To evaluate the effects of subtenon block (SB) as an adjunct to general anaesthesia on postoperative pain, oculocardiac reflex and postoperative nausea and vomiting for vitreoretinal surgery.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
DOUBLE
Enrollment
80
Under general anesthesia and the operating microscope, a Lieberman lid speculum was placed and the conjunctiva was cleaned with 4% povidone iodine solution. The surgeon then created a fornix-based incision through conjunctiva and tenon's tissue inferonasally midway between the insertions of the medial and inferior rectus muscles, with blunt Wescott scissors to expose the scleral surface before tunneling posteriorly with curved Stevens scissors to create a small channel to the posterior subtenon space. A blunt-tipped subtenon cannula was then inserted into the posterior subtenon space, 4mL of 2% lidocaine and 0.5% bupivacaine (50:50) mixture versus saline was introduced and the drug solution was injected slowly into the subtenon space. After administration of local anesthetic mixture, the eyelid was gently taped down, and no ocular massage was performed
King Abdulaziz University Hospital at King Saud University
Riyadh, Riyadh Region, Saudi Arabia
the time to first postoperative analgesic dose
Pain was evaluated using a VNS chart (0-no pain at all, 10-the worst pain imaginable) at 30 min, 1, 2, 4, 6, 12,18 and 24 hours postoperatively. During PACU stay, if the patient complain of pain postoperatively (VNS ≥ 4), morphine boluses of 25 µg /kg (injected at 10-min intervals) was administered intravenously if requested until the pain subsided for a maximum dose of 10 mg. At the end of 2 h, the patients were transferred from the PACU to the ward where the pain was assessed, paracetamol 15 mg/kg was given intravenously and was repeated every 4 hours if needed in the ward by a nurse who is blinded to the study group as paracetamol is the standard post-operative pain medication for patients undergoing ophthalmic surgery at our institute. Time to first post-operative analgesic, which is the time, elapsed between end of the surgical procedure and first administration of an analgesic was noted
Time frame: 24 hrs
postoperative pain scores
Pain was evaluated using a VNS chart (0-no pain at all, 10-the worst pain imaginable) at 30 min, 1, 2, 4, 6, 12,18 and 24 hours postoperatively. During PACU stay, if the patient complain of pain postoperatively (VNS ≥ 4), morphine boluses of 25 µg /kg (injected at 10-min intervals) was administered intravenously if requested until the pain subsided for a maximum dose of 10 mg. At the end of 2 h, the patients were transferred from the PACU to the ward where the pain was assessed, paracetamol 15 mg/kg was given intravenously and was repeated every 4 hours if needed in the ward by a nurse who is blinded to the study group as paracetamol is the standard post-operative pain medication for patients undergoing ophthalmic surgery at our institute. Time to first post-operative analgesic, which is the time, elapsed between end of the surgical procedure and first administration of an analgesic was noted.
Time frame: First 24 hrs after surgery
number of patients requiring rescue analgesics during the 24-h study period
Time frame: during the whole study (6 months)
consumption of rescue analgesics
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The total number of patients receiving rescue analgesia is recorded
Time frame: during the whole study (6 months)
incidence of oculocardiac reflex
Time frame: during time of surgery
incidence of postoperative nausea/vomiting
The incidence of postoperative nausea and vomiting (PONV) was assessed by a nurse (who was blinded to the study drug) for the first 2 h in the PACU and subsequently in the ward at 6, 12 and 24 h and Only 2 possible answers was accepted (yes) or (no). Nausea was defined as subjective sensation of discomfort associated with the awareness of the urge to vomit. Vomiting was defined as a forceful expulsion of gastric contents through the mouth. Rescue antiemetic (Ondansetron 0.15 mg/kg) was given if the patient had persistent nausea or more than a single episode of vomiting or whenever patients request medication and number of patients required rescue anti-emetic postoperatively were recorded
Time frame: First 24 hrs after surgery