American Society of Regional Anesthesia and Pain Medicine May 2017 - 13

patient population by experienced physicians with nearly identical
technique. Indeed, the differences highlight well the problems
with drawing significant conclusions from nonrandomized or
retrospective trials or from low-powered randomized controlled
trials.
Both articles identified potential bias and possible confounders that
could explain the widely disparate outcomes.
In the study of Hanling et al,15 the authors noted that most of their
study population had combat-related PTSD. Furthermore, many
subjects were in the process of disability evaluation, which in part
determines the amount of lifetime disability payments subjects will
receive. Both of these factors are associated with a high rate of
treatment failures. The fact that all patients showed improvement
over time makes this conclusion less plausible, but the possibility
still remains given the low number of subjects enrolled in the study.
In the study of Mulvaney et al,16 the authors noted that most of
the study population consisted of Special Forces members, highly
motivated to redeploy with their units, and that the data were
collected retrospectively with low follow-up rates. However, it
should be added that without randomization, there is a significant
possibility of observer and confirmation bias. For example, the
article points out that many patients inflated their PCL scores in
order to receive an SGB, once they heard from some of the early
participants that the injections helped with symptoms, indicating
that patients may have been actively minimizing their symptoms
to avoid being stigmatized with a psychological diagnosis and/or
not being allowed to deploy with their units. Likewise, patients may
have also underreported post-SGB symptoms in order to ensure
their return to full duty. A well-powered, randomized, blinded study
design with military and civilian populations would mitigate this
type of bias, as it would be evident in both the active and control
arms of the study.
Ultimately, large-scale, randomized, controlled trials or the
formation of an SGB for PTSD registry to track outcomes and
determine if any populations in particular receive benefit or harm
from this novel treatment of PTSD are needed. Fortunately, it
appears that the United States Army Medical Research Acquisition
Activity has funded a more definitive multicentered, well-powered
study at Womack Army Medical Center, Tripler Army Medical Center,
and Landstuhl Regional Medical Center, facilitated by the nonprofit
RTI International research organization.
However, until such time as more conclusive studies can be
completed, current evidence does not support widespread clinical
use of the SGB procedure for PTSD. If it is used, it should be viewed
as a bridging therapy meant to minimize PTSD symptomatology to
allow increased engagement in existing evidence-based treatment
options. In our current clinical practice, we receive requests to

perform SGBs routinely on patients with PTSD; therefore, we
have established practice guidelines to ensure we maximize
the efficacy of these treatments. First, all patients must carry a
diagnosis of PTSD confirmed by a mental health professional. Given
the limited evidence, we do not perform SGBs for other mental
health conditions such as generalized anxiety disorder. Second,
we require that our patients have a therapeutic relationship with
a mental health professional, as current evidence indicates the
SGB procedure to be, at worst, an effective placebo and, at best, a
method of symptom management rather than a cure. Third, each
patient must complete a baseline biopsychosocial questionnaire
that measures relevant parameters related to PTSD as well as
follow-up baseline questionnaires every 4-6 weeks to assess the
efficacy of the SGB procedures and their overall progress with
their condition. Fourth, per previous protocols described in case
reports and prospective studies, we perform all SGB procedures
under continuous ultrasound guidance on the right side with a
standardized dose and volume of local anesthetic (5 mL of 0.25%
bupivacaine with 1:400,000 epinephrine). Finally, we perform
a series of three SGBs separated by 1-2 week intervals and
reassess each patient's progress via a follow-up visit and follow-up
biopsychosocial questionnaire. If the patient is showing substantial
progress with PTSD, we continue the SGBs. If the patient has
demonstrated minimal or no improvement, we discontinue the
SGBs. By following this protocol, we allow patients suffering from
PTSD to receive this experimental treatment, while continuously
monitoring their progress to ensure optimal outcomes for each
patient.
REFERENCES
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Gradus JL. PTSD: National Center for PTSD. Available at: http://www.ptsd.
va.gov/professional/PTSD-overview/epidemiological-facts-ptsd.asp. Published
February 4, 2017. Accessed February 7, 2017.

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Atkinson MP. Institute for Operations Research and the Management Sciences.
A Dynamic Model for Posttraumatic Stress Disorder Among U.S. Troops in
Operation Iraqi Freedom. National Meeting: INFORMS Conference; 2009.

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Committee on the Assessment of Ongoing Efforts in the Treatment of
Posttraumatic Stress Disorder, Board on the Health of Select Populations,
Institute of Medicine. Treatment for Posttraumatic Stress Disorder in Military and
Veteran Populations: Final Assessment. Washington, DC: National Academies
Press; 2014.

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Hoge CW. Interventions for war-related posttraumatic stress disorder:
meeting veterans where they are. JAMA 2011;306(5):549-551. doi:10.1001/
jama.2011.1096.

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Difede J, Olden M, Cukor J. Evidence-based treatment of post-traumatic
stress disorder. Annu Rev Med 2014;65(1):319-332. doi:10.1146/annurevmed-051812-145438.

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Theis FV. Effect of sympathetic neurectomy on the collateral arterial circulation
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Karnosh LJ, Gardner WJ. The effects of bilateral stellate ganglion block on
mental depression: report of 3 cases. Cleve Clin Q 1947;14(3):133-138.

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Hicky A, Hanling S, Pevney E, Allen R, McLay RN. Stellate ganglion block
for PTSD. Am J Psychiatry 2012;169(7):760-760. doi:10.1176/appi.
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Table of Contents for the Digital Edition of American Society of Regional Anesthesia and Pain Medicine May 2017
