Predictors of Epidural Depth in Percutaneous Nephrolithotomy and Model Development
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In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Epidural Anesthesia, Percutaneous Nephrolithotomy (PCNL). Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- China
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Analysis of Factors Influencing Epidural Depth in Patients Undergoing Percutaneous Nephrolithotomy and Development of a Predictive Model
Overview
Accurate estimation of epidural depth is critical for safe epidural anesthesia during percutaneous nephrolithotomy (PCNL). Although various imaging modalities can predict epidural depth, they increase healthcare burden and are not always feasible in emergency or bedside settings. Identifying simple, easily obtainable clinical parameters-such as sex, age, and body mass index (BMI)-for predicting epidural depth has become a research priority. However, systematic investigations specifically targeting the Chinese population remain scarce. This retrospective study aims to identify independent factors influencing epidural depth in PCNL patients and to develop simple, level-specific predictive models for different puncture sites, thereby providing a practical reference for clinical epidural anesthesia.
Detailed description
Percutaneous nephrolithotomy (PCNL) is the standard minimally invasive surgical procedure for removal of kidney stones larger than 2 cm and is established as the gold standard for the management of complex renal calculi. This procedure may be performed under either general anesthesia or regional anesthesia, including epidural or spinal anesthesia. Accumulating meta-analyses have demonstrated that, compared with general anesthesia, regional anesthesia is associated with reduced postoperative pain scores and lower total hospital costs, without compromising the stone-free rate. Furthermore, in awake patients undergoing regional anesthesia, respiratory movements may generate a so-called "respiratory-synchronous stone fragmentation effect," which facilitates the expulsion of stone debris.
Successful epidural anesthesia relies critically on accurate identification of the epidural space and precise control of puncture depth. Insufficient puncture depth may result in improper catheter placement and subsequent block failure, whereas excessive puncture depth increases the risk of dural puncture, leading to cerebrospinal fluid leakage and post-dural puncture headache. In severe cases, inadvertent injection of a large dose of local anesthetics into the subarachnoid space can cause life-threatening cardiovascular and respiratory depression. Therefore, preprocedural estimation of the skin-to-epidural space distance is of considerable clinical importance.
Although racial differences in epidural depth have been reported, systematic investigations specifically targeting the Chinese population remain scarce. Various imaging modalities, including computed tomography, magnetic resonance imaging, and ultrasound, can be used to predict epidural depth. However, these examinations increase healthcare burden and are not always feasible in emergency or bedside settings. Consequently, identifying simple, easily obtainable clinical parameters-such as sex, age, and body mass index (BMI)-for predicting epidural depth has become a research priority.
In this context, the present study aimed to identify factors influencing epidural depth through a retrospective analysis of clinical data from PCNL patients and to develop simple, level-specific predictive models for different puncture sites, thereby providing a practical reference for clinical epidural anesthesia.
Primary outcome measures
- Epidural depth [Time frame: Perioperative/Periprocedural]
Secondary outcome measures (2)
- Adjusted R² [Time frame: through study completion, an average of 1 month]
- Root mean square error (RMSE) [Time frame: through study completion, an average of 1 month]
Eligibility criteria
Inclusion criteria
- Age ≥ 18 years
- Successful epidural puncture and catheter placement using the midline approach
- Clear documentation of puncture level and puncture depth in the anesthesia record
Exclusion criteria
- Dural puncture during anesthesia (including those who subsequently had a successful repuncture)
- Use of the paramedian approach for epidural puncture
- Uncertain epidural anesthesia effect requiring combined general anesthesia
- Incomplete clinical data
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Other
Study locations
China · 1 center
- Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology — Wuhan
Identifiers
NCT: NCT07697053 · EDPN