bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital Subtraction Angiography Versus RealTime Fluoroscopy for Detection of Intravascular
Penetration Prior to Epidural Steroid Injections:
Meta-Analysis of Prospective Studies
Authors: Nader Nader Djalal
Published: February 2021

Background: Neurological injury is a rare but devastating complication of epidural steroid
injections (ESIs) generally thought to arise from neurovascular compromise. The use of real-time
fluoroscopy (RTF) with contrast media is the most common preventative measure taken to avoid
intravascular penetration. In 2002, it was proposed that digital subtraction angiography (DSA)
might be more useful than RTF. Since then, several prospective studies have advocated for its use.
Objectives: As DSA is not currently a “gold standard,” a meta-analysis was performed to
compare the efficacy of DSA versus RTF for detection of intravascular penetration during ESI.
Study Design: Meta-analysis of prospective observational studies.
Methods: A targeted Pubmed search was conducted, yielding 49 reports and 4 manuscripts,
which were analyzed using Review Manager Software (Rev Man 5.2). Inclusion/exclusion criteria:
peer-reviewed prospective reports comparing the sensitivity of DSA to RTF in the same individuals
without change in needle position between comparative imaging. Pooled estimate of odds ratios
with 95% confidence interval using a random effect model was applied.
Results: There were a total of 188 intravascular events from 1,290 ESIs performed. RTF was
able to detect 148 events with DSA detecting an additional 40 events missed by RTF. No major
neurological complications were reported. DSA had a statistically significant favorable odds ratio
over RTF for detection of intravascular penetration during ESI (OR = 1.32 [1.05 – 1.67]; P = 0.02).
Limitations: Although the major methodological aspects of each study assessed in this metaanalysis were quite similar, there were small differences in needle gauge and the selection of
secondary outcome measures. Despite attempts to minimize it, concern for operator bias also
exists.
Conclusions: DSA had a 32% improvement (OR = 1.32) for detection of intravascular penetration
with ESI when compared to RTF. Although this supports advocacy for use of DSA, it also suggests
that there is a greater than 30% “missed-events” rate for detection of vascular penetration
when using RTF for ESI, which does not correlate with the generally reported cumulative rates of
complications (1%). This discrepancy suggests that factors other than vascular events also play a
role in complications. Nonetheless, given the evidence, we advocate for the increased use of DSA
over RTF for transformational ESIs.
Key words: Digital subtraction angiography, real-time fluoroscopy, epidural steroid injection,
complications, outcomes, pain imaging, chronic pain, intravascular injection, meta-analysis
Do Cervical Epidural Injections Provide LongTerm Relief in Neck and Upper Extremity Pain?
A Systematic Review
Authors: Manchikanti Laxmaiah
Published: February 2021

Background: The high prevalence of chronic persistent neck pain not only leads to disability
but also has a significant economic, societal, and health impact. Among multiple modalities
of treatments prescribed in the management of neck and upper extremity pain, surgical,
interventional and conservative modalities have been described. Cervical epidural injections are
also common modalities of treatments provided in managing neck and upper extremity pain.
They are administered by either an interlaminar approach or transforaminal approach.
Objectives: To determine the long-term efficacy of cervical interlaminar and transforaminal
epidural injections in the treatment of cervical disc herniation, spinal stenosis, discogenic pain
without facet joint pain, and post surgery syndrome.
Methods: The literature search was performed from 1966 to October 2014 utilizing data
from PubMed, Cochrane Library, US National Guideline Clearinghouse, previous systematic
reviews, and cross-references.
The evidence was assessed based on best evidence synthesis with Level I to Level V.
Results: There were 7 manuscripts meeting inclusion criteria. Of these, 4 assessed the role
of interlaminar epidural injections for managing disc herniation or radiculitis, and 3 assessed
these injections for managing central spinal stenosis, discogenic pain without facet joint pain,
and post surgery syndrome. There were 4 high quality manuscripts. A qualitative synthesis of
evidence showed there is Level II evidence for each etiology category. The evidence is based
on one relevant, high quality trial supporting the efficacy of cervical interlaminar epidural
injections for each particular etiology.
There were no randomized trials available assessing the efficacy of cervical transforaminal
epidural injections.
Limitations: Paucity of available literature, specifically conditions other than disc herniation.
Conclusion: This systematic review with qualitative best evidence synthesis shows Level II
evidence for the efficacy of cervical interlaminar epidural injections with local anesthetic with
or without steroids, based on at least one high-quality relevant randomized control trial in each
category for disc herniation, discogenic pain without facet joint pain, central spinal stenosis,
and post surgery syndrome.
Key words: Chronic neck pain, cervical disc herniation, cervical spinal stenosis, cervical post
surgery syndrome, cervical discogenic pain, cervical epidural injections, interlaminar epidural
injections, transforaminal epidural injections, steroids, local anesthetic
Comparison of the Effects of Adding
Dexmedetomidine Versus Midazolam to
Intrathecal Bupivacaine on Postoperative
Analgesia
Authors: Samantaray Aloka
Published: February 2021

