A Pilot Study of Stellate Ganglion Blockade + Psychoeducation to Reduce Cardiac Anxiety and PTSD Symptoms in Cardiac Arrest Survivors
Phase: NA
Conditions: PTSD, Cardiac Arrest, Anxiety and Fear, Sleep Disturbance, Health Behavior
Sponsor: Columbia University

 
6/16/2021 
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STUDY TITLE: Stellate Ganglion Blockade to Reduce Posttraumatic stress disorder Symptoms 
in Cardiac Arrest Survivors: A Pilot Randomized Clinical Trial 
 
Principal Investigator: Sachin Agarwal, MD, MPH IRB #: AAAS8305 
Lay Abstract: 
Recent advances in cardiac arrest (CA) treatment have allowed patients to survive neurologically intact, but 1 in 
3 screens positive for Posttraumatic stress disorder (PTSD) symptoms at hospital discharge, increasing their 
r i s k  for poor health-related quality of life and secondary cardiovascular events and mortality. Current 
treatments for PTSD include both psychotherapeutic and medication-based treatments, with little existing 
evidence for effectiveness or are associated with severe side-effects which leads to non-adherence. Sympathetic 
blockade via stellate ganglion block (SGB) has been shown to be effective, fast-acting, with appealing safety 
profile and good patient acceptability and adherence in combat-related PTSD. SGB treatment has never been 
tested to treat PTSD induced by acute medical events such as CA. This will be the first prospective, feasibility, 
and safety study of the stellate ganglion blockade employed as an early, in-hospital intervention to treat PTSD 
after a life-threatening CA. This pilot study will obtain essential data to support a phase 2 adaptive design dose- 
escalation clinical trial assessing the efficacy of SGB for treating early PTSD in CA patients. The findings of this 
trial could revolutionize the management of psychological complications and could potentially improve health- 
related quality of life and event-free survival after CA and other acute medical events like acute coronary 
syndrome and stroke. The trial leverages the expertise of an interdisciplinary team with representation from   
the School of Medicine (neurology, anesthesiology, psychology, and internal medicine), School of Public Health 
(epidemiology), and the School of Nursing. 
 
1. Study purpose and rationale 
 
Every year in the U.S., 500,000 people experience sudden cardiac arrest (CA),1  caused by electrical  
disturbances across cardiac tissue, leading to marked arrhythmia that ultimately result in the heart ceasing to 
pump blood to the brain, lungs, and other organs. Due to advances in bundled post-arrest care, cardio-cerebral 
resuscitation, and effective cooling protocols, a substantial proportion of patients who receive 
guideline based care (nearly 1 in 3 for out-of-hospital and ~50% for in-hospital CA) now survive 
this once universally fatal condition.1-5  While most survivors retain their cognitive function and physical 
independence, many grapple with CA’s psychological consequences in the context of learning that they were 
“clinically dead.” 6-8 In particular, many describe the CA experience as traumatic,6,8 and up to 1 in 3 CA 
survivors subsequently develop posttraumatic stress disorder (PTSD).8,9  Not only is PTSD 
common in CA patients, but there is now evidence that PTSD after CA may influence prognosis. In the first 
prospective study of psychosocial determinants of prognosis after CA (n= 114), we found that 32% screened 
positive for early PTSD at hospital discharge.10  Patients who developed early PTSD symptoms after CA were at 
very high risk  for cardiovascular disease (CVD) events/mortality in the subsequent year (61% with PTSD vs 
24% without PTSD; (HR =3.2; 95% CI, 1.7–6.0).10  Thus, intervening on early PTSD symptoms holds 
promise not only for improving quality of life but for improving prognosis in CA survivors. 
Treatment of early PTSD symptoms after CA requires a timely intervention.11,12  From the 
perspective of prevention research, since medical event-induced PTSD presents itself in medical settings 
compared to other traumas, it constitutes an opportunity for facilitating early intervention. In our recent 
systematic review on early interventions for early PTSD symptoms in survivors of acute medical conditions, 
there was low strength of evidence for early psychological PTSD treatments.13  A separate review of PTSD 
pharmacologic treatments found that medications were associated with severe side-effects and varying onset of 
action leading to high dropout rates, and non-adherence.14 Accordingly, there is a pressing need to explore 
additional treatment options for PTSD induced by acute medical events such as CA. 
Sympathetic blockade via stellate ganglion block (SGB) represents a promising PTSD 
intervention for early PTSD in CA survivors. The SG is a major sympathetic switching and transit 
station for the “fight-or-flight” response; interrupting this complex circuitry with a local anesthetic has 
observable effects on conditions mediated by similar responses, such as PTSD.15,16  A recent sham-controlled 

