Local Complications
They usually consist of nerve damage from incorrect needle placement
rather than from toxicity of the injected solution.[141]
[142]
[143]
[144]
[145]
However, inappropriate formulations (e.g.,
hypotonic solutions, antioxidants, preservatives, wrong solutions) and especially
the use of epinephrine in areas supplied by terminal arteries may result in tissue
ischemia and gangrene. Tissue coring occurs in more than 50% of cases when nonstyletted
needles are used.[146]
After a caudal, epidural,
or spinal block, this could be responsible for the development of epidermoid tumors
within the spinal canal as the patient ages. To prevent this complication, only
styletted needles should be used for performing neuraxial blocks, including caudal
anesthesia.
Some local complications, such as needle trauma or intraneural
injection, may be undetected and can be worsened by simultaneous general anesthesia.
The importance of using appropriate devices, especially short-beveled needles that
are less traumatic, and of locating the position of the needle tip by physical means
cannot be overemphasized.
Placement of catheters for reinjection is a potential source of
complications.[147]
[148]
Leakage around the puncture point occurs in approximately 10% of cases,[149]
and inadvertent removal can occur.[150]
The danger
of bacterial contamination is difficult to evaluate. It seems rather low in some
studies[151]
[152]
and very high in others.[153]
The quality of dressing
at the point of emergence of the catheter through the skin is critical.[154]
[155]
In case of accidental disconnection, the
epidural
catheter should preferably be removed, especially in infants, even though the luminal
content can remain sterile for 8 hours if the intraluminal fluid had remained static.
[156]
Several complications, such as cutting and knotting, become apparent
on removal of the catheter. These complications are often directly related to the
length of catheter introduced into the epidural space, which should usually not exceed
2 to 4 cm.[157]
The overall number of catheter-related
complications has been as high as 19% in a series of 1014 continuous epidurals in
adults[150]
and 11% in a pediatric series.[149]
Malfunctioning of infusion pumps is not unusual.[148]
All these complications have to be detected as early as possible to take adequate
preventive or curative measures.