Background: Dexmedetomidine and midazolam both modulate spinal analgesia by different
mechanisms, and yet, no human studies are available to compare them for postoperative analgesia
after neuraxial administration.
Objectives: We investigated the addition of dexmedetomidine or midazolam to intrathecal
bupivacaine on the duration of effective analgesia and clinical safety profile.
Study Design: Prospective, randomized, double blind, placebo controlled study.
Setting: University teaching hospital.
Methods: The study cohort included a consecutive and prospective series of patients, referred
for endourological procedures. The patients were randomly allocated into 3 groups (20 patients
each) to receive intrathecally 3 mL of 0.5% hyperbaric bupivacaine in combination with 5 mcg of
dexmedetomidine (dexmedetomidine group), 1 mg of midazolam (midazolam group) or 0.5 mL of
0.9% saline (control group). The groups were compared to the regression time of sensory block,
duration of effective analgesia (defined as the time interval between administration of intrathecal
drug to the time of first analgesic request or a numeric rating scale ≥ 4.0), sedation score, and side
effects in the first 24 hours.
Statistics: One way-ANOVA, Kruskal Wallis test, and Chi-square test (χ2), significance level: P < 0.05.
Results: The duration of effective analgesia (time to first analgesic request) was significantly
prolonged in the dexmedetomidine group (286 ± 64 minutes, P < 0.01) when compared with
midazolam group (236.9 ± 64.9 minutes) and the control group (212.7 ± 70.2 minutes). Pairwise
comparisons among the 3 groups with Bonferroni adjustment revealed that patients from the
dexmedetomidine group were more sedated in comparison to the midazolam and control groups at
the end of the first 15 minutes after intrathecal injection [χ2 (2) = 7.157, P = 0.028], with a mean
rank sedation score of 35.58 for dexmedetomidine, 25.00 for midazolam, and 30.93 for control.
No significant differences in the side effects were observed during the study period. Midazolam did
not lengthen the time of the two segment sensory regression or the time to first request analgesia.
Limitation: The study cannot be extrapolated to muscle cutting surgeries under spinal
anaesthesia.
Conclusions: The addition of dexmedetomidine (5 mcg) to 3 mL of intrathecal hyperbaric
bupivacaine (0.5%) significantly prolongs the duration of effective analgesia in comparison to
1 mg midazolam or placebo (0.9% normal saline) with a comparable incidences of side effects.
Key words: Dexmedetomidine, midazolam, intrathecal, spinal anaesthesia, subarachnoid block,
postoperative pain
Pain Physician 20
Blood Testing in Chronic Pain Management
Authors: Deer Timothy R.
Published: February 2021

Blood testing is quickly becoming a useful laboratory tool for opioid prescribers who wish to
document and assess patient tolerance, more objectively monitor patient safety, and evaluate
patient compliance using information that is not available with traditional urine drug testing (UDT).
Blood testing does not need to be performed as frequently as UDT but provides extremely valuable
information which can be used to more accurately evaluate patient compliance and assist with
interpreting blood toxicology results commonly used in impairment or overdose cases.
This narrative review presents the current evidence supporting the use of blood testing within the
chronic pain management setting. In addition, this review aims to introduce and discuss the role of
routine blood testing within the chronic pain management setting.
Blood testing for the purpose of documenting opioid tolerance is a relatively novel tool for pain
physicians and as such this review is not intended to be a comprehensive or exhaustive review
of the scientific or medical literature. Prescribers must also be aware that this type of laboratory
testing need only be administered to chronic pain patients receiving daily opioid therapy. Patients
taking infrequent, low dose, or as needed medications are not anticipated to benefit from this
type of test.
Based on the complexity of both achieving acceptable outcomes with opioid treatment and the
legal and societal issues at hand, we feel that the addition of blood concentration levels will
become the standard of care in the near future.
Key words: Chronic pain, blood testing, opioids, opioid tolerance, patient compliance, opioid
overdose
Assessment of Clinical Outcomes of Cervical
Epidural Neuroplasty Using a Racz-Catheter and
Predictive Factors of Efficacy in Patients with
Cervical Spinal Pain
Authors: Kim Young Hoon
Published: February 2021

Background: Epidural neuroplasty using the Racz catheter has a therapeutic effect in patients
with cervical disc herniation and central stenosis who do not respond to fluoroscopically guided
epidural injections.
Objective: To evaluate the clinical outcomes of cervical epidural neuroplasty in patients with
posterior neck and upper extremity pain and to demonstrate correlations between predictive
factors and unsuccessful results of cervical epidural neuroplasty.
Study Design: Observational study.
Setting: An interventional pain management practice in a university hospital.
Methods: Outcome measures were obtained using the numeric rating scale (NRS) for total
pain, neck pain, arm pain, and sleep disturbance; and the neck pain and disability scale
(NPDS); as well as opioid consumption at preprocedure, one month, 3, 6, and 12 months after
procedure. Successful epidural neuroplasty was defined as 50% or greater reduction from
the preprocedure NRS for total pain, and at least a 40% reduction in the NPDS. We obtained
clinical data and radiologic findings to evaluate correlations between predictive factors and
efficacy of epidural neuroplasty.
Results: Of the 169 patients, successful outcomes were observed in 108 patients (63.9%) at
one month following the procedure, in 109 patients (64.5%) at 3 months, in 96 patients (56.8%)
at 6 months, and in 89 patients (52.7%) at 12 months. Previous surgery, spondylolisthesis,
and ossification of the posterior longitudinal ligament were significantly associated with
unsuccessful outcomes as measured by NRS and NPDS (P < 0.05).
Limitations: Limitations of this evaluation include the lack of a placebo group.
Conclusions: Cervical epidural neuroplasty may be an effective treatment for pain reduction
and functional improvement in patients with cervical spinal pain who did not respond to
conservative treatment, and may decrease surgical demand. Previous surgery, spondylolisthesis,
and ossification of the posterior longitudinal ligament are associated with unsuccesful outcomes
of epidural neuroplasty.
Key words: Cervical spinal pain, epidural neuroplasty, percutaneous adhesiolysis, predictive
factor, racz catheter
Pain Relief Scale Is More Highly Correlated
with Numerical Rating Scale than with Visual
Analogue Scale in Chronic Pain Patients
Authors: Choi Sang Sik
Published: February 2021

