Vital Capacity in Ultrasound Guided Serratus Plane Block in ED Patients With Multiple Rib Fractures
Vital Capacity in Ultrasound Guided Serratus Plane Block in ED Patients With Multiple Rib Fractures
I. Background:

 Patients with multiple rib fractures are challenging from both pulmonary and analgesia
 perspectives. Adequate pain management is essential in prevention of complications secondary
 to decreased inspiratory volume. Significant morbidity and mortality of rib fractures is
 secondary to severe pain that limits ribcage movement, decreases inspiratory volumes and
 causes inadequate cough. Decreased vital capacity predisposes patients to atelectasis,
 abnormal mucous clearance and pneumonia. The objective of this study is to assess the
 efficacy of the serratus anterior plane block (SAPB) in improvement of vital capacity in
 patients with multiple unilateral rib fractures when compared to conventional management with
 medications. Currently, evidence of efficacy of SAPB in managing pain secondary to multiple
 rib fractures is limited to case reports and series, none of which evaluate vital capacity.

 II. Significance:

 The findings of this study may indicate that SAPB is superior to pharmacological management
 in increasing vital capacity in patients with multiple unilateral rib fractures and suggest
 SAPB for first line therapy in patients with rib fractures. The findings may decrease the
 risk of pulmonary complications as well as the use of opiates in management of multiple rib
 fractures in the Emergency Department especially in patients with numerous comorbidities and
 contraindications to conventional treatment modalities. This study may support the need for
 training emergency medicine physicians in bedside SAPB in order to provide the optimal
 therapy for patient with multiple unilateral rib fractures.

 III. Study Objectives:

 The primary objectives are to evaluate whether ultrasound guided SAPB results in a greater
 improvement in percent predicted vital capacity compared to standard therapy with a sham
 injection. The investigators will also evaluate pain scores and the safety profile of the
 SAPB procedure compared to those receiving standard analgesia.

 IV. Hypothesis:

 The primary hypothesis is that SAPB is superior to sham injection in improving the percent of
 predicted vital capacity. The secondary hypothesis is that SAPB will have greater improvement
 in pain scores and have a superior safety profile compared to sham injection.
STUDY DESIGN

 This is a single center prospective, randomized, blinded clinical trial with a convenience
 sample that will be conducted in the Emergency Department of an urban level I trauma center.

 A. Identify and enroll all patients coming in to the ED patient with presumed or clinically
 apparent 2 or more unilateral rib fractures between T3 to T9, with a resting pain score of
 ≥5. All patients meeting exclusion criteria will be excluded.

 B. Randomization procedure:

 1. Pharmacy will dispense 30mL of injectate which will be randomized in block of 10 to
 either the SAPB group (30mL of 0.25% bupivacaine with epinephrine) or sham group (30mL
 of normal saline).

 C. Injection

 1. Patient consent will be obtained and time out will be performed on all patients.

 2. Patients will be placed on cardiac monitor and placed in lateral decubitus or if unable
 to turn, they will be supine.

 3. Under the usual sterile technique, the serratus anterior muscle overlying the 5th rib at
 the mid-axillary line will be identified with ultrasound.

 4. A spinal needle will be introduced in-plane under ultrasound guidance and advanced until
 the needle tip is located in the fascial plane just above the serratus anterior muscle.
 The needle tip will not be advanced unless completely visualized under ultrasound.

 5. Normal saline will be injected first to determine correct location of the needle tip.
 Spreading of fluid along the fascial plane will confirm the correct location of the
 needle tip.

 6. The normal saline will then be switched to the study drug of which 30mL of either normal
 saline or 0.25% bupivacaine with epinephrine which will then be injected into the
 fascial plane as described in Blanco et al, and Hetta et al.

 7. The study drug will be injected 5mL at a time and the patient will be asked if any
 symptoms of Local Anesthetic Systemic Toxicity (LAST toxicity) are present (perioral
 numbness, tinnitus, dizziness).

 8. After injection is completed the needle will be withdrawn and patient will remain on the
 cardiac monitor for another 30 minutes to monitor for symptoms of LAST toxicity (Di
 Gregorio).

 9. This procedure was based on the serratus anterior plane block protocol from Khalil et
 al.

 D. Slow Vital Capacity (SVC) Measurement

 1. SVC will be performed using spirometer that has been internally validated

 2. SVC will be performed by physicians trained by the respiratory therapy department and
 who have demonstrated validation compared to respiratory therapist obtained SVC values

 3. The patient will be sitting up when performing SVC and a script will be followed as to
 how to educate and coach the patient on performing appropriate incentive spirometry
 technique.

 4. At least 3 SVC measurements within 150mL of each other are required to qualify for an
 accurate measurement.

 5. The maximum of these 3 SVC values and a corresponding % predicted SVC will be obtained
 and considered the maximum % predicted SVC.

 6. % Predicted SVC will be obtained based on the National Health and Nutrition Examination
 Survey (NHANES III) calculator through the CDC.

