Radiographic investigation of unilateral epidural block after single injection

Extradural anaesthesia-analgesia in dogs undergoing cholecystectomy: A single centre retrospective study

Objectives

To assess the effects of extradural anaesthesia-analgesia (EAA) in dogs undergoing cholecystectomy.

Materials and methods

Medical records of dogs undergoing cholecystectomy between 2011 and 2019 were retrieved and allocated to two groups depending if analgesia was provided systemically (group SA) or extradurally (EAA). Preoperative data, intraoperative antinociceptive medications, postoperative analgesia, perioperative complications, and food intake were compared.

Results

Overall 41 medical records were included in the study: 19 and 22 dogs were allocated to groups SA and EAA, respectively. In group EAA, an extradural catheter was placed preoperatively in 8 dogs; in the remaining, it was placed postoperatively but an extradural injection was performed preoperatively. The extradural catheter tip was between the 4th lumbar and the 10th thoracic vertebrae. Intraoperatively, nociception was more likely to occur in group SA [OR 55.42 (2.97–1,035.06)]. During the first 24 and 48 h postoperatively, more dogs in group SA required methadone [OR 24 (2.81–268.4) and OR 11.56 (2.37–45.06), respectively] and additional analgesic drugs [OR 25 (3.47–281.9) and OR 35.29 (1.86–668.2), respectively] compared to group EAA. Voluntary postoperative food intake was also significantly higher in group EAA.

Clinical significance

Compared to systemic analgesia, the use of extradural anaesthesia-analgesia reduced perioperative analgesic requirement and promoted postoperative food intake in dogs undergoing cholecystectomy.

Unilateral Epidural Blockade for Lower Limb Fracture Surgery: Parasagittal Epidural Versus Midline Epidural Anesthesia

Objective:

To compare the efficacy of parasagittal interlaminar (PIL) and midline interlaminar (MIL) approaches for epidural block in patients with lower limb orthopedic surgery.

Methods:

This double-blind randomized clinical trial was performed on 40 patients undergoing tibial shaft fracture surgery. In PIL group, an 18-gauge, 3.5 inch, Tuohy needle was placed at the level of L2-3 or L3-4 intervertebral spaces and pushed forward in a posteroanterior (PA) direction vertical to the body surface. After determining the most lateral place for needle arrival in an anteroposterior (AP) view, needle was pushed forward into the epidural space. For the MIL group, needle was pushed forward from the midline interspinous space with the same method. After confirmation of needle position, 1 mL of contrast was injected to confirm the epidural space distribution and then 15 ml lidocaine 2% was injected. The sensory and motor block level, onset, duration, heart rate (HR), mean arterial pressure (MAP), and arterial oxygen saturation (SPO2), and success rate were recorded.

Results:

Mean patients’ baseline characteristics showed no statistically significant difference between the two groups.p>0.05). Outcome measures were statistically different and significantly higher in PIL group (p-values for sensory block level <0.001, motor block level <0.001, duration of sensory block: <0.001 and duration of motor block <0.001 and success rate: <0.001). Hemodynamic variables didn’t show statistically significant difference between the two groups (p-values for Systolic pressure: 0.997, diastolic pressure:0.579, MAP:0.585, HR:0.710).

Conclusion:

Epidural anesthesia with parasagittal interlaminar approach provide deep motor block, high sensory level block, and hemodynamic stability.

Clinical trial registry:

IRCT2017041615515N2

Effects of Epidural Needle Rotation on Evolution of Unilateral Epidural Block and Patients' Hemodynamics beside Recovery Profile in Patients Undergoing Arthroscopic Knee Surgeries; A Randomized Clinical Trial

Objective:

To evaluate the evolution pattern of epidural block after rotating the needle tip 45° to the operative side and evaluate its effects on patients’ hemodynamics and recovery profile in those undergoing arthroscopic knee surgery.

Methods:

Forty participants were randomly subdivided into control and rotation group (n=20). An 18-gauge, 3.5 inch, Tuohy needle was placed at the level of L4-5 and pushed forward into the epidural space through parasagittal approach, in control group, the needle was pushed forward to the epidural space in cephaldad 90 degrees. For the rotation group, the needle was pushed forward to the epidural space and the tip was rotated 45 degrees to the surgical side.15 mL of bupivacaine 0.5% was injected and evolution of sensory and motor blocks until 2-segment regression of the sensory level below to T10 as well as total duration of motor block and surgery were recorded. Hemodynamic parameters (HR, MAP, and SPO2), hypotension, fluid intake, vasopressors, first ambulation and spontaneous urination were recorded. Statistical analysis was performed using SPSS and P≤0.5 considered significant.