The pain relief scale (PRS) is a method that measures the magnitude of change in pain intensity
after treatment. The present study aimed to evaluate the correlation between PRS and changes
in pain determined by the visual analogue scale (VAS) and numerical rating scale (NRS), to
confirm the evidence supporting the use of PRS. Sixty patients with chronic spinal pain that had
a VAS and NRS recorded during an initial examination were enrolled in the study. One week
later, the patients received an epidural nerve block, then VAS, NRS, and PRS assessments were
performed. Differences between VAS and NRS were compared to the PRS and scatter plots and
correlation coefficient were generated. The differences and magnitude of decrease in the VAS
and NRS raw data were converted to percentile values, and compared to the PRS. Both VAS and
NRS values exhibited strong correlations (> 0.8) with PRS. Further, the differences between the
VAS-PRS R (0.859) and NRS-PRS R (0.915) were statistically significant, (P = 0.0259). Compared
to PRS, the VAS and NRS percentile scores exhibited higher correlation coefficients than
scores based on the raw data differences. Furthermore, even when converted to a percentile,
the NRS%-PRS R (0.968) was higher than the VAS%-PRS R (0.904), P = 0.0001. The results
indicated that using the PRS together with NRS in pain assessment increased the objectivity of
the assessment compared to using only VAS or NRS, and may have offset the limitations of
VAS or NRS alone.
Key words: Pain relief scale, numerical rating scale, visual analogue scale, pain measurement,
pain intensity measurement, pain intensity scale
Intrapelvic Obturator Internus Muscle
Injections: A Novel Fluoroscopic Technique
Authors: Valovska Assia
Published: February 2021

The obturator internus (OI) muscle is important in adult chronic noninfectious pelvic,
perineal, gluteal, and retrotrochanteric pain syndromes. Evaluation and management
of these patients’ pain can be challenging because of the complex anatomy of this
region, broad differential diagnosis, and lack of specific physical examination findings.
Consequently, several clinicians have advocated the use of image guided injections to
assist in the accurate diagnosis of OI-related symptoms and provide symptomatic relief
to affected patients. We present 2 case series describing a novel fluoroscopically guided
contrast controlled transpectineal approach to intrapelvic OI injections. Unlike prior
fluoroscopically guided OI injection techniques, the approach described in the present 2
cases utilized multiple standard pelvic views, thus facilitating optimal needle positioning
in three-dimensional space. This technique utilized standard fluoroscopic pelvic views
to accurately measure needle depth within the pelvic cavity permitting the bulk of the
OI to be injected in a controlled and safe fashion. The first patient underwent a left
intrapelvic OI muscle injection with bupivacaine 0.25% and 40 mg methylprednisolone.
The average pre- and postprocedural visual analog pain scale scores were 5 out of 10 and
2 out of 10, respectively, with a self-reported 75% pain reduction. The second patient
underwent a right intrapelvic OI muscle injection with bupivacaine 0.25% and 40 mg
methylprednisolone. The average pre- and postprocedural visual analog scale scores were
8 out of 10 and 1 out of 10, respectively, with a self-reported 90% pain reduction. Larger
scale studies should be undertaken to evaluate the therapeutic efficacy and generalized
accuracy of this technique.
Key words: Obturator internus muscle, pelvic, perineal, gluteal, retrotrochanteric pain,
fluoroscopic, transpectineal
Lumbar Disc Herniation with Contralateral
Radiculopathy: Do We Neglect the Epidural Fat?
Authors: Hao Ding-Jun
Published: February 2021

Lumbar disc herniation (LDH) is the most common cause of radiculopathy, whose pathological
entity underlying nerve root compression is usually on the same side as the symptoms. However,
LDH causing contralateral radiculopathy are sometimes encountered by pain physicians. There
have been tremendous developmens in the treatment options for LDH; the situation of LDH
causing contralateral radiculopathy is indeed a dilemma for some pain physicians. We will report
a case of a patient with a L4-5 disc herniation whose left herniated disc caused radiculopathy
on the right side. After a percutaneous lumbar endoscopic discectomy via the side ipsilateral
to the symptomatic side, this case obtained a significant symptom remission. The migrated
epidural fat is discussed as a cause of associated contralateral neurological deficit. Only via
a surgical approach ipsilateral to the herniated side, could there be a clinical improvement
postoperatively.
Key words: Contralateral symptoms, lumbar disc herniation, radiculopathy, epidural fat
Early Onset of Syringomyelia Presenting With
Hyperhidrosis and Neuropathic Pain in Upper
Limbs in a Paraplegic Patient
Authors: Ekiz Timur
Published: February 2021

Key words: pain, post-traumatic syringomyelia, spinal cord injury, hyperhidrosis, sweating
Sacroiliac Fascial Lipocele Could be a Neglected
Cause of Lumbosacral Pain: Case Study of
Percutaneous Endoscopic Treatment
Authors: Hao Ding-JUn
Published: February 2021

