Comparison Between Peribulbar And Sub-tenon Blocks on Oculocardiac Reflex (OCR) During Pediatric Strabismus Surgery

Anesthesia, Local Clinical Trial

Official title:

A Comparison Between The Effects Of Peribulbar And Sub-tenon Blocks Combined With General Anesthesia On The Incidence Of Oculocardiac Reflex (OCR) During Pediatric Strabismus Surgery: A Double Blinded Randomised Control Study

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06293586
• Other study ID #: MD-11-2022
• Status: Recruiting
• Phase: N/A
• Start date: December 1, 2023
• Est. completion date: March 30, 2024

Study information

• Verified date: February 2024
• Source: Cairo University
• Contact: Essam Nossair, Masters
• Phone: 0201002014809
• Email: e.nossair92[@]gmail.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The aim of this study is to compare between peribulbar block and subtenon block as an adjunct to general anesthesia in children undergoing strabismus surgery on oculocardiac reflex (OCR), post-operative analgesia and postoperative vomiting. Both techniques will be compared to intra-operative intravenous (IV) paracetamol combined with general anesthesia as a sole anesthetic technique.

Description:

120 children, American Society of Anaesthesiology (ASA) I or II, aged 6 to 13 years, scheduled for elective squint surgery under GA will be included in the study. Children with tumors or infections of the orbit, raised intraocular pressure, eye injury, airway abnormalities or who are blind in the eye other than that which will to be operated, will be excluded. Other exclusion criteria will include known allergy to local anaesthetics or nonsteroidal anti-inflammatory drugs (NSAIDS), steroid therapy, those with significant cardiac, respiratory, renal, hepatic, or neurological disorders, mentally challenged children, or parental refusal to participate.

All children will undergo a detailed preanesthetic evaluation including previous history of operations, drug history, physical examination (cardiovascular and respiratory systems, blood pressure, oxygen saturation, airway and dentition, body weight and height). During the pre-anesthesia evaluation, children will be encouraged to report postoperative pain, if present. All children will be fasted for a minimum of 4 hours and premedicated with oral midazolam 0.5 mg/kg 30 minutes before anaesthesia. Anesthesia will be induced with sevoflurane 6% in oxygen or intravenous (i.v.) propofol (2mg/kg), as appropriate for the child's age and preference. Following inhalational induction, an intravenous line will be placed. The airway will be secured using an appropriately sized endotracheal tube (ETT) following intravenous atracurium(0.5 mg.kg) and 1 to 3 min of mask ventilation using isoflurane 1.5% in oxygen.Anesthesia will then be maintained with isoflurane in air-oxygen and end tidal minimal alveolar concentration maintained at 1 to 1.3. ventilation will be established at 6-8ml per kg with a target PECO2 of 32 - 34 and will be adjusted accordingly.

Children will then be randomly allocated to one of three groups; by a nurse who will not participate in the study, reads the number contained in the envelope and makes group assignment.

Children in the control group (group C, n_20) will receive IV paracetamol (20mg/kg).

Children in the sub-tenon group (sub-tenon group (S), n _ 20) will receive a sub-tenon block. Sub-Tenon's anesthesia will be performed with 5% bupivacaine (0.08 ml/kg). Under sterile conditions, a 19-gauge curved, blunt metallic cannula (25 mm) will be inserted into sub-Tenon's space and the local anesthetic will be injected by the ophthalmologist.

The peribulbar group (P group _ 20) will receive peribulbar block with 0.25 mL/kg of a 1:1 mixture of 0.5% bupivacaine and 2% lignocaine containing hyaluronidase (500 IU hyaluronidase has been premixed with 30 mL 2% lignocaine). Peribulbar block using a two-injection technique will be performed by a second anaesthetist.

The children will not be aware to as which group they will be allocated into. Digital oculopression will be performed for 5 minutes. All blocks will be performed by one of the investigators. LAM will be injected both inferotemporallly and superonasally using a 26-G needle. Haemodynamic variables; electrocardiography (ECG), pulse oximetry, noninvasive blood pressure (NIBP) and end tidal carbon dioxide (PECO2); will be monitored continuously and Occurrence of oculocardiac reflex (OCR) will be recorded (either in the form of bradyarrhythmias mostly sinus bradycardia or o) . bradyarrhythmias which is the most common presentation of Oculocardiac reflex (OCR) will be considered as an acute decrease in heart rate below 60 beats/min and will be treated by asking the surgeon to stop stimulation and giving intravenous atropine (0.01 mg.kg), whereas other less common presentations of oculocardiac reflex (OCR) will be managed accordingly. All children will receive Dexamethasone (0.125mg/kg) 30 minutes before the end of surgery. At the end of the procedure, the ETT will be removed after reversing residual neuromuscular blockade with 50 μg·kg-1 neostigmine and 20 μg·kg-1 atropine and adequate spontaneous ventilation established.