 E. Pain scores

 1. Subjects will be asked to rate their maximum pain score from 0-10 with resting breathing
 and with deep breaths.

 Design:

 A. Potential study patients will be identified through review of the emergency department
 (ED) electronic board, and ED physicians will also screen for potential study patients. Pain
 scores are assessed in triage as is standard in the ED.

 B. If the patient has pain from presumed or clinically apparent 2 or more unilateral rib
 fractures between T3 to T9, and he/she has a resting pain score of ≥5 on the Numeric Pain
 Rating Scale, where 0 is no pain, 5 is moderate pain, and 10 is the worst possible pain upon
 initial assessment, then he/she will be eligible to participate in the study.

 The patient will then be asked to participate if he/she does not have any exclusion criteria.

 C. At time of enrollment, the patient will have recorded pain scores, vital signs, and slow
 vital capacity measured.

 D. All patients will then receive ketamine 0.15 mg/kg IV in 100 mL normal saline over 30
 minutes for pain.

 E. Each patient will then be randomized in either of two arms:

 1. Ultrasound guided serratus anterior plane block (SAPB) with 30mL 0.25% bupivacaine with
 epinephrine.

 2. Ultrasound guided serratus anterior plane injection with sham injection with 30mL of
 normal saline.

 6. Investigators will be blinded to the arm that the patient has been randomized to, as the
 randomization will occur through the pharmacy dispensing the medication.

 7. Using an online randomizer in blocks of 10, the pharmacy will dispense either 30mL of
 normal saline for the sham group, or 30mL of 0.25% bupivacaine with epinephrine for the nerve
 block group.

 8. All patients will receive either SAPB or sham injection within an hour of receiving
 ketamine analgesia.

 9. If the patient still has a pain score ≥5 thirty minutes after the injection, the treating
 physician will be informed and the patient will be medicated at the treating physician's
 discretion.

 10. The patient will be followed up with up to 24 hours throughout their hospital stay.

 Data Collection Procedures:

 A. Demographics 1. Age, sex, ethnicity, height B. Past medical history 1. Smoking status
 (current, prior, never smoker), diabetes, cirrhosis, chronic obstructive pulmonary disease
 (COPD), asthma, if patient uses home oxygen C. Injury Mechanism

 1. Occupant in motor vehicle collision, fall from an elevation, fall down stairs, fall from
 standing, pedestrian or bicyclist struck by moving vehicle, bike collision or fall from
 bike while riding, driver or passenger in motorcycle/ATV/motorized scooter collision,
 assault, unknown mechanism, or other

 2. Date and time of injury

 3. GCS score

 4. Injury Severity Scale D. Imaging

 1. Side of rib fractures

 2. Number of rib fractures on x-ray and on CT chest

 3. Rib fracture location: anterior, lateral, posterior, T1-12

 4. Type of imaging showing rib fractures

 5. Presence of following: atelectasis, hemothorax, infiltrate (right/left), interstitial
 edema, pneumothorax, pulmonary contusion E. Medication

 1. Any medications type and dose given prior to randomization

 F. At Time 0 (time of enrollment):

 1. Vital signs

 2. Resting pain score from 0-10

 3. Deep breath pain score from 0-10

 4. Slow Vital Capacity (SVC)

 a. Measured until 3 measurements are within 150mL of each other b. % predicted SVC is
 measured based on NHANES III Calculator using age, sex, ethnicity and height. If
 ethnicity not included in calculator will select Caucasian.

 c. Maximum SVC and maximum % predicted SVC

 5. Symptoms after injection: agitation, dizziness, dysarthria, nausea, new cardiac rhythm
 (significant tachycardia or bradycardia, SVT, etc), new significantly increased
 shortness of breath, perioral numbness, pruritis, seizure, syncope, tinnitus, vomiting
 G. At Time 30 minutes post injection

 1. Vital signs

 2. Resting pain score from 0-10

 3. Deep breath pain score from 0-10

 4. Slow Vital Capacity (SVC)

 1. Measured until 3 measurements are within 150mL of each other

 2. Percentage predicted SVC is measured based on NHANES III Calculator using age, sex,
 ethnicity and height. If ethnicity not included in calculator will select
 Caucasian.

 3. Maximum SVC and maximum % predicted SVC

 5. Symptoms after injection: agitation, dizziness, dysarthria, nausea, new cardiac rhythm
 (significant tachycardia or bradycardia, SVT, etc), new significantly increased
 shortness of breath, perioral numbness, pruritis, seizure, syncope, tinnitus, vomiting
 H. At Time 60 minutes post injection

 1. Vital signs

 2. Resting pain score from 0-10

 3. Deep breath pain score from 0-10

 4. Slow Vital Capacity (SVC)

 1. Measured until 3 measurements are within 150mL of each other

 2. % predicted SVC is measured based on NHANES III Calculator using age, sex, ethnicity and
 height. If ethnicity not included in calculator will select Caucasian.

