Accidental Dural Puncture (also
see Chapter 43
)
A relatively common and problematic complication of epidural placement
is accidental puncture of the dura ("wet tap"), which has an incidence of up to 3%.
[201]
This complication can lead to the development
of PDPH in up to 70% of cases.[202]
The traditional
management of accidental dural puncture is to reposition the epidural at a different
interspace. Recently, however, many anesthesiologists have advocated that the epidural
catheter be passed into the spinal space to become a continuous spinal technique.
[203]
This technique establishes rapid and effective
Figure 58-11
Management of failed intubation in pregnancy with reference
to the presence or absence of fetal distress. ASA, American Society of Anesthesiologists.
(Redrawn from Reisner LS, Benumof JL, Cooper SD: The difficult airway:
Risk, prophylaxis, and management. In Chestnut
DH [ed]: Obstetric Anesthesia: Principles and Practice. St Louis, CV Mosby, 1999,
p 607.)
Figure 58-12
Graphic representation of the factors predictive of a
difficult intubation. Such factors include Malampatti class, short neck (SN), protruding
maxillary incisors (PI), or receding mandible (RM). Data were obtained from 1500
parturients undergoing cesarean section under general anesthesia. Values in parentheses
represent observed incidences of risk factor combinations in the series. (From
Rocke DA, Murray WB, Rout CC, et al: Relative risk analysis of factors associated
with difficult intubation in obstetric anesthesia. Anesthesiology 77:67, 1992.)
pain relief. Analysis of aggregate data from limited retrospective trials demonstrates
a significant reduction in the incidence of PDPH and the need for an epidural blood
patch in patients who receive continuous spinal analgesia after unintentional dural
puncture.[113]
In addition, the catheter provides
excellent labor analgesia and a route toward almost instant onset of blockade for
cesarean section. A recent review of seven cases in which epidural anesthesia was
complicated by an unintentional dural puncture suggested that spinal headache could
be reduced if five steps were followed: (1) injection of CSF from the epidural syringe
back into the subarachnoid space through the epidural needle, (2) insertion of an
epidural catheter into the subarachnoid space, (3) injection of preservative-free
normal saline through the intrathecal catheter before its removal, (4) administration
of continuous intrathecal labor analgesia, and (5) leaving the intrathecal catheter
in situ for a total of 12 to 20 hours.[190]
