In cases of failure, a second EBP was offered to the patient after consultation with a neurologist. For each EBP, the following data were recorded: 1 age, height, and sex of the patient; 2 circumstances of the dural puncture; 3 size and type of the needle used and the level of the dural puncture; 4 difficulties encountered in performing dural puncture; 5 delay in appearance of CSF leak symptoms; and 6 clinical symptoms headache, neck pain, and vestibular, cochlear, and ocular symptoms.
The delay between dural puncture and EBP, EBP level of puncture and difficulties encountered, the volume injected when back, buttock, or leg discomfort or pain appeared, and the total blood volume injected were also recorded. Univariate comparisons between patients with or without incomplete relief including failures of their symptoms after blood patch, and patients with or without failure of blood patch as defined above, were performed using the unpaired Student t test, the Mann—Whitney test, or the Fisher exact method when appropriate.
For continuous variables, the receiver operator characteristic curve was analyzed to determine the best threshold that maximized the sum of sensitivity and specificity.
Statistical analysis was performed on a computer using NCSS 6. During a yr period, patients were included in this observational study. Twenty-three patients were excluded because of missing data fig. Among these patients, regional anesthesia was provided for delivery in 78 women and for surgery in 9 patients. The vertebral space where the dural puncture was performed or occurred is shown in figure 2.
Symptoms of CSF leak were noted after a median delay of 1 day range, 1—10 days after dural puncture. Epidural blood patch was performed after a median delay of 4 days range, 1—53 days after dural puncture. The vertebral space where the EBP was performed is depicted in figure 2.
Only one variable was an independent risk factor for pain during EBP: age less than 35 yr odds ratio, 2. The correlation between the height of the patients and the epidural injected blood volume inducing lumbar discomfort or pain is depicted in figure 3. Table 1 shows the univariate analysis to identify risk factors for either an incomplete relief of symptoms or failure of the EBP. The area under the receiver operator characteristic curve for the diameter of the needle was 0.
The percentage of failure 21 vs. Figure 4 depicts the percentage of incomplete relief of symptoms and failure of EPB according to the size of the needle used for dural puncture. The area under the receiver operator characteristic curve for the delay in EBP was 0. In the multivariate analysis, only the diameter of the needle causing the dural puncture and the presence of neck pain were independent risk factors for incomplete relief of symptoms including failures after EBP, whereas the diameter of the needle causing the dural puncture and the delay in EBP were independent risk factors for a failure of EBP table 2.
Table 1. Percentages of patients with incomplete relief of symptoms including failures and failure of epidural blood patch treatment versus the diameter of the needle performing dural puncture. Percentages of patients with incomplete relief of symptoms including failures and failure of epidural blood patch EBP treatment versus the delay between dural puncture and EBP.
Table 2. Nine patients had an incomplete relief of their symptoms, including two who were considered as treatment failures. The only complication, observed in three patients in our series after EBP, was fever without neurologic complication and without any confirmed pathogen, which resolved spontaneously.
Moreover, we observed that the increasing diameter of the needle causing the dural puncture and the decreasing delay between dural puncture and EBP realization were the two predictive factors of failure of EBP. Otherwise, the populations of patients and the EBP methods used are different between the studies, and these points can explain different results.
Symptoms of CSF leak appeared after a median delay of 1 day after dural puncture and correspond to a resumption of an erect posture by the patient. Neck symptoms and headache were the most frequently reported symptoms. In the current study, vestibular, cochlear, and ocular symptoms were more frequently observed than is apparent from the literature, where they have not been routinely reported. Using multivariate analysis, the diameter of the needle causing the dural puncture was a predictive factor of failure or of incomplete relief of symptoms after an EBP.
Our finding in patients having dural puncture with needles larger than 20 gauge are similar to those reported by Stride and Cooper, 31 who performed EBP after dural tap with gauge Tuohy needles. The clot theory for symptom resolution after EBP can explain that the dural tear is more difficult to plug as its size is bigger. On the other hand, when the size of the dural tap increases, the CSF leak and the decreased CSF volume and pressure are more important.
In this case, it is probably more difficult to restore the normal CSF pressure by compressing the dura with the injected blood. The two theories proposed in the literature to explain EBP efficiency are compatible with our finding that failure or incomplete relief of symptoms after EBP was favored by a larger dural opening. As depicted in figure 4 , the foreseeable EBP effectiveness was different according to the size of the needle causing dural puncture, with a threshold of 20 gauge.
Epidural blood patch was performed after a median delay of 4 days after dural puncture. We found that the percentage of failure of EBP was significantly increased when EBP was performed within 3 days after dural puncture. Symptoms are more severe as the CSF leak is greater, and it is likely that patients experiencing more pain were treated earlier because of the severity of their symptoms. This suggests that the diminished effectiveness of early EBP was more related to the size of the dural puncture and the severity of the CSF leak than with the fact of not delaying EBP.
The only report that supports the clinical impression of benefit in delaying EBP after dura mater puncture is a study by Loeser et al. In this work, the reason why some EBPs were performed very early and the others later is not known. In our study, the mean blood volume injected in the lumbar epidural space was not significantly different in groups of patients with success or failure of the EBP. This suggests that the volume of blood injected does not appear to influence significantly the success of the treatment.