 
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randomized clinical trial (RCT) of active-duty service members with PTSD symptoms showed that two SGB 
treatments were effective in reducing Clinician-Administered PTSD Scale (CAPS) for DSM-5 total symptom 
severity scores over 8 weeks.17 It confirmed the observational data (n=200) showing rapid and clinically 
significant improvement in combat-related PTSD from a single SGB treatment18,19 and persisted beyond 3 
months.19  SGB is shown to be safe,20,21  with good patient acceptability and adherence, particularly in combat 
veterans.22  SGB treatment has never been tested to treat PTSD induced by acute medical events such as CA. 
2. Research   Question(s)/Hypothesis(es): 
 
We propose to conduct a pilot RCT to gain preliminary evidence regarding the acceptability, tolerability, safety 
and efficacy of SGB blockade in patients exhibiting early PTSD symptoms before discharge after CA. We will 
further explore mechanisms of SGB treatment effect and whether it may promote favorable physiology in the 
form of engagement in healthy behaviors, such as physical activity and sleep. We will leverage the 
infrastructure of an ongoing longitudinal cohort study of CA patients10 at Columbia University (PACE Study: 
“Positive and Negative Psychological Predictors of Long -Term Recovery after Cardiac 
Arrest,” IRB# AAAT4053, PI Agarwal) to identify eligible CA patients with high in-hospital PTSD 
symptoms (PCL-5>32).
23,24  We will also utilize questionnaire data collected as part of the PACE study, including 
but not limited to, GENEActive accelerometry data, PCL-5 scores and CQI scores. Consenting patients (N=15) will 
be randomized in a 2:1 ratio to a single SGB Intervention or sham control saline injection in an inpatient, 
monitored setting. Patients, and assessors, i.e. the coordinators administering the questionnaires, will be blinded 
to group assignment. The operator will fill a procedure-related safety questionnaire, and patients will take a 
comfort and satisfaction survey.25  Depression (PHQ-8),26 anxiety (GAD-7)27 will be assessed prior to the 
procedure, and again, in person  or by phone, at 1-week, 4-weeks, and 12-weeks post-procedure. In addition, 
PCL-5 and CQI questionnaires will be administered at the 1-week and 12-week follow-up calls. 
Patients will be screened for adverse events at all follow-up visit time points. The primary outcome will be 
change in PCL-5 score from baseline to 4-weeks, which will be assessed by utilizing data collected as part of the 
PACE study (PI Agarwal, IRB# AAAT4053). The SGB study will assess physical activity and sleep duration 
post-discharge by utilizing wrist-worn accelerometer data collected as part of the PACE study (PI Agarwal, 
IRB# AAAT4053). Patients may enroll and participate in both the PACE study and SGB study concurrently. 
 
Primary Aim 1: Gain preliminary evidence regarding the acceptability, tolerability, and effect of a single SGB 
treatment in CA patients on PTSD symptoms 1 week, 4-weeks, and 12-weeks post-treatment. 
 
Secondary Aim 1: Test whether SGB treatment in CA patients with clinically significant PTSD symptoms is 
associated with improved health behaviors (physical activity and sleep duration) assessed objectively by a 
wrist-worn accelerometer post-discharge. 
 
3. Study Design 
 
This is a single center, randomized, double blinded, sham-procedure-controlled study to evaluate the 
effectiveness of unilateral right-sided stellate ganglion block (SGB) on the acute symptomatology of PTSD, 
evaluated by the PCL-5 pre-treatment and at 1, 4 and 12 weeks. Pre-treatment and 4-week PCL-5 scores will be 
assessed by utilizing data collected as part of the PACE study (PI Agarwal, IRB# AAAT4053). 
 
During the in-clinic session 1 the procedure will be performed at the bedside while in-patient or in the clinic by 
a single operator using NYP standard operating procedure with safe ultrasound techniques. For the active SGB 
arm, 0.5% 8 cc of ropivacaine  and 2 cc of saline, will be injected around and into the site of the ganglion at the 
level of the C6 anterior tubercle. For the sham procedure, 10 cc of preservative-free normal saline will be 
injected into deep musculature anterolateral to C6 anterior tubercle. 
 
