|dc.description.abstract||A project was carried out to compare 3 different techniques of
epidural block. The project was motivated because many shortcomings
were noted in the techniques in current use. These
include a high incidence of hypotension after epidural block.
This incidence was found to be higher than what is usually
reported. The incidence and severity of hypotension was
reduced by using lower dosages of Bupivacaine and by at the
same time avoiding aorto-caval compression. The latter was
achieved by placing the patient in the kneeling position.
The quality of analgesia achieved by using Segmental blockade
was inferior to that achieved by Standard Epidural blockade.
On the other hand, the Modified Segmental block produced results
which were statistically comparible with the Standard Block.
This was not a true reflection of the clinical experience, and
may indicate an inadequacy in our scoring system. Although we
were unable to improve the analgesic quality by Segmental blockade,
this may be merely a factor of inexperience at the present
time, or due to inaccurate catheter placement.
The duration of the second stage, is commonly reported to be
prolonged by epidural blockade. Although we were able to
shorten the second stage by using Segmental blockade, the
difference was not significant.
The Apgar scores of neonates born after epidural block have not
been reported to be negatively influenced by epidural block.
We fond a higher incidence of slightly reduced Apgar scores in
the Standard and Segmental blocks, but acceptable results
after Modified Segmental blockade.
The Acid-base status of mothers and neonates is not known to be
negatively influenced by epidural blockade. Our study confirmed
this. In fact, we found that the umbilical vein p02
values to be significantly higher after the Modified Segmental
block when compared with the other two techniques.
Bupivacaine is to-day regarded as the best drug for epidural·
block. It is however not completely without danger to mother
and foetus. It is important to keep down the dosage of the
drug. We used Bupivacaine with Adrenaline 1:200000. We
found our blood levels to be lower than those reported in the
literature. By using the Segmental blocks, the maternal blood
levels were reduced significantly when compared with those of
the Standard Block.
Because it was reported in the literature that epidural
catheters were difficult to place accurately,we performed
Epidurograms to determine the fate of epidural catheters.
When catheters were threaded for 10 cm or more, accurate placement
was achieved in unacceptably low percentages of patients.
By using the technique of Modified Epidural block, accurate
catheter placement was achieved in 100% of cases. The technique
of placement was safe, repeatable and reliable. It
allows for a more scientific approach to epidural blockade.
Foetal heart rate abnormalities are commonly associated with
epidural blockade. This was confirmed by the present series -
in the first 2 groups. By employing the Modified Segmental
Block, we were able to reduce the incidence of foetal heart
rate abnormalities to nill. This alone has made the project
a worth while undertaking to us.
Flaccidity of the pelvic floor, malposition of the foetal head
and a high instrumental delivery rate are commonly reported
after epidural block. These were confirmed by our Group A.
By using the Segmental Blocks, the incidences of all these
were greatly reduced.
The incidence of major complications in this series was not
greatly elevated above the incidence commonly reported in the
literature. None of the 3 blocks tested was prone to any
particular type of complication.
Although the Modified Segmental block was found to have some
disadvantages, these were outweighed greatly by its advantages •.
We introduced two modifications into the current practice
of Segmental Epidural blockade.
i. We placed the top catheter at T12, after entering the
epidural space in the thoracic region.
ii. We placed patients in the kneeling position during
By these two modifications we hope to have made some contribution
to the present status of epidural blockade. We are
satisfied that this Modified Segmental Blockade has many
advantages over the other techniques in use presently. We
hope to do a further large study using this technique, to
confirm the findings of the present (small) series.||en_ZA