The optimal recommended volume of blood that should be injected during an EBP is also controversial and has tended to increase over time. Gormley 11 initially injected 2 or 3 ml of blood in the epidural space and reported a success in all seven of his patients. Other studies have reported an increase incidence of failure rate or relapse of the symptoms when EBPs were performed using a volume lower than 10 ml.
Although there is no consensus about the optimal EBP volume to inject, the tendency is to use approximately 20 ml. According to proposed EBP mechanisms of action, its efficiency might increase as the amount of blood injected increases, a small volume being unable to cover the dura mater opening or restore CSF pressure. The dorsal epidural space Figure 1 at the interlaminar level is the target site for injection, just deep to the ligamentum flavum.
Relevant anatomic landmarks of the lumbar vertebrae including the posterior element components, interlaminar spaces, spinal canal margins, and disc spaces must all be identified by the operator Figure 2. In the context of post-dural puncture headache, the level of prior puncture is targeted.
In the setting of SIH without an identified leakage site, the L level is initially targeted assuming no anatomic impediments. Infrequently, we perform thoracic and cervical EBP under CT guidance if there is an identifiable leakage site; the CT-guided technique is beyond the scope of this article. The patient should have intravenous access placed on arrival and the ability to withdraw blood easily should be confirmed. The IV arm should be extended for access and to prevent kinking of the catheter.
The IV site must be prepped and draped for sterility. The IV should be tested again with the patient properly positioned to ensure adequate access, as prone positioning often affects access quality and sometimes necessitates new IV placement. Fluoroscopy is used to target the appropriate interlaminar space. For post-dural puncture patients, the level of prior LP should be targeted.
The L2-L3 level is typically inferior to the conus in cases of accidental dural puncture, usually less affected by impeding degenerative changes, and is a relatively superior starting point given that most cases of SIH are associated with upper spine leaks. The tip of a hemostat or metallic pointer is used to mark the center of the interlaminar space on the skin surface.
The site can then be prepped, draped, and anesthetized. This view will illicit location of the needle tip and its relationship to the spinolaminar line. Contrast and primed tubing can then be attached to the spinal needle for a test injection under fluoroscopy to ensure that the needle is superficial to the ligament Figure 8A. The needle can then be advanced under real-time fluoroscopy with continuous gentle pressure on the plunger.
Once the needle has entered the ligament, resistance will noticeably increase and contrast flow will cease. This represents the appropriate location for autologous blood administration. Between 3mL and 5 mL aliquots of fresh, sterilely drawn, autologous blood is utilized for epidural injection. Small aliquots and fresh blood are used to avoid clotting. At the start of injection, a quick fluoroscopic image should be obtained to visualize the injection of the residual contrast within the tubing and needle to ensure that the needle has not moved.
Intermittent fluoroscopy during the initial aliquot injection can then be performed to show that the contrast has dispersed in the epidural space Figure 9. The remainder of the injection should be performed slowly to avoid patient discomfort.
For post-dural puncture headaches, we recommend a target of 10mL mL. In patients with SIH, we recommend a goal of 20 mL initially and up to 30 mL on subsequent encounters. If the patient feels excessive discomfort or pressure, the procedure is terminated and the amount of blood injected is documented.
If there is concern for intrathecal needle placement, check for CSF return or look for a myelographic appearance during contrast administration: on the depth view, small intrathecal injections will first fall dependently and outline the anterior thecal sac Figure Larger injections will outline the nerve roots as in a typical myelogram.
If there is quick dispersion of contrast material, then the needle should be retracted into the epidural space and a repeat test injection performed. This latter group includes paresthesias, neck ache, facial nerve palsy, and lumbovertebral syndrome. Increased CSF pressure may play a role in the rapid resolution of a postdural puncture headache after epidural blood patch and suggests an etiology for some of the reported immediate complications.
In our patient, communicating hydrocephalus was a consequence of his operative procedure. His headache likely was also secondary to increased ICP, even though it had a postural component. We propose the following mechanism for the observed sequence of events: The mass effect from the injection of a large amount of epidural blood acutely increased ICP, and the patient lost consciousness. He gradually awakened after the effect of the benzodiazepine that had been administered was antagonized, but the seal of the dural defect resulted in a gradual further increase in ICP as new CSF was produced.
Two issues particular to this case must be considered along with any conclusion. First, our patient had received midazolam, which could have produced a relative hypercarbia and contributed to an initial ICP increase. Secondly, the administration of 20 ml of epidural blood is certainly generous and likely contributed to the resultant ICP increase.
Whether the outcome would have been the same with a smaller dose of epidural blood is uncertain. We conclude that, under appropriate circumstances, the administration of an epidural blood patch to a patient with increased ICP can be associated with neurologic deterioration.
This possibility should be considered when epidural blood is administered to these patients. Sign In or Create an Account. Advanced Search. Sign In. Skip Nav Destination Article Navigation. Close mobile search navigation Article navigation. Volume 82, Issue 1. Previous Article Next Article. Case Report. Article Navigation. Case Reports January Sperry, MD ; Richard J. Sperry, MD. This Site. Google Scholar.
Joel O. Johnson, MD, PhD. Author and Article Information. Anesthesiology January , Vol. Get Permissions. View large Download slide. J Neurosurg ,
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