Ultrasound-Guided SGB Detailed Procedure Protocol 
 
1. General preparation: We will confirm that advanced cardiac life support (ACLS) equipment and 
capability are current and available in the procedure room. We will also ensure that midazolam, which is 

 
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required to rapidly abate a seizure in the event of an inadvertent vascular injection, is on the ACLS cart. 
 
2. Procedure preparation: Secure an intravenous saline lock in a peripheral vein, connect noninvasive 
physiologic monitors, and place the patient in the supine position with their head rotated slightly to the left. Do 
not use a pillow under the head or neck. A bolster may be placed under the knees for patient comfort. Widely 
prepare the skin over the anterior and right side of the neck with an alcohol and chlorhexidine solution, and 
allow the solution to dry for 1 minute. Perform a “time out” to confirm correct patient, correct procedure, and 
correct side. 

 
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3. Ultrasound positioning: Apply a small amount, approximately 2 grams, of sterile ultrasound gel to the 
anterior neck at the level of the cricoid membrane. While seated on the right side of the patient, place a cleaned 
and prepared high-frequency linear transducer transverse at the 
level of the cricoid membrane (i.e., sixth cervical vertebra, or C6, 
level). Raising the procedure table to about the level of the 
provider’s chest usually facilitates proper ergonomics. The depth 
of the ultrasound unit is set to visualize the ventral border of the 
C6 vertebral body (usually 4 cm in male patients). Identify the 
anterior tubercle of the C6 vertebra. The anterior tubercle of C6 
has a distinct peaked appearance, and the level can be confirmed 
by  being both at the level of the cricoid membrane and by it being 
the most caudad anterior tubercle (which can be confirmed with a 
short-axis slide in a caudad direction towards the clavicle). 
Identify key landmarks: the common carotid artery, interior 
jugular vein (facilitate viewing the entire internal jugular vein by 
having the patient perform the Valsalva maneuver), ventral 
portion of the C6 vertebral body, longus coli muscle overlying the 
vertebral body, longus capitus muscle (usually) overlying the 
anterior tubercle of C6. (Note: there is a high degree of anatomic 
variation in the anterior neck.) While in this transverse view, use 
power Doppler or color Doppler to scan and identify vascular 
structures, especially looking for the well-documented anatomic 
variation of a vertebral artery coursing anterior and medial to the 
anterior tubercle of C6. 
 
4. Procedure: Envisioning a long-axis (or in-plane) lateral 
approach, mentally ensure the needle can reach the target area 
from the lateral neck (Figure 1).  Place a skin wheal of 0.5 mL 
buffered 1% lidocaine at the needle entry site. Using a 3.5-in long 
22-gauge needle (or other appropriate needle), enter the neck 
with the needle in long axis to the ultrasound transducer (“in-
plane” approach) going through sternocleidomastoid, continuing 
just ventral to the tip of the anterior tubercle of C6, then 
continuing on until the needle tip has just penetrated the ventral 
fascia of longus coli, just medial to the longus capitus muscle and 
dorsal to the common carotid artery. The cervical sympathetic 
chain usually courses along the ventral fascia of longus coli at 
this level, and it is 
sometimes, but not always, clearly visible on ultrasound. Initially aspirate to check for no blood in the hub of  
the needle, then slowly inject 0.5% 8 cc of ropivacaine  and 2 cc of saline (over 2 minutes in 0.5 cc aliquots) to 
mitigate risk associated with potential intravascular injection. The (anechoic) injectate should flow just dorsal 
to the ventral fascia of longus coli. There is significant anatomic variation in the anterior neck and slight 
variations of this description may be required. Let the patient know that they can talk during the injection if 
needed. Periodically ask the patient during the injection if they are doing well, and let the patient know that 
questioning them is just another way to monitor how they are doing. It is absolutely critical to constantly keep 
the needle tip in view. If the needle tip cannot be visualized, stop the injection, reacquire needle tip 
visualization, aspirate while  checking for no blood in the hub of the needle, and only then restart the injection. 
 
5. Observation and monitoring: Observe and monitor the patient for at least 30 minutes after completion 
of the injection. Have the patient remain in the supine position (a pillow may be used at this time). The first 
sign of a successful block will often be a sensation change on the right side of the face. Once signs and 
symptoms of Horner’s syndrome are evident, the patient may sit reclined at a 20° angle for the remaining 
observation period. These positions may facilitate productive anesthetic spread. Record the patient’s initial 
response to the injection, the time at which an obvious Horner’s response was evident, and the quantitative 
score of the Horner’s syndrome. Re-emphasize appropriate precautions to the patient before discharge. 

