Pain control of rib fractures is essential for not only primary pain relief but also preventing secondary complications such as atelectasis or pneumonia which increase the hospital stay, as well as the transition to chronic pain.

The cornerstones of analgesic management are oral and intravenous medications such as paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids as well as regional block techniques as paravertebral block and thoracic epidural.

To avoid opioid as well as regional block related side effects such as pneumothorax and hemodynamic instability, previous studies showed that superficial chest wall block such as thoracic erector spinae plane block and serratus anterior plane block had shown a promising success in management of such pain with few side effects.

In an effort to reduce the pain score, hospital stay and improve the patient's capability of physiotherapy this study compares continuous block of parascapular sub-iliocostalis plane block versus continuous thoracic paravertebral block for analgesia in patients with traumatic multiple rib fractures.

The cases will be randomly selected from Zagazig University emergency Hospital with unilateral multiple rib fractures who admitted to thoracic surgery and emergency departments.

All Cases Will Undergo:

• Patient Examination: All participating patients will be interviewed during their preparation. The goal and end points of the study will be discussed with them. Understanding of the blocks will be reviewed and emphasized and informed written consent regarding the procedure will be taken.

On physical examination, special attention will be given to document vital signs, cardiac, chest condition and exclude contraindications. All patients will be investigated by complete blood count, Liver functions tests, kidney functions tests, coagulation profile, arterial blood gases.

Chest trauma score (CTS) (11) will be applied to all patients The CTS is composed of four different components with a point system assigned:

• age (<45 years = 1, 45-65 = 2, >65 = 3)
• pulmonary contusion (none = 0, unilateral minor = 1, bilateral minor = 2, unilateral major = 3, bilateral major = 4) - number of rib fracture (<3 = 1, 3-5 = 2, >5 = 3) - the presence of bilateral rib fracture = 2.

Number of rib fractures and pulmonary contusion were noted from chest X-ray and Computed Tomography (CT). Each parameter has been assigned specific score and final score was calculated by adding scores of each parameter. Final CTS was then calculated which ranges from 2 to 12.

Chest exercise with incentive spirometry to assess the inhaled tidal volume prior to block.

Patients will be instructed to evaluate pain scores by visual analog scale (VAS), which is a simple assessment tool consisting of a 10 cm line, where 0=no pain at all, 1-2=mild pain intensity,3-5=moderate pain intensity, 6-8=severe pain intensity, and 9-10=worst pain was felt.

Assess respiratory functions by peak expiratory flow meter (PEFR)

• Preparations: Intravenous access will be secured and standard monitoring, Electrocardiogram, pulse oximetry, non-invasive blood pressure, will be attached and baseline parameters, basal ABG, pulmonary functions, VAS score (at rest and during cough). After applying routine monitoring and supplemental oxygen will be given. The patients will be allocated randomly into two equal groups (18 patients in each).

1. Group 1 (TPV) (n= 18):

   After cleaning and draping of thoracic vertebral, paravertebral area and the ultrasound probe, Initial ultrasound scanning of required vertebral and paravertebral region is done. Patient position is either sitting or lateral according to patient's convenience with affected side up. Site of injection is chosen two segments below the most cephalad fractured rib. Linear ultrasound probe of 6-13 MHz probe is used for all sonographic assessments. The appropriate thoracic level is identified by cephalad to caudal ultrasound scanning starting from first rib onwards. Afterwards the spinous process and the transverse process of the appropriate thoracic vertebrae and the rib are identified. The midpoint of the transducer is placed in a longitudinal paramedian plane between two transverse processes of chosen vertebral level. Both transverse processed are visualized with the superior costotransverse ligament (SCTL) and the pleura in between ii) Skin to SCTL distance in mm from lateral border of upper transverse process. iii) Skin to pleura distance in mm from lateral border of upper transverse process. An 18 G needle is introduced using out of plane technique. The tip of the needle is advanced under direct visualization till it pieces the SCTL. 5 ml of bupivacaine 0.25% is injected after negative aspiration, while the spread of local anaesthetic and simultaneously anterior pushing of the pleura is observed Afterwards an additional 10 ml bupivacaine 0.25% with one μg per kg of fentanyl is injected. A catheter is threaded 2-3 cm into the paravertebral space after the block and will be secured with adhesive dressing. The threading of the catheter is graded as easy, some resistance, difficult and not possible. The distance travelled by needle is noted. Then, a perioperative elastomeric infusion of 0.125 percent bupivacaine begins at a rate of 5 ml/h via the paravertebral catheter and maintained for a duration of 48 hours.

