Incidence of intravascular penetration in transforaminal cervical epidural steroid injections

STUDY DESIGN A prospective, observational, human, study was conducted. OBJECTIVES To evaluate the incidence of vascular penetration during fluoroscopically guided, contrast-enhanced transforaminal cervical epidural steroid injections, and to determine whether the observation of blood in the needle hub can be used to predict a vascular injection. SUMMARY OF BACKGROUND DATA Incorrectly placed intravascular cervical spinal injections result in medication flow systemically and not to the desired target. A recently published study demonstrates a high incidence of intravascular injections in transforaminal lumbosacral epidural injections. No studies so far have evaluated the incidence of vascular injections in transforaminal cervical epidural steroid injections, nor have they calculated the ability of observed blood in the needle hub to predict a vascular injection in the cervical spine.METHODS The incidence of fluoroscopically confirmed intravascular uptake of contrast was prospectively observed in 337 patients treated with cervical transforaminal epidural steroid injections. The ability of observed blood in the needle hub to predict intravascular injection was also investigated. For each subject, the injection level was chosen on the basis of the clinical scenario including history, physical examination, and review of imaging studies. Some patients had multilevel injections. Using fluoroscopic guidance, the authors placed a 25-gauge needle into the epidural space using a transforaminal approach according to accepted standard technique. Needle tip location was confirmed with biplanar imaging. The presence or absence of blood in the needle hub spontaneously ("flash") and after attempted aspiration by pulling back on the syringe's plunger was documented. Contrast then was injected under real-time fluoroscopy to determine whether the location of the needle tip was intravascular. The results were recorded in a prospective manner indicating the presence or absence of blood in the needle hub and whether a vascular pattern was noted with contrast injection, and these were correlated. Relevant epidemiologic data also were recorded. RESULTS The study included 504 transforaminal epidural steroid injections. The overall rate of fluoroscopically confirmed intravascular contrast injections was 19.4%. Use of observed blood in the needle hub to predict intravascular injections was 97% specific, but only 45.9% sensitive. There was no significant difference in intravascular rates related to age or gender. CONCLUSIONS As compared with a previous study of lumbosacral epidural steroid injections, there is an overall higher incidence of intravascular injections with cervical transforaminal epidural steroid injections. Use of observed blood in the needle hub to predict an intravascular injection is not sensitive, and therefore the absence of blood in the needle hub despite aspiration is not reliable. The reported sensitivity and specificity rates are similar to lumbar data. Fluoroscopically guided procedures without contrast confirmation instill medications intravascularly, and therefore not in the desired epidural location. This study confirms that there is a need not only for fluoroscopic guidance, but also for contrast instillation in cervical transforaminal epidural steroid injections.     

Incidence of simultaneous epidural and vascular injection during lumbosacral transforaminal epidural injections.

BACKGROUND CONTEXT: The incidence of vascular penetration during contrast confirmed fluoroscopically guided transforaminal lumbosacral epidural injections has been reported as 8.9% to 21.3% depending on the level of injection. Recently, intermittent fluoroscopy was shown to miss more than half of the vascular injections observed under live fluoroscopy. The number of misses increased when epidural and vascular contrast flow appeared simultaneously, even if the fluoroscopic image was taken during contrast injection. To date, no studies have documented the incidence of simultaneous epidural and vascular contrast injections. Also, most previous studies of vascular injections did not document use of live fluoroscopy during contrast injection, so the incidence of vascular injections may be higher than reported. PURPOSE: To determine the incidence of simultaneous epidural and vascular contrast injection during lumbosacral transforaminal epidural injections. STUDY DESIGN/SETTING: A prospective, observational, in vivo, study. PATIENT SAMPLE: Patients receiving lumbar transforaminal epidural injections at a university-based outpatient spine center. OUTCOME MEASURES: Incidence of epidural, vascular, and simultaneous epidural and vascular contrast patterns. METHODS: One interventional spine physician and three fellows under his direct supervision recorded contrast patterns observed during 191 fluoroscopically guided lumbosacral transforaminal epidural steroid injections with injection of contrast observed under live fluoroscopy. RESULTS: The incidence of simultaneous epidural and vascular injection during lumbosacral transforaminal epidural injections was 8.9%. The incidence of a vascular injection alone was 4.2%, for a total vascular injection incidence of 13.1%. Subjects with a simultaneous epidural and vascular injection who returned for repeat injection had a statistically significant chance of a repeat simultaneous epidural and vascular injection when the injection was done at the same location. Fluoroscopy time was significantly increased, an average of 8.8 seconds, when a vascular injection was identified. There was no statistically significant correlation between the incidence of simultaneous epidural and vascular injection with subjects' age, sex, level of injection, side of injection, needle gauge, or diagnosis. CONCLUSIONS: Simultaneous epidural and vascular injection is twice as likely to occur as vascular injection alone. Use of intermittent fluoroscopy can miss the transient appearance of the vascular component of these injections, giving the false impression of successful contrast placement. In light of these results, live fluoroscopy is recommended during contrast injection for confirmation of lumbosacral transforaminal epidural injections.     

