1. Introduction
The terms ‘‘regional anaesthesia’’, ‘‘spinal block’’ and ‘‘epidural
block’’ are often used interchangeably. This is incorrect.
Both spinal and epidural block are subsets of regional
anaesthetic.
Spinal block differs from an epidural block in a number of
ways. Firstly, a smaller needle is used to perform a spinal block
than an epidural block. Secondly, the drugs are injected into
the cerebrospinal fluid that bathes the spinal cord. In order
to do that the needle makes a tiny hole in the dura, which is
a tissue encasing the spinal cord and the cerebrospinal fluid.
Small doses of local anaesthetic are required because they
spread more easily in the spinal fluid [1]. With an epidural
block, the drugs are delivered outside the dura, in the epidural
space, hence the name for the block. Occasionally, the
dura can be inadvertently breached in performing an epidural
block, known as a dural puncture. Larger doses of local
anaesthetic are required because the spread is through tissues
rather than fluid [2]. Thirdly, a spinal block is a single injection
of local anaesthetic medications and so there is only one
opportunity to deliver the medications. With an epidural, a
catheter sits in an epidural space so drugs can be delivered as
needed to extend the duration of the block. An epidural block
can be made to last longer than a spinal block [3].
Regional analgesia/anaesthesia is nowadays considered the
optimal technique for obstetric patients. Maternal mortality
under regional anaesthesia is 16 times lower than under general
anaesthesia, mainly due to reduced the risk of gastric aspiration
which is the major cause of direct maternal death [4].
Nevertheless, the optimal method of regional anaesthesia for
delivery and caesarean section remains to be determined.
Spinal anaesthesia has the advantage that profound nerve
block can be produced in lower half of the body by the relatively
simple injection of a small amount of local anaesthetic.
However, the greatest challenge in spinal anaesthesia is to control
the spread of local anaesthetic through the cerebrospinal
fluid (CSF) to provide a block which is adequate for the proposed
surgery without unnecessary extensive spread, and increased
risk of complications [5].
Spinal anaesthetic technique when used for obstetric purpose
might be accompanied by side effects like hypotension,
nausea and vomiting. Prolonged hypotension causes faetal
bradycardia and acidaemia, which can further compromise
critical faetal status. Therefore, extensive clinical investigation
is dedicated to issues of optimal dose and combination of
drugs which would balance haemodynamic stability and effective
analgesia [6]. In our study we use small dose of local anaesthetic
drug with small dose opioids to overcome the above
mentioned side effect.
Most of the previously performed studies concentrated on
the effect of low-dose spinal anaesthesia as a part of combined
spinal–epidural anaesthesia (CSE) in labour, and did not use
low dose spinal anaesthesia only they concluded that low-dose
spinal combined with epidural analgesia offers several theoretical
advantages. The onset of block is faster and block is potentially
denser in comparison with conventional epidural
analgesia [7]. Another advantage associated with CSE analgesia
is adequate analgesia provided by small doses of local anaesthetics
and opioids which cause less haemodynamic
compromise than conventional epidural anaesthesia [8]. In
our study we investigate the analgesic effect of low dose spinal
anaesthesia, the maternal and faetal outcome and we verified
that low dose spinal anaesthesia is sufficient technique for labour
and can be used instead of CSE and produce satisfactory
results for the mother and the baby as well.
Traditional epidural analgesia is the most common technique
for labour analgesia and also for caesarean section when
there is an indwelling epidural catheter present and when epidural
anaesthesia offers advantages over spinal anaesthesia for
example in morbidly obese parturients. The major disadvantage
of epidural analgesia is the slow onset of action, prolonged
labour, and use of Oxytocin augmentations and
increased incidence of instrumental vaginal delivery. Haemodynamic
instability, although less pronounced than in traditional
spinal anaesthesia, might be of clinical relevance, as
well. Another problem is reduced mobility due to motor effects
of local anaesthetics which can cause discomfort and reduce
maternal satisfaction [9].
The maternal and faetal effects of analgesia during labour
remain central to discussions among patients, anaesthesiologists,
and obstetrical caregivers. A number of randomized trials
have taught to address the effects of different strategies for
analgesia on maternal and faetal outcomes. Despite this effort,
it has become increasingly clear that potentially unwanted effects
of analgesia for women in labour and their children cannot
be determined easily. Remaining controversies in
obstetrical anaesthesia include that over the effects of regional
anaesthesia on the progress and outcome of labour, as well as
that over its effects on the neonate [10].
The aim of our study is to proof that single dose spinal
analgesia is efficient, faster, easily performed and less expensive
242 T. AbdElBarr et al.
Open access under CC BY-NC-ND license.
technique that can effectively replace epidural analgesia during normal labour.