Epidural Space Identification: A Meta-Analysis of Complications After Air Versus Liquid as the Medium for Loss of Resistance

Pneumocephalus following fluoroscopy-guided lumbar epidural injection in elderly patients: two cases report and a review of Korean literatures - Two cases report

Background

Pneumocephalus can originate from accidental dural puncture while performing epidural block using the loss-of-resistance (LOR) technique with an air-filled syringe.

Case

We present two cases of pneumocephalus after lumbar epidural block under fluoroscopy for pain control in elderly patients.

Conclusions

Lumbar epidural block should be performed under fluoroscopic guidance in elderly patients with severe lesions. The physician should be aware of the increased possibility of a dural puncture occurring due to anatomical changes in older patients. The use of saline is recommended for the LOR technique. A contrast injection should be used together with the LOR technique to locate the epidural space. If a dural puncture occur, the patient should be carefully monitored to determine whether pneumocephalus has developed.

Intramedullary pneumorrhachis following a cervical epidural steroid injection

Pneumorrhachis (PR) is a rare radiological condition characterized by the presence of intraspinal air. PR is commonly classified as spontaneous (nontraumatic), traumatic, or iatrogenic, and iatrogenic PR is the most common and often occurs secondary to invasive procedures such as epidural anesthesia, lumbar puncture, or spinal surgery. PR is usually asymptomatic, but it can produce symptoms associated with its underlying pathology. Here, we report a rare case of intramedullary cervical PR following a cervical epidural steroid injection (ESI) and include pertinent discussion.

Pneumocephalus and Chemical Meningitis after Inadvertent Dural Puncture during Lumbar Epidural Injection

Inadvertent dural puncture (IDP) is one of the complications of lumbar epidural steroid injections (ESIs). We report a case in which pneumocephalus and chemical meningitis developed at the same time after an IDP during a lumbar interlaminar ESI. A 60-year-old woman presented to the emergency room with thunderclap headache and febrile sensation 3 hours after receiving a lumbar interlaminar ESI. Brain computed tomography (CT) scan showed multiple small foci of air within the subarachnoid space and ventricle. After the admission, the patient was afebrile and reported mild improvement of headache with analgesics. However, 2 days after the admission, headache worsened and fever recurred. Follow-up brain CT scan revealed resolution of the pneumocephalus. A diagnostic lumbar puncture for cerebrospinal fluid (CSF) examination revealed the findings suggestive of aseptic (chemical) meningitis rather than bacterial meningitis. With symptomatic treatment, headache improved and there was no fever after 48 hours. No bacteria, Mycobacterium, or fungi grew in the CSF for 7 days. This case shows an IDP during a lumbar ESI can cause pneumocephalus and chemical meningitis at the same time and efforts should be made to reduce the risk of IDP during lumbar ESIs.

Epidural interlaminar injections in severe degenerative lumbar spine: fluoroscopy should not be a luxury

Objective

To assess technical efficacy, accuracy, and safety of epidural (interlaminar) injections performed blindly in patients with a severely degenerated lumbar spine.

Methods

Over 12 consecutive months, 138 patients with a severe degenerative lumbar spine underwent epidural (interlaminar) injection as therapy for low back pain and neuralgia. Patients had already undergone a blind epidural infiltration with minimum or no pain reduction. The session was repeated in the angiography suite. Patients were placed in the lateral decubitus position. The injection was performed without image guidance by an anaesthesiologist; the target level was defined before the beginning of the procedure. Once air resistance loss was felt it was presumed that the needle was inside the epidural space. Verification of needle position was performed by injection of 1–3 mL of iodinated contrast medium under fluoroscopy in a lateral projection.

Results

Correct needle position inside the epidural space was documented in 82/138 cases (59.4%); unexpected extraepidural location was seen in 56/138 cases (40.6%). Target level was reached in 96/138 cases (69.6%); in 42/138 cases (30.4%) the needle was positioned in a non-target level. In 5/138 (3.6%) cases, there was inadvertent intradural position of the needle. Image guidance was subsequently used for correct positioning of the needle, which was feasible in all cases.

