive HF occurred in 2 of 21 patients (10%) who discontinued furosemide use, and in 1 of 11 patients (9%) who continued furosemide (p = NS). Three patients restarted furosemide for ankle edema and 1 for blood pressure levels >180/100 mm Hg. After 3 months, there were no differences regarding HF symptom scores, blood pressure, heart rate, spirometric results, 6-minute walking distance, or quality of life scores between patients who discontinued use and patients who continued the therapy. In patients successfully withdrawn, Doppler E/A ratio increased from 0.68 +/- 0.05 to 0.79 +/- 0.06 after withdrawal (p <0.01), and maximum blood pressure decrease on active standing changed from -8 +/- 5 mm Hg to +5 +/- 3 mm Hg systolic (p <0.05). Thus, in this pilot investigation of furosemide withdrawal in elderly HF patients without overt congestion and with a normal LV systolic function, withdrawal was successful in almost all patients and was associated with improvement of LV diastolic filling and blood pressure homeostasis on active standing.

Diuretic therapy in elderly heart failure patients with and without left ventricular systolic dysfunction

Long term prescription of diuretics for heart failure is very prevalent among elderly patients, although the rationale for such a treatment strategy is often unclear, as diuretics are not indicated if volume overload is absent. The concept of diastolic heart failure in the elderly might particularly change the role of diuretic therapy, since diuretics may have additional adverse effects in these patients. This paper reviews the effects of diuretic therapy in elderly patients with heart failure, emphasising the differences between patients with normal and decreased left ventricular systolic function. Studies on diuretic withdrawal in elderly patients with heart failure are discussed, with emphasis on issues involved in decision making such as diuretic dose reduction and withdrawal in elderly patients and factors that have been established to predict successful withdrawal. Existing guidelines on the prescription of diuretics in elderly patients with heart failure with normal and decreased left ventricular systolic function and in those with diastolic heart failure are also discussed. By reducing intravascular volume, diuretics may further impair ventricular diastolic filling in patients with diastolic heart failure and thus reduce stroke volume. Indeed, preliminary studies demonstrate that diuretics may provoke or aggravate hypotension on standing and after meals in these patients. Therefore, it is suggested that elderly patients with heart failure with intact left ventricular systolic function should not receive long term diuretic therapy, unless proven necessary to treat or prevent congestive heart failure. This implies that physicians should carefully evaluate the opportunities for diuretic dose tapering or withdrawal in all of these patients, and that a cautiously guided intermittent diuretic treatment modality may be critical in the care for older patients with heart failure with intact left ventricular systolic function.

Monitoring hypovolemia in healthy elderly subjects by measuring blood pressure response to Valsalva's maneuver

Quantification of hypovolemia by physical examination has limited validity. We explored the use of non-invasive measurement of blood pressure (BP) response to Valsalva's maneuver in monitoring hypovolemia in nine healthy elderly volunteers, recruited from participants of the Nijmegen Annual Four-Days Marches. Heart rate (HR), systolic and diastolic BP, and mean arterial pressure (MAP) response (Finapres) to a Valsalva's maneuver as well as clinical and laboratory assessment of fluid balance were determined 5 minutes before, and 3, 5, and 48 hours after administration of 40 mg furosemide orally. Subjects' (4 males aged 74.2 +/- 3.0 years) weight was 66.1 +/- 9.7 kg, mean BP was 139 +/- 21 over 76 +/- 12 mm Hg. A maximum weight loss of -2.8 +/- 0.9% occurred 5 hours after furosemide administration. Systolic and diastolic BP, HR, clinical assessment scores, and serum creatinine and urea nitrogen did not change during the total study period. Significant changes occurred in Valsalva phase I to phase II systolic BP response (difference +14.2 +/- 11.3 mm Hg, ratio difference -0.09 +/- 0.07 after 5 hours, P < 0.01). Changes after 48 hours did not differ from baseline values. Finapres measurement of Valsalva BP response may be useful in monitoring hypovolemia in the elderly.

Furosemide withdrawal improves postprandial hypotension in elderly patients with heart failure and preserved left ventricular systolic function

OBJECTIVE

To assess the effects of furosemide withdrawal on postprandial blood pressure (BP) in elderly patients with heart failure and preserved left ventricular systolic function.

METHODS

Noninvasive measurement of blood pressure (BP) and heart rate, computation of stroke volume and cardiac output (after a 1247-kJ (297-kcal) meal, and Doppler echocardiography before and 3 months after placebo-controlled withdrawal of furosemide therapy.

