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A P Baranowski

Publications and source records attributed to A P Baranowski.

14 recordsLinked to original sources

Evaluation of a needle-free injection system for local anaesthesia prior to venous cannulation.

We evaluated a single-use, disposable, carbon-dioxide-powered, needleless injector (J-Tip, National Medical Products Inc., CA, USA), which is claimed to deliver a virtually painless, subcutaneous injection. Seventy-two patients undergoing various types of surgery had a large-bore intravenous cannula inserted prior to induction of general anaesthesia. Three minutes beforehand, a subcutaneous injection of 0.3 ml of 1% plain lidocaine was administered. Subjects were randomly allocated to receive the lidocaine either by the needleless injector or from a conventional syringe and a 25 G needle. Pain scores were recorded on injection of the lidocaine and on insertion of the cannula. There was significantly less pain on injection with the needleless injector than with the 25 G needle (p < 0.001) but, surprisingly, there was more pain on cannulation (p < 0. 001). We conclude that the device certainly delivers a less painful subcutaneous injection than a 25 G needle, but perhaps provides less effective skin anaesthesia for venous cannulation at sites where the subcutaneous space is small; its use might be better suited to areas where the subcutaneous space is deeper.

Anesthesia, Local

A trial of intravenous lidocaine on the pain and allodynia of postherpetic neuralgia.

This study investigated the effect of intravenous lidocaine at two doses (1 mg/kg and 5 mg/kg over 2 hours) and an intravenous saline placebo on the pain and allodynia of postherpetic neuralgia (PHN). Twenty-four patients were studied using a randomized, double-blind, within-patient crossover design. Each patient received normal saline, lidocaine 0.5 mg/kg/h, and lidocaine 2.5 mg/kg/h for a 2-h period. The McGill Pain Questionnaire Short Form, visual analogue scores (VAS), and area of allodynia were measured at intervals during the infusions. Free plasma lidocaine levels were also measured. The results were statistically analyzed using Student's t-test for paired data. The VAS for ongoing pain showed a significant reduction after all the infusions (P < 0.05). For dynamic pressure-provoked pain, the VAS was unaffected by placebo but showed a reduction at an equal level of significance with both lidocaine infusions (P < 0.05). The area of allodynia of PHN, as mapped by brush stroke, declined in association with intravenous lidocaine (0.5 mg/kg/h = P < 0.05; 2.5 mg/kg/h = P < 0.001). Placebo had no significant effect on the area of allodynia. These findings demonstrate a positive effect on pain and allodynia following a brief intravenous infusion of lidocaine. The higher dose infusion may produce plasma levels in the toxic range, with no significant clinical increase in response.

Aged

The twelfth rib syndrome.

The twelfth rib syndrome appears to be a fairly common and underdiagnosed chronic pain syndrome. It is more common in women than men (3:1) and is usually described as a constant dull ache or sharp stabbing pain that may last from several hours to many weeks. Lateral flexion, rotation of the trunk, and rising from a sitting position classically aggravate the pain. Manipulation of the affected rib and its costal cartilage reproduces it exactly. The diagnosis of this syndrome is clinical, requires exclusion of specific etiologies, and should only be made when the patient's symptoms can be exactly reproduced by manipulation of the affected rib. If symptomatology is complicated, it may be necessary to use an image intensifier for accurate location of the pain locus. Patients with this syndrome can be overinvestigated and have even undergone surgical procedures when this diagnosis has been overlooked. To describe the varied presentation of this syndrome, we describe the clinical manifestations in six patients.

Adult

Aortic stent surgery.

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Aortic Aneurysm, Abdominal

The consequence of delayed versus immediate nerve repair on the properties of regenerating sensory nerve fibres in the adult rat.

Transected saphenous neurones were allowed to regenerate for 3 months via distal stumps of sural nerve following an immediate or a 3 month delayed repair. The number of DRG neurons surviving following the 3 months regeneration period were approximately 60% of normal after both immediate and delayed repair. The percentage of DRG cell bodies identified by the application of Fluro-gold proximal to the repair site and immunopositive for SP, CGRP and galanin was increased following both early and delayed repair compared to baseline values. These values were not significantly different for early repair compared to late repair. Similarly, peripheral measurements of SP in the proximal stump of saphenous nerve (by radioimmunoassay) were not significantly different between models with primary repair compared to delayed repair. These results suggest that the intrinsic regeneration properties of primary sensory neurones are not impaired when repair is delayed.

Anastomosis, Surgical

Substance P in cutaneous primary sensory neurons--a comparison of models of nerve injury that allow varying degrees of regeneration.