Conclusion

Blind interlaminar epidural injections lack the accuracy of exact needle location that imaging guidance offers in approximately 40% of cases, when there is difficult spine anatomy and the initial epidural approach has failed to provide pain relief. Image guidance for interlaminar epidural injection ensures accurate needle placement, enhancing the safety and efficacy of the procedure.

Localization of epidural space: A review of available technologies

Although epidural analgesia is widely used for pain relief, it is associated with a significant failure rate. Loss of resistance technique, tactile feedback from the needle, and surface landmarks are traditionally used to guide the epidural needle tip into the epidural space (EDS). The aim of this narrative review is to critically appraise new and emerging technologies for identification of EDS and their potential role in the future. The PubMed, Cochrane Central Register of Controlled Clinical Studies, and Web of Science databases were searched using predecided search strategies, yielding 1048 results. After careful review of abstracts and full texts, 42 articles were selected to be included. Newer techniques for localization of EDS can be broadly classified into techniques that (1) guide the needle to the EDS, (2) identify needle entry into the EDS, and (3) confirm catheter location in EDS. An ideal method should be easy to learn and perform, easily reproducible with high sensitivity and specificity, identifies inadvertent intrathecal and intravascular catheter placements with ease, feasible in perioperative setting and have a cost-benefit advantage. Though none of them in their current stages of development qualify as an ideal method, many show tremendous potential. Some techniques are useful in patients with difficult spinal anatomy and infants, and thus are complementary to traditional methods. In addition to improving the existing technology, future research should aim at proving the superiority of these techniques over traditional methods, specifically regarding successful EDS localization, better safety profile, and a favorable cost-benefit ratio.

Epidural Steroid Injection Complicated by Intrathecal Entry, Pneumocephalus, and Chemical Meningitis

BACKGROUND

Epidural steroid injections are frequently used to treat back and extremity pain. The procedure is generally safe, with a low rate of adverse events, including intrathecal entry, pneumocephalus, and chemical meningitis.

CASE REPORT

We report a case of a 45-year-old woman who presented to the emergency department (ED) with headache, nausea, vomiting, and photophobia after a lumbar epidural steroid injection. She was afebrile and had an elevated white blood cell count. A non-contrast computed tomography scan of the head revealed pneumocephalus within the subarachnoid space and lateral ventricles. The patient was admitted to the ED observation unit for pain control and subsequently developed a marked leukocytosis and worsening meningismus. A lumbar puncture was performed yielding cerebrospinal fluid (CSF) consistent with meningitis (1,000 total nucleated cells, 89% neutrophils, 85 mg/dL total protein, and no red blood cells). Gram stain revealed no bacteria. The patient was admitted on empiric vancomycin and ceftriaxone. Antibiotics were discontinued at 48 h when CSF cultures remained negative and the patient was clinically asymptomatic. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should consider intrathecal entry and pneumocephalus in patients who present with a headache after an epidural intervention. The management of pneumocephalus includes supportive therapies, appropriate positioning, and supplemental oxygen. These symptoms can be accompanied by fever, leukocytosis, and markedly inflammatory CSF findings consistent with bacterial or chemical meningitis. Empiric treatment with broad-spectrum antibiotics should be initiated until CSF culture results are available.

Distance from Dura mater to spinal cord at the thoracic vertebral level: An introductory study on local subdural geometry for thoracic epidural block

OBJECTIVE

To evaluate the anatomical safety margins in relation to thoracic epidural block by analysing magnetic resonance (MR) images.

METHODS

This retrospective study identified consecutive patients who underwent MR imaging of the thoracic vertebral spine. The distance from the dura mater to the spinal cord (DTC) was measured at different thoracic intervertebral levels using three different pathways as references: the 'U', 'L' and 'M' lines.

RESULTS

A total of 346 patients provided MR images for analysis. The vertical DTC was the longest at the T5/6 intervertebral level (mean ± SD: 4.22 ± 1.43 mm) and the shortest at the T11/12 intervertebral level (mean ± SD: 2.51 ± 0.87 mm). The DTC was the longest on the 'L' line at the T1/2 and T5/6 intervertebral levels and on the 'U' line at the T10/11 intervertebral level. The difference in DTC between the 'U' and 'L' lines was the greatest at the T5/6 intervertebral level.

