Reverse leftover spinal numbness after knee or hip replacement with an intrathecal saline flush

Reversal of Spinal Anesthesia Residual Motor Block Via Intrathecal Catheter: A Pilot Study

Phase 2 Interventional Beth Israel Deaconess Medical Center · NCT07404982

This study tests whether injecting a small amount of sterile saline through a spinal catheter can quickly reduce or eliminate leftover spinal anesthesia in adults having elective lower-extremity joint replacement.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment20 (estimated)
SexAll
SponsorBeth Israel Deaconess Medical Center Academic / other
Locations1 site (Boston, Massachusetts)
Trial IDNCT07404982 on ClinicalTrials.gov

What this trial studies

This is a prospective, randomized Phase 2 interventional study that assigns adults undergoing elective lower-extremity joint replacement to receive either a 10 mL intrathecal normal saline injection via a 24-gauge catheter placed through a 20-gauge Quincke spinal needle or control. The catheter is threaded through the spinal needle into the subarachnoid space to deliver saline after surgery. Outcomes include immediate motor recovery measured in the PACU with a 1-hour post-operative survey, a 3-day follow-up survey, and medical record review. The approach is adapted from obstetric observations where saline given via a spinal catheter reduced headaches, but its use for reversing residual anesthesia in orthopedic patients is being tested.

Who should consider this trial

Good fit: Adults over 18 having elective lower-extremity joint replacement (hip or knee) who are eligible for spinal anesthesia and speak English are the intended participants.

Not a fit: People with contraindications to spinal anesthesia, unheld anticoagulation, prior intracranial bleeding, ASA status above 3, non-English speakers, or those undergoing re-operation on the same joint are unlikely to benefit or be eligible.

Why it matters

Potential benefit: If successful, the method could shorten time to motor recovery and enable earlier mobilization and discharge after joint replacement.

How similar studies have performed: Saline delivered via spinal catheters has been reported to reduce post-dural puncture headache in obstetric patients, but using intrathecal saline to reverse residual motor block in orthopedic patients is novel and unproven.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Patients having elective lower extremity joint replacement surgery
2. Patients \>18 years

Exclusion Criteria:

1. Contraindications to spinal anesthesia (refusal, lumbar spinal hardware, spinal abnormalities)
2. Patient on anticoagulation not withheld
3. Patient receiving re-operation on the same joint
4. Prior intra-cranial bleeding
5. Patient's ASA status \>3
6. Non-English speaking

Where this trial is running

Boston, Massachusetts

Study contacts

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 Joint Replacement SurgeryJoint ReplacementKnee Replacement
Last reviewed 2026-06-09 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.