Correlation of peripheral venous pressure and central venous pressure in surgical patients

OBJECTIVE: To determine the degree of agreement between central venous pressure (CVP) and peripheral venous pressure (PVP) in surgical patients. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Patients without cardiac dysfunction undergoing major elective noncardiac surgery (n = 150). MEASUREMENTS AND MAIN RESULTS: Simultaneous CVP and PVP measurements were obtained at random points in mechanically ventilated patients during surgery (n = 100) and in spontaneously ventilating patients in the postanesthesia care unit (n = 50). In a subset of 10 intraoperative patients, measurements were made before and after a 2-L fluid challenge. During surgery, PVP correlated highly to CVP (r = 0.86), and the bias (mean difference between CVP and PVP) was -1.6 +/- 1.7 mmHg (mean +/- SD). In the postanesthesia care unit, PVP also correlated highly to CVP (r = 0.88), and the bias was -2.2 +/- 1.9 (mean +/- SD). When adjusted by the average bias of -2, PVP predicted the observed CVP to within +/-3 mmHg in both populations of patients with 95% probability. In patients receiving a fluid challenge, PVP and CVP increased similarly from 6 +/- 2 to 11 +/- 2 mmHg and 4 +/- 2 to 9 +/- 2 mmHg. CONCLUSION: Under the conditions of this study, PVP showed a consistent and high degree of agreement with CVP in the perioperative period in patients without significant cardiac dysfunction. PVP -2 was useful in predicting CVP over common clinical ranges of CVP. PVP is a rapid noninvasive tool to estimate volume status in surgical patients.     

Peripheral venous pressure predicts central venous pressure poorly in pediatric patients

Purpose: Using peripheral venous pressure (PVP) instead of central venous pressure (CVP) as a volume monitor decreases patient risks and costs, and is convenient. This study was undertaken to determine if PVP predicts CVP in pediatric patients. METHODS: With ethical approval and informed consent, 30 pediatric patients aged neonate to 12 yr requiring a central venous line were studied prospectively in a tertiary care teaching hospital. In the supine position, PVP and CVP were simultaneously transduced. Ninety-six paired recordings of CVP and PVP were made. Correlation and Bland-Altman analysis of agreement of end-expiratory measurements were performed. RESULTS: The mean (SD; range) CVP was 10.0 mmHg (6.0; -1.0 to 27.0); the mean PVP was 13.7 mmHg (6.3; 0.0 to 33.0); offset (bias) of PVP > CVP was 3.7 mmHg with SD 2.6. The 95% confidence intervals (CI) for the bias were 3.2 to 4.1 mmHg. In the Bland-Altman analysis, lower and upper limits of agreement (LOA; CI in parentheses) were -1.5 (-2.3 to -0.7) and 8.8 (8.1 to 9.6) mmHg. Eight of 96 points were outside the limits of agreement. The correlation of PVP on CVP was r = 0.92, P < 0.0001. For a subset of ten patients (20 simultaneous recordings) with iv catheters proximal to the hand, limits of agreement were better - offset: 3.8 mmHg (+/- 1.4); lower LOA: 1.2 mmHg (0.25 to 2.1); upper LOA: 6.6 mmHg (5.7 to 7.5). CONCLUSION: Peripheral venous pressure measured from an iv catheter in the hand predicts CVP poorly in pediatric patients.     

Can peripheral venous pressure be an alternative to central venous pressure during right hepatectomy in living donors?