 
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Behavioral: Psychoeducation on trauma symptoms and stellate ganglion blockade: All participants will 
complete a single, 30-minute psychoeducation session with the study PI, Dr. Sachin Agarwal. Dr. Agarwal will be 
assisted by a research coordinator for fidelity and note-taking purposes. For Spanish-speaking subjects, a fluent, 
Spanish-speaking research coordinator will serve as the translator for Dr. Agarwal as he conducts the 
psychoeducation session. Dr. Agarwal will use a checklist (attached in RASCAL documents) to ensure that all 
components of the psychoeducation session are fully addressed. The session will be focused on providing the 
patient with information on the following:  
(1) Establish therapeutic relationship and rapport with the subject and provide a general overview of stellate 
ganglion blockade treatment. 
(2) Rationale for stellate ganglion blockade treatment in the context of cardiac arrest-induced PTSD 
symptoms by explaining how the body has a fight-or-flight system that is controlled in part by the stellate 
ganglion. Further, explaining how blocking the action of this part of the body can calm down the fight-or-flight 
part of the body and help reduce the feelings of anxiety that commonly occur. 
(3) Explain the goals of the intervention. 
(4) Review common misconceptions about anxiety and fear after cardiac arrest, and description of empirical 
research showing how distress is associated with interoceptive bias and avoidance of health behaviors. 
Explain how many of these feelings are common in cardiac arrest survivors, and they are often unrelated to 
their risk of cardiac arrest recurrence or other types of cardiac events. Further, help the patient identify 
anxious situations, thoughts, and bodily feelings related their recent cardiac arrest. 
(5) Provide education about safety behaviors (e.g., monitoring bodily processes, reassurance-seeking, 
preventive healthy behaviors).    
 
During the psychoeducation session, Dr.Agarwal will 
review with the subject, important health and 
safety guidelines related to their heart health, 
for the duration of participation in the study. 
Safety will be a core focus of this pilot trial. Dr. 
Agarwal will review what a subject should do , 
should they experience any chest pain or other 
concerning medical symptoms including but not 
limited to: calling 9-1-1, seeking help at the 
Emergency Department and calling their doctor.  
 
To further ensure proper execution of the 
psychoeducation sessions, Dr. Agarwal will 
review and discuss any participant issues with 
SGB study investigator, Jeffrey Birk, PhD.  
 
Measures 
To determine eligibility, we will use a cut point of 32 on The 
PTSD Checklist for DSM-5-Specific for CA (PCL-5) o r  
c a r d i a c - s p e c i f i c  a n x i e t y  m e a s u r e  ( C Q I  
s c a l e  s c o r e ≥1 . 8 1 ) , to categorize participants as likely 
having PTSD as suggested by the National Center for PTSD for 
provisional PTSD diagnosis25 or severe cardiac-specific anxiety 
per previous studies on cardiac arrest patients. The PCL-5 
and CQI will be implemented at the 1-week and 12-week 
follow-up visits to measure symptoms. General anxiety and 
depressive symptoms assessments, adverse events, Attitudes 
and perception questionnaire26 will be administered by an 
RA in-person before discharge and via telephone or secure 
NYP virtual visit system at 1, 4, and 12 weeks follow-up visits 
(Figure 2). 
Figure 2. Study Schema 
 
 
 

 
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Study  procedures 
 
Prior to completing the written informed consent process, an SGB study team member will recruit adult subjects, 
that are more than 18 years of age, inclusive, with a clinical diagnosis of Post-Cardiac Arrest that have been 
hospitalized in one of the ICUs at the Milstein Hospital Building and meet the inclusion/exclusion criteria for the 
STELLATE study, and have been identified to have elevated symptoms of psychological distress tested by the 
approved IRB  "PACE Study: Positive and Negative Psychological Predictors of Long-Term Recovery after Cardiac 
Arrest" study IRB # AAAT4053. Previously the SGB study enrolled subjects from the approved IRB “CANOE Study: 
Cardiac Arrest Neuropsychological Outcomes Evaluation” study IRB # AAAR8497, but effective 6/2/2021 the SGB 
study will only enroll from PACE.  Please note, only PACE subjects who also gave permission to be contacted for 
future research opportunities will be contacted to discuss participation in SGB. Further, PACE subjects who decline 
participation in SGB will not be contacted a second time to participate in the same study. 
 
