SITE OF CENTRAL VENOUS ACCESS IS NOT IMPORTANT FOR FLUID RESUSCITATION AND MONITORING
Objective: To find the correlation between thoracic and femoral central venous pressure (CVP) and changes in femoral CVP, if any, incurred by intra-abdominal pressure.
Study Design: Cross sectional observational study.
Place and Duration of Study: Coronary care unit of National Institute of Cardiovascular Diseases Karachi, from Jul 2017 to Sep 2017.
Material and Methods: We randomly selected 90 patients who had a thoracic central catheter and another femoral catheter in place. A central venous pressure (CVP) pressure was recorded at both sites simultaneously with the same electronic transducer after zero calibration. An intra-abdominal pressure was also noted.
Results: Ninety patients participated in our study where mean age was 58.90 ± 11.34 years. The mean thoracic CVP was 11.22 ± 3.53 mmHg while mean femoral CVP was 11.38 ± 3.53 mmHg, with a mean pressure difference of -0.16 mmHg between the two. We also calculated intra-abdominal pressure with mean of 6.20 ± 2.47 mmHg. The reliability of the two methods was determined by intra class coefficient model where we got a higher value of 0.97 with significant p-value of <0.001. We analyzed the limits of agreement between the two approaches by Bland and Altman plot, where the mean difference between thoracic and femoral CVP was -0.16 mmHg (95 % CI - 0.34 - 0.02).
Conclusion: Central venous pressure can be reliably and accurately measured through femoral site.