Transversus Abdominis Plane Blocks for Ileostomy Takedown: A Prospective Study

Subject Enrollment

The charts of patients who are scheduled for ileostomy takedown surgery will be screened for
eligibility the day before surgery by an investigator on this study. On the day of surgery,
patients will be seen in their pre-operative holding area by a member of their anesthesia
team or the acute pain team. They will be screened for eligibility for anesthesia and
surgery. Once they are cleared for the operating room they will be seen by a resident,
fellow, or attending for the acute pain service, who is an investigator on this study, to
confirm eligibility for this study. A peripheral intravenous line will also be placed as is
standard for the operating room. If it has been determined that they meet eligibility
criteria they will have further discussion with the clinical trials coordinator or an
investigator to determine if the patient would like to participate in this study. If they
would like to proceed as a subject in this study they will be consented. The consent process
will take place in a semi-enclosed space used in preoperative holding to consent for
surgical procedures and anesthesia. Study investigators or coordinators will conduct the
consent process.

Conduct of Study

Study Procedure Overview

The nurses will check the patient into the preoperative holding area and collect usual
preoperative information. Once the patient has consented to be a part of this study they
will be brought to the block room. Standard monitors will be placed and a time- out
procedure will be performed, as is standard for all procedures which take place in the block
room. Side of procedure will be verified. At this time the subject will be randomized to
receive TAP block or placebo by random computer generated assignment that is in a sealed
envelope. The study solution will be prepared by the regional anesthesiologist performing
the procedure. The subject will receive sedation with midazolam and versed titrated to
effect as is standard for all block placements. The subjects' abdomen on the side
ipsilateral to the ileostomy will be sterilely prepared. The ultrasound will have a sterile
dressing placed over the probe and a standard 21 gauge or 22 gauge b-bevel, 10 cm block
needle will be flushed with the study solution. A syringe of 1% lidocaine will also be
prepared to anesthetize the skin prior to insertion of the block needle. The ultrasound will
be placed on the abdomen. Once a good view of the 3 muscle layers of interest is visualized
(internal oblique, external oblique and transverses abdominis) the probe will be held still
and the 1% lidocaine will be used to numb the skin. The block needle will be placed "in
line" with the probe so that the entirety of the needle may be visualized during the
procedure.

Treatment Study Procedure

The TAP block will be placed using a standardized ultrasound guided approach. Subjects
assigned to the study group will have an injection of 30ml of 0.375% bupivacaine, a local
anesthetic with 3mcg/ml of epinephrine placed into the plane between the internal oblique
and the transversus abdominis. The needle will be aspirated every 5 ml to monitor for
possible intravascular injection. During the injection the pulse and EKG will be monitored
as well to screen for intravascular injection. Once the solution has been injected the
needle will be removed from the skin and the area cleaned off with a dry cloth.

Control Study Procedure

The placebo block will be an ultrasound guided subcutaneous injection into the plane of
tissue right before external oblique. The standard ultrasound guided approach will be used.
The solution injected will be 30 ml of sterile preservative free saline. The reason we will
choose to do this injection subcutaneously is because it will minimize patient risk from
this injection. Subcutaneous injections will be far from the peritoneal cavity. By using
normal saline for this injection we eliminate the very small risk of local anesthetic
toxicity. Note that every subject, regardless of group assignment, will receive a very
aggressive pain control regimen (IV PCA-patient controlled analgesia, toradol, scheduled
tylenol, local wound infiltration) for adequate analgesia. Toradol is not routinely used and
is added for purposes of aggressive pain control for all subjects in this study.

Follow up

Subjects will receive a general anesthetic for their surgical procedure. An appropriate dose
of propofol will be used for induction of anesthesia. Fentanyl will be administered for
intra-operative analgesia as deemed necessary by the anesthesia team caring for the patient
in the operating room. No long acting opioids, ketamine, or local anesthetic infusions will
be administered during the case. Dexamethasone (4 mg IV) will be administered at induction
and zofran (4 mg IV) will be administered prior to emergence. Local infiltration of the
wound with local anesthetic will be performed on all subjects, as is standard for this
surgery. The local anesthetic used will be per surgeon preference.

After the Surgery

- All subjects will be started on a hydromorphone patient controlled analgesia (PCA) as
well as toradol (15 mg IV q 6 hours for 24 hours).

- A member of the study protocol or the anesthesia acute pain service will evaluate all
subjects in the PACU.

- They will assess Numeric Rating pain Scores (NRS) 0-10 where 0 represents no pain
and 10 represents the worst pain imaginable, vital signs, and the presence of side
effects including nausea, vomiting and/or pruritis. This pain assessment is
standard care and would happen regardless of study participation.

Day 2 (post operative day 1(POD1))

- Study personnel will evaluate all subjects the morning after surgery. They will assess
current pain scores, duration of block (when known), and the presence of side effects
including nausea, vomiting and/or pruritis. The assessment of pain scores will be the
same assessment as is done on the day of surgery, but at the 24-hour post-surgery
timepoint it is done by the study coordinator for research purposes.

- Medical records will be reviewed in order to collect information about subject's pain
overnight and medication administration. We will also collect age, sex, height, weight,
opioid usage (weekly, monthly, rarely), baseline pain score, and ASA physical status
from the medical record.

Data Recording

After blocks are performed a procedure note will be entered into the medical record of the
subject. The procedure note will document that the subject is enrolled in this study and
that they may have received a TAP block with 30 ml of 0.375% bupivacaine with epinephrine.
It will say that they also may have received a subcutaneous injection of normal saline. The
note will document any complications encountered during block placement and the subjects'
disposition at the time of completion of the block. A record of which subject has received
what type of block, and solution, will be kept in a document held in a locked cabinet in the
block room (within the operating room). This can be referenced and reported to the
anesthesia team caring for the patient if issues arise during patient care which would
necessitate unblinding. Otherwise, on post-operative day 1 (POD1), a procedure note
documenting the actual procedure will be entered into the subject's medical chart. This will
be done after the study data has been collected.

Inclusion Criteria:

1. Patients having an ileostomy takedown alone, on one side of abdomen

2. Ages 18-80 inclusive

3. English speaking

4. BMI less than 40

5. Ability to understand verbal pain scale

6. American Society of Anesthesiologists (ASA) Physical Status 1-3

Exclusion Criteria:

1. Allergy to local anesthetics

2. History of recent/current local or generalized infection

3. Immunocompromised

4. Significant psychiatric disease

5. History of opioid dependence

6. Pregnancy or lactation

7. A prisoner.

8. Significant liver disease

9. Contraindication to ondansetron or dexamethasone

10. Clinically significant cardiac or pulmonary disease