Results:

Sensory block up to T10 level, Complete motor block and time for 2-segment regression of sensory level were earlier in the 45°-rotation than in the control group (p<0.001). Total duration of motor block in control group was lower than rotation group (p<0.001).Hypotension, N&V, vasopressors and fluid intake showed no statistically difference between the two groups (p=0.219). First spontaneous urination and ambulation were significantly lower in rotation group (p<0.001).

Conclusion:

45 degrees’ needle rotation to the surgical side provides a faster block evolution and hastened recovery profile with no significant difference in hemodynamic fluctuations.

Clinical trial registry:

IRCT20130518013364N7

A Computed Tomography-Guided Demonstration of the Unilateral Distribution of Low-Volume Epidural Injectate

OBJECTIVES

The primary objective of this case report was to demonstrate the unilateral distribution of the low volume injectate given in the epidural space when paramedian interlaminar approach is utilized under computed tomography guidance.

METHODS

This was a case report on a single patient with history of unilateral epidural contrast distribution under fluoroscopy views, who presented with bilateral lumbar radicular symptoms, and underwent epidural injections via bilateral paramedian interlaminar approach under computed tomography guidance. Multiple-level computed tomography scans were obtained for demonstration purposes.

RESULTS

There was primarily unilateral distribution of low-volume injectate in the epidural space when paramedian interlaminar approach is utilized.

Comparison of Intraoperative and Postoperative Effects of Lateral Epidural and Midline Epidural Anaesthesia in Patients Undergoing Unilateral Lower Extremity Operation

OBJECTIVE

We aimed to compare lateral and midline epidural anaesthesia using a levobupivacaine-fentanyl combination in patients undergoing unilateral lower extremity operation for anaesthetic effects and postoperative complications.

METHODS

The study included 40 American Society of Anesthesiologists (ASA) I-II group patients. At the L4-5 space, an epidural catheter was placed in patients in Group 1 by directing the tip of the needle at a 45-degree angle to the operation side and in Group 2 with the needle tip in the cephalad direction. Patients in both groups were administered a combination of 10 mL 0.5% levobupivacaine and 50 μg fentanyl via the epidural catheter. Sensorial and motor block levels during the perioperative and postoperative periods and postoperative complications were recorded.

RESULTS

The maximum level of sensory block on the operated side was found to be at the T10 (T8-T10) level in both groups, while the level of sensory block on the non-operated side was at the L2 (L3-T10) level in Group 1, and at the T10 (T8-T10) level in Group 2 (p=0.000). The motor block was more intense on the non-operated side in Group 2 than in Group 1. The postoperative motor block ended earlier in Group 1. The incidence of complication development was similar between the groups.

CONCLUSION

With a shorter lasting and lower level sensorial and motor block, lateral epidural anaesthesia may be a more advantageous method than midline epidural anaesthesia.

The volume effect of lidocaine on thoracic epidural anesthesia in conscious Beagle dogs

OBJECTIVE

To evaluate the volume effect of local anesthetic solution on thoracic epidural analgesia in dogs.

STUDY DESIGN

Prospective, experimental trial.

ANIMALS

Five healthy adult Beagle dogs weighing 9.7 ± 1.3 kg.

METHODS

A catheter was inserted into the seventh thoracic epidural space using a lumbosacral approach, and secured with suture under total intravenous (IV) anesthesia with propofol. Each dog was administered four volume treatments (0.05, 0.10, 0.15 and 0.20 mL kg(-1)) of 2% lidocaine via the catheter at 12 hour intervals. In every treatment, dogs were re-anesthetized with propofol (6 mg kg(-1), IV) and isoflurane, and received iohexol at each volume to visualize the epidural distribution (ED) through computed tomography. Three hours after epidurography, when dogs had recovered from anesthesia, the appropriate volume of lidocaine was injected through the catheter, and sensory blockade (SB) in dermatomes was evaluated by pinching with a mosquito forceps. Results were presented as median (range), and the volume effect on ED and SB was analyzed with one-way Kruskal-Wallis anova.

RESULTS

In proportion to volumes (0.05, 0.10, 0.15 and 0.20 mL kg(-1)), there were significant increases in the extent of ED from 7.4 (5.5-9.0) to 10.4 (8.0-12.0), 13.2 (12.5-13.0), and 15.2 (13.0-18.0) vertebrae, respectively, p < 0.001, and in SB from 2.7 (1.0-5.0) to 6.8 (4.5-10.5), 9.9 (6.5-13.0), and 13.1 (11.0-15.0) dermatomes, respectively, p < 0.001. Unilateral ED and SB were observed in all treatments with various grades, and this distribution was more frequent in the low volume treatments. In the high volume treatments, temporary complications including Horner's syndrome, ataxia, paraplegia, depression, stupor, and intermittent cough occurred often.