We have studied changes in neuropeptide expression in four different models of nerve injury in adult rats. The models involved the cutaneous sural and saphenous nerves, and were associated with different degrees of regrowth and peripheral target reinnervation. These were: simple crush of the nerve, complete cut and self-anastomosis; cut and ligation, and cut and anastomosis of the nerve to an isolated stump of peripheral nerve. Thus, in the first two models a partial or complete reinnervation of peripheral targets was possible, while in the third and fourth it was not. The last model allowed regenerating fibres to come into contact with Schwann cells in the distal stump. We measured substance P-like immunoreactivity in the manipulated nerves (by radioimmunoassay) and the number of manipulated afferents expressing the peptide in dorsal root ganglion cells (by combined immunohistochemistry and retrograde labelling), at time points up to 12 weeks after the nerve manipulations. The retrograde labelling also allowed estimates of cell death. Two weeks after the nerve injuries, when no cell death had occurred, the nerves subjected to a cut lesion (last three models) all showed very low levels of substance P-like immunoreactivity, both in the amounts in peripheral nerve, and in the number of manipulated cell staining positively (P < 0.01). In contrast, the crush model showed no significant change in substance P levels in the nerve (P > 0.05), but a significant increase in the number of immunopositive cells (P < 0.01). Twelve weeks after the nerve manipulations, a variable degree of cell death was seen. Only 9% of afferents in the crush model were lost (P > 0.05 compared with normal) but a 39 and 45% loss was seen in tie and resuture models, respectively, (P < 0.05) for both, compared with normal), and a 63% loss in the stump model (P < 0.01 compared to normal, and P < 0.05 compared to tie and resuture models). An analysis of cell size distributions indicated that cell death affected both large and small cells. At 12 weeks, the levels of substance P in the first two models (associated with peripheral reinnervation) had returned towards, but did not reach, normal (P < 0.01), whilst the stump model showed no significant recovery and the tie model was intermediate. Proportionately more manipulated cells were found to express substance P immunoreactivity in the stump model than expected after allowing for cell death.(ABSTRACT TRUNCATED AT 400 WORDS)

Amputation Stumps

Retrograde labelling of dorsal root ganglion cells in the rat: a quantitative and morphological comparison of Fluoro-Gold with horseradish peroxidase labelling.

We have compared retrograde labelling of rat primary sensory neurons using Fluoro-Gold (FG) and horseradish peroxide conjugated with wheat germ agglutinin (HRP-WGA). Fluoro-Gold 2.5% after 48 h transit time and FG 5% after 24 and 48 h retrogradely labelled similar numbers of cell profiles as HRP-WGA (P greater than 0.1% Student's t-test). The calculated cell size distribution for the above FG groups were similar to those for the HRP-WGA. However, FG 2.5% after a 24 h transit time labelled significantly fewer cells (P less than 0.001 Student's t-test). FG retrograde transport may be used to identify the same population of DRG cells as HRP-WGA.

Animals

The effect of a priming epidural injection of adrenaline on epidural blockade with bupivacaine.

Twenty-four patients receiving epidural anaesthesia were studied to test the hypothesis that 1:200,000 adrenaline administered into the epidural space 5 minutes before 20 ml bupivacaine 0.5% would improve nerve block and delay systemic absorption of the local anaesthetic. Group A/B received 20 ml adrenaline 1:200,000 5 minutes before 20 ml bupivacaine 0.5%, group S/BA 20 ml saline followed by 20 ml bupivacaine 0.5% with 100 micrograms adrenaline, and group S/B saline 20 ml followed by 20 ml plain bupivacaine 0.5%. Mean maximum plasma concentrations of bupivacaine tended to be lower in the adrenaline groups. A delay in the time to peak plasma concentration of bupivacaine was noted in the A/B group; this indicated that priming with adrenaline may be effective at delaying early systemic uptake of the local anaesthetic. In both adrenaline groups a more prolonged epidural block and increased efficacy were noted, although this was only significant for the duration of block at T6 (p = 0.023) and duration of motor block at Bromage level 1 (p = 0.016) in group A/B. There seems little clinical advantage in administering adrenaline 5 minutes before bupivacaine.

Anesthesia, Epidural

A comparison of three methods of axillary brachial plexus anaesthesia.

One hundred patients scheduled for elective outpatient hand surgery had blockade of the axillary brachial plexus by one of three techniques; insertion of a catheter into the brachial plexus sheath (n = 25), use of paraesthesia (n = 50) or use of the nerve stimulator (n = 25) to localise the plexus. Only two patients required general anaesthesia for the planned surgery. Assessment of the dermatomes blocked did not demonstrate a statistical difference between the success rates of the three groups. The more nerves detected in the paraesthesia and the nerve stimulator groups before injection of local anaesthetic the higher the success rate of the block. We advocate use of the nerve stimulator technique in view of the possible risk of neurological damage associated with paraesthesia and the technical difficulties with the catheter technique, for routine brachial plexus blockade.

Axilla

Use of opioids in non-cancer pain.

The use of opioids for chronic pain of non-malignant origin remains controversial. However, problems anticipated from experience with animal experiments and pain-free abusers seldom cause difficulties when opioids are used appropriately to treat pain. With sensible guidelines, and in the context of a multidisciplinary pain clinic, opioids may provide the only hope of relief to many sufferers of chronic pain.

Analgesics, Opioid