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.     

Anaphylaxis associated with, but not caused by, extradural bupivacaine

Identifying anaphylaxis and determining its cause during anaesthesia can be very difficult. We describe a patient who suffered a life- threatening reaction which was diagnosed originally as being caused by bupivacaine. Subsequent investigation and enquiry showed that this was not so and suggested latex as the likely true cause.      

Bioavailability of Aluminum from Drinking Water

Bioavailability of Aluminum from Drinking Water. FULTON, B.,JAW, S., AND JEFFERY, E. H. (1989). Fundam Appl. Toxicol. 12,144–150. Aluminum, present in our drinking water as hydroxideor sulfate, is limited by solubility to 2.5 mg/liter at pH 7.0.This study was carried out to determine if aluminum at dosestypically found in drinking water would accumulate in rat tissuesif a ligand such as citrate at neutral or acid pH is coadministered,or in the absence of citrate at acid pH. Al(OH)₃ or AlCl₃ wasgiven ad libitum in drinking water to male Sprague-Dawley ratsat 0, 0.1, 2.0, or 100 mg/liter, in 4 mM acetate, pH 3.2 (A),4 mM citrate, pH 2.6 (C), 4 mM citrate, pH 7.0 (7C), or distilledwater, pH 7.0(W). After 10 weeks, rats were killed and tissueswere wet-ashed in nitric acid for determination of aluminumby flameless atomic absorption. Copper, iron, and zinc weredetermined by flame atomic absorption. Metal ion concentrationsin tibia, brain, liver, blood, and kidney did not differ significantlybetween treatment groups. Aluminum accumulated in intestinalcells of all 100 mg Al/liter rats, with the C group accumulatingmore aluminum than the A or W groups. In the C group, intestinalaluminum content increased significantly in a dose-dependentmanner. Intestinal iron was decreased significantly in all the100 mg Al/liter groups. Intestinal copper was decreased in theW group at 100 mg Al/liter, with a trend toward a decrease inA and C groups. We conclude that at these low levels studied,aluminum accumulates in intestinal tissue, and that this accumulationis enhanced by citrate ligand. At 100 mg Al/liter, intestinaliron accumulation is decreased, and copper accumulation is marginallydecreased.     

Spinal anaesthesia: an update

Spinal anaesthesia is now practised widely. This article isnot intended to be an exhaustive review; it will focus on somenew developments and techniques.     

Comparison of continuous and intermittent administration of extradural bupivacaine for analgesia after lower abdominal surgery

We have compared intermittent bolus and continuous infusion of extradural local anaesthetic for pain relief in a randomized, double- blind study of 48 patients who underwent major abdominal gynaecological surgery. Each patient received 5 ml of 0.375% bupivacaine hourly, either as a bolus over 5 min or as a constant infusion. Patients who received the intermittent administration technique maintained a more extensive sensory block, reported marginally better analgesia and had a lower requirement for rescue medication. The intermittent bolus technique was not associated with an increase in side effects.      

Gender differences in patients with dizziness and unsteadiness regarding self-perceived disability, anxiety, depression, and its associations

Background

It is known that anxiety and depression influence the level of disability experienced by persons with vertigo, dizziness or unsteadiness. Because higher prevalence rates of disabling dizziness have been found in women and some studies reported a higher level of psychiatric distress in female patients our primary aim was to explore whether women and men with vertigo, dizziness or unsteadiness differ regarding self-perceived disability, anxiety and depression. Secondly we planned to investigate the associations between disabling dizziness and anxiety and depression.

Method

Patients were recruited from a tertiary centre for vertigo and balance disorders. Participants rated their global disability as mild, moderate or severe. They filled out the Dizziness Handicap Inventory and the two subscales of the Hospital Anxiety Depression Scale (HADS). The HADS was analysed 1) by calculating the median values, 2) by estimating the prevalence rates of abnormal anxiety/depression based on recommended cut-off criteria. Mann-Whitney U-tests, Chi-square statistics and odds ratios (OR) were calculated to compare the observations in both genders. Significance values were adjusted with respect to multiple comparisons.

Results

Two-hundred and two patients (124 women) mean age (standard deviation) of 49.7 (13.5) years participated. Both genders did not differ significantly in the mean level of self-perceived disability, anxiety, depression and symptom severity. There was a tendency of a higher prevalence of abnormal anxiety and depression in men (23.7%; 28.9%) compared to women (14.5%; 15.3%). Patients with abnormal depression felt themselves 2.75 (95% CI: 1.31-5.78) times more severely disabled by dizziness and unsteadiness than patients without depression. In men the OR was 8.2 (2.35-28.4). In women chi-square statistic was not significant. The ORs (95% CI) of abnormal anxiety and severe disability were 4.2 (1.9-8.9) in the whole sample, 8.7 (2.5-30.3) in men, and not significant in women.

Conclusions

In men with vertigo, dizziness or unsteadiness emotional distress and its association with self-perceived disability should not be underestimated. Longitudinal surveys with specific pre-defined co-variables of self-perceived disability, anxiety and depression are needed to clarify the influence of gender on disability, anxiety and depression in patients with vertigo, dizziness or unsteadiness.     

Exploratory factor analysis of the Dizziness Handicap Inventory (German version)

Background

The Dizziness Handicap Inventory (DHI) is a validated, self-report questionnaire which is widely used as an outcome measure. Previous studies supported the multidimensionality of the DHI, but not the original subscale structure. The objectives of this survey were to explore the dimensions of the Dizziness Handicap Inventory - German version, and to investigate the associations of the retained factors with items assessing functional disability and the Hospital Anxiety and Depression Scale (HADS). Secondly we aimed to explore the retained factors according to the International Classification of Functioning, Disability and Health (ICF).

Methods

Patients were recruited from a tertiary centre for vertigo, dizziness or balance disorders. They filled in two questionnaires: (1) The DHI assesses precipitating physical factors associated with dizziness/unsteadiness and functional/emotional consequences of symptoms. (2) The HADS assesses non-somatic symptoms of anxiety and depression. In addition, patients answered the third question of the University of California Los Angeles-Dizziness Questionnaire which covers the impact of dizziness and unsteadiness on everyday activities. Principal component analysis (PCA) was performed to explore the dimensions of the DHI. Associations were estimated by Spearman correlation coefficients.

Results

One hundred ninety-four patients with dizziness or unsteadiness associated with a vestibular disorder, mean age (standard deviation) of 50.6 (13.6) years, participated. Based on eigenvalues greater one respectively the scree plot we analysed diverse factor solutions. The 3-factor solution seems to be reliable, clinically relevant and can partly be explained with the ICF. It explains 49.2% of the variance. Factor 1 comprises the effect of dizziness and unsteadiness on emotion and participation, factor 2 informs about specific activities or effort provoking dizziness and unsteadiness, and factor 3 focuses on self-perceived walking ability in relation to contextual factors. The first factor correlates moderately with disability and the HADS (values ≥0.6). The second factor is comparable with the original physical subscale of the DHI and factors retained in previous studies.

Conclusions

The results of the present survey can not support the original subscale structure of the DHI. Therefore only the total scale should be used. We discuss a possible restructuring of the DHI.