 3. Maximum SVC and maximum % predicted SVC

 5. Symptoms after injection: agitation, dizziness, dysarthria, nausea, new cardiac rhythm
 (significant tachycardia or bradycardia, SVT, etc), new significantly increased shortness of
 breath, perioral numbness, pruritis, seizure, syncope, tinnitus, vomiting I. At Time 3-6
 hours post injection

 1. Vital signs 2. Resting pain score from 0-10 3. Deep breath pain score from 0-10 4. Slow
 Vital Capacity (SVC)

 1. Measured until 3 measurements are within 150mL of each other

 2. % predicted SVC is measured based on NHANES III Calculator using age, sex, ethnicity and
 height. If ethnicity not included in calculator will select Caucasian.

 3. Maximum SVC and maximum % predicted SVC 4. Symptoms after injection: agitation,
 dizziness, dysarthria, nausea, new cardiac rhythm (significant tachycardia or
 bradycardia, SVT, etc), new significantly increased shortness of breath, perioral
 numbness, pruritis, seizure, syncope, tinnitus, vomiting J. At Time 12 hours post
 injection 1. Vital signs 2. Resting pain score from 0-10 3. Deep breath pain score from
 0-10 5. Slow Vital Capacity (SVC)

 1. Measured until 3 measurements are within 150mL of each other

 2. % predicted SVC is measured based on NHANES III Calculator using age, sex,
 ethnicity and height. If ethnicity not included in calculator will select
 Caucasian.

 3. Maximum SVC and maximum % predicted SVC

 5. Symptoms after injection: agitation, dizziness, dysarthria, nausea, new cardiac
 rhythm (significant tachycardia or bradycardia, SVT, etc), new significantly increased
 shortness of breath, perioral numbness, pruritis, seizure, syncope, tinnitus, vomiting
 J. On 24 hours post injection

 1. Vital signs

 2. Resting pain score from 0-10

 3. Deep breath pain score from 0-10

 4. Slow Vital Capacity (SVC)

 1. Measured until 3 measurements are within 150mL of each other

 2. % predicted SVC is measured based on NHANES III Calculator using age, sex, ethnicity and
 height. If ethnicity not included in calculator will select Caucasian.

 3. Maximum SVC and maximum % predicted SVC 5. Symptoms after injection: agitation,
 dizziness, dysarthria, nausea, new cardiac rhythm (significant tachycardia or
 bradycardia, SVT, etc), new significantly increased shortness of breath, perioral
 numbness, pruritis, seizure, syncope, tinnitus, vomiting K. Slow vital capacity

 1. Researchers will be trained on appropriate incentive spirometry technique by the
 respiratory therapy team and their accuracy will be confirmed 2. Patients will then be
 instructed to perform SVC, we will get 3 SVC measurements within 150mL of each other and
 then record the maximum SVC.

 3. Percent predicted vital capacity will be calculating using NHANES III L. Time to
 first rescue analgesia post injection M. Medications during first 24 hours of hospital
 stay

 1. 24 hour total morphine milligram equivalent consumption

 1. Calculated based on CDC Morphine Milligram Equivalence (MME) Calculator:
 https://www.cdc.gov/drugoverdose/prescribing/app.html 2. Any antemetics used after
 injection within 24 hours after enrollment 3. Time to administration of first rescue
 analgesia post injection N. Nerve Block performed during inpatient stay

 1. List date/time/type of any additional nerve blocks performed for rib fracture pain
 after the study injection during the patient's hospital stay

 O. Pulmonary complications:

 1. New O2 requirement, BIPAP or intubation, transfer to ICU for respiratory issue,
 development of pneumonia, readmission for pulmonary issue, new need for home O2 P. Nerve
 Block Complications

 1. Development of cellulitis at site of block during hospital stay 2. Pneumothorax
 occurring within 12 hours of injection Q. Discharge Data

 1. If cellulitis developed at the site of injection during hospital stay

 2. If a pneumothorax on the same side of the injection occurred within 12 hours of
 block R. Imaging

 1. Videos of the nerve block performance will be recorded in each patient. These images
 will later be de-identified and reviewed by two independent reviewers not involved in
 the study to determine visually whether the planar spread of anesthetic was correctly
 placed or not correctly placed.
Inclusion Criteria:

 1. 18 years or older

 2. Presumed/Clinically apparent 2 or more acute unilateral rib fractures between T3-T9

 3. Pain Score 5 or greater

 Exclusion Criteria:

 1. GCS<13

 2. Penetrating trauma

 3. Pregnant

 4. Unable to give consent due to dementia or altered mental status

 5. Unable to perform spirometry

 6. Requiring immediate surgical intervention

 7. Known allergy to amide-type local anesthetics

 8. Signs of infection or laceration at injection site

 9. Systolic BP <100 mmHg

 10. History of chronic pain, chronic use of analgesics

 11. History of substance abuse

 12. Painful distracting injury (injury causing significant pain that distracts the patient
 from having reliable scoring of rib fracture pain, i.e. femur fracture, dislocated
 joint)

 13. If patient received any other pain medication besides ketamine prior to the block

 14. Only posterior rib fractures present