Observational studyBMJ open2025
The effect of passive leg raising on the cross-sectional area of the right internal jugular vein in obese patients undergoing surgery: a prospective observational study.
Observational study in BMJ open, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
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Who cites it
2 citing papers in PubMed.
- Effect of 10 cm H₂O positive end-expiratory pressure on right internal jugular vein cross-sectional area in obese patients under general anesthesia: a prospective observational study.BMC anesthesiology · 2026Observational
- Ultrasound-guided supraclavicular internal jugular vein compression to increase internal jugular vein cross-sectional area in hospitalized patients: a prospective observational study in Japan.Acute and critical care · 2025Article
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Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesTo observe the association between passive leg raising (PLR) and the cross-sectional area (CSA) of the right internal jugular vein (IJV) in obese patients undergoing elective surgery.
designProspective observational study with randomised position sequence.
settingSingle-centre, tertiary care hospital in Shanghai, China.
participantsForty obese patients (body mass index (BMI) >30 kg/m²) scheduled for elective surgery were enrolled. Inclusion criteria were American Society of Anesthesiologists Physical Status Classification (ASA) physical status II-III and age ≥18 years. Exclusion criteria included history of neck surgery, severe cardiovascular disease, end-stage renal disease, severe infection or sepsis and significant coagulopathy. OBSERVATIONS: Patients underwent ultrasound measurements of the right IJV in two positions: supine (S0) and passive leg raise at 40° (PLR40). Each position was maintained for at least 1 min prior to measurement. PRIMARY OUTCOME: The primary outcome was to observe whether the CSA of the right IJV differed between the S0 position and passive leg elevation. In post hoc analyses, we examined factors affecting the relative CSA change (CSAγ), including neck circumference, BMI, age, sex, ASA physical status and heart rate as predictors.
resultsThe CSA of the right IJV was significantly larger in the PLR40 position (2.05 cm²) compared to the S0 position (1.67 cm², p=0.003). Linear regression analysis showed a slight positive correlation between neck circumference and the percentage change in CSA (correlation coefficient: 0.066, p<0.05).
conclusionThe CSA of the right IJV was significantly larger in the PLR40 position in obese patients undergoing surgery. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry ChiCTR2400080513.
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