Subtenon Block Combined With General An… | Clinical Trial

Key information

Conditions

Subtenon Anesthesia

Age range

40 year–90 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

King Abdulaziz University Hospital at King Saud University

Riyadh, Riyadh Region, 11411, Saudi Arabia

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Patient undergoing elective retinal surgery under general anesthesia

Exclusion criteria

ASA physical status > Grade II,
psychiatric conditions,
neurological impairment,
deafness with whom communication would be difficult in the postoperative period,
clotting abnormalities,
contraindications for regional anesthesia,
drug abuse,
history of allergy to the study drugs,
previous vitreoretinal or strabismus surgery,
endophthalmitis, or inflammatory eye pathology
taking analgesics, antiemetics or drugs that might affect hemodynamics

Treatment and study plan

2% lidocaine and 0.5% bupivacaine

Drug

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

Sham subtenon block

Drug

Primary outcomes

the time to first postoperative analgesic dose

Time frame: 24 hrs

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

Secondary outcomes

postoperative pain scores

Time frame: First 24 hrs after surgery

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.
number of patients requiring rescue analgesics during the 24-h study period

Time frame: during the whole study (6 months)
consumption of rescue analgesics

Time frame: during the whole study (6 months)

The total number of patients receiving rescue analgesia is recorded
incidence of oculocardiac reflex

Time frame: during time of surgery
incidence of postoperative nausea/vomiting

Time frame: First 24 hrs after surgery

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

Sponsors and collaborators

Lead sponsor

King Saud University

Other

Registry information

Important dates

Study start: 2013
Primary completion: 2014
First posted: Nov 4, 2014
Registry last updated: Nov 4, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.