ObesityUSLMCSEOBNCT07549776
Ultrasound-guided Versus Landmark-based Spinal Anesthesia in Obese Parturients Undergoing Cesarean Section
A study testing Ultrasound-guided preprocedural marking and Landmark-based palpation in people with Obesity and Cesarean Section, run by Instituto Nacional Materno Perinatal, Peru at 1 site in Peru.
Trial summary
Spinal anesthesia is the most commonly used anesthetic technique for cesarean section. However, in obese parturients, identification of the optimal puncture site using anatomical landmark palpation can be challenging because of altered anatomy. Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Obesity, Cesarean Section
- What is being tested?
- Ultrasound-guided preprocedural marking and Landmark-based palpation
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 sitePeru
- Study dates
- 1 Jul 2025to 1 Jan 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years
- Pregnant women undergoing cesarean section
- Body mass index (BMI) ≥ 30 kg/m² at the time of cesarean section
- Scheduled for cesarean section under spinal anesthesia
Who cannot join
- Congenital spinal deformities
- History of spinal surgery
- Coagulopathy
- Infection at the puncture site
- Allergy to local anesthetics
- Emergency cesarean section (NICE category 1)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Ultrasound-guided Versus Landmark-based Spinal Anesthesia in Obese Parturients Undergoing Cesarean Section: a Prospective Comparative Study
Spinal anesthesia is the most commonly used anesthetic technique for cesarean section. However, in obese parturients, identification of the optimal puncture site using anatomical landmark palpation can be challenging because of altered anatomy. Preprocedural ultrasound has been proposed as a tool to improve localization of the puncture site and facilitate neuraxial access.
This is a prospective comparative study included 100 obese parturients undergoing cesarean section under spinal anesthesia. Participants were allocated to one of two comparison groups according to the puncture site localization technique: a preprocedural ultrasound group and an anatomical landmark palpation group.
The primary outcome is the first-attempt success rate, defined as successful cerebrospinal fluid return after the first needle insertion without needle redirection or a new skin puncture. Secondary outcomes include the number of puncture attempts, needle redirections, need for rescue interventions, incidence of paresthesia and vascular puncture during the procedure, and procedural times.
Read the detailed description
This prospective comparative study aims to evaluate the effectiveness of preprocedural ultrasound-guided marking compared with the conventional anatomical landmark palpation technique for spinal anesthesia in obese parturients undergoing cesarean section.
A total of 100 parturients with a body mass index (BMI) ≥ 30 kg/m² were prospectively allocated to one of two comparison groups according to the puncture site localization technique. In the ultrasound group, the puncture site was identified using preprocedural ultrasound to determine the optimal intervertebral space and needle insertion trajectory. In the landmark group, the puncture site was identified using conventional anatomical landmark palpation.
The primary outcome was the first-attempt success rate, defined as successful cerebrospinal fluid return after the first needle insertion without needle redirection or an additional skin puncture. Secondary outcomes included the number of puncture attempts, needle redirections, need for rescue interventions, incidence of paresthesia and vascular puncture during needle insertion, and procedural times (site identification time, puncture time, and total procedure time).
This study evaluated whether preprocedural ultrasound-guided marking improves the technical performance of spinal anesthesia compared with conventional anatomical landmark palpation in obese parturients undergoing cesarean section.
- Conditions
- Obesity, Cesarean Section
- Being tested
- Ultrasound-guided preprocedural marking, Landmark-based palpation
- Keywords
- Ultrasonography, Spinal anesthesia, Cesarean section, Obesity, Neuraxial anesthesia
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultrasound-guided preprocedural markingProcedure or surgery
Preprocedural ultrasound is used to identify and mark the optimal puncture site before spinal anesthesia.
Landmark-based palpationProcedure or surgery
The puncture site is identified using anatomical landmark palpation before spinal anesthesia.
| Study group | Role | What they receive |
|---|---|---|
| Ultrasound-guided group | Active comparator | Preprocedural ultrasound was used to identify and mark the optimal puncture site in obese parturients undergoing cesarean section (n = 50). Receives: Procedure: Ultrasound-guided preprocedural marking |
| Landmark-based group | Active comparator | The puncture site was identified using anatomical landmark palpation in obese parturients undergoing cesarean section (n = 50) Receives: Procedure: Landmark-based palpation |
What is being measured
The primary outcome is the main question the study is designed to answer.
First-attempt success rate of spinal anesthesia
Successful cerebrospinal fluid return after the first needle insertion without redirection.