2. Group 2 (PSIB) (n=18):

While seated with arms draped over body, the patient will receive the PSIB. A high frequency linear ultrasound probe is positioned in a parasagittal plane, at the level of the scapula spine edge, 2 cm from the medial scapular border, while maintaining strict aseptic conditions (fourth rib level). An examination of the trapezius, rhomboid major, iliocostalis, and intercostal muscles is conducted, encompassing both the superficial and deep layers of muscle tissue. By employing an in-plane method, a sono-visible 100 mm 18 G needle is inserted in the vicinity of the fourth rib with a cranial to caudal orientation. The needle is then advanced in the iliocostal-intercostal myofascial plane. Following the confirmation of the needle's position with a 2 ml saline solution, a catheter is inserted 6 cm beyond the needle tip and tunneled beneath the skin. 15 ml of 0.25 percent bupivacaine is injected at the conclusion of the procedure. Then, a perioperative elastomeric infusion of 0.125 percent bupivacaine begins at a rate of 5 ml/h via the PSIB catheter and will be maintained for a duration of 48 hours. Control of breakthrough pain In all groups, if the VAS is at least 3 at rest at any time, a bolus dose of nalbuphine (0.2 mg/kg) will be given for rapid control of pain simultaneously with increasing the infusion rate according to VAS, for severe pain (VAS: 6-8), paracetamol 1gm intravenous infusion every 8 hours is added. catheter removal The catheter will be removed after weaning of infusion rate with accepted VAS, and no more needed.

Data Collection

1. Patients characteristic:

   age, sex, body, height, ASA physical status class, injury severity score (ISS), number of fractured ribs, number of patients with chest tube, length of ICU, and hospital stay.

2. bedside monitoring: heart rate, mean arterial pressure, respiratory rate (RR), recorded every hour for the next 48 hours.

3. inspiratory exercise tolerance by using Hand-held volume targeted incentive spirometry: Patients will be asked to take five deep breaths through incentive spirometers immediately before analgesia (T0) and post block at 1h (T1), 12h (T2), 24 h (T3), 48h (T4), then each breath will take one point and then points and inhaled volumes will be documented in a table (No. of breaths, tidal volume (600,900,1200, ml as marked on the spirometer)).

4. peak expiratory flow rate using peak flowmeter immediately before analgesia (T0) and post block at 1h (T1), 12h (T2), 24 h (T3), 48h (T4) and values will be documented.

5. Visual analogue scale (VAS):

   VAS score will be recorded just before analgesia (T0) and post block at 1h (T1), 12h (T2), 24h (T3), 48h (T4) .at rest and on coughing.

6. OTHERS:

A- Arterial blood gases measurements of SpO2, PaCO2, and O2index (i.e. PaO2/FiO2 ratio) and also respiratory rate will be recorded just before analgesia and after analgesia at 1h, 12h, 24 h, and 48 h.

B- Onset time of sensory block:

Time between injection of local anesthetics drugs and loss of pin prick sensation in nerves distributions, pin prick test will be done with sterile 25G needle.

C- amount of total opioid consumption in 48 hours in block groups starting from the beginning of the local anesthetic block.

D- signs related to the thoracic paravertebral complications such as pneumothorax, hemothorax, epidural block, and catheter related infection will be recorded if occurred, vascular and nerve injury will be assessed and recorded.

E- Degree of patient satisfaction on discharge will be assessed and recorded as follows:

• 1.Completely satisfied
• 2.Satisfied
• 3.Neither satisfied nor unsatisfied
• 4.Completely unsatisfied

Inclusion Criteria:

• Patient written informed consent.
• ASA I to III.
• Age 21-60 years old.
• Gender: Both.
• BMI < 35 Kg/M2.
• Accepted mental state of the patient.
• Patient with unilateral multiple rib fractures (≥2 fractures)

Exclusion Criteria:

• Any trauma in the patient that interfere with the positioning of patients for block.
• Patients who needed mechanical ventilation before or during the study.
• Patients with associated head trauma.
• Patient with hemodynamic instability and need inotropic support. • Patient with abbreviated injury scale (AIS) in extremity more than 2 (10)
• Pathological coagulopathy.
• Infection at the injection site.
• Disturbed conscious level.
• An allergy to local anesthetics or any used drugs in this study.
• Pregnancy.