202412021157
Status:
Tags: Obstetrics, Neuraxial block
Epidural blood patch
The EBP has been the cornerstone of PDPH treatment, since Gormley observed that bloody taps during spinal anaesthesia were associated with a lower PDPH incidence
EBP involves the injection of autologous blood into the epidural space
hypothesized two-fold effect:
- ↑ epidural and lumbar CSF pressure
- stimulating fibroblastic repair in proximity to the dural defect
The immediate but transient increase in epidural volume increases the spinal and intracranial CSF pressure
no demonstrated relationship between the final epidural pressure generated during the procedure and its success
An epidural hematoma is known to be a potent cerebral vasoconstrictor which may contribute to the positive outcome
MRI studies have shown that the mass effect of injected blood lasts only a few hours, and then clot forms within 7 hours, which stimulates fibroblastic and collagen repair of the dural defect, preventing further CSF leakage
Efficacy of an EBP procedure varies significantly, likely reflecting procedural and patient-related factors and the extent of dural damage
For PDPH after spinal anaesthesia, EBP success rates of 75- 96% have been reported
After ADP with large gauge Tuohy needles in obstetrics, complete and permanent resolution of symptoms after one EBP occurs in less than 50% of patients
EPiMAP study
- large prospective international cohort study of 647 obstetric patients
- investigating risk factors for EBP failure after ADP
- complete success
- (defined as an NRS score of 0 in upright position at 4, 24 and/or 48 hours)
- only 33.0%
- Complete failure
- (NRS scores ≥ 7 at one of these time points or the need for a 2nd EBP)
- 28.7%
- 19.8% ultimately requiring second EBP
- no association btwn EBP failure &
- EBP lumbar level,
- position during EBP,
- operator experience
- The only associations with failure of EBP were
- timing of the EBP,
- a history of migraine
- specifically associated with ↑ 2nd EBP,
- (unexpectedly) a higher lumbar level of the original ADP.
- early EBP
- w/i 48 hours after ADP
- more likely to require a repeat procedure
- (not known whether earlier EBP a/w more severe PDPH symptoms)
∴ if an early EBP is recommended to patients, they should be informed of the possibility of a repeat EBP to achieve complete resolution of symptoms
However, delaying an EBP for patients with severe symptoms is not recommended, as it prolongs patient suffering and may ↑ risk of rare severe complications such as subdural hematoma
Complications of EBP
- most common: back pain ~80%
- Chronic headache
- is not significantly reduced in patients who were treated with an EBP
- Serious neurologic conditions:
- Arachnoiditis,
- radiculitis,
- meningitis
- spinal subdural hematoma,