Carotid endarterectomy in the elderly: risk factors, intraoperative carotid hemodynamics and short-term complications: a UK tertiary center retrospective analysis.

This retrospective analysis aims to demonstrate the safety of carotid endarterectomy (CE) in patients >75 years with particular attention paid to intraoperative hemodynamics. Four hundred and ninety-six consecutive patients with >70% symptomatic and asymptomatic stenosis who underwent CE were prospectively assessed and divided into those <75 years (n = 408; mean 64 years) and those >75 years (n = 88; mean 78 years). Associated risk factors, hemodynamic parameters, surgical techniques and 30-day perioperative complications were compared. Carotid artery stump pressures of <25 mmHg (13 versus 29%) and middle cerebral artery velocities of <20 cm/sec (46 versus 29%) were more common in those >75 years (P = 0.0001 and P <0.005, respectively). However, there was no difference in the frequency of intraluminal shunt (34% in both groups) or synthetic patch usage (primary patching: 12.5%, older group versus 11%, younger group; secondary patching: 34% in both groups), and no difference in the combined 30-day stroke and death rates (3.4%, >75 years versus 1.1%, <75 years; P = 0.425). CE in this cohort of patients >75 years was not associated with increased morbidity or mortality. Altered intraoperative hemodynamics were not associated with increased use of shunting or patching. This analysis supports CE as a safe procedure in the elderly.

Microdosimetry of electron microbeams.

Track structures of 25, 50 and 80 keV primary electrons, simulated by the detailed-history Monte Carlo method, were analyzed for the frequency distributions of energy deposited in spheres with a diameter of 1 microm, placed in a cylindrically symmetrical array around the projected initial direction of the primary electron. The frequency mean of specific energy, the dose mean of lineal energy, and the parameters of lognormal functions fit to the dose distributions were calculated as a function of beam penetration and radial distance from the projected beam axis. Given these data, the stochastics of dose and radiation quality for micrometer-scale sites targeted by a medium-energy electron microbeam can be predicted as a function of the site's location relative to the beam entry point.

Venous thromboembolism after acute ischemic stroke: a prospective study using magnetic resonance direct thrombus imaging.

BACKGROUND AND PURPOSE: We prospectively evaluated the prevalence and clinical risk factors for venous thromboembolism (VTE) after acute ischemic stroke using magnetic resonance direct thrombus imaging, a highly accurate noninvasive technique that directly visualizes thrombus.Method-102 unselected patients with AIS receiving standard prophylaxis with aspirin and graded compression stockings (GCS) were sequentially recruited, underwent regular clinical assessments, and were screened for VTE. RESULTS: The prevalence of all VTE, proximal deep vein thrombosis (PDVT), and pulmonary embolism (PE) after 21 days were 40%, 18%, and 12%, increasing to 63%, 30%, and 20% in patients with Barthel indices (BI) of < or =9 2 days after stroke (BI-2< or =9). Clinical deep vein thrombosis and PE occurred in 3% and 5% overall; half these events were overlooked by the attending team. The true incidence of clinical events is probably higher because the natural history of subclinical PDVT was modified by screening and anticoagulation. BI-2< or =9 or nonambulatory status 2 days after stroke were the clinical factors most strongly associated with subsequent VTE on univariate analysis. Odds ratios for any VTE and PDVT for BI-2< or =9 versus >9 were 8.3 (95% CI, 2.7 to 25.2) and 8.1 (95% CI, 1.7 to 38.3) on multivariable analysis. CONCLUSIONS: BI < or =9 or nonambulatory status around the time of admission identifies a subgroup of acute ischemic stroke patients at very high risk for VTE in whom the current strategy of thromboprophylaxis may be inadequate. Future thromboprophylactic studies should focus on the patients at high risk defined in this study.

Analysis of low-energy electron track structure in liquid water.

An implementation is presented of interaction cross sections for non-relativistic electron track structure simulations. The model, incorporating liquid-phase cross sections for inelastic interactions and improved algorithms for elastic scattering, is applied to Monte Carlo simulation of the track structure of low-energy electrons. Benchmark distributions and mean values are presented for several measures of penetration distances that characterize the general physical extent of the track structure. The results indicate that, except for the last approximately 500 eV of energy loss, electron tracks have a quasi-linear character; this suggests that a major part of an electron track may be reasonably described by a lineal-energy-like characterization.

Dehydration and venous thromboembolism after acute stroke.