RESULTS

Of 20 patients with heart failure (mean+/-SEM age, 75+/-1 years; left ventricular ejection fraction, 61%+/-3%), 13 were successfully able to discontinue furosemide therapy. At baseline, 11 (55%) of the 20 patients (had maximum postprandial systolic BP declines of 20 mm Hg or more. In the withdrawal group, the maximum systolic BP decline lessened from -25+/-4 to -11+/-2 mm Hg (P<.001) and the maximum diastolic BP from -18+/-3 to -9+/-1 mm Hg (P= .01), compared with no changes in the continuation group. In the withdrawal group, maximum postprandial declines in stroke volume and cardiac output decreased from -9+/-1 to -4+/-2 mL (P =.01) and from -0.6+/-0.2 to -0.2+/-0.1 L/min) (P = .04), respectively. The baseline maximum postprandial systolic BP decrease was correlated with the ratio of early to late flow (n = 20; Spearman rank correlation coefficient, 0.58; P = .007). For patients in the withdrawal group, the changes in postprandial systolic BP response were independently related to changes in peak velocity of early flow (n = 13; r2= 0.61; P = .003).

CONCLUSIONS

Postprandial hypotension is common in elderly patients with heart failure and preserved left ventricular systolic function. The withdrawal of furosemide therapy ameliorates postprandial BP homeostasis in these patients, possibly by improving left ventricular diastolic filling.

Tracking the long-term decline and recovery of an isolated population

Effects of small population size and reduced genetic variation on the viability of wild animal populations remain controversial. During a 35-year study of a remnant population of greater prairie chickens, population size decreased from 2000 individuals in 1962 to fewer than 50 by 1994. Concurrently, both fitness, as measured by fertility and hatching rates of eggs, and genetic diversity declined significantly. Conservation measures initiated in 1992 with translocations of birds from large, genetically diverse populations restored egg viability. Thus, sufficient genetic resources appear to be critical for maintaining populations of greater prairie chickens.

Prescription patterns of diuretics in Dutch community-dwelling elderly patients

AIMS

To describe age- and gender-related prescription patterns of diuretics in community-dwelling elderly, and to compare diuretics to other cardiovascular (CV) medications.

METHODS

Cross-sectional study of patient-specific prescription data derived from a panel of 10 Dutch community pharmacies. Determination of proportional prescription rates and prescribed daily dose (PDD) of diuretics, cardiac glycosides, nitrates, angiotensin converting enzyme (ACE) inhibitors, beta-adrenoceptor blockers, and calcium channel blockers in all 5326 patients aged 65 years or older dispensed CV medications between August 1st, 1995 and February 1st, 1996.

RESULTS

Diuretics were prescribed to 2677 of 5326 patients (50.3%), 1325 patients (24.9%) using thiazides and 1198 patients (22.5%) using loop diuretics. Prescription rates of loop diuretics increased from 15.1% in patients aged 65-74 years to 37.2% in patients aged 85 years or older. Rates also increased for digoxin and nitrates. Rates for thiazide diuretics remained unchanged with age; rates for beta-adrenoceptor blockers, ACE inhibitors and calcium channel blockers declined with age. Thiazides were prescribed to 30.1% of women compared with 16% of men (P < 0.001). Average PDD was 135 +/- 117% of defined daily dose (DDD) for loop diuretics, and highest for bumetanide (245 +/- 2.01% of DDD, equivalent to 2.5 +/- 2.0 mg). Average PDD was 74 +/- 40% of DDD for thiazides, and highest for chlorthalidone (100 +/- 49% of DDD, equivalent to 25 +/- 12 mg).

CONCLUSIONS

Important characteristics of diuretic usage patterns in this elderly population were a steep increase in loop diuretic use in the oldest old, a large gender difference for thiazide use, and high prescribed doses for thiazides.

Use of diuretics and opportunities for withdrawal in a Dutch nursing home population

BACKGROUND

Diuretics are frequently used by elderly patients and overprescription has been suggested. However, the present withdrawal patterns of these medications in clinical practice elderly patients are unclear.

METHODS

Retrospective medical record analysis of all 584 patients aged 75 years or older admitted to a 240-bed nursing home facility in the years 1990-1994. One-year follow-up by record review and collection of updated information from nursing home physicians.

