Paravertebral Nerve Blocks in Neonates and Infants Undergoing Repair of Aortic Coarctation, A Pilot Study
Phase: PHASE4
Conditions: Congenital Heart Disease
Sponsor: Emory University

 
 
 
 
 
 
 
 
Paravertebral Nerve Blocks in Neonates and Infants Undergoing 
Repair of 
Aortic Coarctation, A Pilot Study 
NCT03408340 
 
Date: 09Dec2021 
IRB00093442 

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Study Title:  Paravertebral Nerve Blocks in Neonates and Infants Undergoing Repair of 
Aortic Coarctation, A Pilot Study
Short Title:  Paravertebrals
Principal Investigator:  
, MD
Abstract
Repair of aortic coarctation is a commonly performed operation.  The repair is performed via 
thoracotomy which is a surgical incision that is commonly complicated by atelectasis, 
desaturation, and pain in the adult population. To prevent these complications, it has been 
shown that regional or neuraxial anesthesia can decrease the amount of pain the patient has, 
which allows for deeper breathing and fewer desaturations from atelectasis.  We propose, in this 
study, to examine the benefits of paravertebral peripheral nerve block in the neonatal and infant 
populations.  Regional anesthesia has the potential to decrease narcotic requirements in 
children undergoing painful operations, decrease ventilator time, and manipulate the stress 
response to surgery. [1] [2] [3]
One of the most severe morbidities associated with this operation is paraplegia.  Paraplegia 
during this operation is thought to occur from decreased spinal cord perfusion, either during the 
cross-clamp period (the period when then aorta is clamped to allow for the repair to occur) or 
from compromised blood flow as a result of the repair.  Though it is not typical to monitor spinal 
cord perfusion during repair of aortic coarctation, there is evidence that spinal cord perfusion 
can be monitored with near infrared spectroscopy (NIRS), a non-invasive light probe that 
measures regional oxygen saturation. [4]
The study population for this project will include neonates and infants (less than 1-year-old) who 
are undergoing repair of aortic coarctation via thoracotomy with no other simultaneous surgical 
procedure.  The patients will undergo a standardized anesthetic.  Patients in the experimental 
arm will receive a paravertebral nerve block for intraoperative and postoperative pain control 
supplemented with narcotic as needed while the control arm will receive standard of care, which 
will include additional narcotic as indicated and local anesthetic infiltrated into the wound after 
the procedure.  Each group will have their spinal cord regional saturations measure with NIRS.  
Regional anesthetic techniques in children are relatively low risk endeavors and the primary 
concern is risk of regional block failure.  More significant, but very rare complications could 
include local anesthetic systemic toxicity (LAST), tissue hematoma (bleeding), epidural 
hematoma (bleeding), unintentional epidural spread, and prolonged sensory blockade. [5]
The primary aim of this study is to determine the feasibility of studying whether a single-shot 
paravertebral nerve block is effective in providing intraoperative and postoperative pain control 
in infants undergoing a thoracotomy for coarctation of the aorta.  This will be determined by 
comparing morphine equivalent consumption in the standard of care and intervention groups. 
Secondary outcomes include plasma epinephrine levels (three times per patient) to determine 
stress hormone response in  both groups, NIRS values to monitor the difference in spinal cord 
oxygen supply between the intervention and control group, time to first feeding (another 
measure of pain control in this age group), and total ventilator time.