The safety of living donors is a matter of cardinal importance in addition to obtaining optimal liver grafts to be transplanted. Central venous pressure (CVP) is known to have significant correlation with the amount of bleeding during parenchymal transection and many centers have adopted CVP monitoring for right hepatectomy. However, central line cannulation can induce some serious complications. Peripheral venous pressure (PVP) has been suggested as a comparable alternative to CVP. The aim of this study was to determine whether a clinically acceptable agreement or a reliable correlation between CVP and PVP exist and if CVP can be replaced by PVP in living liver donors. A central venous catheter was placed through the right internal jugular vein and a peripheral venous catheter was inserted at antecubital fossa in the right arm. CVP and PVP were recorded in 15-minute intervals in 50 adult living donors. The paired data were divided into 3 stages: preparenchymal transection, parenchymal transection, and postparenchymal transection. A total of 1,430 simultaneous measurements of CVP and PVP were recorded. Overall, the PVP, CVP, and bias were 7.0+/-2.46, 5.9+/-2.32, and 1.16+/-1.12 mmHg, respectively. A total of 88.9% of all measurements were clinically within acceptable limits of bias (+/-2 mmHg). Regression analysis showed a high correlation coefficient between PVP and CVP (r=0.893; P<0.001) and the limits of agreement were -1.03 to 3.34 overall. In conclusion, frequencies of differences, bias, correlation coefficient, and limits of agreement between PVP and CVP remained relatively constant throughout the operation. Therefore, PVP measurement in the arm can be an alternative to predict CVP and further, obviate central venous catheter-related complications in living liver donors.     

Peripheral venous pressure is an alternative to central venous pressure in paediatric surgery patients

BACKGROUND: Peripheral venous pressure (PVP) is easily and safely measured. In adults, PVP correlates closely with central venous pressure (CVP) during major non-cardiac surgery. The objective of this study was to evaluate the agreement between CVP and PVP in children during major surgery and during recovery. METHODS: Fifty patients aged 3-9 years, scheduled for major elective surgery, each underwent simultaneous measurements of CVP and PVP at random points during controlled ventilation intraoperatively (six readings) and during spontaneous ventilation in the post-anaesthesia care unit (three readings). In a subset of four patients, measurements were taken during periods of hypotension and subsequent fluid resuscitation (15 readings from each patient). RESULTS: Peripheral venous pressure was closely correlated to CVP intraoperatively, during controlled ventilation (r=0.93), with a bias of 1.92 (0.47) mmHg (95% confidence interval = 2.16-1.68). In the post-anaesthesia care unit, during spontaneous ventilation, PVP correlated strongly with CVP (r = 0.89), with a bias of 2.45 (0.57) mmHg (95% confidence interval = 2.73-2.17). During periods of intraoperative hypotension and fluid resuscitation, within-patient changes in PVP mirrored changes in CVP (r = 0.92). CONCLUSION: In children undergoing major surgery, PVP showed good agreement with CVP in the perioperative period. As changes in PVP parallel, in direction, changes in CVP, PVP monitoring may offer an alternative to direct CVP measurement for perioperative estimation of volume status and guiding fluid therapy.     

Correlation of peripheral venous pressure and central venous pressure in kidney recipients

BACKGROUND AND OBJECTIVE: Previous studies in adults have demonstrated a clinically useful correlation between central venous pressure (CVP) and peripheral venous pressure (PVP). The current study prospectively compared CVP measurements from a central versus a peripheral catheter in kidney recipients during renal transplantation. METHODS: With ethics committee approval and informed consent, 30 consecutive kidney recipients were included in the study. We excluded patients who had significant valvular disease or clinically apparent left ventricular failure. For each of 30 patients, CVP and PVP were measured on five different occasions. The pressure tubing of the transducer system was connected to the distal lumen of the central or to the peripheral venous catheter for measurements following induction of anesthesia, after induction, 1 hour after induction, reperfusion of the kidney, and the end of the operation, yielding 150 hemodynamic data points. Each hemodynamic measurement included heart rate, mean arterial pressure, mean CVP, and mean PVP determined at end-expiration. RESULTS: The mean PVP was 13.5 +/- 1.8 mm Hg and the mean CVP was 11.0 +/- 1.5 mm Hg during surgery. The mean difference was 2.5 +/- 0.5 (P < .01). Repeated-measures analysis of variance indicated a highly significant relationship between PVP and CVP (P < .01) with a Pearson correlation coefficient of 0.97. CONCLUSION: Under the conditions of this study, PVP showed a consistently high agreement with CVP in the perioperative period among patients without significant cardiac dysfunction.     

