Condition category
Eye Diseases
Date applied
30/09/2008
Date assigned
31/10/2008
Last edited
31/10/2008
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information

Type

Scientific

Primary contact

Dr Jawad Mustafa

ORCID ID

Contact details

South Infirmary Hospital
Cork
-
Ireland

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

Efficacy of Sub-Tenon's block using an equal volume of local anaesthestic administered either as a single or as divided doses

Acronym

SubTenon

Study hypothesis

Our hypothesis was that a divided injection into the Sub-Tenon’s space would achieve greater, more consistent and more rapid motor blockade then a single injection using equal volumes and mixtures of local anaesthetic solution.

Ethics approval

Ethics Committee of Cork University Hospital, approval received in 2003.

Study design

Single blinded, prospective, randomised controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Hospitals

Trial type

Treatment

Patient information sheet

Condition

Cataract surgery

Intervention

On arrival in the induction room, intravenous excess was secured and monitoring with non-invasive blood pressure (NIBP), electrocardiogram (ECG), and pulse oximetry (Datex AS3) established. Topical anaesthesia was established by instillation of benoximate eye drops and after 2 minutes an eye speculum inserted. With the eye in neutral position, the conjunctiva was lifted in the infranasal quadrant with the help of Moorsfields forceps and using Westcott's scissors a small incision was made in the conjunctiva. A 19 gauge Stephens's cannula was carefully placed subconjuctivally into the Sub-Tenon's space.

In group 1, 5 ml of local anaesthetic solution comprising 2.5 ml of 2% lignocaine with 1:200,000 adrenaline, 15 IU/ml of hyaluronidase and 2.5 ml of 0.5% bupivacaine was injected over thirty seconds. After the injection orbital pressure was applied for two minutes.

In group 2, 3 ml of the same anaesthetic solution described above was injected and cannula withdrawn followed by application of orbital pressure for 2 minutes. A further 2 ml of the same anaesthetic solution was injected through the same conjunctival incision with approx three minutes between the two injections.

Intraocular pressures were measured by a hand held tonometer (knowa) prior to injection and six minutes after the first (or sole) injection and compared with pre-injection value.

Intervention type

Drug

Phase

Not Specified

Drug names

Benoximate, lignocaine, adrenaline, hyaluronidase, bupivacaine

Primary outcome measures

Measurement of movement was performed by the operating surgeon who was unaware of the anaesthetic technique used in all four quadrants (inferior, superior, redial, lateral) using a vernier calliper and scored according to movement:
0 = no movement
1 = movement of less than 2 mm
2 = movement of more than 2 mm

Motor function was evaluated at two time intervals, 3 and 6 minutes after the initial injection. Overall movement score was obtained by combining the scores of these four muscles. This score ranged from 0 (no movement) to 8 (complete movement) and was categorised into two groups, akinesia (score 0 - 4) and no akinesia (score 5 - 8).

All measured during the surgery.

Secondary outcome measures

Chemosis and subconjuctival haemorrhage were also assessed by surgeons before starting surgery as mild, moderate or severe. All measured during the surgery.

Overall trial start date

01/06/2003

Overall trial end date

31/12/2003

Reason abandoned

Eligibility

Participant inclusion criteria

1. American Society of Anaesthesiologists (ASA) I - III patients undergoing cataract surgery
2. No age range, both male and female patients

Participant type

Patient

Age group

Other

Gender

Both

Target number of participants

60

Participant exclusion criteria

1. Allergy to any of the drugs administered
2. Impaired mental status
3. Uncontrolled glaucoma
4. Clotting abnormalities
5. Recent surgical procedure on the same eye

Recruitment start date

01/06/2003

Recruitment end date

31/12/2003

Locations

Countries of recruitment

Ireland

Trial participating centre

South Infirmary Hospital
Cork
-
Ireland

Sponsor information

Organisation

Cork University Hospital (Ireland)

Sponsor details

Wilton
Cork
-
Ireland

Sponsor type

University/education

Website

Funders

Funder type

Other

Funder name

Investigator initiated study - no extra funding required as Sub-Tenon's block is routinely used

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes