I read with interest the article "Central Venous Pressure Monitoring: What's the Evidence",
that was published in the January issue of the American Journal of Nursing (AJN). AJN is running 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, rather based on how we have always done things in practice or based on research that was not credible.
This article looks at the evidence behind using 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 intravasuclar volume, nor is it an accurate predictor of fluid responsiveness-that is, whether a patient will respond to a fluid bolus with an increase in stroke volume (Marik, P., 2008). The authors of the AJN article critically appraised the evidence and determined:
- 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, either a fluid bolus or the use of a vasoactive medication (Kupchik, N. & Bridges, E., 2012).
What does the evidence tell us? It tells us we can not base treatment decisions on one hemodynamic indice. Rather, when making treatment decisions, the clinician needs to look at the entire hemodynamic picture including heart rate, BP, MAP, and urine output for example, when determining what is 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).
Anne Dabrow Woods MSN RN CRNP
Chief Nurse and Publisher