Potential participants will be asked to review a screening verbal consent form with the SGB study team member. 
After reviewing the document, the participant will provide verbal consent to complete screening procedures and 
then will answer the questions outlined in the attached document titled, "SGB Screening questions 11_23_2020." 
Participants who meet all screening eligibility will then review the informed consent form with the SGB study team 
member and provide written consent to participate. 
 
First In-Clinic Visit (90 minutes) 
Consenting patients will be randomized in a 2:1 ratio to a single SGB intervention or sham control saline 
injection. Depression (PHQ-8)27  and generalized anxiety (GAD-7)28 will be assessed prior to the procedure. 
Patients, and assessors, i.e. the coordinators administering the questionnaires, will be blinded to 
group assignment. The anesthesiologist will remain unblinded. A safety questionnaire related to the 
procedure will be filled by the operator. Post-procedure, patients will complete the Attitudes and perception 
survey on the comfort and satisfaction associated with it. PTSD (PCL-5) and cardiac-specific anxiety (CQI)29 
collected as part of the PACE study will be used as eligibility criteria for enrollment into the SGB study. These 
measures will only be asked at the 1-week and 12-week follow-up visits for SGB.       
 
Participation in this study will be documented in each participant’s EPIC electronic medical record and study staff 
will access medical records in order to extract health-related data and ensure participant safety throughout the 
duration of the study. 
 
Post-Discharge Accelerometry: Sleep and physical activity data will be collected as part of the IRB-
approved PACE protocol (PI Agarwal, IRB# AAAT4053), using a GENEActiv accelerometry 
device. The sleep and physical activity data collected as part of PACE will later be linked 
with the SGB dataset. SGB subjects recruited from t he PACE study will not receive an 
additional GENEActiv device to wear as part of their participation in SGB.  
 
1, and 12 weeks Post-procedure (3o -60 minutes each) 
Participants will complete the PCL-5, PHQ-8, GAD-7, CQI and Attitudes and perception questions at the 1 
and 12-week follow up visits.  Subjects will be asked about any ED visits or hospitalizations they 
have experienced since their last contact with the study team. Hospitalization records will be 
obtained for those reporting events. In addition to asking about ED visits/hospitalizations during each 
follow-up visit, throughout the duration of participation, research staff will monitor the EPIC EHR system on a 
weekly basis to review any ED visits/hospitalizations within NYP. 
 
4 weeks Post-procedure (3o -60 minutes) 
Participants will complete the PHQ-8, GAD-7, and Attitudes and perception questions at the 4-week follow up 
visit.  Subjects will be asked about any ED visits or hospitalizations they have experienced 
since their last contact with the study team. Hospitalization records will be obtained for 
those reporting events. In addition to asking about ED visits/hospitalizations during each follow-up visit, 
throughout the duration of participation, research staff will monitor the EPIC EHR system on a weekly basis to 
review any ED visits/hospitalizations within NYP. 

 
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Statistical  Procedures: 
Data analysis for the primary outcome will be performed according to the intent-to-treat principle with an 
analogous secondary analysis conducted with the per-protocol population. The primary outcome of this study 
will be tested for differences between arms. The primary outcome will be analyzed using a linear model for 
continuous variable that accounts for treatment assignment, and baseline PCL-5 score. 95% confidence 
intervals will be produced for each of the arms. We are establishing a 10-point change in PCL-5 score from 
baseline to follow-up 4 weeks after SGB as a clinically meaningful change. Consequently, as a part of the 
primary outcome analyses, point and interval estimates of the change will be generated for each treatment 
arm to evaluate whether one or both arms reach the level of clinically meaningful change. 
 
4. Compensation 
 
Participants receive $50 at the completion of the first in-clinic visit 60-minute baseline/pre- 
intervention/intervention session. They receive $25 for completing follow-up phone call 1, $50 for completing 
follow-up phone call 2 and $50 for completing follow-up phone call 3. Therefore, the total possible 
compensation for completing the study is $175 for each participant. All compensation will be in the form of a 
PayCard. 
 