Influence of needle type on the incidence of intravascular injection during transforaminal epidural injections: a comparison of short-bevel and long-bevel needles

Background contextVascular penetration and injection of corticosteroids into a vessel during lumbosacral transforaminal epidural injection is a suspected cause of myelopathy. Blunt needles have been suggested to avoid vascular penetration, but they are difficult to navigate. Another alternative to the standard long-bevel sharp needles is the short-bevel needles. Some have postulated that short-bevel needles are the best option for high-risk spine injections because they maintain navigation characteristics while potentially reducing the risk of complications. To date, no studies have been performed to either confirm or refute this.PurposeThe purpose of this study was to determine if there is a difference in the incidence of vascular penetration during lumbosacral transforaminal epidural injections between short-bevel and long-bevel needles.Study design/settingThis is a prospective, observational, in vivo study.Patient sampleThe sample comprises patients receiving lumbosacral transforaminal epidural injections at a university-based outpatient spine center.Outcome measureThe outcome measure was the incidence of vascular contrast patterns observed under live fluoroscopy.MethodsOne interventional spine physician recorded contrast patterns observed during 158 fluoroscopically guided lumbosacral transforaminal epidural injections under live fluoroscopy using two different types of needle tips.ResultsVascular injections were observed in 22 of the 158 injections, for an overall incidence of 13.9%. The incidence of vascular injections in the short-bevel group was 15.6% (10/64) and in the long-bevel group was 12.8% (12/94). This difference was not statistically significant (p=.6447). A secondary analysis was performed to determine if the needle gauge influenced the incidence of vascular injections, and again, there were no statistical differences in the overall rates of vascular injection.ConclusionsIn comparison with long-bevel needles, short-bevel needles do not reduce the risk of inadvertent vascular injection in lumbosacral transforaminal epidural injections.     

Incidence of intravascular uptake in lumbar spinal injection procedures

STUDY DESIGN: Multicenter, prospective, observational study. OBJECTIVES: To document the incidence of and factors associated with intravascular uptake during lumbar spinal injection procedures. SUMMARY OF BACKGROUND DATA: In prior reports, the incidence of inadvertent intravascular needle placement during contrast-enhanced, fluoroscopically guided lumbar spinal injection procedures has been incidentally noted to range from 6.4% to 9.2%. We present the first systematic prospective documentation of intravascular uptake of contrast dye during different types of lumbar injection procedures. METHODS: Fifteen interventional spine physicians in seven centers recorded data regarding intravascular uptake during 1219 contrast-enhanced, fluoroscopically guided lumbar spinal injection procedures. RESULTS: The overall incidence of intravascular uptake during lumbar spinal injection procedures as determined by contrast enhanced fluoroscopic observation is 8.5%. Caudal and transforaminal routes have the highest rates at 10.9% and 10.8%, respectively, followed by zygapophyseal joint (6.1%), sacroiliac joint (5.3%), and translaminar (1.9%) injections. Intravascular uptake is twice as likely to occur in those patients over rather than under 50 years of age. Preinjection aspiration failed to produce a flashback of blood in 74% of cases that proved to be intravascular upon injection of contrast dye. CONCLUSION: The incidence of intravascular uptake during lumbar spinal injection procedures is approximately 8.5%. The route of injection and the age of the patient greatly affect this rate. Absence of flashback of blood upon preinjection aspiration does not predict extravascular needle placement. Contrast-enhanced, fluoroscopic guidance is recommended when doing lumbar spinal injection procedures to prevent inadvertent intravascular uptake of injectate.     

