NCT07424417

Upper Extremity Position and Intraocular Pressure During Spinal Anesthesia

Effect of Upper Extremity Position on Intraocular Pressure During Spinal Anesthesia in Open Inguinal Hernia Repair: A Randomized Controlled Trial

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 105 (actual)
• Sponsor: Elazıg Fethi Sekin Sehir Hastanesi · Academic / Other
• Sex: All
• Age: 18 Years – 80 Years
• Healthy volunteers: Not accepted

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.

Conditions

• Intraocular Pressure
• Spinal Anesthesia
• Surgical Positioning
• Inguinal Hernia

Interventions

Type	Name	Description
OTHER	Upper Extremity Positioning	Upper extremity positioning during spinal anesthesia for open inguinal hernia repair. Participants will be randomly assigned to one of three arm positions: (1) adduction alongside the body, (2) 90° abduction, or (3) arms crossed over the chest. The assigned position will be maintained throughout the surgical procedure.
OTHER	Upper Extremity Positioning	Upper extremity positioning during spinal anesthesia for open inguinal hernia repair. Participants will be randomly assigned to one of three arm positions: (1) adduction alongside the body, (2) 90° abduction, or (3) arms crossed over the chest. The assigned position will be maintained throughout the surgical procedure.
OTHER	Upper Extremity Positioning	Upper extremity positioning during spinal anesthesia for open inguinal hernia repair. Participants will be randomly assigned to one of three arm positions: (1) adduction alongside the body, (2) 90° abduction, or (3) arms crossed over the chest. The assigned position will be maintained throughout the surgical procedure.

Timeline

• Start date: 2025-11-20
• Primary completion: 2026-02-10
• Completion: 2026-02-10
• First posted: 2026-02-20
• Last updated: 2026-02-20

Locations

1 site across 1 country: Turkey (Türkiye)