Ultrasonography Versus Palpation for Spinal Anesthesia in... | NCT03792191

Label	Type	Description	Intervention Names
Ultrasonography	Experimental	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia will be administered with injection of intrathecal bupivacaine and intrathecal fentanyl.	Radiation: Lumbar Spinal Ultrasonography Procedure: Spinal Anesthesia Drug: Intrathecal Bupivacaine Drug: Intrathecal Fentanyl
Palpation	Active Comparator	Sham ultrasound procedure. Conventional landmark palpation and skin marking.Spinal anesthesia will be administered with injection of intrathecal bupivacaine and intrathecal fentanyl.	Radiation: Sham Ultrasound Procedure Procedure: Conventional Landmark Palpation Procedure: Spinal Anesthesia Drug: Intrathecal Bupivacaine Drug: Intrathecal Fentanyl

Name	Type	Description	Arm Group Labels	Other Names
Lumbar Spinal Ultrasonography	Radiation	Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the intervertebral space with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 intervertebral spaces.

Measure	Description	Time Frame
Number of Needle Passes Required to Obtain Free Cerebrospinal Fluid Flow	Needle pass is any forward introduction of the spinal needle after its complete or incomplete withdrawal, including the first attempt.	Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

Measure	Description	Time Frame
Number of Skin Punctures Required to Obtain Free Cerebrospinal Fluid Flow	Skin puncture is any separate skin puncture by the spinal needle after its complete withdrawal, including the first attempt.	Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

Name	Affiliation	Role
Mohamed M Tawfik, MD	Mansoura University Hospital	Study Director
Mohamed A Tolba, MSc	Mansoura University Hospital	Principal Investigator

Facility	Status	City	State	ZIP	Country	Contacts
Department of Anesthesia, Mansoura University Hospitals		Al Mansurah	Dakahlia Governorate	35511	Egypt

PubMed Identifier	Type	Citation	Retractions
37188389	Derived	Tawfik MM, Tolba MA, Ismail OM, Messeha MM. Ultrasonography versus palpation for spinal anesthesia in obese parturients undergoing cesarean delivery: a randomized controlled trial. Reg Anesth Pain Med. 2024 Jan 11;49(1):41-48. doi: 10.1136/rapm-2022-104272.

ID	Title	Description
FG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Type	Includes Protocol	Includes SAP	Includes ICF	Document Label	Document Date	Document Uploaded Date	Document File Name
Prot_SAP	Yes	Yes	No	Study Protocol and Statistical Analysis Plan	Dec 31, 2018

ID	Title	Description
BG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
BG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Sliding the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
BG002	Total	Total of all reporting groups

Units	Counts
Participants	BG000140 BG001140 BG002280

Type

Title

Description

Population Description

Reporting Status

Anticipated Posting Date

Parameter Type

Dispersion Type

Unit of Measure

Calculate Percentage

Time Frame

Units Analyzed

Denominator Units Selected

Arm/Group Information

Denominators

Classes

Analyses

Primary

Number of Needle Passes Required to Obtain Free Cerebrospinal Fluid Flow

Needle pass is any forward introduction of the spinal needle after its complete or incomplete withdrawal, including the first attempt.

Posted

Median

Full Range

needle passes

Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Units	Counts
Participants	OG000140 OG001140

Title

Denominators

Categories

Title	Measurements
	OG0003(1 to 34) OG0013(1 to 23)

Group IDs	Group Description	Statistical Method	Statistical Comment	P-Value	P-Value Comment	Parameter Type	Parameter Value	Dispersion Type	Dispersion Value	Confidence Interval Sides	Confidence Interval %	CI Lower Limit	CI Upper Limit	CI Lower Limit Comment	CI Upper Limit Comment	Estimate Comment	Tested Non-Inferiority	Non-Inferiority Type	Non-Inferiority Comment	Other Analysis Description
OG000 OG001		Wilcoxon (Mann-Whitney)		0.62		Median Difference (Final Values)	0.00007			2-Sided	95	-0.00005	1					Superiority

Secondary

Number of Skin Punctures Required to Obtain Free Cerebrospinal Fluid Flow

Skin puncture is any separate skin puncture by the spinal needle after its complete withdrawal, including the first attempt.

