Nalbuphine, Fentanyl and no Additive to Local Anaesthetic Mixture

Nalbuphine has been used as an adjuvant to bupivacaine in intrathecal,epidural, caudal anesthesia and peripheral nerve blocks showing an increase in the efficacy and the duration of postoperative analgesia. The aim of this study is evaluation of the effect of 4 mg Nalbuphine when used as an adjuvant to a local anesthetic mixture in peribulbar block undergoing posterior chamber surgery in adult patients and comparing it with adding Fentanyl 20 μg to LAM and LAM alone

120 patients (40 in each group) scheduled for elective posterior chamber surgery using peribulbar block. Patients of Group N received 6 ml of 0.5% bupivacaine 1 ml hyaluronidase (75 IU), and 4mg of Nalbuphine in 1 ml of saline (total 8 ml) and patients of Group F received 6 ml of 0.5% bupivacaine 6 ml of 0.5% bupivacaine 1 ml hyaluronidase (75 IU), and 20 μg fentanyl in 1 ml saline (total 8 ml) and Group C received 6 ml of 0.5% bupivacaine,1 ml hyaluronidase (75 IU) and1 ml saline (total 8 ml).

Study outcomes included evaluation and scoring (onset and duration) of eyelid and globe akinesia, total 15-min akinesia score and duration of block.

Intraoperative hemodynamic measures were measured every 15 minutes during the whole procedure and every 30 minutes during the first two postoperative (PO) hours.. PO analgesia was hourly-assessed using Visual Analogue Score (VAS) and analgesia was provided at VAS of \>5.

Anesthetic procedure After securing intravenous access, non-invasive monitoring for blood pressure (SBP, DBP, MAP), E.C.G, and pulse oximetry (SpO2) were applied. tetracaine eye drops 0.5% applied to all patients as topical anesthesia. All patients were sedated using midazolam (0.05 mg/kg) as a preanesthetic medication I.V prior to receive LAM injection with nasal oxygen mask. Two ml of lidocaine 2% were diluted with 8 ml saline 3ml of LAM assigned for each group was injected in the medial canthus (the tunnel between the caruncle and the medial canthal angle) using needle 3-cm length and 27G inserted at angle of 45° between the caruncle and medial canthal angle till the tip of the needle touch the ethmoid bone then the direction of the needle was changed to 90° with the hub of the needle at level of the iris. Another 5 ml of LAM was injected at the extreme inferotemporal border of the orbit with the same needle directed downward and medially below the globe. Light orbital compression applied for 1 minute; then eye was evaluated 1, 3, 5 and 10 minutes for appearance of proptosis and chemosis.

All patients receive intraoperative non-invasive monitoring for blood pressure measures (SBP, DBP, MAP),E.C.G, and pulse oximetry (SpO2) prior to local anesthetic injection.

Eligibility Criteria:
Inclusion Criteria:

* patients aged 40-70 years.
* both sex.
* ASA physical status Ι\&II.
* Patient with axial globe length below 26

Exclusion Criteria:

* Refusal of the patient to participate in the study.
* Coagulation abnormalities(INR\>1.4).
* More than ASA II.
* High myopia with axial length more than 26 mm.
* Mentally retarded patients and failure of proper communication as in deafness .
* Morbidly obese patients(BMI\>35)
* Patients with glaucoma (increased IOP\>20mmgh)
* Patients with history of hypersensitivity to study drugs