Children will then be transferred to the recovery room, where they will be kept for 2 to 3 hours. On arrival in the recovery room, the child's' behavior and postoperative pain level will be assessed at 30 min by the recovery room nurse who will not be aware of the block using the modified objective pain scale (MOPS) [10] which assess pain via 5 points (crying, facial expressions, posture of the trunk, posture of the legs, and motor restlessness) with a minimum score of 0 and a maximum score of 10. 0-1 (no pain), 2-5 (mild), 6-7 (moderate), and 8-10 (severe) out of 10.

For pain judged as moderate or severe (MOPS > 5), ibuprofen 10mg/kg will be administered orally. After 2 hours in the recovery area, the children's pain will be assessed by Modified objective pain scale (MOPs) at 2 and 4 hours. Requirement of postoperative analgesia will be recorded. The incidence of PONV will be recorded. Numeric scoring will be used for PONV (0 = no nausea; 1 = nausea is present, but no vomiting; 3 = vomiting once within 30 min; 4 = vomiting two or more times within 30 min). Ondansetron (0.1 mg/kg, i.v.) will be given in cases of vomiting. The data collector will not be aware of the intervention the child will receive

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 140
• Est. completion date: March 30, 2024
• Est. primary completion date: March 30, 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 6 Years to 13 Years

Eligibility

Inclusion Criteria:

• Participants were children (6-13 years), ASA I-II patients, scheduled to undergo strabismus surgery.

Exclusion Criteria:

• Children with tumors or infections of the orbit, raised intraocular pressure more than 20 mm Hg, axial length more than 28 mm, eye injury, airway abnormalities or who were blind in the eye other than that which was to be operated on were excluded. Other exclusion criteria included patients undergoing revision surgery, known allergy to local anesthetics or non-steroidal antiinflammatory drugs (NSAIDs), steroid therapy, parental refusal to participate and patients with INR more than 1.5 or with platelets less than 100.

Related Conditions & MeSH terms

• Anesthesia, Local
• Eye Diseases
• Ophthalmopathy
• Pediatric ALL
• Strabismus

Intervention

Procedure:
• peribulbar block
Peribulbar block using a two-injection technique was performed by a second anesthetist under sterile conditions and before the application of surgical drapes. LAM was injected both infratemporal and superonasally using a 26-G needle, in contrast to the single infratemporal injection approach. Gentle digital oculopression was performed for 5 minutes
• sub-tenon block
Children in the sub-Tenon group received a sub-Tenon block. Sub-Tenon's anesthesia was performed with 0.5% bupivacaine (0.08 ml/kg), bearing in mind not to exceed the maximum dose. Under sterile conditions, a 19- gauge curved blunt metallic cannula (25 mm) was inserted into sub-Tenon's space and the local anesthetic was injected by the ophthalmologist after the application of surgical drapes.

Drug:
• Paracetamol
Children in the control group received IV paracetamol (15 mg/kg) after induction of anesthesia before any surgical intervention.

Locations

Country	Name	City	State
Egypt	Cairo University faculty of medicine	Cairo

Sponsors (1)

Lead Sponsor	Collaborator
Cairo University

Country where clinical trial is conducted

Egypt, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Post-operative pain using the MOPS	pain assessed using the MOPS	4 hours
Other	Post-operative analgesia requirements	pethidine 0.5 mg/kg was administered IV	4 hours
Other	The incidence of POV using numeric scoring	using Numeric scoring at 30 minutes and 2h post-operative	2 hours
Other	Complications resulting from orbital regional anesthesia were recorded	e.g.: subconjunctival hemorrhage, local anesthetic toxicity, chemosis, optic neuropathy, extra-ocular muscle paresis	2 hours
Other	Total intraoperative atropine requirements	Brady arrhythmias intraoperatively which are the most common presentation of OCR was considered when an acute decrease in heart rate below 60 beats/min and was treated by asking the surgeon to stop stimulation and giving intravenous atropine (0.01 mg. kg)	2 hours
Primary	The incidence of intraoperative oculocardiac reflex (OCR)	drop in heart rate below 60 bpm	2 hours
Secondary	blood pressure	blood pressure in mmhg will be recorded preop, after induction, and every 15 minutes.	2 hours
Secondary	heart rate	heart rate as beats per minute will be recorded preop, after induction, and every 15 minutes.	2 hours