The present clinical study will be undertaken to evaluate the effect of Ultrasound-guided Deep versus Superficial continuous Serratus Anterior Plane Block for pain management in patients with multiple rib fractures.

Thoracic blunt trauma, especially when multiple rib fractures are associated, is challenging to manage and causes significant morbidity due to the severe pain implied.

Patients can present with respiratory compromise as their capacity to expand the thorax is limited by pain. As a result, they are at high risk to develop atelectasis and pneumonia.

the key goal of management is adequate analgesia and pulmonary volume expansion Various strategies to treat such pain have been utilized, including regional analgesia (intrapleural, intercostal paravertebral nerve blockade), and neuraxial analgesia (thoracic epidural analgesia (TEA), intrathecal opioids).

The use of neuraxial analgesia in polytrauma is frequently limited by the need for aggressive venous thromboembolic (VTE) prophylaxis, and positioning of the patient for a neuraxial approach may be impossible.

There is a growing interest in exploring treatments that are less invasive than EA and can be performed on patients who have contraindications to neuraxial analgesia. Ultrasound-guided Serratus Anterior Plane (SAP) block is a recent technique, first described by Blanco et al. in 2013, that provides analgesia for the thoracic wall by blocking the lateral branches of the intercostal nerves from T2 to L2. It is a safe, simple to perform block with no significant contraindications or side effects. he described 2 potential spaces, one superficial and another deep to serratus. The SAPB has been used effectively for the management of pain in the context of rib fractures, thoracoscopic surgery, thoracotomy, breast surgery, and post-mastectomy pain syndrome, few studies compared the two approaches, and the difference between them has not yet been studied in patients with multiple rib fractures.

Inclusion Criteria:

• Adult patients of either sex, having three or more unilateral fracture ribs and admitted to the trauma ICU, Rib fractures were confirmed by X-ray and CT scan reads.

Exclusion Criteria:

• significant head injury and unconsciousness (GCS less than 14)
• Patients with significant pain from other injuries
• pathological obesity (body mass index ≥35)
• history of drug allergy local anesthetics
• local infection at the injection site
• inability to obtain consent from patient or surrogate, and patient refusal

neither the patient or the investigator included in data collection will be aware of the type of block performed or the group allocation