Incidence of intravascular injection and the spread of contrast media during S1 transforaminal epidural steroid injection by two approaches: anteroposterior vs oblique

The aim of this randomised study was to compare the incidence of intravascular injections during S1 transforaminal epidural steroid injection performed in the anteroposterior and oblique views. We also compared epidural spread patterns of contrast media, which included 201 injections at the S1 level. The overall incidence of intravascular injection during S1 transforaminal epidural steroid injection in the anteroposterior view was 29% (29/99), significantly higher than in the oblique view (11%, 11/102, p = 0.001). There were no significant differences between the two groups for epidural spread of contrast media in cases where intravascular injections did not occur (p = 0.77). Performing S1 transforaminal epidural steroid injection in the oblique view rather than the anteroposterior view reduces the risk of intravascular injections.     

Utility of the anesthetic test dose to avoid catastrophic injury during cervical transforaminal epidural injections

Background context

Reports of serious complications from cervical transforaminal epidural corticosteroid injections often consider accidental intra-arterial injection the most likely mechanism of injury. As a result, many physicians have instituted methods to prevent intravascular injections. Routine use of the anesthetic test dose is one such method. The utility of the anesthetic test dose in this function has not been characterized in the current literature.

Purpose

The aim of this study was to determine the utility of injecting an anesthetic test dose before cervical transforaminal epidural corticosteroid injection and estimate the rate of false-negative intravascular contrast injection using live fluoroscopy and digital subtraction angiography (DSA).

Study design

Two-center retrospective study.

Patient sample

A consecutive cohort of men and women, ages of 23 to 83, who underwent cervical transforaminal epidural injection and received the anesthetic test dose after contrast injection was negative for vascular uptake, observed using live fluoroscopy or DSA.

Outcome measures

Response to the anesthetic test dose was documented in each procedure note and recorded as either positive or negative.

Methods

Records of three physiatrists at two academic spine centers (Center A and Center B) were reviewed to identify all patients who received a cervical transforaminal epidural injection during the preceding 5 years, resulting in a cohort of consecutively treated patients at each center. Each patient record was reviewed for demographics, indication for injection, procedure level and side, needle gauge, use of DSA, volume and type of anesthetic test dose used, and result of test dose injection. The test dose was considered positive if the following occurred: agitation or other sudden central nervous system change; gross motor deficits and/or paresthesias in the trunk, legs, or contralateral arm; systemic symptoms of anesthetic toxicity including cardiac arrhythmia, perioral numbness, metallic taste, dizziness, and/or ringing in the ear. For analysis, injections were separated into groups to compare results at Center A to Center B and to compare injections that used DSA to those that did not. The incidence of a positive response was calculated as a percentage from the total number of injections in the group. Differences between groups were analyzed for statistical significance using the Fisher exact test.

Results

Six hundred seventy-eight injections were included. Of these, 349 were performed at Center A with test doses given after contrast injection under live fluoroscopy. The remaining 329 were performed at Center B, 183 also using live fluoroscopy, and 146 using DSA. The overall incidence of a positive anesthetic test dose was 0.59% (4/678). There was no significant difference between the incidence at each of the two centers (0.86% [3/349] vs. 0.30% [1/329]; p=.63). The overall incidence after live fluoroscopy was 0.75% (4/532) and after DSA was 0% (0/146), but this difference was not statistically significant (p=.58). Positive symptoms elicited by test dose administration included midneck and contralateral arm pain, metallic taste, dizziness, tachycardia, full body paresthesias, auditory changes, slurred speech, and motor ataxia. In all four cases with a positive response, the procedure was immediately terminated, symptoms resolved, and no lasting complications were observed.

Conclusions

The routine use of an anesthetic test dose appears to be safe and capable of detecting potentially dangerous intravascular injections undetected by conventional techniques. Positive responses occur in a small portion of those who receive the test dose injection. Further studies are required to determine the optimal dose and concentration of anesthetic to be used and the time required for observation after test dose administration.     