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The following aims are proposed:
Primary Aim
1. Determine the feasibility of studying whether total narcotic administration is less in 
subjects who receive the peripheral nerve block versus standard of care.  
Hypothesis: Patients undergoing the experimental technique, paravertebral nerve block, will 
have less pain and therefore will consume fewer morphine equivalents in the 48-hour post-op 
follow-up period.  This difference will be measurable and provide sample size estimations for 
future studies.
Evaluation Method: All narcotics used in the 48-hour post-op period will be tabulated and 
converted to morphine equivalents.  Other non-narcotic analgesics will also be tabulated, but 
can’t be converted to morphine equivalents. 
Secondary Aims
2. Measure whether spinal cord perfusion can be improved during aortic cross clamp by 
improving collateral blood flow with regional anesthesia techniques. 
Hypothesis: Near infrared spectroscopy (NIRS) values will decrease in the control and study 
group during aortic cross clamp but values in the study group will be 41% higher than control 
due to increased collateral blood flow.
Evaluation Method: Continuous measurement of spinal cord NIRS values during repair of aortic 
coarctation, including the aortic cross clamp period.
3. Determine the total time required for post-op ventilation in each group. 
Hypothesis: Post-op ventilation times will be lower in those patients undergoing the 
experimental technique, paravertebral nerve block, because these patients will have less 
respiratory splinting from better analgesia and be less sedated from less sedative and analgesic 
use.
Evaluation Method: Time until extubation.
4. Determine the time to first feeding in each group.
Hypothesis: Patients who undergo the experimental technique, paravertebral nerve block, will 
have earlier return to feeding since they will have better analgesia and less sedation from 
narcotics.
Evaluation Method: Time until first feeding.
5. Measure stress response to surgery in the experimental and control groups.
Hypothesis: Patients who undergo the experimental technique, paravertebral nerve block, will 
have better suppression of the natural stress response to surgery.
Evaluation Method: Plasma epinephrine levels measured at baseline (before incision), 
postoperatively (just before transfer to the Intensive Care Unit), and 24 hours postoperatively.

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Introduction, Background, and Significance to Our Mission
Repair of aortic coarctation is a commonly performed operation.  The repair is performed via 
thoracotomy which is a surgical incision that is commonly complicated by atelectasis, 
desaturation, and pain in the adult population. To prevent these complications, it has been 
shown that regional or neuraxial anesthesia can decrease the amount of pain the patient has, 
which allows for deeper breathing and fewer desaturations from atelectasis.  We propose, in this 
study, to examine the benefits of paravertebral peripheral nerve block in the neonatal and infant 
populations.  Regional anesthesia has the potential to decrease narcotic requirements in 
children undergoing painful operations, decrease ventilator time, and manipulate the stress 
response to surgery. [1] [2] [3]
Pain remains a significant concern in the neonatal and infant populations.  There is evidence 
that pain is often undertreated in order to accomplish other goals of medical management 
including earlier extubation.  Furthermore, pain control with narcotic medications are an 
additional concern and withdrawal from narcotics can become an issue in those neonates and 
infants requiring long-term administration of these medications.  Therefore, further study into 
alternative methods of pain control are warranted.
Significance:
Specific Aim #1:
Use of paravertebral nerve block in these patients may improve pain control for these patients 
and decrease the total burden of narcotic administered.
Specific Aim #2: 
Use of regional anesthesia to encourage collateral blood flow may be spinal cord protective as 
evidenced by an improvement in the NIRS during aortic cross clamp in the experimental group.   
Specific Aim #3:
Decreased time to extubation may be made possible in the experimental group, which would 
help to prevent ventilator associated complications including barotrauma, pneumothorax, 
pneumomediastinum and ventilator associated pneumonia.
Specific Aim #4:
Decreased time to first feeding may be facilitated by earlier extubation and less sedation in the 
experimental group.
Specific Aim #5:
Decreased stress response to surgery is generally associated with fewer physiologic 
perturbations and may be facilitated by the use of regional anesthesia compared to the standard 
of care group. 
Experimental Design and Methods
Design:
This study is designed to be a prospective, randomized, non-blinded clinical trial. After informed 
and written parental consent, a total of 30 neonates and infants (<1 year old) will be enrolled. 
Subjects will be assigned to nerve block or SOC in a 1:1 ratio. Random treatment assignment 

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will be accomplished using a permuted block design with random block sizes of 2 or 4. 
Randomization will be done by study statistician using SAS v. 9.4 (Cary, NC). 
Study Population: 
A total of 30 neonates and infants, defined as children less than 12 months of age, will be 
enrolled in this study.  The subjects will be scheduled for elective or semi-elective cardiac 
surgery at Children’s Healthcare of Atlanta.
The following criteria will be used to determine patient eligibility:
Inclusion Criteria:

