| Journals Reviewed:
BJA, CJA.
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| Abstracted by: Dr A Rowse; (Registrar, University of the
Witwatersrand) |
Summary of abstract
Short notes on spinals.
(You may wish to briefly browse our editorial comment
).
Intrathecal midazolam
Forty five patients were divided into three groups, receiving
placebo, 0.2ml of 0.5% midazolam, or 0.4ml of 0.5% midazolam (preservative
free).
Intrathecal midazolam significantly prolongs the analgesic effects
of intrathecal bupivacaine in a dose-dependent fashion, and decreases
oral analgesic consumption in the first twenty-four hours.
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Article 1:
Intrathecal midazolam increases the analgesic effects of spinal
blockade with bupivacaine in patients undergoing haemorrhoidectomy
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Brit J Anaesth 2001 86 77-9 |
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Article type:
Clinical Study |
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Authors:
Kim MH & Lee YM. (Korea)
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Small dose spinals for Gynaecological laparoscopy
Forty women were randomised to receive spinal anesthesia
(1% lignocaine 10 mg, sufentanil 10 µg and sterile water 1.8 ml)
or general anaesthesia (propofol and nitrous oxide).
Shorter times from end of surgery to exit from theatre, straight leg-raise,
deep knee bends, and Aldrete score over nine, were noted in the spinal
group. There was however little difference in total phase I and II stays.
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Article 2:
Small-dose selective spinal anaesthesia for short-duration
outpatient gynaecological laparoscopy: recovery characteristics
compared with propofol anaesthesia.
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Br. J. Anaesth. 2001 86: 570-572 |
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Article type:
Clinical Study |
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Authors:
Stewart AVG, et. al. (Canada)
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Spinals and arthroscopy
Eighty four patients were randomised to either spinal anaesthesia
or a standardised general anaesthetic.
The group undergoing general anaesthesia experienced more:
- pain
- analgesic consumption
- sore throats
when compared with those having spinals. Other characteristics were similar (times
to sit, walk and void, and length of stay in post-anaesthesia care unit
and ambulatory surgical unit). Backache was commoner in the spinal group
(35% vs 14%).
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Article 3:
Spinal anaesthesia improves the early recovery profile of patients
undergoing ambulatory knee arthroscopy.
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Can J Anaesthesia 2001 48(4) 369-74.
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Article type:
Clinical Study |
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Authors:
Wong, J. et al. (Canada)
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Persistent back-pain after Spinals
In a questionnaire based survey of 245 patients, only 122/218 patients
having a single spinal anaesthetic returned a completed questionnaire.
This rather poor response rate renders the conclusions of the study
open to question, although one could argue that those who developed
new back pain would have been likely to respond. In fact, the study
concludes that only one person developed new back pain - people who
had back pain pre-operatively, tended to have back pain post-operatively,
something that isn't entirely surprising.
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Article 4:
Persistent back-pain after spinal anaesthesia in the non-obstetric
setting: incidence and predisposing factors
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Brit J Anaesth 2001 86 535-9 |
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Article type:
Clinical Study |
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Authors:
Schwabe K, Hepf HB (Germany)
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Editorial
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Well, what drugs can one safely put into the cerebrospinal fluid?
Anaesthetists (and others) certainly seem willing to try a variety.
Browsing through the literature of the past ten or so years, we find
chaps testing:
- morphine
- sufentanil
- fentanyl
- octreotide
- somatostatin
- adrenaline (epinephrine)
- baclofen
- bupivacaine
- lignocaine (lidocaine)
- beta-endorphin, and dynorphin
- neostigmine
- clonidine
- adenosine
- glucose
- magnesium
- ketamine
- prostaglandin E1
- substance P antagonists
- prednisolone
- enkephalinase inhibitors
- .. and so on.
Admittedly, many of the above drugs have only been used experimentally
in animals. Several agents appear to have demonstrable
neurotoxicity when given intrathecally, including substance P antagonists,
somatostatin, enkephalinase inhibitors, tonicaine, and butorphanol.
What worries us is that clinicians are not only continuing to use agents
with proved neurotoxicity (such as lignocaine), but seem willing to
accept new potentially harmful agents into clinical use!
Take midazolam. A study by Nishiyama et al [Anesth Analg 1999 Sep;89(3):717-20]
suggested no damage to the cord when administered intrathecally in cats,
and similarly, repeated intrathecal injection of midazolam in rats was
without adverse effects. [Eur J Anaesthesiol 1998 Nov;15(6):695-701].
In contrast, Svensson demonstrated neurotoxicity with chronic subarachnoid
administration of midazolam to rats! [Reg Anesth 1995 Sep-Oct;20(5):426-34].
In addition, Erdine et al [Pain 1999 Mar;80(1-2):419-23] showed histological
lesions even with preservative-free midazolam administered to rabbits. These results were
supported by work on neonatal rabbits [Paediatr Anaesth 1997;7(5):385-9]
where toxicity was attributed to the pH of the midazolam solution.
As far back as 1991, Malinovsky alleged that midazolam is neurotoxic
when administered intrathecally [Anesthesiology 1991 Jul;75(1):91-7].
With no compelling reason to administer midazolam intrathecally, and
the suspicion that even preservative-free midazolam is neurotoxic when
administered by this route, it seems most inadvisable to use intrathecal
midazolam in humans! We are surprised that the authors of
Article 1 do not even address the papers querying the safety of
midazolam!
Ed
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