Trans-nasal Sphenopalatine Ganglion Block Versus Ultrasound-guided Bilateral Greater and Lesser Occipital Nerve Block for Management of Post-Dural Puncture Headache.

• Type of Study:

Exploratory single-blind randomized comparative trial. (Only the data collection personnel were blinded to the group assignment).

• Study Settings: Ain Shams University Hospitals.
• Study Period: 6 months
• Study Population:

All patients included in this study met the International Headache Society criteria for diagnosis of PDPH, as follows:

1. headache that:
2. worsens within 15 minutes of sitting or standing; b) improves within 15 minutes after lying down; c) must have one of the following associated manifestations of: neck stiffness, tinnitus, hypoacusis, or photophobia;
3. dural puncture has been performed;
4. headache develops within 5 days after dural puncture. The headache should have persisted for at least two days and must have been intractable to conservative treatment with fluids, caffeine, paracetamol, and other nonopioid analgesics. Failure of conservative management was defined as headache score \> 4/10 on a numerical rating scale (NRS) when the patient assumed an upright position. -Inclusion Criteria: Physical status: ASA 1 or 2 and candidates for spinal anesthesia undergoing elective lower abdominal surgeries. Age group: 18-45 years. Sex: Both sexes Body mass index of less than 35 kg/m2 -Exclusion Criteria: Declining to give written informed consent. History of allergy to the medications used in the study. Contraindications to regional anesthesia (including coagulopathy, and local infection). Psychiatric disorder and/or Drug Addiction. American Society of Anesthesiologists (ASA) Physical Status Class III and more. Moderate to severe hepatic and renal diseases. Emergency surgeries. Nasal septal deviation, Nasal deformity and/or nasal bleeding. Had received opioids less than 12 hours before study inclusion. History of migraines or persistent headaches. •Sampling Method: Patients fulfilling inclusion criteria will be randomly divided into two groups using their computer-generated random numbers. •Sampling Size: An exploratory study will be conducted that includes at least 50 participants (25/group) to compare the efficacy of trans-nasal sphenopalatine ganglion block (TNSGB) and greater and lesser occipital nerve block (GALONB) to relieve PDPH and its associated symptoms. •Ethical Considerations: The study will be performed after ethical committee approval and informed consent from the patients after full explanation of the procedure, possible side effects and complications. Informed written consent was taken from all patients after explaining the study procedure in detail.

• Study Procedure:
• Pre-operative Settings: All patients will have the same preoperative preparation and anesthetic technique. History and general examination will be done to all patients and routine investigations will be done preoperatively as laboratory investigations (complete blood picture, bleeding time, INR, partial thromboplastin-time, and blood chemistry as liver and kidney function tests). Age, weight, and sex will be recorded.
• Intra-operative Settings: Inside the operating room/ward, intravenous access will be inserted, monitor connected and baseline non-invasive blood pressure (NBP), heart rate (HR), electrocardiography (ECG) and oxygen saturation (SpO2) will be measured. Patients were randomly allocated into 2 groups.
• TNSPGB Group: The patient was placed supine with shoulders slightly elevated to flex the neck and extend the head. Then anterior nares were inspected for polyps, tumors, or significant septal deviation. Long cotton-tipped applicators saturated with lidocaine 2% were inserted into each naris, until properly seated in the posterior nasopharynx. These were left in place for 10 minutes to lubricate and anesthetize the mucous membrane, making the procedure more comfortable. Then a mixture of 3 mL of 2 mL lidocaine 2% plus 1 mL dexamethasone 4 mg were injected through the applicators in the sphenopalatine area in each nostril. (Youssef et al., 2021) Then the patient was positioned sitting and pain assessments were recorded. o GALONB Group: The back of the head was sterilized with an antiseptic solution and the landmarks at the base of the skull were identified while the patient in the prone position. The landmarks were located on the medial third of a line drawn from occipital protuberance to mastoid process. At this level, the greater and lesser occipital nerves lie along the superior nuchal line medial to the occipital artery, halfway between the occipital protuberance and mastoid process. Under Ultrasound guidance, the skin was infiltrated with 1-2 mL of lidocaine 2%, using a 25-gauge needle. Then the block was performed in this area with a mixture of 3 mL of 2 mL lidocaine 2% plus 1 mL dexamethasone 4 mg to block greater and lesser occipital nerves. Then the procedure was repeated on the other side. After the procedure, the presence of bilateral occipital numbness was confirmed after 30 minutes. The patient was then positioned sitting and pain scoring was assessed. *Both blocks will be done and/or supervised by an expert all through.