Reversal of Spinal Anesthesia Residual Motor Block Via Intrathecal Catheter

The purpose of this study is to determine the feasibility of administering a predetermined amount of normal saline into the intrathecal or subarachnoid space via a small spinal catheter to reduce or eliminate the effects of previously injected spinal anesthetic following lower extremity orthopedic surgery.

This is a prospective, randomized, interventional study to assess the feasibility and effectiveness of administering normal saline into the intrathecal or subarachnoid space through a small gauge epidural catheter via a single spinal needle to reverse residual anesthesia following lower extremity orthopedic surgery. This method is adapted from observations in obstetric populations where saline administered via the spinal catheter reduced headaches. This study investigates whether orthopedic patients will also receive unique benefits. Research procedures overview: * Randomization to intervention or control arm, * Use of 6-inch BD 20-gauge Quincke spinal needle, through which a B. Braun Perifix 24-gauge polyurethane catheter * Administration of normal saline * Administration of post-operative survey while in the PACU 1 hour * Follow-up survey 3 days post-surgery * Medical record review and abstraction.

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