BACKGROUND: Although it is widely assumed that dehydration predisposes to venous thromboembolism (VTE), there are no clinical studies to support this. AIM: To evaluate the relationship between biochemical indices of dehydration and VTE after acute ischaemic stroke (AIS). DESIGN: Prospective observational study. METHODS: Unselected AIS patients (n = 102) receiving standard thromboprophylaxis with aspirin and graded compression stockings, underwent serial measurements of serum urea, creatinine and osmolality, and were screened for VTE using magnetic resonance direct thrombus imaging. RESULTS: Serum osmolality of >297 mOsm/kg, urea >7.5 mmol/l and urea:creatinine ratio (mmol:mmol) >80 a few days post-AIS were associated with odds ratios for VTE of, respectively, 4.7, 2.8 and 3.4 (p = 0.02, 0.05, 0.02) on multivariable analysis. DISCUSSION: Dehydration after AIS is strongly independently associated with VTE, reinforcing the importance of maintaining adequate hydration in these patients.

Screening for proximal deep vein thrombosis after acute ischemic stroke: a prospective study using clinical factors and plasma D-dimers.

Deep vein thrombosis (DVT) remains common in patients with acute ischemic stroke (AIS) receiving aspirin and graded compression stockings (considered standard thromboprophylaxis in the UK), most events occurring in patients with Barthel indices (BI) of <9 ('severe stroke') around the time of admission. In the absence of data indicating improved clinical outcomes with use of low-dose anticoagulant thromboprophylaxis, we evaluated the hypothesis that plasma D-dimers (D-d) might be a valuable initial screening test for proximal DVT (PDVT), facilitating selective use of imaging. One hundred and two unselected AIS-patients receiving aspirin/graded compression stockings thromboprophylaxis were screened for DVT using magnetic resonance direct thrombus imaging, a highly accurate non-invasive technique which directly visualizes thrombus. D-d (VIDAS and IL test D-d assays) were measured on recruitment and at weekly intervals. Median D-d were significantly higher throughout the study in patients with severe stroke who developed PDVT vs. those with severe stroke not developing PDVT, differences being most marked around day 9. Depending on the discriminatory threshold used, a single D-d measurement at this time in patients with severe-AIS allowed identification of a subgroup with ~50% prevalence of PDVT. Sensitivity of these strategies for PDVT was 67-83%, at a cost of imaging 22-30% of the entire cohort of patients. A single measurement of BI around the time of admission and D-d level at day 9 in AIS-patients receiving aspirin/graded compression stockings thromboprophylaxis allows identification of a subgroup containing a substantial proportion of all PDVTs who could be selectively imaged.

Anticoagulation or inferior vena cava filter placement for patients with primary intracerebral hemorrhage developing venous thromboembolism?

BACKGROUND: Most patients with primary intracerebral hemorrhage developing clinically apparent proximal deep vein thrombosis (DVT) and/or pulmonary embolism (PE) require treatment with either anticoagulants or inferior vena cava filter insertion. Although the latter probably reduces the immediate risk of incident or recurrent PE and surmounts the undefined risk of recurrent intracranial bleeding with anticoagulation, the issue of preventing further thrombus propagation is not addressed, and there are associated short- and long-term risks, including a greater incidence of recurrent DVT. SUMMARY OF REVIEW: There are no data from randomized trials to clarify optimum treatment in these patients; indeed, the feasibility of such studies is questionable. Hence, treatment decisions continue to be made on an individualized basis and should include assimilation of information on key factors such as time elapsed post-stroke and lobar versus deep hemispheric location of the index event, natural history studies demonstrating a two-fold risk of recurrent intracerebral hemorrhage in the former subgroup. CONCLUSIONS: In patients selected for anticoagulation, data from nonstroke patients suggest that a 5- to 10-day course of full-dose low-molecular-weight heparin followed by 3 months of lower-dose low-molecular-weight heparin is at least as effective as warfarin and may be associated with fewer hemorrhagic complications.

Prediction of hypertension in chronic hemodialysis patients.