CONCLUSION

Differences in the DTC were observed among the thoracic intervertebral levels. The variability of the safety margin according to the angle of needle insertion was the largest at the T5/6 intervertebral level.

A proposal of a simple epidural simulator for training novice anesthesiologists

PURPOSE

Confirming the epidural space during epidural anesthesia relies mainly on feel and experience, which are difficult techniques for a trainee to learn. We designed an epidural simulator for trainees to experience loss of resistance (LOR) and various degrees of pressure resistance.

METHODS

The simulator consists of a Perifix(®) LOR syringe and 1-, 5-, 10- and 50-mL syringes assembled by three-way stopcocks. A total of 89 anesthesiologists evaluated the simulator, given the choice of either the intermittent technique with air or continuous technique with saline. Sudden LOR and applicability of the simulator for training purposes were assessed using the numerical rating score (NRS). Pressure resistance at each lumbar structure was evaluated by the anesthesiologists using the intermittent technique with air.

RESULTS

Seventy-four anesthesiologists used the intermittent technique with air and 15 used the continuous technique with saline. The NRSs for sudden LOR and the applicability for training purposes were 8 and 9 (median), respectively. The pressure resistance to a 50-mL syringe was regarded as the epidural space (odds ratio 602.3 for 5-mL syringe and 144.4 for 10-mL syringe) by 89 % of anesthesiologists using air for LOR. Resistance to the 10-mL syringe was most frequently considered as muscle, subcutaneous fat, or the interspinous ligament, while resistance to the 1-mL syringe was considered as the ligamentum flavum (odds ratio 2.3 for 5-mL syringe and 18.6 for 10-mL syringe).

CONCLUSIONS

Our epidural simulator is a simple, low-cost device that can be easily constructed. It was shown to provide valid haptic feedback as a promising tool for training novice anesthesiologists.

Pneumocephalus after lumbar epidural steroid injection: a case report and review of the literature

Pneumocephalus may occur after inadvertent injection of air into the subarachnoid space while performing epidural anesthesia using a loss-of-resistance technique with air in the syringe. We report a case of pneumocephalus after an interlaminar epidural steroid injection using the loss-of-resistance to air technique. In this report, we examine the etiology, the expected course of symptoms, and resolution, as well as treatment, of pneumocephalus following a systematic literature review.

Asymptomatic pneumomediastinum resulting from air in the epidural space -a case report-

There are no reports regarding pneumomediastinum caused by thoracic epidural block complications. We believe that it is possible to experience an occurrence of pneumomediastinum caused by air in the epidural space after performing a thoracic epidural block using the loss of resistance (LOR) technique with air. We report a witnessed case where pneumomediastinum appeared after a thoracic epidural block. Pneumorrrhachis, paravertebral muscle emphysema, and pneumomediastinum were diagnosed by Positron Emission Tomography-Computed Tomography. Although extremely rare, pneumomediastinum can be caused by an epidural block using LOR technique with air. In order to avoid the above danger, the use of saline or very minimal amount of air is required during a careful LOR technique.

Prevention of post-dural puncture headache in parturients: a systematic review and meta-analysis

Post-dural puncture headaches (PDPHs) present an important clinical problem. We assessed methods to decrease accidental dural punctures (ADPs) and interventions to reduce PDPH following ADP. Multiple electronic databases were searched for randomised clinical trials (RCTs) of parturients having labour epidurals, in which the studied intervention could plausibly affect ADP or PDPH, and the incidence of at least one of these was recorded. Forty RCTs (n = 11,536 epidural insertions) were included, studying combined spinal-epidurals (CSEs), loss of resistance medium, prophylactic epidural blood patches, needle bevel orientation, ultrasound-guided insertion, epidural morphine, Special Sprotte needles, acoustic-guided insertion, administration of cosyntropin, and continuous spinal analgesia. The RCTs for CSE, loss of resistance medium, and prophylactic epidural blood patches were meta-analysed. Five methods reduced PDPH: prophylactic epidural blood patch {four trials, median quality score = 2, risk difference = -0.48 [95% confidence interval (CI): -0.88 to -0.086]}, lateral positioning of the epidural needle bevel upon insertion (one trial, quality score = 1), Special Sprotte needles [one trial, quality score = 5, risk difference = -0.44 (95% CI: -0.67 to -0.21)], epidural morphine [one trial, quality score = 4, risk difference = -0.36 (95% CI -0.59 to -0.13)], and cosyntropin [one trial, quality score = 5, risk difference = -0.36 (95% CI -0.55 to -0.16)]. Several methods potentially reduce PDPH. Special Sprotte needles, epidural morphine, and cosyntropin are thus far each supported by a single, albeit good quality trial. Prophylactic blood patches are supported by three trials, but these had flawed methodology. Mostly, trials were of limited quality, and further well-conducted, large studies are needed.

