Comparison of Anesthetic Techniques on Total Hip Arthroplasty

To compare analgesia and orthopedic rehabilitation milestones in patients receiving either
spinal anesthesia (local anesthetic plus opioid) or general endotracheal anesthesia with
lumbar plexus block.

: Total hip arthroplasty (THA) is a common surgery worldwide. Despite the prevalence of this
procedure, there is no "gold standard" anesthetic. Several different techniques are
utilized. The two most common anesthesia modalities are: 1) spinal anesthesia 2) general
anesthesia (with or without a peripheral nerve block). The choice of anesthetic technique is
often based on the training and experience of the anesthesia provider, as well as the
culture of the institution. Both spinal anesthesia (consisting of local anesthetic and
opioid) and general anesthesia (combined with lumbar plexus nerve block) can provide
adequate intra-operative anesthesia as well as prolonged post-operative analgesia. The goal
of this study is to determine if the choice of one of these two anesthetic techniques
influences postoperative pain scores and orthopedic rehabilitation markers in patients
undergoing primary THA.

Several studies have compared spinal versus general anesthesia in terms of post-operative
pain relief, nausea and vomiting, blood loss, and deep venous thrombosis. Most of these
studies did not utilize a lumbar plexus nerve block for postoperative analgesia in the
general anesthesia subjects. The investigators are not aware of any randomized, controlled
studies examining differences in orthopedic outcomes when THA is performed under spinal
anesthesia or general anesthesia with lumbar plexus nerve block. These two anesthetic
techniques result in different degrees of intraoperative muscle relaxation which may affect
post-operative range of motion. Analgesic differences between the two techniques may also
affect range of motion and post-operative ambulation.

The investigators propose to compare post-operative pain scores as a primary outcome in
patients receiving either spinal anesthesia (bupivicaine with morphine) or general
anesthesia with lumbar plexus block for THA. Orthopedic outcomes, including distance of
first ambulation, physical therapy range of motion, and limb length discrepancies will be
measured as secondary outcomes. Continuous pulse oximetry and capnograpahy data will be
recorded for 24 hours postoperatively on all patients. The incidence of urinary tract
infections and post-operative nausea and vomiting between groups will be additional measured
outcomes.

Inclusion Criteria:

- Elective primary THA

- Surgery by Dr. Fenwick and Dr. Raab

- Anesthesia clinic pre-operative appointment

- ASA I, II, III

Exclusion Criteria:

- Revision THA

- Prior THA on opposite side

- Traumatic hip injury

- Contraindication to neuraxial or regional anesthesia

- History of post-operative nausea and vomiting > 2 prior general anesthetics

- Allergy to local anesthetics, morphine, hydromorphone, dexamethasone, or ondansetron

- History of substance abuse or chronic narcotic use

- Severe degenerative joint disease to non-operative joint impairing ambulation

- Severe back pain or spinal cord stenosis limiting ambulation

- BMI > 40