Height-based versus conventional spinal anesthetic dosing for older adults having lower-limb surgery

COMPARISON OF HEMODYNAMIC AND ANAESTHETIC OUTCOMES BETWEEN HEIGHT-BASED AND CONVENTIONAL SPINAL ANAESTHETIC DOSING IN GERIATRIC PATIENTS UNDERGOING LOWER LIMB ORTHOPAEDIC SURGERIES

This trial tests if using a height-based spinal anesthesia dose instead of a fixed dose reduces low blood pressure and improves block timing in people aged 60–80 having elective lower-limb orthopedic surgery.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 104 (estimated)
• Ages: 60 Years to 80 Years
• Sex: All
• Sponsor: Shaheed Mohtarma Benazir Bhutto Institue of Trauma (other)
• Locations: 1 site (Karachi, Sindh)
• Trial ID: NCT07363941 on ClinicalTrials.gov

What this trial studies

This single-center, randomized interventional trial will enroll patients aged 60–80 scheduled for elective lower-limb orthopedic procedures and randomly assign them to either height-based spinal dosing or a conventional fixed spinal dose with concealed allocation using SNOSE. Investigators will record baseline demographics, measure supine height precisely, and monitor intraoperative hemodynamics including hypotension and bradycardia as primary safety outcomes. Secondary outcomes include onset and duration of sensory and motor block and other anesthetic characteristics. Data will be collected on standardized forms after institutional ethics approval and informed consent.

Who should consider this trial

Good fit: Ideal participants are adults aged 60–80 with ASA I–III status scheduled for elective lower-limb orthopedic surgery who will receive spinal anesthesia, are at least 150 cm tall, are not on antihypertensive or beta-blocker therapy, and can provide informed consent.

Not a fit: Patients under 150 cm tall, those taking antihypertensive agents or beta blockers, people with significant neurological disease, sepsis, coagulopathy, or those requiring emergency procedures are excluded and unlikely to benefit from the study approach.

Why it matters

Potential benefit: If successful, the approach could reduce intraoperative hypotension and bradycardia and produce more predictable anesthesia, potentially lowering complication rates and improving recovery.

How similar studies have performed: Similar height- or weight-adjusted spinal dosing approaches have shown mixed but promising results in reducing excessive block height and hypotension in older adults, though large definitive trials are limited.

Eligibility criteria

Inclusion Criteria:

Individuals aged 60 to 80 years. Either gender (male or female). Patients who are ASA physical status I-III. Individuals scheduled to undergo elective lower limb orthopaedic surgeries (e.g., fracture fixation, total knee replacement, open reduction and internal fixation).

Patients planned to receive spinal anaesthesia as the primary anaesthetic technique.

Those who provide informed written consent for participation in the study.

Exclusion Criteria:

Individuals exhibiting a stature inferior to 150 cm. Patients receiving anti-hypertensive drugs or those on beta blockers or beta-agonists.

Patients with a history of neurological disease like CVA or Parkinsonism. Patients presenting with sepsis (≥ 2 positive SIRS criteria with positive aseptically obtained blood or wound culture).

Patients with a history of coagulation disorders like haemophilia or vWD or those with a history of anti-platelet drug intake in the last 2 weeks.

Individuals possessing a documented history of hypersensitivity reactions to pharmacological agents utilized in the research.

Patients who will be diagnosed with a skin infection at the spinal needle puncture site.

Patients undergoing emergency orthopaedic procedures requiring immediate intervention

Where this trial is running

Karachi, Sindh

• Shaheed Mohtarma Benazir Bhutto Institue of Trauma — Karachi, Sindh, Pakistan (RECRUITING)

Conditions: Geriatric Population, Spinal Anesthesia Induced Hypotension, Spinal Anesthesia in Elderly Patients