Effect of Lateral Decubitus Position After Spinal Anesthesia on Hemodynamic Stability in High-Risk Geriatric Patients

The Effects of Lateral Decubitus Positioning After Spinal Anesthesia on Hemodynamic Stability in High-Risk Geriatric Patients Undergoing Lower Extremity Orthopedic Surgery: A Prospective Randomized Controlled Trial

Spinal anesthesia is a common and preferred anesthetic technique for lower extremity orthopedic surgery in elderly patients. However, it can cause a significant drop in blood pressure (hypotension), especially in high-risk older patients with multiple medical conditions. This complication can lead to serious consequences such as heart attack, stroke, or death in vulnerable patients.

This study investigates whether keeping patients in a lateral (side-lying) position for 15 minutes after spinal anesthesia - instead of immediately turning them onto their back (supine position) - can reduce the risk of hypotension. When a patient lies on their side after receiving spinal anesthesia with a heavy (hyperbaric) local anesthetic, the medication tends to stay concentrated on the lower (operative) side, resulting in a more limited nerve block. This may help preserve blood pressure stability.

We will enroll 70 patients aged 65 years or older with high anesthetic risk (ASA physical status III or IV) scheduled for unilateral lower extremity orthopedic surgery under spinal anesthesia. Patients will be randomly assigned to two groups: one group will be kept in the lateral decubitus position (operative side down) for 15 minutes before being turned supine, and the other group will be turned supine immediately after spinal anesthesia. Blood pressure, heart rate, and oxygen saturation will be monitored continuously. The primary outcome is the incidence of hypotension during the first 15 minutes after spinal anesthesia.

Inclusion Criteria:

• Age 65 years or older
• ASA physical status classification III or IV
• Scheduled for unilateral lower extremity orthopedic surgery (hip fracture, femur fracture, knee arthroplasty, tibia-fibula fracture, or similar procedures)
• Eligible for spinal anesthesia
• Written informed consent obtained

Exclusion Criteria:

• Contraindications to spinal anesthesia (coagulopathy, recent anticoagulant or antiplatelet use without adequate washout period, local infection at injection site)
• Severe neurological disease or pre-existing motor or sensory deficit
• Significant spinal deformity (severe scoliosis, kyphosis) or history of previous spinal surgery
• Known allergy to local anesthetics
• Decompensated heart failure (ejection fraction below 30%)
• Uncontrolled hypertension (systolic blood pressure above 180 mmHg or diastolic blood pressure above 110 mmHg)
• Emergency surgery
• Severe hypovolemia or active bleeding
• Advanced dementia or inability to communicate
• Body mass index above 40 kg/m²
• Refusal to participate