Rates of lumbosacral transforaminal injections interpreted as intravascular: fluoroscopy alone or with digital subtraction

We investigated the rate of injections interpreted as intravascular during imaging of lumbosacral transforaminal epidural injections, using fluoroscopy alone or with digital subtraction. We evaluated 732 injections performed on 348 patients: 8.1% (59/732) and 10.5% (77/732) of injections were interpreted as intravascular during fluoroscopy and digital subtraction, respectively, p = 0.13. The odds ratio (95% CI) for interpreting injections as intravascular increased for both fluoroscopy and digital subtraction fluoroscopy, with: each year of age, 1.04 (1.01–1.07) and 1.03 (1.00–1.06), p = 0.011 and 0.024, respectively; sacral compared with lumbar injections, 10 (5–19) and 8 (5–15), p < 0.001 for both. The odds ratio for intravascular injection increased with three other variables during digital subtraction fluoroscopy: spinal stenosis, 5.1 (1.5–17.1), p = 0.009; failed back surgery syndrome, 4.3 (1.2–15.8), p = 0.025; compression fracture, 8.0 (1.6–39.4), p = 0.011.     

Accuracy of blind versus fluoroscopically guided caudal epidural injection.

STUDY DESIGN: A prospective observational study of a case series of patients with low back pain referred for epidural injection of corticosteroid. OBJECTIVES: To evaluate the accuracy of caudal epidural injections performed without the use of fluoroscopic guidance and to determine the value of specific clinical tests performed during the procedure in predicting successful epidural needle placement. SUMMARY OF BACKGROUND DATA: Epidural injection of corticosteroid is one of many treatments currently used in the nonsurgical management of low back pain. The face validity of many studies evaluating the efficacy of epidural corticosteroid injections has been criticized for use of a blind technique. Although there currently is no consensus in the spine literature as to whether epidural injection of corticosteroid (by any technique) is effective, it is imperative first to establish the accuracy of the technique being used. METHODS: A total of 54 consecutive patients underwent fluoroscopically guided caudal epidural injections. Needle insertion was performed blindly (without the use of fluoroscopic guidance), and the success of needle placement was predicted according to the presence of palpable landmarks, palpation of subcutaneous airflow, and the subjective impression that the needle was in a satisfactory position. These clinical criteria then were compared with the position of the needle as seen under fluoroscopy and the spread of radio-opaque contrast in the epidural space after the procedure. RESULTS: Successful injection placement on the first attempt occurred in 74.1% of the patients. Results were improved when anatomic landmarks were identified easily (87.5%) and no air was palpable subcutaneously over the sacrum when injected through the needle (82.9%). The combination of these two signs predicted a successful injection in 91.3% of attempts. CONCLUSIONS: Caudal epidural injection is performed ideally with fluoroscopic guidance as the gold standard for accurate drug placement. If fluoroscopic guidance is unavailable, impractical, or contraindicated, the presence of readily palpable anatomic landmarks at the sacral hiatus and the absence of palpable subcutaneous airflow over the sacrum significantly increase the operator's confidence in the likelihood of an accurate injection even before any products are administered into the epidural space.     

Fluoroscopically guided epidural blood patch in patients with postdural puncture headache after spinal and epidural anesthesia

Postdural puncture headache (PDPH) is one of the major complications after spinal and epidural anesthesia. An epidural blood patch (EBP) may be applied when PDPH persists regardless of conservative treatment. We describe the results of management including fluoroscopically guided EBP in a series of patients with moderate to severe PDPH. From January 2007 to December 2009, PDPH developed in 15 of 3,381 patients (0.44%) who received epidural or spinal anesthesia: 5 (0.21%) after general anesthesia combined with epidural anesthesia, 8 (0.81%) after spinal anesthesia, and 2 (3.14%) after combined spinal and epidural anesthesia. Of 15 patients, PDPH was relieved without the EBP in 9 patients and 6 patients required the EBP. EBP was performed under fluoroscopy in a prone position; a 4:1 mixture of autologous blood and contrast medium was injected to cover the site of dural puncture. The success rate of fluoroscopically guided EBP was 100% with a mean blood volume of 7.2 ml. No complications were associated with EBP except for a mild backache. Fluoroscopically guided EBP may be successfully and safely performed to treat persistent PDPH with a relatively small volume of blood for epidural injection.     