CONCLUSIONS AND CLINICAL RELEVANCE

The increase in volume of local anesthetic solution improved SB by resulting in more consistent bilateral dermatome blockade as well as an extended blockade. However, caution should be exerted, as higher volume injections of lidocaine caused side effects in all dogs.

Some epidurographic explanations for incomplete epidural analgesia coverage in the absence of a catheter

STUDY OBJECTIVE

To determine the impact of the plica mediana dorsalis (PMD) on injected contrast media spread in the epidural space.

DESIGN

Prospective interventional study.

SETTING

Academic medical center.

PATIENTS

30 chronic pain patients ranging in age from 37 to 71 years, undergoing epidural steroid injection.

INTERVENTIONS AND MEASUREMENTS

Epidurograms were evaluated for the 1) presence or absence of a PMD and 2) bilateral differential density and the extent of contrast spread on either side of the midline, horizontally and vertically.

RESULTS

The PMD (defined as midline radiolucency in epidurograms) was observed in (80%) 24/30 patients based on the epidurograms that were evaluated. Denser contrast spread on one side was found in (79%) 19/24 patients who had the PMD and in (33%) 2/6 patients who did not have the PMD (P = 0.03). Horizontal and vertical asymmetrical spread of the contrast was observed in (67%) 16 of 24 patients with the PMD and in (50%) 3 of 6 of patients without the PMD in each direction independently.

CONCLUSION

The difference in density of contrast spread on either side of the midline carries important clinical implications in understanding the pathogenesis of inadequate epidural analgesia and/or unilateral excessive motor weakness or numbness.

Predictors of laterality of motor block during epidural analgesia in a mixed surgical population

BACKGROUND

Predictors of laterality of motor block during epidural analgesia are currently unknown, as studies so far have yielded conflicting results. We aimed to evaluate predictors of post-operative asymmetric lower extremity motor blockade in a mixed surgical population.

METHODS

This is a retrospective analysis of 578 consecutive patients with post-operative epidural analgesia for a variety of surgical procedures. A priori determined potential predictors of unilateral motor block were age, gender, body mass index, type of surgical procedure, vertebral level of puncture, catheter insertion depth into the epidural space and concentration of local anaesthetic. Logistic regression analysis was employed for evaluating predictors of laterality.

RESULTS

Unilateral motor block occurred in 29.2% of the patients. Univariate logistic regression analysis showed that young age, female gender, gynaecologic procedures, a low puncture level, an increased depth of catheter insertion and a high ropivacaine concentration (2 mg/ml vs. less than 2 mg/ml) were significantly associated with increased incidence of laterality. Multivariate analysis revealed that age (OR = 0.73 per decade increase, P = 0.00001), the vertebral level of epidural puncture (OR = 1.37 per lowering vertebral level, P < 0.000001) and the depth of catheter insertion (OR = 1.46 per centimetre deeper, P = 0.001) were independent predictors of unilateral motor block.

CONCLUSION

These results suggest that young patients with lumbar epidural analgesia or deep catheter insertion should be frequently monitored for the occurrence of laterality of motor block. Also, these results provide support for a prospective study to determine the optimal catheter insertion depth to decrease the risk of unilateral motor block.

Unilateral hemiparesis with thoracic epidural in an adolescent

Objective. Unilateral sensory and motor blockade is known to occur with epidural anesthesia but is rarely reported in children. The differential diagnosis should include the presence of a midline epidural septum. Case Report. We describe a case of a 16-year-old adolescent who developed repeated complete unilateral extensive epidural sensory and motor blockade with Horner's syndrome after thoracic epidural catheter placement. This unusual presentation of complete hemibody neural blockade has not been reported in the pediatric population. Maneuvers to improve contralateral uniform neural blockade were unsuccessful. An epidurogram was performed to ascertain the correct location of the catheter within the epidural space and presence of sagittal compartmentalization. Conclusion. This case report highlights a less frequently reported reason for unilateral sensory and motor blockade with epidural anesthesia in children. The presence of a midline epidural septum should be considered in the differential diagnosis of unilateral epidural blockade.

Dispersal pattern of injectate after lumbar interlaminar epidural spinal injection evaluated with computerized tomography

Study Design Retrospective analysis of lumbar computed tomographic epidurograms. Objective To evaluate the dispersal pattern of injectate after interlaminar lumbar epidural steroid injections. Summary Prior studies have evaluated the dispersal patterns of injectate after lumbar epidural steroid injections using fluoroscopy with varying results. To date, there have been no studies evaluating the dispersal pattern utilizing computerized tomography. Methods Ten epidurograms were analyzed after lumbar interlaminar epidural steroid injection. The epidurograms were examined, evaluating the dispersal pattern in longitudinal flow as well as circumferential flow. In addition, pain values were assessed with the visual analogue scale. Results Mean diffusion in the rostral direction was 9.8 cm (standard deviation 4.0 cm, range 4.0 to 15.0 cm). Mean diffusion in the caudal direction was 5.4 cm (standard deviation 1.4 cm, range 3.0 to 8.0 cm). Both rostral and caudal flow had a p value < 0.001. The circumferential flow was 360 degrees in 9 of 10 cases. In addition, there was significant (p = 0.006) reduction in pain. Conclusion Interlaminar lumbar epidural steroid injections are an effective treatment modality for various spine-related conditions. The injectate diffuses throughout the epidural space with nearly uniform circumferential flow as well as significant rostral and caudal flow.