Measured: During the spinal anesthesia procedure
Secondary outcomes (7)
Number of puncture attempts
Total number of needle insertions required to achieve successful spinal anesthesia
Measured: During the spinal anesthesia procedure
Number of needle redirections
Number of needle redirections during a single puncture attempt
Measured: During the spinal anesthesia procedure
Need for rescue intervention
Requirement of assistance by a more experienced operator to complete the procedure
Measured: During the spinal anesthesia procedure
Incidence of paresthesia
Occurrence of paresthesia during needle insertion
Measured: During the spinal anesthesia procedure
Incidence of vascular puncture
Occurrence of vascular puncture during needle insertion
Measured: During the spinal anesthesia procedure
Total procedure time
Time from initial identification of the puncture site to successful cerebrospinal fluid return
Measured: During the spinal anesthesia procedure
Puncture time
Time from needle insertion to successful cerebrospinal fluid return
Measured: During the spinal anesthesia procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Apr 2026
- Study start1 Jul 2025
- Primary completion1 Jan 2026
- Study completion1 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- Participants were prospectively allocated to one of two comparison groups according to the puncture site localization technique (preprocedural ultrasound marking or anatomical landmark palpation) before spinal anesthesia.
- Masking
- None (open label)
- Enrolment
- 100 participants (actual)
Sponsor and investigators
- Lead sponsor
- Instituto Nacional Materno Perinatal, Peru
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, EDDISSON REYNALDO QUISPE PILCO, Instituto Nacional Materno Perinatal, Peru
- Investigators
- Eddisson R Quispe Pilco, MD, Principal investigator, National Maternal and Perinatal Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07549776
- Sponsor's protocol ID
- 0107-DG-0080-OEAIDE-I
- Acronym
- USLMCSEOB
- Status last verified
- Jul 2026
- First submitted
- 9 Apr 2026
- Last updated
- 7 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: URL address will be offered or information will be sent by email.
Publications
Khoo AK, Huynh A, Pelecanos A, Eley VA. Does preprocedural ultrasound prior to lumbar neuraxial anesthesia or analgesia increase first-pass success in adults with obesity? A systematic review. Health Sci Rep. 2024 Nov 6;7(11):e70039. doi: 10.1002/hsr2.70039. eCollection 2024 Nov.
PubMed 39507679Zhang Y, Peng M, Wei J, Huang J, Ma W, Li Y. Comparison of ultrasound-guided and traditional localisation in intraspinal anesthesia: a systematic review and network meta-analysis. BMJ Open. 2023 Nov 2;13(11):e071253. doi: 10.1136/bmjopen-2022-071253.
PubMed 37918920Li M, Ni X, Xu Z, Shen F, Song Y, Li Q, Liu Z. Ultrasound-Assisted Technology Versus the Conventional Landmark Location Method in Spinal Anesthesia for Cesarean Delivery in Obese Parturients: A Randomized Controlled Trial. Anesth Analg. 2019 Jul;129(1):155-161. doi: 10.1213/ANE.0000000000003795.
PubMed 30234528Perlas A, Chaparro LE, Chin KJ. Lumbar Neuraxial Ultrasound for Spinal and Epidural Anesthesia: A Systematic Review and Meta-Analysis. Reg Anesth Pain Med. 2016 Mar-Apr;41(2):251-60. doi: 10.1097/AAP.0000000000000184.
PubMed 25493689
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ultrasound-guided Versus Landmark-based Spinal Anesthesia in Obese Parturients Undergoing Cesarean Section: a Prospective Comparative Study
- ClinicalTrials.gov ID
- NCT07549776
- Acronym / sponsor ID
- USLMCSEOB / 0107-DG-0080-OEAIDE-I
- Conditions
- Obesity, Cesarean Section
- Keywords
- Ultrasonography, Spinal anesthesia, Cesarean section, Obesity, Neuraxial anesthesia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 100 participants (actual)
- Lead sponsor
- Instituto Nacional Materno Perinatal, PeruUniversity, hospital or other
- Study start
- 1 Jul 2025 (actual)
- Primary completion
- 1 Jan 2026 (actual)
- Study completion
- 1 Jan 2026 (actual)
- First posted
- 24 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Spinal anesthesia is the most commonly used anesthetic technique for cesarean section. However, in obese parturients, identification of the optimal puncture site using anatomical landmark palpation can be challenging because of altered anatomy. Preprocedural ultrasound has been proposed as a tool to improve localization of the puncture site and facilitate neuraxial access.
This is a prospective comparative study included 100 obese parturients undergoing cesarean section under spinal anesthesia. Participants were allocated to one of two comparison groups according to the puncture site localization technique: a preprocedural ultrasound group and an anatomical landmark palpation group.
The primary outcome is the first-attempt success rate, defined as successful cerebrospinal fluid return after the first needle insertion without needle redirection or a new skin puncture. Secondary outcomes include the number of puncture attempts, needle redirections, need for rescue interventions, incidence of paresthesia and vascular puncture during the procedure, and procedural times.
Detailed description
This prospective comparative study aims to evaluate the effectiveness of preprocedural ultrasound-guided marking compared with the conventional anatomical landmark palpation technique for spinal anesthesia in obese parturients undergoing cesarean section.