RESULTS

Two hundred and twenty patients (37.7%) used diuretics, and use increased with age (p < 0.05). Reported indications for prescription were heart failure (n = 77), hypertension (n = 38), ankle edema without heart failure (n = 21), or not reported (n = 84). Diuretics were withdrawn in 82 of 220 patients (37.3%), but a doubtful actual indication for diuretic use was found in 72 of the remaining 138 patients (52.2%). After withdrawal, the probability of remaining free from diuretics for at least one year was 0.47. There were no reports of life-threatening or fatal incidents after withdrawal. Mortality rates for the patients whose diuretics were withdrawn did not differ from patients continuing on diuretics.

CONCLUSIONS

Withdrawal of diuretics was frequently performed and often successful. In addition, doubtful indications for diuretics were found in half of the patients continuing on these medications, suggesting additional opportunities for diuretic withdrawal.

Loop diuretics in patients aged 75 years or older: general practitioners' assessment of indications and possibilities for withdrawal

OBJECTIVE

To examine the indications for prescription and possibilities for withdrawal of loop diuretics in community-dwelling patients aged 75 years or older, as reported by their general practitioners (GPs).

METHODS

Analysis of dispensary data to identify patients aged 75 years or older using loop diuretics on 1 February 1996. Questionnaires were sent to the GPs of these patients to inquire about the indications for loop diuretic prescription and the necessity for continuation. We subsequently determined loop diuretic prescription rates in the survey population over the next 9 months.

SETTING

A panel of nine Dutch community pharmacies.

RESULTS

Questionnaires were returned for 338 out of 667 patients (50.7%) using loop diuretics on 1 February 1996. Reported indications for loop diuretic use were heart failure in 223 patients (66.0%), hypertension in 35 patients (10.4%), and a combination of both in 23 patients (6.8%). Loop diuretics were used for ankle edema in 27 patients (8.0%) and for unknown reasons in another 27 patients (8.0%). Continuation of treatment was considered unnecessary by GPs in 66 out of 338 patients (19.5%). However, prescription rates for these 66 patients in the following months were no different from rates for the remaining 272 patients. Loop diuretics were still prescribed to 47 of 66 patients (71.2%) after 12 weeks, and to 26 patients (39.4%) after 36 weeks.

CONCLUSIONS

GPs reported substantial opportunities for withdrawal of loop diuretics in patients over 75 years of age, but this did not influence actual prescription rates in these patients. Future studies should explore means of facilitating withdrawal of these medications in this population.

Use of the Valsalva manoeuvre to identify haemodialysis patients at risk of congestive heart failure

BACKGROUND

In the presence of elevated cardiac filling pressures, the decline of blood pressure (BP) during the straining phase of a Valsalva manoeuvre is blunted or absent. We compared the use of non-invasively measured BP response to a Valsalva manoeuvre with clinical assessment and bioimpedance measurements to identify haemodialysis patients at risk of acute congestive heart failure (CHF).

METHODS

Continuous BP response (Finapres) to a Valsalva manoeuvre, clinical assessment by nephrologists, and bioimpedance estimations of extracellular fluid volume were determined before and after haemodialysis, once every week during a 5-week period. Acute CHF was defined according to preset clinical and radiological criteria.

RESULTS

Participants (age 60+/-19 years, six females, nine males) had an average predialysis weight of 66.8+/-11.8 kg. Patients were dialysed for 3.8+/-0.8 h with a mean ultrafiltration of 2.4+/-1.1 litres. Valsalva systolic BP ratios (phase 2 to 1) decreased significantly during dialysis from 0.81+/-0.11 to 0.73+/-0.10 (P<0.05). Five patients experienced an episode of acute CHF. The Valsalva BP ratios for these patients before and after dialysis (0.89+/-0.05 and 0.78+/-0.05 respectively) were higher than for the remaining ten patients (0.77+/-0.10 and 0.70+/-0.11, respectively) (P<0.05). A cutoff Valsalva BP ratio of 0.82 resulted in positive and negative predictive values for CHF of 62 and 100% respectively. No differences in clinical assessment or bioimpedance parameters were found, with the exception of postdialysis diastolic BP and predialysis ankle oedema. After treatment of CHF, Valsalva BP ratios decreased significantly without changes in the other hydration parameters.

CONCLUSIONS

Non-invasive assessment of the BP response to a Valsalva manoeuvre appears to be a potential tool for identifying patients at risk of acute CHF during maintenance haemodialysis.

