Effect of Adding Dexamethasone to Bupivacaine 0.25% in SCPB on Surgical Field Visibility During Tympanomastoid Surgery

The aim of this study is to evaluate the efficacy of adding dexamethasone to bupivacaine 0.25% in ultrasound-guided SCPB on surgical field visibility during tympanomastoid surgery.

Tympanomastoid surgery is a commonly performed otological procedure performed to treat various middle ear pathologies, including chronic otitis media, cholesteatoma, and mastoiditis (1). One of the most significant complications associated with tympanomastoid surgery is bleeding, which can result in surgical difficulties, prolonged operative time, and increased morbidity (2).

Pain is also a major concern post-surgery and can lead to patient discomfort and dissatisfaction (3). Achieving optimal surgical field visibility is of paramount importance to ensure precise and safe surgical interventions. However, the presence of intraoperative bleeding and inadequate visualization can significantly impede the surgeon's ability to perform the procedure effectively, leading to potential complications and suboptimal outcomes (4).

Conventional methods for pain management during tympanomastoid surgery often involve general anesthesia or local infiltration of anesthetic agents around the surgical site. However, these techniques may not adequately address pain control and can be associated with unwanted systemic side effects (5).

To minimize bleeding and pain and improve surgical field visualization, anesthetic techniques such as induced hypotension have been used to achieve adequate homeostasis and surgical field visualization during surgery (4).

Induced hypotension involves reducing systemic blood pressure, thereby decreasing blood flow to the surgical site, minimizing the risk of bleeding, and improving the surgical field's visualization, leading to better surgical outcomes (5). However, induced hypotension can lead to cerebral hypoperfusion, organ damage, and other serious complications (6).

The use of regional anesthesia techniques, such as ultrasound-guided superficial cervical plexus block (SCPB), has gained considerable attention as a potential adjunct to general anesthesia (7). SCPB block involves the deposition of local anesthetic agents around the superficial cervical plexus, which provides sensory innervation to the ear, mastoid, and surrounding structures (8).

The SCPB provides effective analgesia and reduces sympathetic activity, resulting in reduced bleeding and improved surgical conditions (9). Also, the superficial cervical plexus provides sensory innervation to the ear and surrounding structures, reducing pain perception during and after surgery (10).

Modern medicine focuses on enhancing patient outcomes and reducing surgical complications through improved surgical field visualization. Advanced imaging technologies like intraoperative MRI or CT scanners offer real-time, high-resolution images, aiding accurate tumor localization (11). Fluorescence-guided agents like indocyanine green enhance visualization of blood vessels, lymph nodes, and tumors during surgery. Augmented reality (AR) and virtual reality (VR) systems provide valuable guidance, allowing surgeons to identify critical structures, plan optimal incisions, and simulate complex procedures pre-surgery. Robot-assisted surgery offers enhanced precision and 3D visualization through high-definition cameras. These combined methods lead to safer and more effective surgical interventions (12).

Recent studies have suggested that combining bupivacaine, a long-acting local anesthetic, with dexamethasone, a potent anti-inflammatory agent, may offer several advantages (13). Bupivacaine provides prolonged pain relief, while dexamethasone reduces local inflammation and edema, potentially improving surgical field visibility (14).

To our knowledge, this is the first randomized clinical trial investigating the effect of adding dexamethasone to bupivacaine 0.25% in ultrasound-guided SCPB on surgical field visibility during tympanomastoid surgery in adults.

Eligibility Criteria:
Inclusion Criteria:

1. ASA I \& ASA II patients
2. Patients undergoing tympanomastoid surgery.
3. Age group: from 21 to 70 years old.
4. Duration of surgery less than 5 hours.

Exclusion Criteria:

* Patient refusal.
* Uncooperative patients.
* Allergy to local anesthetics or dexamethasone.
* Anatomical abnormalities include malformations, deformities, growths, or structural irregularities.
* Infection at injection site.
* Coagulopathy: PTT \> 40 seconds, INR \> 1.4, platelet count \< 100x10⁹. or drug induced bleeding disorders