BACKGROUND: There are no universally accepted criteria for the diagnosis of hypertension in hemodialysis (HD) patients. We sought to determine the clinical performance of predialysis and postdialysis systolic and diastolic blood pressure values (BPs) in diagnosing hypertension or assessing its control. METHODS: Seventy patients [77% African American, 46% females, mean age 59 +/- 17 (SD) years, 34% diabetics] on chronic HD underwent a single 44-hour interdialytic ambulatory blood pressure monitoring (ABPM) and concomitant recording of BP by conventional syphygmomanometer in the HD unit for two weeks. Hypertension was defined as systolic BP (SBP) > or =135 mm Hg or diastolic BP (DBP) > or =85 mm Hg on an average 44-hour ABPM. RESULTS: Average ABP was 144 +/- 22/81 +/- 11 mm Hg. Seventy-three percent of the patients had systolic hypertension; 40% had diastolic hypertension, and 24% were normotensive or had well-controlled BP. Area under the curve of receiver operating characteristic (ROC) curves exceeded 80% for all BPs, but the thresholds for best sensitivity and specificity were markedly different for predialysis and postdialysis BPs. A two-week averaged predialysis BP of > 150/85 mm Hg or a postdialysis BP of > 130/75 mm Hg had at least 80% sensitivity in diagnosing hypertension. Specificity of at least 80% was achieved if predialysis BP of > 160/90 mm Hg or postdialysis BP of > 140/80 mm Hg was used. There was poor agreement between HD unit BP and ABP values. CONCLUSIONS: HD unit BP values can be used to identify the presence or absence of hypertension, although prediction of ambulatory BPs from HD unit BP values cannot be made reliably in individual patients.

Caregiving tasks among family caregivers of patients with lung cancer.

PURPOSE/OBJECTIVES: To describe family caregivers' perceptions of time spent and difficulty experienced with performing specific caregiving tasks for patients with lung cancer. To compare adult child and spousal caregivers in relation to time and difficulty of tasks. DESIGN: A secondary analysis of data from a study using a cross-sectional, descriptive, comparison design. SETTING: A university outpatient oncology center, two veterans administration outpatient clinics, and a private outpatient oncology practice. SAMPLE: 78 family caregivers of patients with lung cancer (62 spouses and 16 adult children). METHODS: Data that previously had been collected using a structured interview guide were analyzed using descriptive statistics, comparison of item means, and multivariate analysis of variance. MAIN RESEARCH VARIABLES: Time and difficulty with caregiving tasks. FINDINGS: The most time-consuming tasks for adult children and spouses were providing emotional support, transportation, and monitoring symptoms. The most difficult duties were emotional support, behavioral management, monitoring symptoms, and household tasks. Time and difficulty of tasks did not differ significantly between adult child and spousal caregivers. CONCLUSIONS: Some caregivers may require guidance in providing transportation, emotional support, behavioral management, and symptom management. IMPLICATIONS FOR NURSING PRACTICE: Oncology nurses can make a significant impact in assisting family members in providing care by addressing the provision of transportation, emotional support, behavioral management, and symptom management.

Patent foramen ovale in elderly stroke patients.

The aim of this study was to determine the incidence of echocardiographically detectable patent foramen ovale (PFO) in elderly patients who have strokes from cerebral infarction, as well as to assess the association between PFOs and other risk factors for stroke disease. Forty-three patients aged > or = 65 years admitted consecutively with cerebral infarction shown on computerised tomography of the brain were assessed using transoesophageal echocardiography. A PFO was present in 8 (19%) of the 43 patients. Four patients (50%) in this PFO group had stroke risk factors. Two were in atrial fibrillation and, of the six patients in sinus rhythm, a risk factor was present in two, both of whom had diabetes mellitus. A PFO was not detected in 35 patients. Twenty-nine (83%) of the patients in this group had risk factors, with 18 having two or more. Seven patients were in atrial fibrillation. Of the 28 patients in sinus rhythm, risk factors were present in 22 (78%).

Acute confusion secondary to pneumocephalus in an elderly patient.

PRESENTATION: an 83-year-old man was admitted to hospital with acute confusion 3 days after a direct flight from Australia. OUTCOME: computed tomography (CT) brain scan and magnetic resonance imaging head scan revealed the cause to be pneumocephalus, apparently the result of barotrauma caused by Valsalva manoeuvres when he attempted to unblock his nose during the flight. After 5 days of nursing in the vertical position the patient's Abbreviated Mental Score returned to normal. A CT brain scan 6 weeks later showed complete resolution of the pneumocephalus.

An unusual cause of falls in an elderly patient.

Falls are common in the elderly, often causing considerable morbidity and mortality. Prevention is therefore important and is based on determining the cause. We present an elderly patient who had multiple falls during the day due to recurrent daytime sleep episodes, an entity we believe has not previously been reported.

Malabsorption in the elderly. 1: Examination, history and investigation.

Malabsorption in elderly patients has varied presentations, and can be overlooked. A high index of clinical suspicion is required. This, the first of two articles, discusses the principal causes, clinical features and initial investigations of malabsorption in the elderly.