An interventional study of Unilateral Spinal Anesthesia and Bilateral Spinal Anesthesia in Spinal Anesthesia and Hemodynamic Changes, sponsored by Kayseri City Hospital. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 65 Years and older. Per ClinicalTrials.gov, last updated 2026-08-27.
Sponsored by Kayseri City Hospital · Not applicable, Interventional, and Other
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.
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.
Kayseri City Hospital is the lead sponsor of 49 studies on the registry; 15 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients receive unilateral spinal anesthesia and hemodynamic parameters are monitored using the PRAM method during surgery.
Procedure: Unilateral Spinal Anesthesia
Patients receive bilateral spinal anesthesia and hemodynamic parameters are monitored using the PRAM method during surgery.
Procedure: Bilateral Spinal Anesthesia
Unilateral spinal anesthesia administered for unilateral lower extremity surgery.
Bilateral spinal anesthesia administered for unilateral lower extremity surgery.
Cardiac Index Measured Using PRAM During Spinal Anesthesia
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.
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 Measured Using PRAM During Spinal Anesthesia
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.
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 Measured Using PRAM During Spinal Anesthesia
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.
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 Measured Using PRAM During Spinal Anesthesia
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.
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 Measured Using PRAM During Spinal Anesthesia
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.
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 Measured Using PRAM During Spinal Anesthesia
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.
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 Measured Using PRAM During Spinal Anesthesia
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.
Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.
Maximum Rate of Arterial Pressure Rise Measured Using PRAM
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.
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 Measured Using PRAM
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.
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 Measured Using PRAM During Spinal Anesthesia
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.
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 During Spinal Anesthesia
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.
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 During Spinal Anesthesia
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.
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 During Spinal Anesthesia
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.
Time frame: From immediately before spinal anesthesia until completion of surgery, assessed at baseline and every 10 minutes for up to 180 minutes.
Plan to share: No
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Started May 2026 (actual). Primary completion is estimated for Aug 2026, 3 months after the start.
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Kayseri City Hospital