[Recruitment and selection of test subjects for scientific research in geriatrics: literature review and experiences of the Nijmegen NESTOR study]

The conduct of research in geriatric medicine differs from that in other medical specialties in a number of ways. In geriatric research it is almost impossible to study a large, homogeneous group of subjects, suffering solely from the problem to be studied. Moreover, measurements and questionnaires should be short, simple and not very troublesome. These differences are due to the heterogeneity of geriatric patients and the high prevalence of multimorbidity, often resulting in impaired physical, psychological and social performance. In this article a number of issues which are important for successful recruitment and selection of subjects for geriatric research are discussed. First, a review of relevant literature is given, and subsequently, experiences concerning recruitment and selection appreciated in the Nijmegen geriatric research programme' are described. This programme was part of the governmental Netherlands Programme for Research on Ageing (NESTOR). According to the literature the efficacy of recruitment may be improved by: personal contact between researcher and subject in view, introduction of the selection criteria already at the time of subjects' recruitment, a balance between research burden and profit, sufficient rewards for participation, both financially and non-financially, maximal effort in the subjects' transport, and also piloting of the recruitment procedure. In the NESTOR-studies the average number of subjects who were recruited and who completed the studies was low (23%), because a lot of the recruited subjects did not meet the selection criteria or considered participation as too troublesome. Subjects who agreed to participate showed high research compliance.

Validation of multi-frequency bioelectrical impedance analysis in detecting changes in fluid balance of geriatric patients

OBJECTIVES

Multi-Frequency Bioelectrical Impedance Analysis (MFBIA) is a quick, simple, and inexpensive method to assess body fluid compartments. This study aimed at determining the validity of MFBIA in detecting clinically relevant changes of fluid balance in geriatric patients.

DESIGN

A prospective, observational study.

SETTING

The 22-bed Geriatric Department of the University Hospital Nijmegen.

PARTICIPANTS

Hospitalized patients were eligible if they did not have a pacemaker, were not suffering from terminal illnesses, and did not have psychogeriatric diseases likely to interfere with capacity to consent or comply. During a 16-months period, 218 patients were admitted, of whom 78 patients were eligible and 53 consented to participate.

MEASUREMENTS

Each subject's fluid balance was diagnosed twice a week as dehydrated, overhydrated, or euvolemic, based on standardized physical examination, laboratory tests, and weight evaluation. Changes in fluid balance were quantified by measuring total body water (TBW) and extracellular fluid (ECF) applying deuterium- and bromide-dilution techniques. Impedance at 1, 5, 50, and 100 kHz and body weight were measured daily. Sensitivity and Guyatt's responsiveness indexes of MFBIA in detecting dehydration and overhydration were determined.

RESULTS

In total, 1071 MFBIA measurements were performed, during which 14 transitions from dehydration to euvolemia and 13 transitions from overhydration to euvolemia were monitored. Rehydration of dehydrated patients caused an increase in TBW and ECF of 3.4 +/- 1.8 L and 1.9 +/- 1.9 L, respectively, which resulted in significant decreases in impedance of 133 +/- 67 omega at 1 kHz and 93 +/- 61 omega at 100 kHz (P = .001). Treatment of overhydrated patients caused a TBW and ECF loss of 3.8 +/- 4.2 L and 3.1 +/- 3.8 L, respectively, which resulted in significant increases in impedance of 104 +/- 72 omega at 1 kHz and 81 +/- 68 omega at 100 kHz (P < .001). Sensitivity of a single MFBIA in diagnosing dehydration and overhydration was 14% and 17%, respectively. Responsiveness indexes of weighing and MFBIA for dehydration and overhydration were similar at all frequencies and greater than one.

CONCLUSION

The sensitivity of a single impedance measurement in detecting dehydration and overhydration was low. However, responsiveness of serial measurements to intra-individual changes in fluid balance was good. Therefore, this noninvasive technique may be used in clinical practice to improve monitoring fluid balance in geriatric patients, especially when daily weighing is difficult.

Diuretic usage and withdrawal patterns in a Dutch geriatric patient population

OBJECTIVES

To describe diuretic usage and withdrawal patterns in a population of very old geriatric patients and to evaluate the long-term probability of remaining free from diuretic therapy after withdrawal.

DESIGN

Retrospective analysis of medical records and 1-year follow-up study.

SETTING

University Hospital Nijmegen and Rijnstate Hospital Arnhem, a non-academic teaching hospital, The Netherlands.

PARTICIPANTS

All 1547 patients, aged 75 years or older, visiting geriatric medicine departments in the two hospitals for the first time in the years 1990 through 1993.

MEASUREMENTS

Data on medical history, physical examinations, and medication use were obtained from medical records. Diuretic withdrawal and motivation was recorded as reported. Record review indicating diuretic withdrawal prompted a 1-year follow-up investigation and collection of additional updated information from family care and/or nursing-home physicians.