Influence of Needle Tip Position on Injectate Spread in 406 Interlaminar Lumbar Epidural Steroid Injections1

PURPOSE

To retrospectively evaluate flow patterns of interlaminar lumbar epidural steroid injections and compare these patterns to needle tip position.

MATERIALS AND METHODS

This study was approved by the institutional review board and complied with HIPAA guidelines. The requirement for informed consent was waived. Fluoroscopic images from 701 consecutive lumbar epidural steroid injections in 485 patients were reviewed. Vertebral level, needle placement, and injectate flow patterns were determined from procedural images. History of previous spinal operations was determined from procedural records. A subset of patients with three or more injections at the same site was also examined. Patterns in the data were evaluated with chi(2) tests and t tests.

RESULTS

Images from 406 lumbar epidural steroid injections, one per patient (214 women, 192 men; mean age, 59.8 years), were used for final analysis. Midline injections were less likely to result in unilateral flow than a more lateral approach (P>.001). Flow within only the posterior epidural space was associated with unilateral flow (P=.001). Patients with previous spinal operations were more likely to have cephalad or caudad flow of less than one vertebral level than patients without a history of spinal operations (P<.001). Flow varied considerably within a series of injections in a single patient.

CONCLUSION

Epidural injectate flow is highly variable, both among patients and between injections in a single patient. Fluoroscopic monitoring and administration of contrast material mixed with medication, allowing visualization of the full extent of medication flow, are essential to ensure adequate coverage of the target area.

A Prospective, Randomized Evaluation of the Effects of Epidural Needle Rotation on the Distribution of Epidural Block

We evaluated the effects of turning the tip of the Tuohy needle 45 degrees toward the operative side before threading the epidural catheter (45 degrees -rotation group, n = 24) as compared to a conventional insertion technique with the tip of the Tuohy needle oriented at 90 degrees cephalad (control group, n = 24) on the distribution of 10 mL of 0.75% ropivacaine with 10 microg sufentanil in 48 patients undergoing total hip replacement. The catheter was introduced 3 to 4 cm beyond the tip of the Tuohy needle. A blinded observer recorded sensory and motor blocks on both sides, quality of analgesia, and volumes of local anesthetic used during the first 48 h of patient-controlled epidural analgesia. Readiness to surgery required 21 +/- 6 min in the control group and 17 +/- 7 min in the 45 degree-rotation group (P > 0.50). The maximum sensory level reached on the operative side was T10 (T10-7) in the control group and T9 (T10-6) in the 45 degree-rotation group (P > 0.50); whereas the maximum sensory level reached on the nonoperative side was T10 (T12-9) in the control group and L3 (L5-T12) in the 45 degree-rotation group (P = 0.0005). Complete motor blockade of the operative limb was achieved earlier in the 45 degree-rotation than in the control group, and motor block of the nonoperative side was more intense in patients in the control group. Two-segment regression of sensory level on the surgical side was similar in the two groups, but occurred earlier on the nonoperative side in the 45 degree-rotation group (94 +/- 70 min) than in the control group (178 +/- 40 min) (P = 0.0005). Postoperative analgesia was similar in the 2 groups, but the 45 degree-rotation group consumed less local anesthetic (242 +/- 35 mL) than the control group (297 +/- 60 mL) (P = 0.0005). We conclude that the rotation of the Tuohy introducer needle 45 degrees toward the operative side before threading the epidural catheter provides a preferential distribution of sensory and motor block toward the operative side, reducing the volume of local anesthetic solution required to maintain postoperative analgesia.

IMPLICATIONS

Turning the Tuohy introducer needle 45 degrees toward the operative side before threading the epidural catheter is a simple maneuver that produces a preferential distribution of epidural anesthesia and analgesia toward the operative side, minimizing the volume of local anesthetic required to provide adequate pain relief after total hip arthroplasty.

Unilateral Horner's syndrome and brachial plexus anesthesia during lumbar epidural blockade

Horner's syndrome is a rare side effect of epidural analgesia. In association with ipsilateral brachial plexus block, it has only been reported once before, in French. Unilateral blockade has also been reported, although its etiology is unclear and may be multifactorial. The patient described here experienced an asymmetrical epidural blockade with a unilateral Horner's syndrome and ipsilateral brachial plexus block.