Is Femoral Vein Diameter a Reliable Marker of Central Venous Pressure?

Objective: To determine the correlation of femoral vein diameter with central venous pressure.Study Design:  Cross-sectional analytical study.Place and Duration of Study: The study was carried out at the Intensive Care Unit (ICU) of Combined Military Hospital (CMH), Peshawar, Pakistan from March 2021 to July 2021.Materials and Methods: This study was done on patients aged ≥18 years who were admitted to the intensive care unit and had a central venous line passed. Patients with lower extremity deep vein thrombosis, conditions associated with raised intra-abdominal pressure like pregnancy or recent laparotomy and those unable to lie supine were excluded. Central venous pressure was measured by a manual manometer. Femoral vein diameter was also measured in horizontal and vertical dimensions at the bedside and the mean was calculated.   Results: There were 150 patients, including 109 (72.7%) males and 41 (27.3%) females, with a mean age of 36.53 ± 13.83 years. Mechanical ventilation was given to 17 (11.33%) patients. The mean central venous pressure and femoral vein diameter were 8.82 ±3.87 cm and 9.36 ± 3.14 cm, respectively. The overall regression was statistically significant (r=0.407, p<0.001). Femoral vein diameter significantly predicted central venous pressure (0.502, p<0.001).Conclusion: Femoral vein diameter can be used as a bedside non-invasive method to determine central venous pressure.