Editor’s note: This post is by Anne Dabrow Woods, MSN, RN, CRNP, who is AJN‘s publisher and chief nurse and publisher of Wolters Kluwer Health Medical Research. It was originally published on the blog of Lippincott’s Evidence-Based Practice Network.
I read with interest the article “Central Venous Pressure Monitoring: Where’s the Evidence?” (purchase required for nonsubscribers) in the January issue of AJN. It’s part of a series called Critical Analysis, Critical Care, which will appraise the evidence regarding common critical care practices. So much of what we do in nursing is not based on evidence but on how we have always done things in practice—or on research that was not credible.
This article looks at the evidence supporting the use of central venous pressure (CVP) monitoring alone to guide treatment decisions for patients. According to the article, a 2008 systematic review by Marik and colleagues concluded that CVP is not an accurate indicator of intravascular volume, nor is it an accurate predictor of fluid responsiveness (whether a patient will respond to a fluid bolus with an increase in stroke volume). The authors of the AJN article critically appraised the evidence and determined the following:
- The relationship between intravascular volume and CVP is a weak relationship and clinicians should not use CVP to estimate a patient’s intravascular volume.
- The absolute CVP value or a change in CVP should not be used to predict a change in the stroke volume or cardiac index.
- There is not an absolute CVP value that can be used to determine what the next step of treatment should be, be it a fluid bolus or the use of a vasoactive medication.
In brief, the evidence tells us that we can’t base treatment decisions on just one hemodynamic indice. The clinician needs to look at the entire hemodynamic picture, including, for example, heart rate, blood pressure, mean arterial pressure, and urine output, when determining the best treatment option for the patient.
Kupchik, N. & Bridges, E., 2012. Central venous pressure monitoring: what’s the evidence? American Journal of Nursing. 112 (1).
Marik, P. et al. 2008. Does central venous pressure predict fluid responsiveness? A systematic review of the literature and the tale of seven mares. Chest. 134(1).