Neonate or Infant (<12 months age) at the time of surgery

>=2.5 kg at the time of surgery

Undergoing aortic coarctation repair via left thoracotomy

Parent or legal guardian willing to participate, and able to understand and sign the 
provided informed consent  
Exclusion Criteria:

Intubated prior to surgery (patients who have been intubated and subsequently 
extubated may be included)

Ongoing septicemia or localized skin infection on the back

Parent or legal guardian unwilling to participate or unable to understand and sign the 
provided informed consent

Known coagulation defect

Allergy to local anesthetics
Enrollment/Consent process:
The Institutional Review Board will approve informed consent documents prior to 
commencement of the study. Only those patients who meet the entry criteria will be considered 
as possible study candidates.  A thorough discussion between the parents or legal guardian and 
the principal investigator, or the study coordinator will occur during the study consent process.  
No study related procedure will occur prior to obtaining appropriate informed consent.  
All participants in this study will be neonates or infants (<12 months old).  Patients will be 
enrolled consecutively as they present to Children’s Healthcare of Atlanta.  The parents or legal 
guardian of the neonate will be approached on the day prior to surgery or at presentation to the 
preoperative evaluation clinic by the investigators or the study coordinator to discuss the goals, 
benefits and risks of the project.  Written informed consent will be obtained following this 
discussion.  For the occasions when parents do not arrive at the hospital until the day of 
surgery, they will be approached only if there is sufficient time to allow for their full 
consideration.

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Study Description:
Participants in the study will be randomized to the control arm or experimental arm using 
computer-generated random assignment, which will be prepared at the start of the study and 
the assignments held in sealed envelopes.  Once the participant is enrolled in the study and 
consent has been obtained the investigator will open the next consecutive sealed envelope 
which contains the patient’s group assignment (experimental or control). If the participant is 
enrolled in the study and randomized to the experimental procedure an informed consent for 
treatment must be signed. This is the standard of care for this type of procedure.
Participants in the control arm will undergo an anesthetic consistent with the standard of care.  
The patient will be induced for anesthesia with propofol 3mg/kg or ketamine 2mg/kg (if there is 
intravenous access) or sevoflurane with 1 mcg/kg of fentanyl and 1.2 mg/kg rocuronium once IV 
access is established.  The patient will be intubated; intravenous and intra-arterial access will be 
obtained and the patient will be positioned for surgery.  A NIRS pad will be used for cerebral 
oximetry as well as another NIRS pad for spinal cord oximetry.  Fentanyl may be used as 
needed for additional analgesia and anesthesia will be maintained with sevoflurane.  The skin 
will be infiltrated at the conclusion of surgery with less than 1 mL/kg of 0.25% bupivacaine with 
epinephrine 1:200k.  The patient will be returned to the ICU intubated unless the anesthesia 
provider considers them to be an excellent candidate for early extubation.  Every patient will 
have an epinephrine level drawn pre-incision in the operating room, post-operatively upon 
arrival to the intensive care unit, and 24-hours post-operatively (unless there is no existing 
vascular access that allows the level to be drawn 24-hours post-operatively). The 24-hour post-
operative time point will be defined as 24-hours after arrival to the CICU.
Participants in the experimental arm will undergo an anesthetic that includes the regional 
anesthetic technique, paravertebral nerve block.  The patient will be induced for anesthesia with 
propofol 3mg/kg or ketamine 2mg/kg (if there is intravenous access) or sevoflurane with 1 
mcg/kg of fentanyl and 1.2 mg/kg rocuronium once IV access is established.  A NIRS pad will 
be used for cerebral oximetry as well as another NIRS pad for spinal cord oximetry. The patient 
will be intubated, and then will be positioned laterally for the nerve block at approximately the 
left T3-4 level.  A 13-6 MHz, linear ultrasound probe with a sterile sheath will be used to provide 
imaging for the paravertebral nerve block.  A Pajunk SonoPlex 50mm, 22 gauge, facet tip 
needle will be used.  The injected solution will be 1 mL/kg of 0.2% ropivacaine with 5 mcg/mL 
(1:200k) epinephrine. Ropivacaine is a standard drug used in this patient population for regional 
nerve blocks and is non-experimental as part of this protocol.  The paravertebral block needle 
insertion site and sterile field will be observed and the block will be performed or supervised by 
one of the study investigators. Fentanyl may be used as needed for additional analgesia and 
anesthesia will be maintained with sevoflurane.  The skin will not be infiltrated with additional 
local anesthetic at the conclusion of the case. Every patient will have an epinephrine level 
drawn pre-incision in the operating room, post-operatively upon arrival to the intensive care unit, 
and 24-hours post-operatively (unless there is no existing vascular access that allows the level 
to be drawn 24-hours post-operatively). The 24-hour post-operative time point will be defined as 
24-hours after arrival to the CICU.
Post-operative pain control in either the control or experimental (paravertebral nerve block) 
group will be accomplished with intravenous, rectal, and oral analgesics.  Patients will receive 
scheduled rectal acetaminophen while intubated and oral acetaminophen once they have 
progressed to oral intake of formula.  Intravenous fentanyl or morphine will be used for 