The pathological entities commonly associated with lumbosacral pain are the intervertebral
discs, facet joints or surrounding muscle. However, in the absence of diagnostic confirmation
of the aforementioned structures, the diagnosis may become confusing and intractable.
Sacroiliac fascial lipocele (SFL), namely, pannicular hernia, could be a neglected cause. First
reported by Ficarra et al in 1952, it was highlighted by the formation of lipocele in the
sacroiliac fascia. Mostly, it could be spontaneously eliminated under conservative therapy.
However, for intractable pain, surgical intervention may be the only choice. We will first
present a typical case of SFL which was treated by percutaneous endoscopic surgery.
Ultimately, a satisfactory outcome was achieved and maintained at 12 months follow-up.
It is important to distinguish SFL some cases with lumbosacral back pain. Detailed physical
examination, superficial ultrasonography and diagnostic nerve block are extremely valuable
for acquiring a precise diagnosis. Overall, when considering the clinical outcome of such
cases and the foregoing benefits, percutaneous endoscopic treatment could be an efficacious
alternative treatment for SFL-related lumboscral back pain.
Key words: Lumbosacral pain, hernia, panniculitis, endoscopes, minimally invasive surgery
Incidence of Serotonin Syndrome in Patients
Treated with Fentanyl on Serotonergic Agents
Authors: Gulur Padma
Published: February 2021

Background: There has been a recent surge in the literature highlighting the association of
fentanyl as precipitating serotonin syndrome in patients on a serotonergic agent.
Objective: The purpose of our study was to understand the incidence of serotonin syndrome in
patients who receive fentanyl while on serotonergic agents.
Study Design: This retrospective analysis was conducted from 2012 to 2013 after approval
from the Institutional Review Board. We searched for all patients that had received a serotonergic
agent and were admitted to the hospital during the study period. Next, we split these patients
into 2 groups by placing all patients who had received fentanyl and a serotonergic agent into
one group. We then searched for any of the Hunter Serotonin Toxicity Criteria in the records of
patients that had received both fentanyl and a serotonergic agent. Further, we searched for all
patients with serotonin syndrome mentioned in their records.
Setting: This study was conducted at a 900 bed tertiary care academic center.
Results: Over the 2 year study period, 112,045 patients were on a serotonergic agent, and
4,538 of these patients were treated with both fentanyl and a serotonergic agent. A search for
Hunter’s Criteria through the records of the patients receiving both fentanyl and a serotonergic
agent revealed 23 patients had been documented with some of these symptoms. On detailed
chart review, only 4 [95% CI 1 – 10] of these patients truly met Hunter’s Criteria for serotonin
syndrome. We then searched all admissions for a diagnosis code of serotonin syndrome during
the study period. Five additional cases of serotonin syndrome were found, but none of these
patients were treated with fentanyl.
Limitations: Some of the limitations of our study include that it represents a single institution,
although it is a large academic center. An inherent limitation may be the under diagnosis of
serotonin syndrome.
Conclusion: The incidence of serotonin syndrome in patients who receive both fentanyl and a
serotonergic agent is low.
Key words: Fentanyl, serotonin syndrome, serotonergic drugs, opioids, SSRI, antidepressant
An Overview of Offset Analgesia and the
Comparison with Conditioned Pain Modulation:
A Systematic Literature Review
Authors: Hermans Linda
Published: February 2021

Background: Offset analgesia (OA) is an increasingly described phenomenon to measure
endogenous pain inhibition, in which a greater decrease in pain intensity is experienced than would
be predicted by the decrease in painful stimulation. The temporal filtering in this OA phenomenon
differs from the spatial filtering in the commonly described conditioned pain modulation (CPM).
Yet, the knowledge on the efficacy of OA in chronic pain patients is scarce, compared to CPM
efficacy.
Objective: This systematic review has been conducted to provide an overview of the current
knowledge regarding OA, and to compare it to CPM.
Study Design: A systematic review of research studies that investigated the application or
mechanisms of OA.
Setting: The present study took place at Ghent University and the University of Antwerp.
Methods: This systematic review follows the PRISMA guidelines. The electronic databases Pubmed
and Web of Science were searched in January 2015. Full text clinical reports addressing OA were
included. The checklists for randomized controlled trials, case-control studies, and cohort-studies
provided by the Dutch Institute for Healthcare Improvement and the Dutch Cochrane Centre were
used to assess methodological quality. The articles received a level of evidence A1, A2, B, C, or
D, based on study design and risk of bias. These levels were used to determine the strength of
conclusion (level 1 to 4).
Results: Seventeen articles met the inclusion criteria. Sixteen studies used quantitative sensory
testing to provoke OA; however, differences in protocols are present. OA can function as a nonopioid mediated assessment tool for endogenous pain inhibition, and activates brain regions such
as periaqueductal gray (PAG), dorsolateral prefontral cortex, insula, medulla, pons and cerebellum,
indicating strong brain derived pain modulation. The primary somatosensory cortex is, conversely,
less activated during OA. OA is decreased in neuropathic patients. Nonetheless, evidence for the
influence of individual factors on OA is limited. OA and CPM seem to rely on different mechanisms.
Limitations: Search strategy was taken wide, wherefore a large variety of research perspectives
were included.
Conclusions: This systematic review displays OA as a temporal filtering mechanisms that is
more brain-derived compared to the spatial assessment method CPM. There is strong evidence
for reduced OA in neuropathic patients, however, evidence regarding OA in (sub)acute and central
sensitization patients, and the influence of personal factors on OA is currently scarce and needs
further investigation.
Key words: Endogenous pain inhibition, pain modulation, OA, temporal filtering, CPM, spatial
filtering, pain pathways
Particulate vs Non-Particulate Steroids for
Transforaminal Epidural Steroid Injections:
Systematic Review and Meta-analysis of the
Current Literature
Authors: Makkar Jeetinder Kaur
Published: February 2021