A total of 100 parturients with a body mass index (BMI) ≥ 30 kg/m² were prospectively allocated to one of two comparison groups according to the puncture site localization technique. In the ultrasound group, the puncture site was identified using preprocedural ultrasound to determine the optimal intervertebral space and needle insertion trajectory. In the landmark group, the puncture site was identified using conventional anatomical landmark palpation.
The primary outcome was the first-attempt success rate, defined as successful cerebrospinal fluid return after the first needle insertion without needle redirection or an additional skin puncture. Secondary outcomes included the number of puncture attempts, needle redirections, need for rescue interventions, incidence of paresthesia and vascular puncture during needle insertion, and procedural times (site identification time, puncture time, and total procedure time).
This study evaluated whether preprocedural ultrasound-guided marking improves the technical performance of spinal anesthesia compared with conventional anatomical landmark palpation in obese parturients undergoing cesarean section.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Participants were prospectively allocated to one of two comparison groups according to the puncture site localization technique (preprocedural ultrasound marking or anatomical landmark palpation) before spinal anesthesia.
| Arm | Type | Receives |
|---|---|---|
| Ultrasound-guided group | Active comparator | Procedure: Ultrasound-guided preprocedural markingPreprocedural ultrasound was used to identify and mark the optimal puncture site in obese parturients undergoing cesarean section (n = 50). |
| Landmark-based group | Active comparator | Procedure: Landmark-based palpationThe puncture site was identified using anatomical landmark palpation in obese parturients undergoing cesarean section (n = 50) |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age ≥ 18 years
- Pregnant women undergoing cesarean section
- Body mass index (BMI) ≥ 30 kg/m² at the time of cesarean section
- Scheduled for cesarean section under spinal anesthesia
Key exclusion criteria (6 listed)
- Congenital spinal deformities
- History of spinal surgery
- Coagulopathy
- Infection at the puncture site
- Allergy to local anesthetics
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ultrasound-guided preprocedural markingPreprocedural ultrasound is used to identify and mark the optimal puncture site before spinal anesthesia. | Procedure or surgery | Ultrasound-guided group |
| Landmark-based palpationThe puncture site is identified using anatomical landmark palpation before spinal anesthesia. | Procedure or surgery | Landmark-based group |
Primary outcome
First-attempt success rate of spinal anesthesia
Time frame: During the spinal anesthesia procedure
Successful cerebrospinal fluid return after the first needle insertion without redirection.
7 secondary outcomes
Number of puncture attempts
Time frame: During the spinal anesthesia procedure
Number of needle redirections
Time frame: During the spinal anesthesia procedure
Need for rescue intervention
Time frame: During the spinal anesthesia procedure
Incidence of paresthesia
Time frame: During the spinal anesthesia procedure
Incidence of vascular puncture
Time frame: During the spinal anesthesia procedure
Total procedure time
Time frame: During the spinal anesthesia procedure
Puncture time
Time frame: During the spinal anesthesia procedure
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2026.
- Background: PubMed 39507679Khoo AK, Huynh A, Pelecanos A, Eley VA. Does preprocedural ultrasound prior to lumbar neuraxial anesthesia or analgesia increase first-pass success in adults with obesity? A systematic review. Health Sci Rep. 2024 Nov 6;7(11):e70039. doi: 10.1002/hsr2.70039. eCollection 2024 Nov.
- Background: PubMed 37918920Zhang Y, Peng M, Wei J, Huang J, Ma W, Li Y. Comparison of ultrasound-guided and traditional localisation in intraspinal anesthesia: a systematic review and network meta-analysis. BMJ Open. 2023 Nov 2;13(11):e071253. doi: 10.1136/bmjopen-2022-071253.
- Background: PubMed 30234528Li M, Ni X, Xu Z, Shen F, Song Y, Li Q, Liu Z. Ultrasound-Assisted Technology Versus the Conventional Landmark Location Method in Spinal Anesthesia for Cesarean Delivery in Obese Parturients: A Randomized Controlled Trial. Anesth Analg. 2019 Jul;129(1):155-161. doi: 10.1213/ANE.0000000000003795.
- Background: PubMed 25493689Perlas A, Chaparro LE, Chin KJ. Lumbar Neuraxial Ultrasound for Spinal and Epidural Anesthesia: A Systematic Review and Meta-Analysis. Reg Anesth Pain Med. 2016 Mar-Apr;41(2):251-60. doi: 10.1097/AAP.0000000000000184.
- Individual participant dataSharing planned: Yes. URL address will be offered or information will be sent by email.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Eddisson R Quispe Pilco, MD principal investigator
National Maternal and Perinatal Institute
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultrasound-guided preprocedural marking and Landmark-based palpation in people with Obesity and Cesarean Section, run by Instituto Nacional Materno Perinatal, Peru at 1 site in Peru.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 7 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Peru. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
First-attempt success rate of spinal anesthesia (time frame: During the spinal anesthesia procedure). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07549776, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Jul 2026.