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NCT Number: NCT07789795

Hemodynamic Effects of Bilateral and Unilateral Spinal Anesthesia Using the Continuous Pressure Recording Analytical Method.

This randomized controlled study aims to compare the intraoperative hemodynamic effects of unilateral and bilateral spinal anesthesia in elderly patients undergoing elective total hip arthroplasty. Seventy-four patients aged 65 years and older will be randomized into two groups: unilateral spinal anesthesia (n=37) and bilateral spinal anesthesia (n=37).

Hemodynamic parameters including cardiac output, stroke volume, stroke volume variation, pulse pressure variation, and systemic vascular resistance will be continuously monitored using the Pressure Recording Analytical Method (PRAM)-based MostCare monitoring system. Intraoperative fluid requirements and vasopressor consumption will also be evaluated.

The study seeks to determine whether unilateral spinal anesthesia provides greater hemodynamic stability and reduces the need for fluid administration and vasopressor support compared with conventional bilateral spinal anesthesia in elderly patients undergoing hip arthroplasty.

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Key information

Conditions

Spinal Anesthesia Hemodynamic Changes

Age range

65 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

Hip arthroplasty is a commonly performed orthopedic procedure in elderly patients. Due to age-related physiological changes and the high prevalence of cardiovascular comorbidities, maintenance of intraoperative hemodynamic stability is essential in this population. Spinal anesthesia is widely used for lower extremity orthopedic surgery; however, sympathetic blockade may result in hypotension and impaired tissue perfusion, particularly in elderly patients.

Unilateral spinal anesthesia has been proposed as an alternative technique that may reduce the extent of sympathetic blockade and provide greater cardiovascular stability compared with conventional bilateral spinal anesthesia. Nevertheless, evidence regarding the advanced hemodynamic effects of these two techniques remains limited.

This prospective randomized controlled study aims to compare the hemodynamic effects of unilateral and bilateral spinal anesthesia in patients aged 65 years and older undergoing elective total hip arthroplasty. A total of 74 patients will be randomized to receive either unilateral spinal anesthesia (n=37) or bilateral spinal anesthesia (n=37).

Before spinal anesthesia, all participants will receive standard sedation with fentanyl (1-2 mcg/kg) and midazolam (0.015-0.03 mg/kg). Hemodynamic monitoring will be performed using the MostCare monitoring system based on the Pressure Recording Analytical Method (PRAM) through a radial arterial catheter.

The following hemodynamic parameters will be recorded at baseline, immediately after spinal anesthesia, and at predefined intraoperative time points: heart rate (HR), mean arterial pressure (MAP), peripheral oxygen saturation (SpO2), cardiac index (CI), stroke volume index (SVI), stroke volume variation (SVV), pulse pressure variation (PPV), systemic vascular resistance (SVR), oxygen delivery (DO2), oxygen delivery index (DO2I), maximal pressure rise during systole (dP/dtmax), cardiac cycle efficiency (CCE), and arterial elastance (Ea).

In addition, intraoperative vasopressor requirement (ephedrine use) and operative duration will be recorded and compared between study groups.

The primary objective is to determine whether unilateral spinal anesthesia provides superior hemodynamic stability compared with bilateral spinal anesthesia in elderly patients undergoing hip arthroplasty. The investigators hypothesize that unilateral spinal anesthesia will be associated with reduced hemodynamic fluctuations and lower vasopressor requirements compared with bilateral spinal anesthesia.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults aged 65 years and older.
  • Patients scheduled for elective total hip arthroplasty.
  • Patients with an American Society of Anesthesiologists (ASA) physical status classification of II, III, or IV.
  • Patients with a Glasgow Coma Scale (GCS) score of 13-15 who are conscious and able to cooperate.
  • Patients with suitable peripheral arterial anatomy for PRAM monitoring.
  • Patients who provide written informed consent to participate in the study.
  • Patients without any clinical contraindication to spinal anesthesia. -