Background: The efficacy of particulate and non-particulate steroids in patients receiving
epidural steroid injections remains unclear.
Objective: The purpose of this meta-analysis was to compare the efficacy of particulate
and non-particulate steroids in patients receiving epidural injections for radicular pain over 3
months.
Study Design: Systematic review and meta-analysis.
Methods: We reviewed PubMed, PubMed Central, Scopus, Central Register of Clinical
Trials of the Cochrane Collaboration, Google Scholar, and Directory of open access journals
for trials that compared efficacy of particulate steroid with non-particulate. A meta-analysis
was performed on treatment related to mean change in visual analogue score (VAS) between
the particulate and non-particulate steroids. Two authors independently reviewed the data for
inclusion.
Results: Seven studies comprising 3,542 patients in the particulate group and 856 patients in
the non-particulate group were included. Pooled mean maximum change of VAS was higher by
0.53 (95% CI: 0.14 to 0.92; P = 0.007; I2 = 50.2%) in the particulate group compared to the
non-particulate group. The non-particulate group had a larger proportion of patients with more
than 50% pain relief than the particulate group [OR 0.81 (95% CI: 0.68 to 0.97, P = 0.024).
Limitations: Limited number of trials that fit the inclusion criteria and were available for
analysis.
Conclusions: As the use of particulate steroids seems to be associated with slightly better
VAS scores only, clinicians need to weigh their clinical relevance in the light of complications
and recent FDA recommendations on the use of particulate steroids.
Key words: Meta-analysis, particulate epidural steroids, non-partiuclate epidural steroids,
efficacy, decrease in pain scores
Effectiveness of Splanchnic Nerve Neurolysis
for Targeting Location of Cancer Pain:
Using the Pain Drawing as an Outcome Variable
Authors: Novy Diane
Published: February 2021

The effectiveness of splanchnic nerve neurolysis (SNN) for cancer-related abdominal
pain has been investigated using numeric pain intensity rating as an outcome variable.
The outcome variable in this study used the grid method for obtaining a targeted pain
drawing score on 60 patients with pain from pancreatic or gastro-intestinal primary
cancers or metastatic disease to the abdominal region. Results demonstrate excellent
inter-rater agreement (intra-class correlation [ICC] coefficient at pre-SNN = 0.97 and
ICC at within one month post-SNN = 0.98) for the grid method of scoring the pain
drawing and demonstrate psychometric generalizability among patients with cancerrelated pain. Using the Wilcoxon signed rank test and associated effect sizes, results
show significant improvement in dispersion of pain following SNN. Effect sizes for the
difference in pre-SNN to 2 post-SNN time points were higher for the pain drawing
than for pain intensity rating. Specifically, the effect size difference from pre- to within
one month post-SNN was r = 0.42 for pain drawing versus r = 0.23 for pain intensity
rating. Based on a smaller subset of patients who were seen within 1 – 6 months
following SNN, the effect size difference from pre-SNN was r = 0.46 for pain drawing
versus r = 0.00 for pain intensity rating. Collectively, these data support the use of
the pain drawing as a reliable outcome measure among patients with cancer pain for
procedures such as SNN that target specific location and dispersion of pain.
Key words: Cancer pain, pain drawing, splanchnic block
Efficacy and Safety of Ketamine Added to
Local Anesthetic in Modified Pectoral Block for
Management of Postoperative Pain in Patients
Undergoing Modified Radical Mastectomy
Authors: Sherif Fatma Adel El
Published: February 2021

Background: Breast surgery is an exceedingly common procedure with an increased incidence
of acute and chronic pain. Pectoral nerve block is a novel peripheral nerve block alternative to
neuro-axial and paravertebral blocks for ambulatory breast surgeries.
Objectives: This study aims to compare the analgesic efficacy and safety of modified Pecs
block with ketamine plus bupivacaine versus bupivacaine in patients undergoing breast cancer
surgery.
Study Design: A randomized, double-blind, prospective study.
Setting: Academic medical center.
Methods: This study is registered at www.clinicaltrials.gov under number: (NCT02620371)
after approval by the ethics committee of South Egypt Cancer Institute, Assuit University,
Assuit, Egypt. Sixty patients aged 18 – 60 years scheduled for modified radical mastectomy
were enrolled and randomly assigned into 2 groups (30 patients each):
Control group patients were given ultrasound-guided, Pecs block with 30 mL of 0.25%
bupivacaine only. Ketamine group patients were given ultrasound-guided, Pecs block with 30
mL of 0.25% bupivacaine plus ketamine hydrochloride (1 mg/kg). Patients were followed up
for 48 hours postoperatively for vital signs, VAS score, first request of rescue analgesia and total
morphine consumption, sedation score, and side effects.
Results: Ketamine plus bupivacaine in Pecs block compared to bupivacaine alone prolonged
the mean time of first request of analgesia (18.25 ± 1.98), (12.56 ± 2.64), respectively (P <
0.001), reduced total morphine consumption (12.50 ± 4.63), (18.86 ± 6.28), respectively (P =
0.016). With no significant difference in hemodynamics, respiratory rate, oxygen saturation,
VAS and sedation scores, and side effects observed between the 2 groups (P > 0.05).
Limitations: This study is limited by its sample size.
Conclusion: The addition of ketamine to modified Pecs block prolonged the time to first
request of analgesia and reduced total opioid consumption without serious side effects in
patients who underwent a modified radical mastectomy.
Key words: Ketamine, bupivacaine, pecs block, postoperative, pain, breast cancer
Subtle Sensory Abnormalities Detected by
Quantitative Sensory Testing in Patients with
Trigeminal Neuralgia
Authors: Krauss Joachim K.
Published: February 2021