Posted

Median

Full Range

skin punctures

Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Secondary

Rate of Successful Obtaining of Free Cerebrospinal Fluid Flow at the First Needle Pass

Needle pass is any forward introduction of the spinal needle after its complete or incomplete withdrawal, including the first attempt.

Posted

Count of Participants

Participants

Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Secondary

Rate of Successful Obtaining of Free Cerebrospinal Fluid Flow at the First Skin Puncture

Skin puncture is any separate skin puncture by the spinal needle after its complete withdrawal, including the first attempt.

Posted

Count of Participants

Participants

Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Secondary

Duration of the Spinal Procedure

The duration from starting the first skin puncture by the spinal needle to obtaining free CSF flow

Posted

Median

Full Range

seconds

Assessed from enrollment in the study until completion of cesarean delivery

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Secondary

Patient Satisfaction

Patient satisfaction from the procedure assessed immediately after intrathecal injection using a 5-point scale (1 = very unsatisfied; 2 = unsatisfied; 3 = fair; 4 = satisfied; and 5 = very satisfied).

Posted

Median

Full Range

units on a scale

Assessed at 1 minute after intrathecal injection

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Secondary

Number of Participants With Vascular Puncture

Number of participants with unintentional vascular puncture by the needle during performing the spinal procedure

Posted

Count of Participants

Participants

Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Secondary

Number of Participants With Paresthesia

Number of participants with paresthesia reported by the subjects during performing the spinal procedure

Posted

Count of Participants

Participants

Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Secondary

Number of Participants With Failure to Obtain Free Cerebrospinal Fluid Flow

Number of participants with failure to obtain free cerebrospinal fluid flow after adequate needle passes at 6 separate skin punctures.

Posted

Count of Participants

Participants

Assessed from starting the first attempt of spinal anesthesia until successful administration of spinal anesthesia, an average of 10 minutes

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

Secondary

Number of Participants With Failed Spinal Block

Number of participants with failed spinal block defined as an upper sensory level below T6 assessed by pinprick.

Posted

Count of Participants

Participants

Assessed up to 20 minutes after intrathecal injection

ID	Title	Description
OG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space
OG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space

ID	Term
D000765	Anesthesia, Conduction
D000758	Anesthesia
D000760	Anesthesia and Analgesia

ID	Title	Description	Deaths (Affected)	Deaths (At Risk)	Serious Events (Affected)	Serious Events (At Risk)	Other Events (Affected)	Other Events (At Risk)
EG000	Ultrasonography	Preprocedural lumbar spinal ultrasonography and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Lumbar Spinal Ultrasonography: Ultrasonography of the lumbar spines using an 8-2 MHz curved array transducer. Identification of the interspace with the best image. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space	0	140	0	140	0	140
EG001	Palpation	Sham ultrasound procedure. Conventional landmark palpation and skin marking. Spinal anesthesia was administered with injection of intrathecal bupivacaine and intrathecal fentanyl. Sham Ultrasound Procedure: Moving the ultrasound probe on the patient's back with the machine in the freeze position. Conventional Landmark Palpation: Conventional palpation of the anatomical landmarks. The line crossing the iliac crests (Tuffier line) was assumed to cross the spine at L4 spinous process or L3-L4 intervertebral space. Identification of the widest interspace. Marking the patient's skin with horizontal and vertical lines over the L3-L4 and L2-L3 interspaces. Spinal Anesthesia: Spinal anesthesia using a 25- or 22-gauge spinal needle Intrathecal Bupivacaine: Bupivacaine 12.5 mg (2.5 mL 0.5%) was administered in the subarachnoid space Intrathecal Fentanyl: Fentanyl 15 μg was administered in the subarachnoid space	0	140	0	140	0	140