Exclusion criteria

  • Glasgow Coma Scale (GCS) score <13.
  • Age below 65 years.
  • History of previous major neurosurgical intervention.
  • Anatomical abnormality, vascular defect, or infection at the site intended for arterial catheter placement for PRAM monitoring.
  • Severe spinal deformity (e.g., severe scoliosis, previous spinal fusion surgery, or spinal trauma).
  • Current anticoagulant therapy or coagulopathy (INR >1.5 or platelet count <75,000/mm³).
  • Presence of skin infection or systemic infection/sepsis.
  • Severe hypovolemia or decompensated cardiac disease in which spinal anesthesia is contraindicated.
  • Known allergy or hypersensitivity to local anesthetics or sedative agents.
  • Local infection or wound at the planned spinal puncture site.
  • Clinical contraindication to spinal anesthesia (e.g., increased intracranial pressure, septicemia, or severe hypotension). -

Treatment and study plan

Unilateral spinal anesthesia

Procedure

Unilateral spinal anesthesia administered for unilateral lower extremity surgery.

Bilateral Spinal Anesthesia

Procedure

Bilateral spinal anesthesia administered for unilateral lower extremity surgery.

Primary outcomes

  1. Cardiac Index Measured Using PRAM During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Cardiac index will be measured using the Pressure Recording Analytical Method (PRAM) and reported in L/min/m². Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  2. Stroke Volume Index Measured Using PRAM During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Stroke volume index will be measured using the Pressure Recording Analytical Method (PRAM) and reported in mL/beat/m². Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  3. Stroke Volume Variation Measured Using PRAM During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Stroke volume variation will be measured using the Pressure Recording Analytical Method (PRAM) and reported as a percentage. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  4. Pulse Pressure Variation Measured Using PRAM During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Pulse pressure variation will be measured using the Pressure Recording Analytical Method (PRAM) and reported as a percentage. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  5. Systemic Vascular Resistance Measured Using PRAM During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Systemic vascular resistance will be measured using the Pressure Recording Analytical Method (PRAM) and reported in dyn·s/cm⁵. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  6. Oxygen Delivery Index Measured Using PRAM During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Oxygen delivery index will be measured using the Pressure Recording Analytical Method (PRAM) and reported in mL/min/m². Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  7. Arterial Elastance Measured Using PRAM During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Arterial elastance will be measured using the Pressure Recording Analytical Method (PRAM) and reported in mmHg/mL. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  8. Maximum Rate of Arterial Pressure Rise Measured Using PRAM

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    The maximum rate of arterial pressure rise (dP/dtmax) will be measured using the Pressure Recording Analytical Method (PRAM) and reported in mmHg/s. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  9. Cardiac Cycle Efficiency Measured Using PRAM

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Cardiac cycle efficiency (CCE) will be measured using the Pressure Recording Analytical Method (PRAM) and reported as a dimensionless value. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  10. Oxygen Delivery Measured Using PRAM During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Oxygen delivery (DO₂) will be measured using the Pressure Recording Analytical Method (PRAM) and reported in mL/min. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  11. Mean Arterial Pressure During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Mean arterial pressure (MAP) will be measured using invasive arterial pressure monitoring and reported in mmHg. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  12. Heart Rate During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Heart rate (HR) will be recorded using standard perioperative monitoring and reported in beats per minute. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

  13. Peripheral Oxygen Saturation During Spinal Anesthesia

    Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.

    Peripheral oxygen saturation (SpO₂) will be measured using pulse oximetry and reported as a percentage. Measurements recorded at each study time point will be compared between the unilateral and bilateral spinal anesthesia groups.

Sponsors and collaborators

Lead sponsor

Kayseri City Hospital

Other Gov

Registry information

Official study title

Comparison of the Hemodynamic Effects of Bilateral and Unilateral Spinal Anesthesia in Hip Arthroplasty Surgeries in Elderly Patients Using the Continuous Pressure Recording Analytical Method.

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Aug 27, 2026
Registry last updated
Aug 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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