Background: Trigeminal neuralgia (TN) is characterized by paroxysmal pain attacks affecting
the somatosensory distributions of the trigeminal nerve. It is thought to be associated with a
neurovascular conflict most frequently, but pathomechanisms have not been fully elucidated. In
general, no sensory deficit is found in routine clinical examination. There is limited data available,
however, showing subtle subclinical sensory deficits upon extensive testing.
Objective: We used quantitative sensory testing (QST) to detect abnormalities in sensory
processing in patients with TN by comparing the affected and non-affected nerve branches with
their contralateral counterparts and by comparing the results of the patients with those of controls.
Study Design: Observational study.
Setting: University Hospital, Departments of Neurosurgery, Institute for Cognitive and Clinical
Neuroscience.
Methods: QST was conducted on 48 patients with idiopathic TN and 27 controls matched
for age and gender using the standardized protocol of the German Neuropathic Pain Network.
Stimulations were performed bilaterally in the distribution of the trigeminal branches. The patients
had no prior invasive treatment, and medications at the time of examination were noted.
Results: In patients with TN deficits in warm and cold sensory detection thresholds in the affected
and also the non-affected nerve branches were found. Tactile sensation thresholds were elevated
in the involved nerve branches compared to the contralateral side.
Limitations: More data are needed on the correlation of such findings with the length of history
of TN and with changes of the morphology of the trigeminal nerve.
Conclusions: QST shows subtle sensory abnormalities in patients with TN despite not being
detected in routine clinical examination. Our data may provide a basis for further research on the
development of TN and also on improvement after treatment.
Key words: Quantitative sensory testing, trigeminal neuralgia, facial pain, neuropathic pain,
microvascular decompression, cranial nerve
Transversus Abdominis Plane Block in
the Management of Acute Postoperative
Pain Syndrome after Caesarean Section: A
Randomized Controlled Clinical Trial
Authors: Petrucci Emiliano
Published: February 2021

Background: The international literature is unclear regarding the analgesic efficacy of the
transversus abdominis plane block (TAPB) after a Caesarean section (CS).
Objectives: The aim of this study was to determine whether a correctly performed
ultrasound-guided TAPB (USG-TAPB) could provide better control of acute postoperative pain
during the first 72 hours after CS and if it could provide a faster postoperative recovery.
Study Design: A double-blind, randomized, controlled clinical trial on pregnant women
who underwent CS.
Setting: Pain clinic and Anesthesia and Intensive Care Unit in an academic hospital.
Methods: A double-blind, randomized, controlled study was conducted with 96 patients
who underwent CS. The patients in both groups received subarachnoid anesthesia (SAB) with
13 mg of 0.5% isobaric levobupivacaine. The patients were randomized so that some received
USG-TAPB with local anesthetic, and the remainder received USG-TAPB with saline. The
patients’ demographic information and data regarding anesthesia, hemodynamic changes,
side effects, acute rest and incident postoperative pain, painkiller consumption, recovery time
of bowel function, and the time of hospital discharge were recorded.
Results: Our data reinforce the assumption that if TAP block is performed correctly and is
part of a multimodal analgesic scheme, effective pain control is possible both for somatic and
visceral acute pain. Furthermore, the need for painkillers is reduced, and their related side
effects are moderate, yielding a positive benefit/cost ratio.
Limitations: USG-TAPB provides good analgesia for acute postoperative somatic pain, but
opiates were still needed for the management of visceral acute postoperative pain.
Conclusions: These results could confirm the assumption that the correct performance of
an USG-TAPB as part of a multimodal analgesic treatment could represent a viable alternative
to common analgesic procedures performed for acute postoperative pain control after a CS.
Key words: Bowel function, Caesarian section, incident pain, local anesthetics, multimodal
analgesic treatment, postoperative recovery, rest pain, ultrasound-guided TAP block
Fluoroscopically Guided Thoracic Interlaminar
Epidural Injection: A Comparative Epidurography
Study Using 2.5 mL and 5 mL of Contrast Dye
Authors: Hong JiHee
Published: February 2021

