Regional block and DVT prophylaxis

The last few years have seen increasing concerns among anaesthetistsabout the risks of pharmacological prophylaxis for thromboembolicdisease. Increased bleeding during or after surgery is one concern,but of greater significance is the possibility of an increasedpredisposition to haematoma formation when regional block isused. Most of the recent consideration of this problem has beenin relation to vertebral canal haematoma formation after centralnerve block. Some thought must be given also to the possibilityof haematoma formation after peripheral techniques when thetarget nerve is deeply placed so that pressure cannot be usedto control bleeding after needle insertion. However, this reviewwill be focused on vertebral canal haematoma.     

Motor unit characteristics in healthy subjects and those with postpoliomyelitis syndrome: a high-density surface EMG study

The purpose of this study was to identify optimal ways to detect neurogenic changes with high-density surface electromyography (HD-sEMG). For this purpose, we searched for the variables that most clearly discriminated between postpoliomyelitis and healthy subjects. We obtained HD-sEMG from the quadriceps muscle at different force levels in nine subjects with postpoliomyelitis syndrome and in matched healthy controls. Single motor unit action potentials (MUAPs), extracted from the HD-sEMG signal and the raw signal itself, were analyzed. Areas under the curve of the extracted MUAP waveform, indicating motor unit size, perfectly separated both groups. Raw signal analysis showed significant differences between groups for the monopolarly recorded amplitude up to 60% of maximal force and for the level of interference at higher force levels (40-100% force). We conclude that with HD-sEMG it is possible to detect neurogenic motor unit changes noninvasively, both by analysis of the raw signal itself and by analysis of extracted single MUAPs. The diagnostic yield of the single MUAP analysis is clearly higher. These findings point toward applications for clinical practice and invite further studies exploring the diagnostic value of HD-sEMG.     

Duration of untreated psychosis vs. N-acetylaspartate and choline in first episode schizophrenia: a 1H magnetic resonance spectroscopy study at 4.0 Tesla

N-acetylaspartate (NAA) has been associated with neuronal integrity and function, and choline-containing compounds have been linked to neuronal membrane integrity. This study examined the influence of the duration of untreated psychosis, duration of prodromal symptoms and total length of untreated illness on these markers of neuronal loss or damage. In vivo 1H magnetic resonance spectroscopy data were acquired from 1.5-cc volumes in the left anterior cingulate and left thalamus of 19 never-treated first episode schizophrenic subjects using STEAM20 at 4.0 Tesla. Duration of untreated psychosis, prodrome and total length of untreated illness were correlated with levels of NAA and choline. No significant correlation was observed between NAA and duration of untreated psychosis and untreated illness in both regions examined. Thalamic NAA negatively correlated with duration of prodromal symptoms. A positive correlation between choline and duration of untreated psychosis was identified in both regions studied. Delays in treatment of psychotic symptoms of schizophrenia were not associated with a reduction in markers of neuronal integrity or function in contrast to longer prodromal periods, which were associated with lower NAA. Neuronal damage, potentially detectable via lower NAA, may be occurring before the onset of psychosis. Increased choline is associated with longer duration of untreated psychosis and could indicate that psychosis-related membrane alterations precede the appearance of NAA reductions observed by studies of chronic schizophrenia.     

Comparative study of proton and phosphorus magnetic resonance spectroscopy in schizophrenia at 4 Tesla

This study used high-field magnetic resonance spectroscopy to examine the correlation of 1H and 31P metabolite levels in patients with schizophrenia and normal controls. 1H and 31P in vivo spectra were acquired successively from the left anterior cingulate and left thalamus of nine chronic schizophrenic patients and eight comparable healthy controls. A significant positive correlation between glutamine (Gln) and phosphoethanolamine (PEtn) was found in the left anterior cingulate of patients. In the left thalamus of patients, a significant negative correlation between N-acetylaspartate (NAA) and glycerophosphocholine (GroPCho) was found. No significant correlations were found in controls. The correlation between glutamine and phosphoethanolamine may reflect a link between neurotransmission alterations and membrane phospholipid metabolism alterations. The negative correlation between N-acetylaspartate and glycerophosphocholine may reflect the presence of neurodegeneration.     