经椎问孔硬膜外注射后血管内显影：颈椎和腰椎节段的对比研究

背景经椎间孔硬膜外注射（transforaminalepiduralinjection,TEI）常用于治疗神经根性疼痛。然而,许多已发表的研究表明,TEI后可有严重并发症,且多发生在颈椎段水平;对该并发症的一种解释是操作者不慎将药物误注射入血管内。本研究的目的在于鉴别TEI时颈椎段和腰椎段血管内注射的发生率。方法将伴有神经根性疼痛症状或者带状疱疹相关性疼痛的患者前瞻性地分为2组,由作者中的一位对其实施颈椎段或腰椎段TEI。以双平面X线透视确认穿刺针的理想位置后,操作者在实时显影的X线透视下,以0．3—0．5ml／s的速度持续注入非离子型造影剂和生理盐水混合液3ml。结果共实施了182例TEI,其中56例（30．8％）出现了血管内显影,45例发生在颈椎段TEI（cervicalTEIs,CTEIs）,11例发生在腰椎段TEI（1umbarTEIs,LTEIs）。出现神经周围和血管内同时显影的发生率分别是：CTE[s52．1％、LTEIs9％,仅出现血管内显影的比例是：CTEIs11．3％、LTEIs0．9％。结论佃s血管内注射的发生率明显高于LTEIs,提示实施CTEIs时应更加谨慎。此外,CTEIs时血管内注射的发生率高于已有的文献报道,这个发现提示检测TEI血管内注射时,选用适宜容量的造影剂（3ml）是必要的,尤其是在同时出现神经周围和血管内显影时。     

经椎间孔增强神经根造影引导下硬脊膜激素类注射治疗腰椎间盘突出症

目的探讨经椎间孔增强神经根造影引导下硬脊膜激素类注射(ESIs)治疗腰椎间盘突出症的临床疗效。方法对59例腰椎间盘突出症患者行经椎间孔增强神经根造影引导下ESIs治疗。采用疼痛VAS评分和JOA评分评价疗效。结果患者均获得随访,时间12~16个月。VAS评分与JOA评分术后12个月与术前比较差异均有统计学意义(P<0.05)。治疗改善率85.1%±13.9%,优良率94.9%。患者均未发生重要血管、神经损伤、血肿压迫及感染等严重并发症。结论经椎间孔增强神经根造影引导下ESIs是治疗腰椎间盘突出症的有效方法。     

Detection of intravascular injection of regional anaesthetics in children

Purpose

Detection of intravascular injection of local anaesthetic during placement of regional blocks in children by using epinephnne-induced tachycardia or hypertension may produce false positive and false negative findings. This study evaluates ECG changes as markers of intravascular injection of local anaesthetics with epinephnne, during placement of epidural blocks in children.

Methods

Observational study in a teaching hospital of all epidural anaesthetics administered to paediatnc patients dunng one year. General anaesthesia, where used, was not controlled. An ECG rhythm strip was recorded during test dose injection and analyzed for changes in rate, rhythm, and T-wave configuration.

Results

During the study penod, 742 paediatnc epidural blocks were administered. There were 644 caudal (284 without catheters). 97 lumbar, and one thoracic epidural anaesthetics. Satisfactory placement was achieved in 97.7% of patients. Intravascular injection was detected in 42 (5.6%) of epidural anaesthetics (3.8% and 6.7% of straight needle and catheter injections, respectively). Detection was by immediate aspiration of blood in six patients, and by heart rate increases > 10 bpm in 30. Five had heart rate decreases suggesting a baroreceptor response. Five had heart rate increases < 10 bpm that were possible responses to noxious stimuli. Of 30 patients with known intravascular injection and for whom ECG strips were available, 25 (83%) had T-wave amplitude increases > 25%. and 29 (97%) had ECG changes in T-wave or rhythm in response to the epinephrine injection. There were no false positives.

Conclusion

In order to reduce risks associated with epidural anaesthesia in children, epinephnne should be added to the local anaesthetic test dose, the ECG should be monitored continuously for changes in heart rate, rhythm, and T-wave amplitude. Epidural injections should be given in small increments.     

