An interventional study of DSCSA-Guided Individualized Spinal Anesthesia Dosing and Bupivacaine in Intraoperative Hypotension, Spinal Aneshtesia and TURP(Transurethral Resection of Prostate), sponsored by Istanbul University. Enrolling by invitation at 1 site in Turkey (Türkiye). Open to male participants aged 40 Years and older. Per ClinicalTrials.gov, last updated 2026-10-01.
Sponsored by Istanbul University · Not applicable, Interventional, and Supportive care
This randomized controlled study will evaluate whether individualizing the dose of spinal anesthesia according to the ultrasound-derived dural sac cross-sectional area (DSCSA) can improve hemodynamic stability in patients undergoing transurethral resection of the prostate (TURP).
Participants aged 40 years or older will be randomly assigned to one of two groups. In the individualized-dose group, the anteroposterior diameter of the dural sac will be measured by ultrasound at the L3-L4 level, and DSCSA will be calculated from this measurement. The dose of intrathecal bupivacaine will then be individualized according to the calculated DSCSA. In the control group, participants will receive a fixed dose of intrathecal bupivacaine. Both groups will also receive intrathecal fentanyl.
The main outcome is the incidence of intraoperative hypotension. The study will also evaluate the number of hypotensive episodes, minimum mean arterial pressure, vasopressor and atropine requirements, sensory and motor block characteristics, respiratory monitoring parameters, cerebral oxygenation, and adverse events.
The study aims to determine whether a DSCSA-guided dosing strategy can reduce excessive spinal block and improve hemodynamic stability while maintaining effective spinal anesthesia.
This prospective, randomized controlled study compares two routinely used approaches to determining the intrathecal bupivacaine dose for spinal anesthesia in patients undergoing transurethral resection of the prostate (TURP). No new drug, new indication, or experimental treatment will be introduced. Both dosing approaches are currently used in routine clinical practice; the study will prospectively and randomly compare their clinical effects.
Participants will be randomly assigned to either a dural sac cross-sectional area (DSCSA)-guided individualized dosing group or a fixed-dose control group.
Before spinal anesthesia, the anteroposterior diameter of the dural sac will be measured by ultrasound at the L3-L4 intervertebral level. DSCSA will be calculated using the formula A = π × (D/2)².
In the individualized-dose group, a DSCSA of 150 mm² will be used as the reference value corresponding to 10 mg of intrathecal bupivacaine. The bupivacaine dose will be adjusted proportionally according to the participant's calculated DSCSA and limited to a minimum of 6 mg and a maximum of 12.5 mg. Fentanyl 25 micrograms will be added intrathecally.
In the fixed-dose group, participants will receive 10 mg (2 mL of 0.5%) intrathecal bupivacaine together with fentanyl 25 micrograms.
Spinal anesthesia will be performed at the L3-L4 intervertebral space using a 27-gauge Quincke needle. Standard intraoperative monitoring will be performed according to the study protocol. Sensory and motor block characteristics and hemodynamic variables will be recorded prospectively for comparison between the two dosing strategies.
885 studies on the registry are indexed under Hypotension; 195 are open to participants now.
This study's planned enrollment of 60 is below the median of 87 across 590 interventional studies indexed under Hypotension.
Browse Hypotension studies →Istanbul University is the lead sponsor of 511 studies on the registry; 78 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 1 (20%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
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.
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.
The dural sac cross-sectional area (DSCSA) will be estimated from the ultrasound-measured anteroposterior dural sac diameter at the L3-L4 level. The intrathecal bupivacaine dose will be individualized according to the DSCSA, using 150 mm² as the reference area corresponding to 10 mg bupivacaine. The calculated bupivacaine dose will be limited to 6-12.5 mg. Fentanyl 25 micrograms will also be administered intrathecally.
Procedure: DSCSA-Guided Individualized Spinal Anesthesia Dosing · Drug: Bupivacaine · Drug: Fentanyl (FEN)
Participants will receive a fixed intrathecal dose of 10 mg (2 mL of 0.5%) bupivacaine together with fentanyl 25 micrograms.
Drug: Bupivacaine · Drug: Fentanyl (FEN)
The dural sac cross-sectional area (DSCSA) is calculated from the ultrasound-measured anteroposterior dural sac diameter at the L3-L4 level. The intrathecal bupivacaine dose is individualized according to DSCSA.
Hyperbaric bupivacaine is administered intrathecally in both study groups. In the DSCSA-guided group, the dose is individualized according to DSCSA, using 150 mm² as the reference corresponding to 10 mg, with a permitted dose range of 6 to 12.5 mg. In the fixed-dose group, 10 mg (2 mL of 0.5% bupivacaine) is administered.