Keratographie (Hornhauttätowierung) bei Hornhautleukom

BACKGROUND: Since antiquity attempts have been made to minimize disfigurement and stigmatization of patients with leukoma. Keratography is a relatively new method for imprinting color pigments into the corneal stroma with an entomological needle. MATERIALS AND METHODS: Keratography was performed in 20 patients at the University Eye Hospital, Munich, between November 1997 and September 1999. Patients had either a leukoma that did not tolerate prothesis or had another cloudy corneal disease. The operation was carried out in our outpatient clinic under local anesthesia. RESULTS: There was a single operation in three patients, two operations in nine, three operations in six, and four operations in two. Postoperatively 33% of patients complained of pain. No postoperative bacterial keratitis or perforation occurred. CONCLUSION: All patients were highly satisfied. The long-term stability of color pigments must still be evaluated.     

Effect of immobilization on ankle dorsiflexion strength

This study was performed in order to determine the loss of strength of the dorsiflexors in healthy persons after immobilization of the ankle, and the ability of these muscles to regain strength. First, isometric ankle dorsiflexion strength was measured in 33 healthy male and 39 female subjects in age categories 20-40 and 40-80 years, in order to obtain reference data and to determine the reproducibility of the measurement protocol. Gender, age and ankle position had a significant influence on the ankle dorsiflexion torque. Secondly, torque was measured in 15 patients after 4-6 weeks' immobilization of the ankle due to a fracture. A 28% decrease in dorsiflexion torque was seen. Strength reduction in neutral position and in 30 degrees plantar flexion was not significantly different. Without specific therapy restoration of torque was almost complete 6 weeks after cast removal.     

Increased rigidity and priming of polymorphonuclear leukocytes in sepsis.

It has been proposed that abnormal mechanical properties may contribute to capillary retention of polymorphonuclear leukocytes (PMN) in sepsis, leading to the development of organ dysfunction. The present study was designed to determine whether PMN rigidity is increased in severe sepsis, and whether changes in the rheologic behavior of PMN correlate with the clinical course in sepsis. Eighteen adults with severe sepsis were studied over a period of 14 d; 11 survived and seven died. PMN deformation behavior was investigated via micropore filtration, using the cell transit analyzer. On Day 0, PMN rigidity was 2.5-fold greater for sepsis patients than for five normal controls (p < 0.001). PMN rigidity progressively improved over the 14 d study period for patients who recovered, but not for those who died; clinical indicators correlated with PMN rigidity. Patient PMN also exhibited a 5-fold greater increase in rigidity in response to formyl-methionylleucylphenylalanine (fMLP) than did control PMN. Both the increased rigidity and enhanced response to fMLP could be simulated in vitro by incubation of normal PMN with tumor necrosis factor-alpha (TNF-alpha). We conclude that circulating PMN are more rigid in severe sepsis, and are "primed" for an augmented response to chemotactic stimuli. These findings support the hypothesis that cytokine-mediated increases of PMN rigidity may lead to sequestration of these cells in capillaries and to the consequent impairment of microvascular perfusion in sepsis.     

Prevalence of risk factors for cardiovascular disease in Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986-1992

BACKGROUND: By 2016, the proportion of Canadians older than 65 years of age will increase to 16%, and there will be an increase in the absolute number of cases of cardiovascular disease in older Canadians. The Canadian Heart Health Surveys database provides information about this population upon which health policy related to cardiovascular disease can be based. This paper presents for the first time population-based data on the risk factors for cardiovascular disease in older Canadians. METHODS: Canadians from all 10 provinces participated in surveys of cardiovascular risk factors; health insurance registries were used as sampling frames. In each province, probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps were asked to participate in interviews and to undergo testing at clinics for major risk factors for cardiovascular disease. RESULTS: A total of 2739 men (response rate 70%) and 2617 women (response rate 66%) aged 55 to 74 years participated in the survey and also provided follow-up clinical measurements at the clinic. Overall, 52% of participants were hypertensive, 26% had isolated systolic hypertension, and 30% had a total blood cholesterol level of 6.2 mmol/L or greater. Rates of current smoking were lower in women than men (17% v. 22%). Overall, 87% of men and 78% of women who were current smokers smoked at least 10 cigarettes per day. Only slightly more than half of participants exercised at least once a week for at least 15 minutes, and almost half had a body mass index of 27 or greater. In only 4% was no major risk factor for cardiovascular disease detected. INTERPRETATION: Significant numbers of older Canadians have one or more major risk factors for cardiovascular disease. Many of these risk factors are amenable to modification.