Combined Lumbosacral Nerve Block Versus Spinal Anesthesia for Cognitive Function After Hip Prothesis

Cognitive Changes After Hip Prosthesis; Comparison Between Combined Lumbosacral Nerve Block Versus Spinal Anesthesia: a Double Blind Randomized Clinical Trial

Hip fracture is a potentially devastating event, and serious surgical and medical complications occur frequently especially for elderly patients. Delirium is one of the common complications after hip surgery. Controversy exists regarding the possible impact of type of anesthesia (nerve block versus spinal) upon acute and long-term cognitive decline.

The primary objective is to assess the association between type of anesthesia (nerve block vs. spinal anesthesia) and risk of cognitive decline (CD). The secondary objective is to compare intra-operative hemodynamic changes, use of vasopressor drugs, and use of post-operative analgesics with respect to the type of anesthesia.

Prospective, double blind randomized clinical trial of hip fracture patients who will be assessed for CD pre- and postoperatively, using the Mini Mental State Examination (MMSE). The presence of CD will be determined at follow-up evaluation up to three months after surgery.

Prospective, double blind randomized clinical trial of hip fracture patients who will be assessed for CD pre- and postoperatively, using the Mini Mental State Examination (MMSE). The presence of CD will be determined at follow-up evaluation up to three months after surgery. Patients undergoing hip surgery will be randomized into two groups. Group 1 will receive unilateral lumbosacral nerve block (sciatic nerve block and paravertebral block at levels L3-L4 and L4-L5) as well as placebo injection (1 ml normal saline) at the spinal anesthesia level (L3-L4 or L4-L5). The sciatic nerve will be injected by 20 ml of the anesthetic mixture whereas levels L3-L4 and L4-L5 will be injected by a total of 20 ml of the anesthetic mixture without exceeding the maximum injected volume of 1 ml/kg. Group 2 will receive spinal anesthesia (3 ml of 0.5% bupivacaine) in addition to placebo injection at the sciatic, L3-L4 and L4-L5 levels.

Inclusion Criteria:

• Admitted with a hip fracture (femoral neck, trochanteric or sub-trochanteric)
• 40 kg in weight and higher

Exclusion Criteria:

Patients who are:

• Uncooperative
• Considered as moribund by the orthopedic surgeon at admission
• Alzheimer
• Severe cognitive impairment (MMSE<18)
• Absolute contraindication for spinal anesthesia (assessed preoperatively)
• Allergy to local anesthesia