The technical aspects of epidural steroid injections: a national survey

Although epidural steroid injections (ESIs) are a common treatment for chronic pain conditions, it is not clear whether there is consensus on their technical aspects. The current literature suggests that variations in technical aspects may affect ESI outcomes. The goal of the survey was to help establish a standard frame of reference for the performance of ESIs. We analyzed survey results from 68 academic anesthesia programs and 28 private practices in the United States. The main finding in this survey is that there is no clear-cut consensus as to the ideal method to perform ESI. There is a wide variation among individual practices in almost every technical aspect of ESI. Private practices use significantly more fluoroscopy than academic centers. The large difference was found in the cervical region where 73% of private practices and only 39% of academic institutions polled perform the ESIs with fluoroscopic guidance (P = 0.005). A similar discrepancy was found in approaches to the epidural space after laminectomy where 61% of private practices, but only 15% of academic centers, use the transforaminal approach. The study results indicate that there is no consensus, and that there is a wide variation in current practices. IMPLICATIONS: A national survey of practices performing epidural steroid injections was conducted. The purpose was to establish whether consensus exists on technical aspects of this procedure. The study results indicate that there is no consensus, and that there is a wide variation in current practices.     

Approaches in injections for radicular pain: The transforaminal, epidural and transfacet approaches

Spinal injections must be carried out adhering to very strict conditions. However, these procedures have almost come to be seen as everyday and may be practised under quite questionable conditions. The recent reports of new and extremely serious neurological complications have changed the attitudes of those making referrals as well as the attitudes of the interventional radiologists carrying out these procedures. The range of indications for transforaminal injections has shrunk in favour of epidural injections. Where the transforaminal approach is still used, the needle must be positioned extremely accurately. A prior radioopaque contrast medium injection is essential from a safety perspective. The transforaminal epidural injection via the transfacet approach looks to be a promising alternative that is strictly avascular.     

Obstetric epidural test doses

A number of obstetric fatalities related to epidural anaesthesia have been reported recently. In each case catheter or needle misplacement had resulted in a lethal intrathecal or intravascular injection. In this review these cases and a number of other similar but nonfatal reports are examined. In many cases, essential safety checks such as the aspiration test and the test dose had not been performed before the epidural injection but in others one or both of these tests had been used and had failed to predict the complication. Safety test failures generally occurred because ineffective tests were used or because effective tests were inadequately interpreted. This is not surprising because although textbooks recommend a bewildering variety of test doses, they seldom give precise details as to how they should be conducted. A detailed test dose protocol is recommended, which will safely warn of epidural catheter and needle misplacement in the most effective manner possible. If the protocol is used, accidental subarachnoid and intravascular injections can be reduced to a minimum, but they will still occur. It is emphasised that these complications should not cause fatalities if trained personnel and adequate resuscitation facilities are available.     

Fluoroscopically guided low-volume peritendinous corticosteroid injection for Achilles tendinopathy. A safety study

BACKGROUND: The safety and efficacy of corticosteroid injection for the treatment of Achilles tendinopathy is not known, with some reports indicating the hazard of tendon rupture and others extolling the efficacy of such injections. This study was undertaken to assess the safety of fluoroscopically guided corticosteroid injections into the peritendinous space for the treatment of Achilles tendinopathy. METHODS: A series of patients was treated with fluoroscopically guided corticosteroid injections into the space surrounding the Achilles tendon. Major and minor complications were recorded, as were the number of repeat injections, the duration of symptomatic relief attained with the injection, and a subjective rating of symptoms related to the Achilles tendon. RESULTS: Of eighty-three patients who had been treated, seventy-eight were available for follow-up and forty-three met our requirement for a minimum two-year follow-up (average duration of follow-up, 37.4 months). No major complications and one minor complication occurred in the forty-three patients. Seventeen (40%) of the patients reported improvement after the procedure, twenty-three (53%) thought that their condition was unchanged, and three (7%) felt that their condition was worse than it had been prior to the injection. CONCLUSIONS: This retrospective cohort study establishes the safety of low-volume injections of corticosteroids for the treatment of Achilles tendinopathy when the needle is carefully inserted into the peritendinous space under direct fluoroscopic visualization.     

Does epinephrine improve the diagnostic accuracy of aspiration during labor epidural analgesia?