Background: Thoracic epidural anesthesia (TEA) is frequently used to maintain intraoperative
analgesia. After injecting the initial bolus dose of epidural local anesthetics (LA), intermittent
injection of LA through an epidural catheter is required to maintain the intraoperative analgesia.
For intermittent epidural administration, usually 2 – 5 mL of LA has been used. However, no studies
have suggested an optimal volume of LA of TEA for intermittent epidural administration of TEA.
Objective: We focused on identifying an optimal volume of LA of TEA using epidurography of
the thoracic level with 2 different volumes of contrast dye.
Study Design: Prospective, randomized study.
Setting: An interventional pain management practice in South Korea.
Methods: After Institutional Review Board approval, 70 patients undergoing thoracic epidural
catheterization for upper abdominal and thoracic surgery were randomly assigned to one of the
2 contrast dye volume groups of 35 patients each (A, 2.5 mL and B, 5.0 mL). Epidurography was
evaluated to confirm how many spinal segments were covered by contrast dye. The spreads in the
cephalad and caudad directions were also evaluated.
Results: The total number of vertebral segments evaluated by contrast dye were 7.5 ± 2.0, and
8.4 ± 2.6, respectively in groups A and B. The number of patients who showed contrast dye spread
of more than 5 vertebral segments was 34/35 (97%) in both groups. Group B resulted in higher
contrast dye distribution in the cephalad direction compared to group A (T2.6 vs. T3.6 ).
Limitations: We used a test dose of contrast dye to confirm the contrast was in epidural space,
not intrathecal or vascular, before injection of the main dose of contrast dye. The present study did
not include the volume of test dose.
Conclusion: The volume of 2.5 mL for intermittent epidural administration would be enough
for the analgesic effect of upper abdominal and thoracic surgery while avoiding excessive upper
thoracic and cervical spread.
Key words: Thoracic epidural anesthesia, intermittent epidural administration, optimal volume,
epidurography, cephalad, caudad, analgesic effect
Ultrasound-Guided Intermediate Site Greater
Occipital Nerve Infiltration: A Technical
Feasibility Study
Authors: Zipfel Jonathan
Published: February 2021

Background: Two studies recently reported that computed tomography (CT) guided
infiltration of the greater occipital nerve at its intermediate site allows a high efficacy rate with
long-lasting pain relief following procedure in occipital neuralgia and in various craniofacial
pain syndromes.
Objective: The purpose of our study was to evaluate the technical feasibility and safety of
ultrasound-guided intermediate site greater occipital nerve infiltration.
Study Design: Retrospective study.
Setting: This study was conducted at the imaging department of a 1,409 bed university
hospital.
Methods: Local institutional review board approval was obtained and written consent was
waived. In this retrospective study, 12 patients suffering from refractory occipital neuralgia or
craniofacial pain syndromes were included between April and October 2014. They underwent
a total of 21 ultrasound-guided infiltrations. Infiltration of the greater occipital nerve was
performed at the intermediate site of the greater occipital nerve, at its first bend between
obliqus capitis inferior and semispinalis capitis muscles with local anestetics and cortivazol.
Technical success was defined as satisfactory diffusion of added iodinated contrast media in the
fatty space between these muscles depicted on control CT scan. We also reported first data of
immediate block test efficacy and initial clinical efficacy at 7 days, one month, and 3 months,
defined by a decrease of at least 50% of visual analog scale (VAS) scores.
Results: Technical success rate was 95.24%. Patients suffered from right unilateral occipital
neuralgia in 3 cases, left unilateral occipital neuralgia in 2 cases, bilateral occipital neuralgia in
2 cases, migraine in one case, cervicogenic headache in one case, tension-type headache in 2
cases, and cluster headache in one case. Block test efficacy was found in 93.3% (14/15) cases.
Clinical efficacy was found in 80% of cases at 7 days, in 66.7% of cases at one month and in
60% of cases at 3 months. No major complications were noted.
Limitations: Some of the limitations of our study include that it represents a single institution.
The low number of infiltrations included in this study, for this guidance procedure, is another
bias.
Conclusions: This ultrasound-guided infiltration technique appears to be feasible, safe, nonionizing, and fast when targeting the greater occipital nerve in its intermediate portion. This
imaging guidance modality should be used in routine clinical practice.
Key words: Greater occipital nerve, infiltration, ultrasound guidance, corticosteroids,
occipital neuralgia, craniofacial pain syndrome
Contrast Runoff Correlates with the Clinical
Outcome of Cervical Epidural Neuroplasty
Using a Racz Catheter
Authors: Kim Young Hoon
Published: February 2021

Background: Epidural neuroplasty using a Racz catheter has a therapeutic effect. Studies
have found no correlation between foraminal stenosis and the outcome of epidural neuroplasty,
which is thought to depend on contrast runoff.
Objective: To examine the correlation between the contrast spread pattern and pain reduction
in cervical epidural neuroplasty using a Racz catheter.
Study Design: Retrospective study.
Setting: An interventional pain-management practice in a university hospital.
Methods: Fluoroscopic images were reviewed retrospectively. The spread of contrast from
the neural foramen to a nerve root was called contrast runoff. If the contrast did not spread in
this manner, then there was no contrast runoff. We defined successful epidural neuroplasty as
a 50% or greater reduction from the pre-procedure numeric rating scale (NRS) score for total
pain, and an at least 40% reduction in the neck pain and disability scale (NPDS) score.
Results: This study reviewed 169 patients. Among the patients who had a contrast runoff
pattern, the epidural neuroplasty was rated as successful in 96 (74.4%), 97 (75.2%), 86
(66.7%), and 79 (61.2%) cases one, 3, 6, and 12 months after the procedure, respectively.
When there was no contrast runoff, the epidural neuroplasty was successful in 12 (30%), 12
(30%), 10 (25%), and 10 (25%) cases at one, 3, 6, and 12 months after the procedure (P <
0.001). Logistic regression of the contrast spread pattern and predicting successful epidural
neuroplasty gave similar results. Patients with a contrast runoff pattern had odds ratios of
6.788, 7.073, 6.000, and 4.740 at one, 3, 6, and 12 months, respectively (P < 0.001).
Limitations: This study lacked a control group, and the patients were not classified by their
diagnosed disease, such as spinal stenosis, herniated nucleus pulposus, and post-spinal surgery
syndrome.
Conclusions: Cervical epidural neuroplasty with a contrast runoff pattern had a higher
success rate. Contrast runoff should be observed during neuroplasty, even in the presence of
foraminal stenosis.
Key words: Cervical spinal pain, contrast, contrast runoff, epidural neuroplasty, percutaneous
adhesiolysis, Racz catheter
Intrathecal Bupivacaine Monotherapy with a
Retrograde Catheter for the Management of
Complex Regional Pain Syndrome of the Lower
Extremity
Authors: McRoberts W. Porter
Published: February 2021