RESULTS

A total of 593 three patients (38.3%) were using diuretics. Use of diuretics increased with age from 33.6% in patients aged 75 to 79 years to 47.4% in patients aged 90 years or older (P < .05). Diuretics were withdrawn in 218 patients (36.8%), in 101 patients because of doubts about the initial or persistent indication for diuretic use and in 91 patients because of adverse effects. No reasons for withdrawal were reported in 26 patients. Withdrawal of diuretics was attempted more often in cases of diuretic prescriptions for unknown reasons (51.2%) or ankle edema without heart failure (45.0%) than when prescriptions were for heart failure (28.5%) or hypertension (35.4%). The overall probability of remaining free of diuretic therapy for 1 year was 0.41. Success of diuretic withdrawal was significantly less when congestive heart failure was the initial indication for prescription (probability 0.24). We did not find other clinical parameters related to the success of withdrawal.

CONCLUSIONS

Our study demonstrates that diuretic therapy can be withdrawn for at least a 1-year period in a substantial number of very old geriatric patients receiving these medications, regardless of the initial indications for prescription. However, withdrawal is performed without application of uniform criteria. Future prospective studies should be directed at developing clear guidelines for diuretic withdrawal in order to facilitate identification of eligible patients and to further improve the success of withdrawal attempts.

Validation of multifrequency bioelectrical impedance analysis in monitoring fluid balance in healthy elderly subjects

BACKGROUND

Multifrequency Bioelectrical Impedance Analysis (MFBIA) is a novel method to assess body composition in elderly subjects. However, it is unclear whether MFBIA can detect changes in body water compartments in elders. We aimed to determine the within-subject variability of MFBIA and the responsiveness to a diuretic intervention in aged subjects with a stable fluid balance.

METHODS

We selected 12 healthy active elderly subjects (5 male, 7 female) with a mean age of 75 years. Total body water and extracellular fluid (ECF) were measured by deuterium oxide- and potassium bromide-dilution techniques. Within-subject variability in total body MFBIA was assessed by performing four measurements at 1, 5, 50, and 100 kHz within a 2-month period. Subsequently, responsiveness of MFBIA to the ECF loss caused by oral administration of 40 mg of furosemide was determined.

RESULTS

Within-subject variability in MFBIA at 1, 5, 50, and 100 kHz expressed as standard deviations was 21, 19, 14, and 14 Ohm (omega), respectively. Furosemide caused a mean weight loss of 1.8 +/- 0.6 kg, which resulted in significant increases in impedance of 57 +/- 24 omega at 1 kHz and 37 +/- 12 omega at 100 kHz (p < .001). The responsiveness of MFBIA for the diuretic intervention was best at 5 kHz (responsiveness index = 1.98).

CONCLUSIONS

Within-subject variability of MFBIA was small in healthy elderly subjects with stable fluid balance. Responsiveness of MFBIA to 9% furosemide-induced ECF loss was excellent. These data support the necessity for further clinical assessment of the value of MFBIA in monitoring fluid balance in geriatric patients.

Hepatitis-B-virus resistance to lamivudine given for recurrent infection after orthotopic liver transplantation

BACKGROUND

Orthotopic liver transplantation for end-stage hepatitis-B-virus (HBV) infection is commonly complicated by recurrence of HBV. Lamivudine, a cytosine nucleoside analogue, has been shown to suppress HBV infection. We report the development of resistance to lamivudine in three patients who underwent transplantation for end-stage liver disease secondary to hepatitis B.

METHODS

Two of the patients received lamivudine for recurrent HBV infection after transplantation, whereas the third patient began treatment 1 month before transplantation in an attempt to prevent HBV recurrence after transplantation. The three patients initially responded well to treatment, but viral recurrence occurred after 9-10 months of treatment in all patients. HBV DNA was amplified from serum and sequenced through a conserved polymerase domain-the tyrosine, methionine, aspartate, aspartate (YMDD) locus. We assessed the susceptibility of HBV to lamivudine by infecting primary human hepatocytes with serum taken before the start of treatment and after recurrence in varying concentrations of lamivudine.

FINDINGS

DNA sequencing showed a common mutation within the YMDD locus of the HBV polymerase gene in all patients during lamivudine treatment. In hepatocyte cultures infected with pretreatment serum, HBV DNA concentrations were reduced to less than 6% of those in control cultures by addition of lamivudine in concentrations as low as 0.03 mumol/L. By contrast, in cultures treated with serum taken after recurrence, HBV DNA concentrations did not fall below 20% of control values, even with lamivudine at 30 mumol/L.

