Page 92 - Journal of Special Operations Medicine - Summer 2015

without specialized equipment.) An overall score of not a right-sided SGB. This has precedent consistent
3–6 points can be categorized as a dense and obvious with other normal anatomic variations, and although
Horner’s syndrome. Although we created this scale from we have a reasonably supported hypothesis on why the
our experience as a reasonable method for quantifying right-sided SGB works, it appears to be a reasonable
19
SGB block density, this scale requires validation and may option to perform SGB on the left side in appropriate
need adjustment. nonresponders.
• When grading Horner’s syndrome, make sure the patient
is sitting upright and not facing a bright light. A differ- There are no contraindications to treating patients undergo-
ence in pupil size can be more difficult to establish in ing concomitant therapy for PTSD. For a study population,
patients with dark iris color or if the patient is supine patients should be on a stable dose of any psychoactive medi-
and facing bright ceiling lights. cation for at least 3 months. Additionally, do not initiate any
• A third-party medical professional is preferred for quan- new therapies for the first 3 months after SGB. However, for a
titative grading of Horner’s syndrome, to remove poten- nonstudy treatment population, starting therapy as indicated
tial bias on the part of the physician performing the SGB. is appropriate. SGB has immediate effects, unlike cognitive be-
• Arm temperature change after SGB is extraneous for havioral therapy or pharmacotherapy. After SGB, ask patients
PTSD indication because SGB is not treating an upper- to voluntarily refrain from using pharmacologic or alcoholic-
limb condition. beverage sleep aids if they usually use one, as they may no
• A patient can be determined to have Horner’s syndrome longer be needed.
at any time up to 15 minutes after the procedure. Record
the number of minutes after SGB is complete. It appears
to be irrelevant if Horner’s syndrome occurs after 15 Ultrasound-Guided SGB Procedure
minutes; in our experience the resultant block will not The following are procedural guidelines for ultrasound-
be of sufficient density for the patient to have potential guided, right-sided SGB. This is a procedure that requires a
benefit. high level of skill in ultrasound-guided injections and the abil-
• If the patient does not have a dense and obvious Horn- ity to safely handle potential adverse events, including airway
er’s syndrome within 15 minutes, immediately repeat the management. Specific medical credentialing for this procedure
block on the same (right) side. is required.
• Our recommended dose for an ultrasound-guided SGB
is 7–8mL of 0.5% ropivacaine, so the total dose for a 1. General preparation: Confirm that advanced cardiac life
second SGB still would be well below the toxic thresh- support (ACLS) equipment and capability are current and
old for ropivacaine. Ropivacaine is used for its decreased available in the procedure room. Also ensure that midazolam,
toxicity compared to bupivacaine, but 0.5% bupivacaine which is required to rapidly abate a seizure in the event of an
is a reasonable alternative. If higher doses or a different inadvertent vascular injection, is on the ACLS cart.
long-acting anesthetic are used, ensure the total dose for
the second injection is at a safe level, keeping in mind the 2. Informed consent: Obtain informed consent from the pa-
highly vascular nature of the neck region. tient prior to conducting the procedure. Horner’s syndrome
• Lower doses and lower concentrations of ropivacaine is a desired effect, and if it does not occur, the injection may
(or bupivacaine) can achieve a sympathetic blockade; have to be repeated. Inadvertent temporary block of nerves in-
however, in our experience, we did not achieve an ad- nervating the larynx may occur in up to 15% of cases and may
equate clinical response despite signs and symptoms of result in a temporary hoarse voice or a sensation that there is
Horner’s syndrome when compared to our standard something in the back of the throat, otherwise called “globus
recommended dose. Thus, the “density” of the Horner’s sensation,” and can last up to 10 hours following injection. Al-
syndrome may be clinically significant. though rare, more serious complications include seizure from
• If the patient does not have obvious Horner’s syndrome inadvertent injection of local anesthetic into a blood vessel, or
on the second attempt, consider re-attempting by an- a hematoma or localized collection of blood that could com-
other more experienced physician or different method in promise the airway and result in death. If a patient experiences
1 week. significant and increasing pain in the neck—more than just a
• If the SGB is successful but symptoms do not abate, mild soreness from the needle—they should understand that
strongly consider any reasonable alternative diagnosis this is not normal and should immediately seek medical atten-
(generalized anxiety disorder, and so forth). tion, as it could represent a hemorrhage in the neck. Although
• The SGB is a standard procedure for board-certified highly unlikely, pneumothorax has been reported with SGB. It
pain medicine physicians, and is widely available at is acceptable for the patient to talk during the injection. The
many hospitals and interventional pain clinics. All cur- patient should let the provider know if they have any new or
rent indications for SGB share the exact same level of strange sensations during the procedure, including tingling of
evidenced-based recommendation as for treating anxiety the skin or mouth, ringing in the ears, or just feeling odd.
symptoms associated with PTSD. 1
• In otherwise appropriate patients that did not respond 3. Procedure preparation: Secure an intravenous saline lock in
to a properly performed right-sided SGB, repeat the SGB a peripheral vein, connect noninvasive physiologic monitors,
on the left side at the same level. This is anecdotal and and place the patient in the supine position with their head
based on a few cases, but there appears to be a subset rotated slightly to the left. Do not use a pillow under the head
of the population that responds to a left-sided SGB but or neck. A bolster may be placed under the knees for patient

82 Journal of Special Operations Medicine Volume 15, Edition 2/Summer 2015