Adding low-dose IV ketamine to spinal anesthesia to prolong numbness for lower-limb surgery in older adults

Effect of Intravenous Ketamine Combined With Spinal Anesthesia on Sensory Block Duration Compared to Spinal Anesthesia Alone in Lower Limb Surgeries in Geriatrics: A Randomized Controlled Double-Blinded Trial.

Not applicable Interventional Cairo University · NCT07520487

This test will see if giving a small IV ketamine bolus and infusion with spinal anesthesia prolongs the sensory block in people aged 65 and older having elective lower‑limb surgery.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment61 (estimated)
Ages65 Years and up
SexAll
SponsorCairo University Academic / other
Locations1 site (Cairo, Giza Governorate)
Trial IDNCT07520487 on ClinicalTrials.gov

What this trial studies

Older adults scheduled for elective lower‑limb surgery under spinal anesthesia will receive standard spinal anesthesia with hyperbaric bupivacaine 0.5% and be assigned to either an IV ketamine arm (0.2 mg/kg bolus diluted to 5 ml followed by 0.1 mg/kg/hr infusion) or a placebo saline arm (5 ml bolus followed by matching infusion). The primary outcome is duration of sensory block measured by dermatome level over time after spinal injection. Secondary observations include postoperative analgesia requirements and hemodynamic/neurologic safety in the geriatric population. The protocol excludes patients with coagulopathy, preexisting neurologic disorders, local infection at the needle site, known drug allergies, or those who refuse participation.

Who should consider this trial

Good fit: Adults aged 65 years or older of either sex with ASA physical status I–III scheduled for elective lower‑limb surgery in the supine position under spinal anesthesia are ideal candidates.

Not a fit: Patients with coagulopathy, preexisting neurological disorders, local infection at the puncture site, known hypersensitivity to the drugs used, or who are unwilling to participate are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, adding low‑dose IV ketamine could prolong postoperative sensory block, reduce opioid needs, and improve pain control after lower‑limb surgery in older adults.

How similar studies have performed: Some prior perioperative ketamine studies have shown reduced opioid use and prolonged analgesia, but IV ketamine specifically combined with spinal bupivacaine in geriatric lower‑limb surgery is relatively under‑studied.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients aged 65 years and older

  * Both sexes
  * American Society of Anesthesiologists (ASA) physical status I, II, III
  * Scheduled for elective lower limb surgeries under spinal anesthesia in supine position

Exclusion Criteria:

* Patient's refusal.

  * Pre-existing neurological disorders.
  * Coagulopathy (i.e., Platelets ≤ 60,000 and/or INR\> 1.5).
  * Localized infection at the site of needle insertion.
  * Known hypersensitivity or allergies to any of the used drugs

Where this trial is running

Cairo, Giza Governorate

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions IV Ketamine With Spinal Blockketaminespinal blockdermatomeaging
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.