After pilot study no difference in the primary end point was found between the two primary. Non-inferiority trial not deemed feasible.

The study evaluates the hemodynamic effect of lumbosacral plexus blockades versus spinal anesthesia for hip replacement. Half of participants will receive lumbosacral plexus blockade and the other half will receive continuous spinal anesthesia.

Patients for total hip replacement will be randomized for surgical anesthesia with either lumbosacral plexus blockade or continuous spinal anesthesia. All patients will receive central venous, arterial and spinal catheters. Hemodynamics will be monitored with transpulmonary thermodilution and pulse contour analysis. Perineural injection of study medicine around the lumbar and sacral plexus will be performed guided by ultrasound and nerve stimulation. Study medicine will be injected in divided doses in the spinal catheter. Treatment will be blinded using double-dummy technique. After the first intrathecal dose of study medicine, the hemodynamic response will be monitored for 60 minutes. Patients will then be transferred to the operating room, where total hip replacement will be performed in lumbosacral plexus blockade or spinal anesthesia according to randomization.

Inclusion Criteria:

• Patients for total hip replacement at Aarhus University Hospital
• Age >= 50 years
• American Society of Anesthesiologists physical status classification score I-III
• Informed consent

Exclusion Criteria:

• Lack of ability to cooperate
• Lack of ability to speak Danish
• Chronic pain, that demands opioid treatment. Not inkl. hip pain.
• Previous venous thromboembolic event
• Previous major back surgery
• Severe cardiopulmonary disease (NYHA class 4)
• Severe untreated hypertension (systolic blood pressure > 160 mm Hg or diastolic blood pressure > 110 mm Hg)
• Obesity (BMI > 35 kg/m^2)
• Pregnancy
• Allergy towards the used local analgetics
• Current treatment with amiodarone or verapamil

Anonymized data will be made available through Danish Data Archive.