Low central venous pressure is not associated with low perfusion event in the setting of septic shock: A randomized controlled trial

Background: Guyton’s concept of hemodynamic physiology shows that venous return depends on the value of central venous pressure (CVP); the lower CVP value, the higher gap between CVP and mean circulatory filling pressure (MCFP), and so the venous return and cardiac output. However, the association between CVP value and microcirculation perfusion has not been revealed. Our study was performed to investigate the association between low and high CVP values with microcirculation and perfusion in septic shock patients. Methods: This randomized clinical trial was performed in an adult intensive care unit (ICU) of a referral hospital. Data collection began after the ethics certificate and location permissions were released. Included samples were patients with septic shock according to the latest definition and aged 18 to 60 years. Patients with primary heart problems, right heart failure or congenital heart disease, chronic severe obstructive pulmonary . disease, kidney stones or tumors, and chronic kidney disease were excluded. Subjects were divided into two groups: low (0-4 mmHg) and high (8-10 mmHg) CVP. CVP and perfused vessel density (PVD) in sublingual microcirculation were measured accordingly. Results: There were 43 subjects: 22 subjects with low CVP and 21 with high CVP. PVD on day-0 to day-7 examination in low CVP compared to high CVP group, respectively, were 12.5 (7.0-15.4) vs 13.85 (3.4-15.6) (p=0.903); 12.9 (7.6-17.9) vs 8.5 (1.4-17.5) (p=0.036); 12.7 (6.5-15.5) vs 12.85 (7.6-18.2) (p=0.800); 11.5 (3.8-32.5) vs 10.35 (1.3-14.2) ( p=0.435); 13.3 (7.1-17.5) vs 11.6 (2.7-18.6) (p=0.586); 9.9 (1.0-14.6) vs 10.45 (4.0-15.8) (p=0.918); 10.0 (3.5-17.1) vs 11.9 (4.1-16.3) (p=0.498); and 10.2 (4.3-13.3) vs 13.45 (4.8-16.7) (p=0.074). Conclusion: There was no significant difference in microcirculation perfusion between the low and high CVP groups.