5. Eligibility 
 
Inclusion  criteria 
 
1. Age 18 years or older 
2. Fluent in English or Spanish 
3. A diagnosis of cardiac arrest (CA) 
4. Admitted to the NYPH ICUs 
5. Enrolled in the PACE study (IRB# AAAT4053) and agreed to be contacted for future research 
opportunities 
6. Elevated symptoms of psychological distress 
a. PCL-5 > 32 at discharge or CQI scale score≥1.81 
Exclusion criteria 
1. A prior SBG treatment 
2. Severe brain injury defined as Cerebral Performance Category Score ≥3, and/or significant 
aphasia, dysarthria, or cognitive impairment precluding ability to complete study questionnaires 
as determined by interviewer 
3. Terminal non-cardiovascular illness (life expectancy <1 year) 
4. Severe mental illness requiring urgent psychiatric hospitalization 
5. Alcohol or substance abuse that would impede ability to complete study 
6. Unavailable for telephone and in-person follow-up 
7. Allergy to amide local anesthetics (e.g., ropivacaine, bupivacaine) 
8. Pre-existing contralateral Horner’s syndrome 
9. Pregnancy 
10. Current anticoagulant use 
11. History of a bleeding disorder 
12. Infection or mass at injection site 
13. Prior Recurrent laryngeal nerve injury 

 
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6. Risks 
In the most recent data on 113 individuals (100 men; 
mean [SD] age, 37.3 [6.7] years)19 who were 
randomized to SGB treatment vs sham (74 to SGB 
treatment and 39 to sham treatment), there were 
total of 3 (0.04%) adverse events, 2 were definitely 
related and one possibly related, to the SGB 
treatment (see Figure 5). There were no adverse 
event in the sham treatment. In other RCT and case 
series of SGB for PTSD,17,22 there have been no 
instances of serious complications reported and there 
was no significant difference in the rate of minor 
injection related complications between the SGB and 
sham injection groups. Garneau et al.32 reported that 
they encountered no complications in SGB applied 
under USG guidance to 40 patients including a 
control group. Wei et al.33 presented total of 156 
SGBs results applied under USG guidance in 16 
patients with CRPS. They reported that the frequency 
of mild complications (such as hoarseness, 
dysphagia) was 13.5%.   Horner’s syndrome is a 
desired effect, and if it does not occur, the injection 
may have to be repeated. 
 
Inadvertent temporary block of nerves innervating the larynx may occur in up to 15% of cases and may result 
in a temporary hoarse voice or a sensation that there is something in the back of the throat, and can last up 
to 10 hours following injection. Although rare, more serious complications include seizure from inadvertent 
injection of local anesthetic into a blood vessel, or a hematoma or localized collection of blood that could 
compromise the airway and result in death. If a patient experiences significant and increasing pain in the 
neck—more than just a mild soreness from the needle—we will immediately seek medical attention, as it 
could represent a hemorrhage in the neck. Although highly unlikely, pneumothorax has been reported with 
SGB. It is acceptable for the patient to talk during the injection. The patient should let the provider know if 
they have any new or strange sensations during the procedure, including tingling of the skin   or mouth, 
ringing in the ears, or just feeling odd. 
 
7. Benefits 
 
There is no direct benefit to participation except that participants in the intervention arm may experience 
reduction in their anxiety symptoms associated with PTSD. Patients may have some variation of feeling 
“relaxed, light, and calm.” Additionally, the pilot study will contribute to scientific knowledge about stress, 
emotion, and autonomic nervous system of the human body. 
 
8. Alternatives 
 
The alternative is not to participate in the study. 
 
 
 
 
 
 
 
 
Figure 5. Common Adverse events 

 
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9. Data and Safety Monitoring 
 
As this study presents risk to participants, data and safety monitoring will be conducted by the study staff as 
directed by the principal investigator. Thus, there is a plan for a Data Safety and Monitoring Board (DSMB) 
established to support the Roybal Centers to adjudicate the adverse events. Investigators and research 
assistants will meet weekly to discuss any problems with the study, in particular, whether there were any 
unexpected complaints about the study procedures or questionnaires, or whether there were any breaches in 
data confidentiality (which will be reported to the IRB as required by policy). If unexpected complaints 
about the procedures or questionnaires are generated, then the study may be stopped or altered prior to 
recruiting  the full sample. An exhaustive checklist of most to least common SGB procedure-related adverse 
events will be determined from the operator and patients. In the RCT and case series of SGB for PTSD there 
were no  instances of serious complications reported and there was no significant difference in the rate of 
minor injection related complications between the SGB and sham injection groups. 
Investigators and research assistants will meet weekly to discuss any problems with the study, in particular, 
whether there were any unexpected complaints about the study procedures or questionnaires, or whether 
there were any breaches in data confidentiality (which will be reported to the IRB as required by policy). If  
unexpected complaints about the procedures or questionnaires are generated, then the study may be stopped   
or altered prior to recruiting the full sample.