Complex regional pain syndrome (CRPS) presents a therapeutic challenge due to its
many presentations and multifaceted pathophysiology. There is no approved treatment
algorithm and clinical interventions are often applied empirically. In cases of CRPS
where symptoms are localized to an extremity, a targeted treatment is indicated. We
describe the use of intrathecal bupivacaine monotherapy, delivered through a retrograde
catheter, in the treatment of CRPS affecting the lower extremity. The patient, a 57-yearold woman with a history of failed foot surgery, was seen in our office after 2 years of
ineffective treatments with local blocks and neurolytic procedures. We advanced therapy
to moderately invasive procedures with an emphasis on neuromodulation. A combined
central and peripheral stimulation technique that initially provided 75% pain relief, failed
to provide lasting analgesia. We proceeded with an intrathecal pump implant. Based on
the results of dorsal root ganglion (DRG) mapping, L5-S1 was identified as the optimal
target for therapy and a retrograde catheter was placed at this level. Various intrathecal
medications were tested individually. An intrathecal morphine trial was ineffective (visual
analog scale [VAS] 7), while intrathecal clonidine provided excellent pain relief (VAS
0) that was limited by severe side effects. Bupivacaine provided 100% analgesia with
tolerable side effects (lower extremity weakness and minor bladder incontinence) and
was selected for intrathecal infusion. After 14 months, bupivacaine treatment continued
to control pain exacerbations. We conclude that CRPS patients benefit from early
identification of the predominant underlying symptoms and a targeted treatment with
moderately invasive techniques when less invasive techniques fail.
Key words: Intrathecal bupivacaine, bupivacaine monotherapy, retrograde catheter,
complex regional pain syndrome (CRPS), dual stimulation, dosal root ganglion (DRG)
testing
Radiofrequency Ablation of the Sphenopalatine
Ganglion Using Cone Beam Computed
Tomography for Intractable Cluster Headache
Authors: Kaveeshvar Hirsh
Published: February 2021

Percutaneous radiofrequency ablation (RFA) of the sphenopalatine ganglion (SPG) has been
shown to be an effective modality of treatment for patients with intractable chronic cluster
headaches (CHs). While the use of fluoroscopy for RFA of the SPG is common, to our knowledge
there are no documented cases of procedures using cone beam computed tomography (CBCT)
for image guidance. We present a case report of a patient suffering from chronic intractable
CH with complete long-lasting relief after RFA of the SPG using CBCT. The case reaffirms the
potential efficacy of RFA of the SPG in a case of chronic cluster headache as well as the use of
CBCT as a superior alternative to bi-plane fluoroscopy for image guidance in the management
of chronic CH.
Key words: Cone beam computed tomography, sphenopalatine ganglion block, cluster
headache, interventional pain, autonomic cephalalgia, radiofrequency ablation
Epidural Blood Patch for the Treatment of
Spontaneous and Iatrogenic Orthostatic
Headache
Authors: Kim Jae Hun
Published: February 2021

Background: The cerebrospinal fluid (CSF) leakage could be happened spontaneously or
related to the procedures such as spinal anesthesia, epidural anesthesia, CSF tapping, intrathecal
chemotherapy or other spinal procedures. The leakage of CSF leads to intracranial hypotension of
which distinguishing clinical feature is orthostatic headache. The epidural blood patch is a goldstandard treatment for intracranial hypotension-related orthostatic headaches.
Objective: We conducted this study to compare the efficacy and number of epidural blood
patches for spontaneous and iatrogenic orthostatic headaches.
Study Design: Retrospective study.
Setting: University hospital inpatient and outpatient referred to our pain clinic.
Methods: Sex, weight, height, cause of orthostatic headache, leakage site evaluation test,
epidural blood patch injection level, number of administered epidural blood patches, and pain
intensity data were collected. We classified patients into two groups according to the cause of
orthostatic headache: spontaneous (Group S) and iatrogenic (Group I). Patients with myelograms
were also divided into 2 groups: multiple cerebrospinal fluid (CSF) leakages and no multiple
leakages.
Results: Overall, 133 patients (162 procedures) were managed using epidural blood patches.
Groups S and I included 34 and 99 patients, respectively. In Group I, 90.9% of the patients
achieved complete recovery following a single procedure, whereas 44.1% of Group S patients
required repeated procedures. The average number of administered epidural blood patches was
significantly higher in Group S (1.48 ± 0.64) than in Group I (1.11 ± 0.35; P = 0.007). Among 23
patients evaluated via myelography, 12 had multiple CSF leakages. Patients with multiple leakages
required a significantly higher number of epidural blood patches, compared to patients without
multiple leakages (P = 0.023).
Limitations: This retrospective study reveals several limitations including insufficient evaluation
of CSF leakage site by myelogram and the retrospective nature of the study itself.
Conclusions: Most patients with iatrogenic orthostatic headache required a single epidural blood
patch, although most did not undergo a myelogram or similar test. Patients with spontaneous
orthostatic headache or multiple CSF leakages were more likely to require a repeated epidural
blood patch.
Key words: CSF leakage, dural puncture, epidural blood patch, intracranial hypotension,
orthostatic headache, spinal headache