Effect of Upper Extremity Position on Intraocular Pressure During Spinal Anesthesia in Open Inguinal Hernia Repair: A Randomized Controlled Trial
Overview
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Elazıg Fethi Sekin Sehir Hastanesi
- Enrollment
- 105
- Locations
- 1
- Primary Endpoint
- Change in Intraocular Pressure
Overview
Brief Summary
This prospective randomized controlled trial aims to evaluate the effect of different upper extremity positions on intraocular pressure (IOP) in adult patients undergoing open inguinal hernia repair under spinal anesthesia. Participants will be randomly assigned to one of three arm positions: adduction alongside the body, 90° abduction, or arms crossed over the chest. IOP will be measured using a Tono-Pen AVIA tonometer at predefined intraoperative time points. Hemodynamic parameters including mean arterial pressure, heart rate, and oxygen saturation will also be recorded. The primary outcome is the change in intraocular pressure over time among the three groups. The findings of this study may provide clinically relevant data regarding the impact of upper extremity positioning on ocular physiology during spinal anesthesia.
Detailed Description
Intraocular pressure (IOP) is influenced by aqueous humor dynamics as well as episcleral venous pressure, which may be affected by body and extremity positioning. Changes in venous return, intrathoracic pressure, and systemic hemodynamics during surgical positioning may lead to measurable alterations in IOP. Although the effects of head and body position on IOP have been investigated, the impact of different upper extremity positions during spinal anesthesia has not been clearly established.
This prospective randomized controlled trial will be conducted at Elazığ Fethi Sekin City Hospital. Adult patients (18-80 years, ASA I-III) scheduled for elective open inguinal hernia repair under spinal anesthesia will be included. After written informed consent, participants will be randomly assigned using sealed opaque envelopes to one of three upper extremity positions: (1) arms adducted alongside the body, (2) arms positioned at 90° abduction, or (3) arms crossed over the chest.
Intraocular pressure will be measured bilaterally using a Tono-Pen AVIA tonometer by the same ophthalmologist. Measurements will be performed at predefined time points: before spinal anesthesia (T0), 5 minutes after spinal anesthesia (T1), at surgical incision (T2), at 15 minutes (T3), at 30 minutes (T4), at skin closure (T5), and in the recovery unit (T6). Head and neck position will be maintained neutral throughout the procedure.
Hemodynamic parameters including mean arterial pressure, heart rate, and oxygen saturation will be recorded simultaneously. The primary outcome is the change in IOP over time between the three groups. Secondary outcomes include hemodynamic changes and group-by-time interaction effects.
Data will be analyzed using appropriate parametric or non-parametric tests according to distribution. Repeated measurements will be evaluated using linear mixed-effects models. A p-value <0.05 will be considered statistically significant.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Other
- Masking
- None
Masking Description
Due to the nature of the intervention (upper extremity positioning), blinding of participants and care providers is not feasible. The study will be conducted as an open-label trial.
Eligibility Criteria
- Ages
- 18 Years to 80 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Age between 18 and 80 years
- •ASA physical status I-III
- •Scheduled for elective open inguinal hernia repair
- •Planned spinal anesthesia
- •Ability to undergo preoperative intraocular pressure measurement
- •Provision of written informed consent
Exclusion Criteria
- •ASA physical status IV-V
- •Age under 18 or over 80 years
- •Known diagnosis of glaucoma or ocular hypertension
- •Active ocular infection
- •History of ocular surgery within the past 6 months
- •Inability to cooperate with intraocular pressure measurement
- •Conversion from spinal to general anesthesia
- •Requirement of positive pressure ventilation
- •Hemodynamic instability during measurement
Arms & Interventions
Adduction Position
Participants will undergo spinal anesthesia and open inguinal hernia repair with both arms positioned alongside the body in adduction throughout the surgical procedure.
Intervention: Upper Extremity Positioning (Other)
90° Abduction Position
Participants will undergo spinal anesthesia and open inguinal hernia repair with both arms positioned at 90 degrees of abduction during the procedure.
Intervention: Upper Extremity Positioning (Other)
Arms Crossed Over Chest Position
Participants will undergo spinal anesthesia and open inguinal hernia repair with both arms positioned crossed over the chest during the procedure.
Intervention: Upper Extremity Positioning (Other)
Outcomes
Primary Outcomes
Change in Intraocular Pressure
Time Frame: From baseline (T0, before spinal anesthesia) to recovery unit (T6), during the intraoperative period (approximately 60-90 minutes).
Intraocular pressure measured bilaterally using a Tono-Pen AVIA tonometer at predefined time points (T0-T6) during spinal anesthesia and surgery.
Secondary Outcomes
No secondary outcomes reported