Aspiration reliably detects almost all IV multiorifice epidural catheters. Although a supplemental epinephrine 15-microg test dose may detect the rare IV catheter that does not yield blood on aspiration, false-positive epinephrine responses may cause some women to unnecessarily undergo repeat epidural catheter insertion. We evaluated 532 consecutive eligible patients requesting neuraxial labor analgesia. Patients were excluded if they had a contraindication to epinephrine or if they received intrathecal sufentanil/bupivacaine. Multiorifice catheters were inserted 4-6 cm into the epidural space as part of an epidural (n = 305) or combined spinal-epidural (n = 270) technique. We used aspiration, a lidocaine/epinephrine test dose, and bolus injection or infusion of dilute bupivacaine/sufentanil solutions to systematically determine IV, intrathecal, or epidural catheter location. Aspiration alone detected 47 of 48 intravascular catheters. There were 10 positive epinephrine responses: 2 were true positives, 7 were falsely positive (subsequent local anesthetic injection/infusion produced bilateral sensory change and analgesia), and 1 catheter was removed without further testing. Aspiration detected almost all intravascular catheters. Although the epinephrine test dose did detect one catheter that proved to be in a blood vessel, 87.5% of positive responses occurred in women without intravascular catheters. IMPLICATIONS: Epidural catheters may enter a blood vessel. Many clinicians use epinephrine to detect these catheters. Because aspiration alone detects almost all IV multiorifice catheters in laboring women, a subsequent epinephrine test dose may be unnecessary.     

Fluoroscopically guided epidural block in the thoracic and lumbar regions

BACKGROUND AND OBJECTIVES: Epidural block in the midthoracic region is difficult, even with fluoroscopically guided methods, because of the inability to view the interlaminar space on radiographs. We have, therefore, proposed fluoroscopically guided epidural block for the midthoracic region, as well as other thoracic and lumbar regions, by use of the pedicle as a landmark to show the height of the interlaminar space. METHODS: Twenty patients scheduled to receive an indwelling epidural catheter at Th6-7, Th9-10, Th12-L1, or L3-4 were studied. The skin insertion site was at the junction of a line parallel to the vertebral column that passed through the middle of the pedicle and the lower border of vertebral body, immediately inferior to the target interlaminar space on an anteroposterior radiograph. The needle was walked up the lamina, and the interlaminar space was sought near the midline of the vertebra at the height of the pedicle. RESULTS: Epidural block was easily performed in all cases. No difference was observed in the angulation of the epidural needle among the groups; the mean inward and upward angulation were 38 degrees and 63 degrees , respectively, although the skin insertion site relative to the spinous process was different among the groups. CONCLUSIONS: This study showed the usefulness of our fluoroscopically guided method for the midthoracic region, and other thoracic and lumbar regions. We propose an alternative method for a blind epidural approach at Th6-7, Th9-10, Th12-L1, or L3-4.     

Adverse central nervous system sequelae after selective transforaminal block: the role of corticosteroids.

BACKGROUND CONTEXT: Selective transforaminal epidural injections are frequently employed in the treatment of pain emanating from the spine. Complication rates are typically low and include paresthesia, hematoma, epidural abscess, meningitis, arachnoiditis and inadvertent subdural or subarachnoid injection. Persistent paraplegia after lumbar transforaminal block has been recently reported. Undetected intra-arterial injection has been implicated as a possible cause. PURPOSE: We present a case of massive cerebellar infarction after uneventful selective cervical transforaminal block. Intra-arterial injection of corticosteroid is implicated with focus on particulate size of compound versus blood vessel dimension. Light microscopic data are presented to confirm the potential for embolic vascular occlusion. STUDY DESIGN/SETTING: Case report; light microscopic data. PATIENT SAMPLE: A patient underwent selective transforaminal block on the right at the C5-C6 level. There was C5-C6 disc herniation documented by magnetic resonance imaging and C6 radiculopathy by electromyographic studies. OUTCOME MEASURES: Patient follow-up from medical office records. METHODS: Needle placement at the C5-C6 foramen on the right was confirmed by biplanar fluoroscopy and injection of contrast medium. Frequent heme-negative aspirations were documented. RESULTS: In this patient, quadriparesis ensued shortly after injection of corticosteroid solution. The patient was admitted to the neurosurgical intensive care unit and ultimately underwent brainstem decompressive surgery when focal neurologic deficits became evident. Working diagnosis was massive cerebellar infarct. Light microscopic data are presented to illustrate particulate size in corticosteroid solutions and potential for embolic microvascular occlusion. Corticosteroid suspensions (and to a lesser extent solutions) contain large particles capable of occluding metarterioles and arterioles. CONCLUSIONS: We present a case of quadriparesis and brainstem herniation after selective cervical transforaminal block. We propose a potential role for corticosteroid particulate embolus during unintended intra-arterial injection as a potential mechanism.