Fentanyl 25 micrograms is administered intrathecally together with bupivacaine in both study groups.
Incidence of Intraoperative Hypotension
Intraoperative hypotension is defined as a decrease in mean arterial pressure (MAP) of ≥20% from baseline or an MAP \<65 mmHg. Participants meeting either criterion at least once during surgery will be classified as having intraoperative hypotension. The outcome will be reported as the percentage of participants with intraoperative hypotension.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Number of Intraoperative Hypotension Episodes
Number of intraoperative hypotension episodes recorded for each participant. Hypotension is defined as a decrease in mean arterial pressure (MAP) of ≥20% from baseline or an MAP \<65 mmHg.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Minimum Intraoperative Mean Arterial Pressure
Lowest mean arterial pressure (MAP), measured in mmHg, recorded during the intraoperative period.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of Participants With a ≥30% Decrease in Mean Arterial Pressure
Percentage of participants experiencing at least one decrease in mean arterial pressure (MAP) of ≥30% from baseline during surgery.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of Participants Requiring Ephedrine
Percentage of participants receiving at least one intravenous dose of ephedrine for treatment of intraoperative hypotension.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Total Ephedrine Dose
Total intravenous ephedrine dose, measured in milligrams (mg), administered to each participant during surgery.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of Participants Requiring Atropine
Percentage of participants receiving intravenous atropine for treatment of intraoperative bradycardia.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Total Atropine Dose
Total intravenous atropine dose, measured in milligrams (mg), administered to each participant during surgery.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Maximum Sensory Block Level
Highest cephalad sensory block level achieved after spinal anesthesia, assessed by the pin-prick test and recorded as the corresponding dermatomal level.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Time to Achieve T10 Sensory Block
Time, measured in minutes, from completion of intrathecal injection to achievement of a T10 sensory block, assessed using the pin-prick test.
Time frame: Up to 30 minutes after spinal anesthesia
Time to Two-Dermatome Sensory Regression
Time, measured in minutes, from the maximum sensory block level to regression of the sensory block by two dermatomes, assessed using the pin-prick test.
Time frame: From maximum sensory block until two-dermatome regression, assessed up to 3 hours after spinal anesthesia
Time to Recovery to Modified Bromage Score 0
Time, measured in minutes, from completion of intrathecal injection until recovery to a Modified Bromage score of 0, indicating complete recovery of lower-extremity motor function.
Time frame: From completion of spinal anesthesia until recovery to Modified Bromage score 0, assessed up to 3 hours after spinal anesthesia
Number of Integrated Pulmonary Index ≤4 Episodes
Number of episodes in which the Integrated Pulmonary Index (IPI) is ≤4. The IPI is a composite score ranging from 1 to 10 based on end-tidal carbon dioxide, respiratory rate, oxygen saturation, and pulse rate; lower scores indicate greater respiratory compromise.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Incidence of Adverse Events
Percentage of participants experiencing at least one adverse event recorded during the intraoperative study period.
Time frame: During surgery (from completion of spinal anesthesia until the end of surgery)
Mean Left Regional Cerebral Oxygen Saturation During the First 60 Minutes
Mean left regional cerebral oxygen saturation (rSO₂), measured continuously by frontal near-infrared spectroscopy (NIRS) during the first 60 minutes after spinal anesthesia. The outcome will be reported as the mean rSO₂ value.
Time frame: During the first 60 minutes after spinal anesthesia
Minimum Regional Cerebral Oxygen Saturation
Lowest regional cerebral oxygen saturation (rSO₂) value recorded by frontal near-infrared spectroscopy (NIRS) during the first 60 minutes after spinal anesthesia.
Time frame: During the first 60 minutes after spinal anesthesia
Maximum Relative Decrease in Regional Cerebral Oxygen Saturation
Maximum relative decrease in regional cerebral oxygen saturation (ΔrSO₂max) from the baseline value during the first 60 minutes after spinal anesthesia, measured by frontal near-infrared spectroscopy (NIRS).
Time frame: During the first 60 minutes after spinal anesthesia
Plan to share: No
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Started Aug 2026 (actual). Primary completion is estimated for Nov 2026, 2 months after the start.
Of 210 non-industry interventional studies with no phase under Hypotension, half reached primary completion within 12 months of starting (the median), counting those still running; a quarter within 6 and three quarters within 22. This study's planned 2 months is below that.
Counting every sponsor, half of 217 studies reached it within 12 months; a quarter within 6 and three quarters within 22.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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