Ketamine versus midazolam as an adjuvant to peribulbar block using single inferonasal injection in patients undergoing vitreoretinal surgery: A randomized controlled trial

Evaluating the role of midazolam and ketamine as adjuvants to the peribulbar block in lengthier ophthalmic procedures such as vitreoretinal surgeries.

Parallel group randomized controlled clinical trial with 1:1:1 allocation ratio.

Research Institute of Ophthalmology, Giza, Egypt.

We will include adult (30-65 years-old) male or female patients, indicated for vitreoretinal surgeries (with axial length 20-29 mm), and are American Society of Anesthesiologists (ASA) physical status I or II. We will exclude uncooperative patients, patients who can’t lie flat for the duration of the procedure (such as orthopneic patients and those with skeletal problems), and those having coagulopathy or using anticoagulant drugs.

The trial has three groups. Control group (Group C) includes 31 patients. Each will receive peribulbar anesthesia in the form of 4 ml of lidocaine 2%, 75 units of hyaluronidase, and 4 ml of bupivacaine 0.5% to which 1 ml of normal saline is added. Midazolam group (Group M) includes 31 patients. Each will receive peribulbar anesthesia in the form of 4 ml of lidocaine 2%, 75 units of hyaluronidase, and 4 ml of bupivacaine 0.5% to which 1 mg midazolam is added. Ketamine group (Group K) includes 31 patients. Each will receive peribulbar anesthesia in the form of 4 ml of lidocaine 2%, 75 units of hyaluronidase, and 4 ml of bupivacaine 0.5% to which 25 mg of ketamine is added.

Primary outcomes include the onset of globe akinesia and the duration of analgesia. Secondary outcomes include the duration of motor block, the onset of corneal anesthesia, lid akinesia, and the vital data (blood pressure, oxygen saturation, and pulse rate).

We will use the sequentially numbered, opaque sealed envelopes method. We will use envelopes that are impermeable to intense light, and the allocation sequence will be concealed from the physicians enrolling and assessing participants. To prevent subversion of the allocation sequence, the name and hospital admission number of the participant will be written on the envelope. Carbon paper will transfer the information onto the allocation card inside the envelope. Corresponding envelopes will be opened only after the enrolled participants complete all baseline assessments and it is time to allocate the intervention.

Only participants will be blinded to the type of intervention.

Ketamine versus midazolam for peribulbar block in vitreoretinal surgeries IPD set (all collected deidentified IPD).

Beginning 12 months and ending 24 months following article publication.

Researchers from academic institutions whose proposal for the use of data has been approved by an independent review committee identified for this purpose.

For IPD meta-analysis.

From the PI.

A proposal for the use of data to be submitted to the PI, then evaluated by an independent review committee identified for this purpose.