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breakthrough pain while intubated and until oral intake is tolerated.  Once oral intake is 
resumed, the patient will be provided with oral oxycodone as needed for pain and additional 
doses of IV morphine as needed for severe pain..  If the patient is not yet ready for extubation 
and requires additional sedation, intravenous doses of midazolam may be required.
Sample Size/Statistics
This protocol is designed as a pilot study with limited-efficacy testing. The primary goal is to 
demonstrate the feasibility of a subsequent randomized clinical trial. In doing so, we will assess 
the capacity for recruitment and caregiver consent to random assignment. An additional 
exploratory aim is to evaluate the preliminary efficacy of using a single-shot paravertebral nerve 
block to decrease perioperative morphine consumption. Because this is a pilot study, the 
proposed study is likely underpowered to detect a statistically significant result. However, the 
results (i.e. effect sizes) from this study will be used in sample size and power calculations for a 
future, larger RCT.  We expect that there will be a trend toward lower morphine equivalent 
consumption in the experimental group that will either reach statistical significance or provide a 
better estimation of necessary sample size for future funding from extramural sources.
The most similar study available for comparison examined the use of paravertebral nerve 
catheters in infants undergoing thoracotomy to repair long-gap esophageal atresia.  This study 
was retrospective and several days of morphine consumption were observed.  In this 
retrospective trial of 17 patients, the authors observed a decrease of 36% in morphine 
consumption per day (p<0.001).[6]  If such a dramatic decrease in morphine consumption is 
observed during our prospective study, then it is adequately powered at current sample size 15 
in each arm, total 30 patients.
Descriptive statistics will be calculated for all variables of interest and include means and 
standard deviations, medians and ranges or counts and percentages, as appropriate. Summary 
measures will be tabulated overall and by treatment group. Recruitment and consent rates will 
be calculated with associated 95% confidence intervals. Primary and secondary outcomes will 
be compared between the two intervention groups. Continuous measures will be compared 
between groups using two-sample t-tests or Wilcoxon rank-sum tests while categorical variables 
will be compared using Chi-square tests or Fisher exact tests. Because this is a pilot study, 
effect sizes will be calculated for all outcomes and will include difference in means, difference in 
rates, or risk ratios with associated 95% confidence intervals. Analysis will follow the intention to 
treat principal where all subjects are analyzed based on their randomly assigned treatment 
whether or not they received the treatment. A p-value less than 0.05 will be considered 
statistically significant and all statistical testing will be two-sided, unless otherwise noted. 
Analysis will be conducted using SAS v. 9.4 (Cary, NC) and under direction of the pediatric 
biostatistics core. 
Adverse Event Reporting
Monitoring of Adverse Events (AEs) and Serious Adverse Events (SAEs) is an important aspect 
of data collection.  The study subjects will be reviewed on a case-by-case basis.  The principal 
investigator will determine the seriousness of each adverse event and whether or not the event 

