Relation between central venous pressure values and outcome in critically ill patients

Background Central venous pressure (CVP) was the most commonly used parameter to guide fluid responsiveness. However, recent studies showed that there is no correlation between CVP and circulating blood volume, and CVP more than 8 mmHg is independently associated with a higher mortality and increased risk of acute kidney injury in patients with sepsis and heart failure.Objective The aim of this study was to assess the effect of CVP over 7 days after ICU admission on clinical prognosis and mortality.Patients and methods The study was conducted on 218 patients in whom hemodynamic monitoring was required, and CVP was measured from the first day of ICU admission. Three values of CVP were selected to be measured (the values once inserted, the peak values, and the mean values of CVP) throughout the monitoring process over 7 days of ICU admission. Acute Physiology and Chronic Health Evaluation II score was calculated on admission, and Sequential Organ Failure Assessment (SOFA) score was calculated every other day. Length of ICU stay, mechanical ventilation days, and mortality at days 7 and 28 were recorded.Results Although the initial CVP values were only correlated with mean of SOFA scores, mean and peak CVP values were correlated with Acute Physiology and Chronic Health Evaluation II score, mean SOFA score, mechanical ventilation days, and mortality. Only peak CVP showed correlation with mean creatinine, and only mean CVP values were correlated with length of ICU stay. According to mean CVP values, patients were classified as low CVP (<8 mmHg), intermediate CVP (8–12 mmHg), and elevated CVP (>12 mmHg). The elevated mean CVP group was associated with increased 28-day mortality, and regarding further investigations such as renal function, duration of mechanical ventilation, and laboratory results related to organ dysfunction, it also demonstrated that higher mean CVP group was associated with poor ICU outcome for patients in ICU settings.Conclusion The study showed that for patients in ICU settings, elevated mean CVP load was associated with poor clinical outcome and prolonged treatment in ICU. Level and duration of elevated mean CVP should be evaluated, and more effort should be made to establish the cause and appropriate treatment for elevated mean CVP.