INTERPRETATION

Resistance to lamivudine has been reported in HIV patients with mutations in the YMDD locus of the polymerase gene. Our findings indicate a common mechanism of lamivudine resistance for HIV and HBV that involves similar point mutations in homologous domains of the viral polymerases.

Intraindividual reproducibility of postprandial and orthostatic blood pressure changes in older nursing-home patients: relationship with chronic use of cardiovascular medications

OBJECTIVES

Although postprandial and orthostatic hypotension are commonly observed in nursing home residents, their reproducibility, relationship to each other, and association with chronic use of cardiovascular medications are poorly understood.

DESIGN

We examined blood pressure (BP) and heart rate (HR) before and after postural change, and before and after a 419-kcal meal in 22 nursing home residents (mean age 89 +/- 5 (SD) years), each on two occasions, to determine reproducibility changes. These studies were repeated in 17 residents, with and without previous administration of cardiovascular medications, in random order.

SETTING

Hebrew Rehabilitation Center for the Aged, an academic long-term care facility.

RESULTS

Systolic BP declined an average (+/- SE) of 16 +/- 4 mm Hg and 12 +/- 4 mm Hg during the first and second meal studies, respectively. Mean intra-class correlation of postprandial systolic BP values during the two studies was 0.88 (95% CI 0.85-0.97). Systolic BP increased significantly during the first posture test to a maximum of 8 +/- 6 mm Hg at 6 minutes. There was no significant difference over time in postural systolic BP between the two tests. Repeated postural studies showed a mean intra-class correlation of 0.72 (95% CI 0.62-0.92) for changes in systolic BP. Cardiovascular medications had no additional effect on postprandial or orthostatic BP and HR changes. During the first studies, 10 subjects had postprandial hypotension, and three subjects had orthostatic hypotension, but only two of 22 subjects had both.

CONCLUSIONS

Patterns of systolic BP response to meals or postural change are reproducible. BP responses to meals and postural change seem to be unaffected by potentially hypotensive medications in chronic users. Postprandial hypotension is distinct from orthostatic hypotension, occurring more commonly than orthostatic hypotension and infrequently together in the same patients.

(-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine (524W91) inhibits hepatitis B virus replication in primary human hepatocytes

The anti-hepatitis B virus (HBV) activity of (-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine (524W91) in cultures of primary human hepatocytes was examined. 524W91 was anabolized to the active 5'-triphosphate in these cells. HBV replication was equally inhibited in cultures incubated with 524W91 when the drug was added 24 h preinfection, at infection, or 24 h postinfection. 524W91 inhibited HBV replication by 50% at less than 20 nM in human hepatocytes.

Postprandial hypotension in elderly patients with unexplained syncope

BACKGROUND

Syncope in older patients may be caused by a variety of disorders, including hypotension, but frequently remains unexplained. Postprandial hypotension is a common disorder of blood pressure regulation in the elderly.

OBJECTIVE

To determine the pathogenic mechanisms and potential role of postprandial hypotension in elderly patients with otherwise unexplained syncope.

METHODS

We studied 16 elderly patients with unexplained syncope and nine elderly controls. Blood pressure, heart rate, forearm vascular resistance, plasma norepinephrine level, and cardiac and splanchnic blood volumes were measured before and after a 1680-kJ meal.

RESULTS

Eight elderly patients with syncope had postprandial hypotension, with a decline in supine mean arterial blood pressure of 17 +/- 2 mm Hg after a meal (P < .001). The blood pressure remained unchanged after the meal in the other patients with syncope and the controls. In patients with postprandial hypotension, systemic vascular resistance fell after the meal, while it remained unchanged in the other groups. Heart rate and plasma norepinephrine level increased to a similar extent in all three groups. Forearm vascular resistance increased only in the control subjects. Splanchnic blood volume increased by 26% (P < .01) in patients with syncope who had postprandial hypotension and by 22% (P < .01) in control subjects. Splanchnic blood volume remained unchanged in the patients with syncope without postprandial hypotension.

CONCLUSIONS

Postprandial hypotension may be an important causative factor in elderly patients with unexplained syncope. The evaluation of syncope in elderly patients should therefore include blood pressure measurements surrounding a meal. Elderly patients with syncope who have postprandial hypotension fail to maintain systemic vascular resistance, probably because of splanchnic blood pooling without a compensatory increase in peripheral vascular resistance.