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was related to the study.  Adverse events potentially associated with paravertebral nerve blocks 
include (from most to least common): block failure, vascular puncture, deep tissue hematoma 
(SAE), epidural hematoma (SAE), hypotension, lung puncture, pneumothorax, and local 
anesthetic systemic toxicity (SAE). Hypotension will be defined as a mean arterial pressure less 
than 30 mm Hg during the first 24 hours after arrival to the CICU.
Generally, paravertebral nerve blocks are felt to be safe in the pediatric population.  They have 
an adverse event rate comparable to other regional anesthesia blocks, less than is reported with 
thoracic epidural analgesia.  The incidence of local anesthetic toxicity is 0-0.015%, paresthesia 
0.004-0.17%, and infection 0-0.5%. Overall, Vecchione et al report a major complication rate of 
1 per 2,390 paravertebral nerve blocks and a minor complication rate of 13.2%, largely 
associated with catheter malfunctions rather than single-shot paravertebral nerve block 
complications.[7]  Pneumothorax has only been reported in adult literature and basically 
becomes irrelevant in the setting of thoracotomy (as pneumothorax cannot develop during an 
open chest procedure). [8]  There has also been publication demonstrating efficacy of 
paravertebral nerve block catheters in infants who need long-term mechanical ventilation after 
long-gap esophageal atresia repair with no significant morbidity related to paravertebral nerve 
block catheter placement. [6]
After enrollment, the principal investigator or designee will collect the adverse experiences from 
the medical record.  Serious Adverse Events (life-threatening, requiring intervention) will be 
reported to the IRB within guidelines set by the IRB.  
The amount of blood drawn for this study should not affect the transfusion requirements of the 
surgical procedure (total 6mL per patient).    Standard of care will be followed for all lab draws to 
ensure there is no increased risk of infection from phlebotomy.
Data Safety Monitoring Plan
A potential risk of this study is related to patient confidentiality since protected health information 
is included in the study data.  This risk will be minimized by only recording information 
absolutely necessary to fulfill the study’s objectives.  Information directly identifying patients will 
be excluded (names, addresses, telephone numbers, social security numbers, e-mail 
addresses, and account numbers).  Once lab samples are collected, they will be identified only 
by the study number assigned to the patient.  Additionally, in the research database, patients 
will be identified only by their assigned study number.  The database, along with the code 
linking a subject’s identity to an assigned number, will be locked in the office of the principal 
investigator or designee. 
The study subjects will be reviewed on a case-by-case basis by the entire pediatric cardiac 
anesthesia division and pediatric cardiac surgery division in a weekly quality conference.  
Quarterly, experienced cardiac anesthesiologists not involved in the study will review each study 
subject’s reported adverse events and assess whether or not the event could be related to the 
study. 
References

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1.
Wolf, A.R., E. Doyle, and E. Thomas, Modifying infant stress responses to major surgery: spinal vs 
extradural vs opioid analgesia. Paediatr Anaesth, 1998. 8(4): p. 305-11.
2.
Bosenberg, A.T.H., G. P.; Wiersma, R., Oesophageal atresia: caudo-thoracic epidural anaesthesia 
reduces the need for post-operative ventilatory support. Pediatr Surg Int, 1992. 7(4): p. 289-291.
3.
Bosenberg, A. and R.P. Flick, Regional anesthesia in neonates and infants. Clin Perinatol, 2013. 
40(3): p. 525-38.
4.
Berens, R.J., et al., Near infrared spectroscopy monitoring during pediatric aortic coarctation 
repair. Paediatr Anaesth, 2006. 16(7): p. 777-81.
5.
Polaner, D.M., et al., Pediatric Regional Anesthesia Network (PRAN): a multi-institutional study 
of the use and incidence of complications of pediatric regional anesthesia. Anesth Analg, 2012. 
115(6): p. 1353-64.
6.
Bairdain, S., et al., Paravertebral nerve block catheters using chloroprocaine in infants with 
prolonged mechanical ventilation for treatment of long-gap esophageal atresia. Paediatr 
Anaesth, 2015. 25(11): p. 1151-7.
7.
Vecchione, T., D. Zurakowski, and K. Boretsky, Thoracic Paravertebral Nerve Blocks in Pediatric 
Patients: Safety and Clinical Experience. Anesth Analg, 2016. 123(6): p. 1588-1590.
8.
Richardson, J. and P.A. Lonnqvist, Thoracic paravertebral block. Br J Anaesth, 1998. 81(2): p. 230-
8.