The effect of adding different doses of neostigmine in peribulbar block for intraoperative anesthesia and post-operative analgesia in cataract surgery

Evaluation of the efficacy and safety of adding two different doses of neostigmine to the local anesthetic lidocaine in peribulbar anesthesia for cataract surgery.

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

Research Institute of Ophthalmology, Giza, Egypt.

We will include adult (30-70 years-old) male or female patients, indicated for cataract surgery who are ASA I, II or III. We will exclude patients with any of the following conditions: coagulopathy or on anticoagulant drugs, infection at the site of the surgery, posterior staphyloma, allergy to any of the used drugs, and bronchial asthma or bradyarrhythmia.

The trial has three groups. Control group (Group C) includes 20 patients. Each will receive 9 ml of lidocaine 2% (containing 1 ml = 10 unit of hyaluronidase) + 1 ml of saline. Intervention group 1 (Group N1) includes 20 patients. Each will receive 9 ml of lidocaine 2% (containing 1 ml = 10 unit of hyaluronidase) + 0.5 mg of neostigmine. Intervention group 2 (Group N2) includes 20 patients. Each will receive 9 ml of lidocaine 2% (containing 1 ml = 10 unit of hyaluronidase) + 0.25 mg of neostigmine

The primary outcome variables include hemodynamics (heart rate, blood pressure, oxygen saturation) and the onset of motor and sensory blocks. The secondary outcomes include the duration of the block, patient's and surgeon's satisfaction, postoperative pain using VAS, and the first dose of analgesic required.

We used the sealed, opaque sequentially numbered envelopes method for randomization and allocation concealment of patients included in this trial. We used 60 identical, opaque, letter-sized envelopes. We used rolls of household aluminum cooking foil that we cut into 60 sheets (of the same width as and twice the height of the envelope). We prepared 60 envelope-sized sheets of white paper and 60 envelope-sized sheets of single sided carbon paper. We wrote “Treatment A” on 20 paper sheets, “Treatment B” on another 20 sheets, and “Treatment C” on the last 20 sheet. To prepare 20 “Treatment A” envelops, we selected one envelope-sized sheet of of Treatment A and placed one sheet of carbon paper on top of the Treatment A allocation paper with the carbon side facing the paper, then we put both papers inside a foil wrapper. Then, the completed insert was placed into a blank envelope with the carbon paper closest to the front of the envelope. Finally, the envelop was sealed and we signed across the seal. We completed all the 20 “Treatment A” envelops the same way. We prepared 20 “Treatment B” envelops and 20 “Treatment C” envelops the same way as “Treatment A” envelops. The three sets of envelops were combined and we shuffled them thoroughly. Then, using a pen we marked a number on the front of each envelope sequentially from 1 to 60. The carbon paper inside the envelope will transfer this number to the allocation paper inside. Finally, we placed these envelopes into a plastic container, in numerical order, ready for use.

Participants, care providers carrying out the peribulbar block, and those assessing the participants' outcomes will be blinded to the type of intervention.

Neostigmine in peribulbar block for cataract surgery IPD set (all collected deidentified IPD).

Beginning 6 months and ending 36 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.