Pregnancy Related
Conditions
Keywords
Anatomical Landmarks
Brief summary
This study is a randomized clinical trial to evaluate the accuracy of the novel SAIL technique compared to the classic intercristal line technique in estimating the L4-L5 interspace for labor epidural or spinal anesthesia placement. The investigators hypothesize that the SAIL technique will be more accurate in successfully locating the L4-L5 interspace in pregnant women than the classic intercristal line technique.
Detailed description
The current standard technique aiming at identifying the L4-L5 intervertebral space as a reference point before performing a neuraxial block relies on the correct clinical estimation of the intercristal line. The classic intercristal line technique uses an imaginary line that intersects the iliac crests to determine a safe puncture level to access. In pregnant women, the classic technique fails to identify the safe puncture level 40 % of the time. The newly proposed Sacral Anatomical Interspace Landmark (SAIL) technique consists of using the sacral bone to determine a safe puncture level to access. Lumbar ultrasound will determine the accuracy of each clinical technique in identifying the L4-L5 interspace (target).
Interventions
OTHERClassic Intercristal Line Technique
Researcher will use the classic technique to estimate the L4-L5 interspace. The classic technique begins by palpating both the right and left posterior iliac crests and following the imaginary line that intersects each (intercristal line) with the non-dominant hand to the spine where it is estimated to intersect the L4 spinous process or L4-L5 interspace. A marker pen will mark an X lateral to the estimation, opposite side from the estimation of the other technique.
OTHERNovel SAIL Technique
Researcher will use the novel technique to estimate the L4-L5 interspace. The SAIL technique begins by palpating the sacrum and the researcher sliding the non-dominant hand up the dorsal surface of the sacrum to the first interspace (L5-S1) and then up one more interspace to estimate the L4-L5 interspace. A marker pen will mark an X lateral to the estimation, opposite side from the estimation of the other technique.
Sponsors
University of Michigan
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Masking description
The estimation marks from each technique (two total) will be on the back of the patient (one on the left flank, one on the right flank), therefore the patient does not know where the marks are. Additionally, each mark will be covered with a taped on gauze pad to conceal it so that the two investigators are blinded to each others assessment. The ultrasound clinician will be masked to the two estimations. The marks will still remain covered while the interspace is determined by the third assessor using lumbar ultrasound.
Intervention model description
All patients will undergo estimation of the L4-L5 interspace using the classic and novel technique, followed by identification of the interspace using lumbar ultrasound.
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Ultrasound-determined gestation age greater than or equal to 37 weeks * Expressed interest or indication for epidural anesthesia * Patients in the first stage of labor
Exclusion criteria
* Patients perceived or indicating that she is unable to cooperate with positioning * BMI greater than 45 kg/m2 * Previous spine surgery or known spinal deformities * Impaired decision making abilities * non-English speaking
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Accuracy, as measured by percentage of estimations that correctly match ultrasound determined interspace | From enrollment to the end of data collection, approximately 15 minutes | Percentage of trials for the novel and classic technique respectively that the estimation correctly matches the L4-L5 interspace as determined by lumbar paramedian ultrasound will serve as a measure of accuracy |
Countries
United States
Outcome results
None listed