Geriatric, Hypotension Drug-Induced, Orthopedic Surgery Patients, Spinal Aneshtesia
Conditions
Keywords
hypotension, spinal anesthesia, lateral decubitus position, geriatric, hyperbaric bupivacaine, unilateral spinal block, hemodynamic stability, orthopedic surgery, ASA III-IV
Brief summary
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.
Interventions
After spinal anesthesia with 12 mg of 0.5% hyperbaric bupivacaine administered in the sitting position, patients are immediately placed in the lateral decubitus position with the operative side down. This position is maintained for 15 minutes to allow gravity-dependent concentration of the hyperbaric local anesthetic on the operative side, achieving predominantly unilateral sympathetic block. Patients are then repositioned supine for surgery.
OTHERImmediate Supine Positioning
After spinal anesthesia with 12 mg of 0.5% hyperbaric bupivacaine administered in the sitting position, patients are immediately placed in the supine position. This results in bilateral distribution of the hyperbaric local anesthetic and serves as the active comparator.
Sponsors
University of Health Sciences Balikesir Hospital Eduation and Research
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Masking description
The investigator assessing sensory block levels and recording hemodynamic parameters was blinded to group allocation. Blinding of participants and care providers was not possible due to the nature of the positional intervention.
Intervention model description
Two parallel groups: lateral decubitus position (operative side down) for 15 minutes after spinal anesthesia versus immediate supine position after spinal anesthesia.
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of Hypotension | From spinal anesthesia to 15 minutes after administration | Hypotension defined as a decrease of 20% or more from baseline mean arterial pressure (MAP) or MAP below 65 mmHg, occurring at any time point between 1 and 15 minutes after spinal anesthesia. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of Bradycardia | From spinal anesthesia to 30 minutes after administration | Bradycardia defined as heart rate below 50 beats per minute at any time point during the study period, treated with intravenous atropine 0.5 mg bolus. |
| Ephedrine Requirement | From spinal anesthesia to 30 minutes after administration | Total dose of ephedrine (mg) administered intravenously for treatment of hypotension. Ephedrine given as 5-10 mg IV bolus, repeated if necessary. |
| Atropine Requirement | From spinal anesthesia to 30 minutes after administration | Total dose of atropine (mg) administered intravenously for treatment of bradycardia. Atropine given as 0.5 mg IV bolus when heart rate falls below 50 beats per minute. |
| Maximum Sensory Block Level | From spinal anesthesia to 30 minutes after administration | Highest dermatomal level of sensory block assessed by pin-prick test on the operative side, recorded as thoracic dermatome level (T6-T12). |
| Incidence of Unilateral Sensory Block | 15 and 30 minutes after spinal anesthesia administration | Proportion of patients achieving unilateral block, defined as complete sensory block at T10 or above on the operative side with no block below T12 on the contralateral side, assessed at 15 and 30 minutes after spinal anesthesia. |
Contacts
CONTACTHasan Duman, M.D.
Outcome results
None listed