Incidence and predictors of immediate complications following perioperative non-obstetric epidural punctures

Background

Epidural Anesthesia (EA) is a well-established procedure. The aim of the present study was to evaluate the incidence of immediate complications following epidural puncture, such as sanguineous puncture, accidental dural perforation, unsuccessful catheter placement or insufficient analgesia and to identify patient and maneuver related risk factors.

Methods

A total of 7958 non-obstetrical EA were analyzed. The risk of each complication was calculated according to the preconditions and the level of puncture. For probabilistic evaluation we used a logistic regression model with forward selection.

Results

The risk of sanguineous puncture (n = 247, 3.1%) increases with both the patient’s age (P = 0.013) and the more caudal the approach (P < 0.01). Dural perforation (n = 123, 1.6%) was found to be influenced only by advanced age (P = 0.019). Unsuccessful catheter placement (n = 68, 0.94%) occurred more often in smaller individuals (P < 0.001) and at lower lumbar sites (P < 0.01). Amongst all cases with successful catheter placement a (partial) insufficient analgesia was found in 692 cases (8.8%). This risk of insufficient analgesia decreased with patient’s age (P <0 .01), being least likely for punctures of the lower thoracic spine (P < 0.001).

Conclusions

Compared to more cranial levels, EA of the lower spine is associated with an increased risk of sanguineous and unsuccessful puncture. Insufficient analgesia more often accompanies high thoracic and low lumbar approaches. The risk of a sanguineous puncture increases in elderly patients. Gender, weight and body mass index seem to have no influence on the investigated complications.

Appropriate length of epidural catheter in the epidural space for postoperative analgesia: evaluation by epidurography

In current practice, the length of epidural catheter that should be left in the epidural space is not standardised for effective postoperative analgesia. This prospective, randomised, double-blinded study aimed to determine the most appropriate length of epidural catheter that should be inserted into the epidural space for postoperative analgesia. We recruited 102 women and assigned them into three study groups (3, 5 and 7 cm insertion). An epidural catheter was inserted and epidurography was performed. Postoperatively, mean pain scores, motor and sensory levels, and any complications associated with the epidural catheter were recorded. No statistically significant difference for mean postoperative pain score was found at all study timings. Motor and sensory blockade was also statistically insignificant. Unilateral sensory analgesia developed in one patient in the 7 cm group and epidural catheter dislodgement was observed in four patients in the 3 cm group. In order to minimise catheter-related complications for postoperative analgesia, the most appropriate length that an epidural catheter should be left in the epidural space is 5 cm. You can respond to this article at http://www.anaesthesiacorrespondence.com.

What's new in obstetric anesthesia?

The current article covers some of the major themes that emerged in 2009 in the fields of obstetric anesthesiology, obstetrics, and perinatology, with a special emphasis on the implications for the obstetric anesthesiologist.

Epidural analgesia for labor: Current techniques

Epidural analgesia is an extremely effective and popular treatment for labor pain. In this review, we trace the history of the use of epidural analgesia and its refinements. We then outline the goals of treatment and methods used to attain those goals. The use of low concentrations of local anesthetics, combined with lipid-soluble opioids, does not impede the progress of labor or depress the newborn. The incidence of side effects is low. Maintenance of analgesia that allows patient control enhances patient satisfaction.