Aim

 This study was conducted to assess the degree of relationship between peripheral venous pressure and central venous pressure in patients undergoing CABG. 

Background

 Although, cannulation of a large central vein is the standard method for monitoring central vein pressure and providing secure vascular access, this method has serious complications. Moreover, previous studies in adults have demonstrated a clinically useful correlation between central and peripheral venous pressure. 

Method

 In this cross-sectional study, 100 adult patients with the mean age of 61 years that underwent coronary artery bypass graft surgery in Shahid Rajaei Heart Center were enrolled. Peripheral venous pressure through a short 16-18 G catheter and central venous pressure through central line (inserted in right-internal jugular or subclavian vein) were monitored simultaneously in 5 stages: following the induction of anesthesia before, after and during cardiopulmonary bypass and after sternum closure. The results were analyzed by SPSS.  

Findings

 Findings indicated that the mean value of peripheral venous pressure was 11 mmHg and the mean value of central venous pressure was 9.5 mmHg, therefore the mean difference was 2±0.5 mmHg. The correlation of peripheral venous pressure and central venous pressure was 0.95 (P≤0.001) in all 5 evaluating times. Changes in other parameters did not affect the relationship between these two parameters. 

Conclusion

 We concluded that peripheral venous pressure can be used as a predictor of central venous pressure in patients with coronary artery bypass graft surgery.

Abstract

Aim.This study aimed to compare pulse pressure variation (PPV) with central venous pressure (CVP) in checking out and optimizing fluid volume in mechanically ventilated patients admitted to intensive care unit after cardiac surgery.

Background.In clinical area, assessment of body fluid and determination of the intravascular volume  after major surgeries such as heart surgery is a significant challenge. The initial purpose of intravascular volume assessment in patients with hemodynamic instability is to determine whether they would benefit from fluid administration or not.

Method. In the present study a prospective descriptive-analytic design was used. Thirty mechanically ventilated patients admitted to intensive care units of Rajaee Heart Center, Tehran, Iran, were recruited in the study after cardiac surgery based on inclusion criteria. Data collection tools included demographic and clinical data sheets. Hemodynamic parameters such as CVP, systolic and diastolic pressures (for calculating pulse pressure and its variation) were recorded by bedside monitoring. Cardiac Index (CI) was measured by non invasive continuous cardiac output monitoring (NICCOMO) system. Data were analyzed in SPSS version 20, using statistical tests.

Findings. The mean changes of CVP, before and five minutes after fluid administration, were significantly different (10.10±6.01 mmHg and 12.37±6.34 mmHg, respectively, p=0.015). The mean changes in arterial pulse pressure, before and five minutes after fluid administration, were significantly different (16.94±8.32 mmHg and 12.77±4.02 mmHg, respectively, P=0.005). At the cut point 2.8 lit/min/m2 for CI, the sensitivity and specificity values for PPV>13%, were 0.71 and 0.61, respectively. Also, at the same cut point, the sensitivity and specificity values for CVP<5mmHg, were 0.11 and 0.84, respectively. These findings suggest a higher diagnostic power  of  PPV compared to CVP to assess fluid volume.

Conclusion.It seems that in the mechanically ventilated patients after heart surgery, PPV dynamic index is preferred to CVP static index to evaluate and maintain fluid volume.