Study of Relationship between Central Venous Pressure and Peripheral Venous Pressure during Intraoperative Period in Neurosurgical Patients

Abstract

IntroductionPatients undergoing neurosurgery are at risk of significant blood loss and resulting hemodynamic changes. In case of sudden blood loss, volume of blood in arteries is maintained at expense of that in veins, manifesting as low central venous pressure (CVP) 1 associated with tachycardia initially and, a fall in arterial pressure is a late sign of hypovolemia. Monitoring of CVP is, therefore, of great assistance during hypovolemia.CVP is the pressure within the intrathoracic venae cavae, measured by insertion of catheter via the internal jugular or subclavian vein, which is normally equal to the right atrial pressure, unless there is obstruction in the venae cavae. The value used in clinical practice is the pressure recorded at the base of c-wave, at the end of expiration, while the subject is supine. This represents the pressure in the right atrium immediately before the start of ventricular systole. 2 CVP is often used to estimate right ventricular preload, which 15Background and Objectives Central venous pressure (CVP) and peripheral venous pressure (PVP) are strongly correlated during various surgeries. This study was designed to examine the consistency of CVP-PVP relationships in circumstances of rapidly fluctuating hemodynamics in neurosurgical patients. Prime objective of this study was to determine if PVP can be an effective alternative to invasive CVP for assessing volume status during neurosurgical procedures when expertise, equipment, and patient's condition contraindicate invasive monitoring. Subjects and Methods After the approval by the Institutional Ethics Committee, CVP and PVP were measured in 50 neurosurgical patients of the American Society of Anesthesiologists grade I and II operated in supine position. Paired measurements of CVP and PVP were made every 20 minutes, from the starting of anesthesia until the end of surgery; however, in situations of hemodynamic instability, the readings were taken every 5 minutes of interval. Results The study showed a strong correlation between CVP and PVP (Pearson's correlation coefficient between CVP and PVP, r = 0.89; 95% CI: 0.81-0.93; p < 0.001). Mean CVP was 5.7 ± 0.8 mm of Hg, mean PVP was 10.4 ± 0.6 mm of Hg, and bias between CVP and PVP was 4.7 ± 0.4 (95% CI: − 4.61 to − 4.83). The Bland-Altman analysis showed that limit of agreement to be 4.0 to 5.5 mm of Hg. Conclusion This study demonstrated a strong correlation between CVP and PVP. Therefore, PVP monitoring may be a reliable alternative to CVP monitoring during neurosurgery.

Comparison between Peripheral and Central Venous Catheters Regarding Venous Pressure and Complications among Critically Ill Patients

“…Practicing a modern hemodynamic observation method at the stand of evidence and scientific reasoning will open a new gateway to less complicated yet effective critical care to patients [1].Some studies were conducted among critically ill patients and found the agreement's degree is a high between CVP and PVP [1,22]. Stated the monitoring of PVP could be utilized as a normal, priceimpacting as well as a minimum intrusive alternative to monitoring the CVP and with low morbidity complications [23,24].…”