Effect of catheter site on the agreement of peripheral and central venous pressure measurements in neurosurgical patients

STUDY OBJECTIVE: Previous studies suggest a correlation of central venous pressure (CVP) with peripheral venous pressure (PVP) in different clinical setups. The aim of this study was to investigate the effect of measurement site on PVP and its agreement with CVP in patients undergoing general anesthesia. DESIGN: Prospective randomized study. SETTINGS: University hospital. PATIENTS: Thirty patients of American Society of Anesthesiologists physical status I and II undergoing elective craniotomy. INTERVENTIONS: Patients were randomly assigned into Group A (antecubital; n=15) and Group D (dorsum hand; n=15) for antecubital and hand dorsum catheterization sites, respectively. Central venous pressure and PVP were monitored throughout the study. A total of 1925 simultaneous measurements were recorded at 5-minute intervals. Bland-Altman assessment for agreement was used for CVP and PVP in 2 groups. MEASUREMENTS: Peripheral venous pressure measurements were within the range of +/-2 mm Hg of CVP values, in 93.9% of the measurements in Group A, and in 91.2% of the measurements in Group D. Considering all measurements, mean bias was -0.072 mm Hg (95% CI, -0.134 to -0.010). Group A measurements showed a bias (CVP-PVP) of 0.173+/-3.557 mm Hg, whereas the bias was -0.122+/-4.322 mm Hg (mean+/-SDcorrected for repeated measurements) in Group D. All of the measurements were within mean+/-2SD of bias, which means that PVP and CVP are interchangeable in our clinical setting. CONCLUSION: Peripheral venous pressure measurement may be a noninvasive alternative for estimating CVP in patients undergoing elective neurosurgical operations. Measuring PVP from hand dorsum does not interfere with the agreement of CVP and PVP.     

Peripheral venous pressure as a hemodynamic variable in neurosurgical patients

Neurosurgical patients undergoing either craniotomy or complex spine surgery are subject to wide variations in blood volume and vascular tone. The ratio of these variables yields a pressure that is traditionally measured at the superior vena cava and referred to as "central venous pressure" (CVP). We have investigated an alternative to CVP by measuring peripheral venous pressure (PVP), which, in parallel animal studies, correlates highly with changes in absolute blood volume (r = 0.997). We tested the hypothesis that PVP trends parallel CVP trends and that their relationship is independent of patient position. We also tested and confirmed the hypothesis, during planned circulatory arrest, that PVP approximates mean systemic pressure (circulatory arrest pressure), which reflects volume status independent of cardiac function. PVP was compared with CVP across 1026 paired measurements in 15 patients undergoing either craniotomy (supine, n = 8) or complex spine surgery (prone, n = 7). Repeated-measures analysis of variance indicated a highly significant relationship between PVP and CVP (P < 0.001), with a Pearson correlation coefficient of 0.82. The correlation was best in cases with significant blood loss (estimated blood loss >1000 mL; r = 0.885) or hemodynamic instability (standard deviation of CVP > 2; r = 0.923). Implications: In patients undergoing either elective craniotomy or complex spine surgery, peripheral venous pressure (PVP) trends correlated with central venous pressure (CVP) trends with a mean offset of 3 mm Hg (PVP > CVP). PVP trends provided equivalent physiological information to CVP trends in this subset of patients, especially during periods of hemodynamic instability. In addition, measurements made during a planned circulatory arrest support the hypothesis that PVP approximates mean systemic pressure (systemic arrest pressure), which is a direct index of patient volume status independent of cardiac or respiratory activity.     

Usefulness of a central venous catheter during hepatic surgery

Aim: Central venous catheter (CVC) is often inserted during liver resection because a low central venous pressure (CVP) reduces blood loss and the procedure may be associated with circulatory impairment. The aim of the study was to evaluate the usefulness of a CVC besides the measurements of CVP, and whether peripheral venous pressure (PVP) measurement could be used reliably in place of CVP.
Methods: We conducted an observational study during a 16-month period. Number of CVC inserted, expected surgical difficulties, and intraoperative complications which could lead to treatment involving a CVC were prospectively recorded and analysed. Measurements of CVP and PVP were simultaneously obtained at different times during surgery. Bias and limits of agreement with their 95% confidence interval (95% CI) were calculated.
Results: Of the 101 patients included, 28 had expected surgical difficulties. Of the 75 CVCs inserted, only six (8%) were used for another purpose that CVP measurement in patients with expected surgical difficulties. A total of 124 measurements in 23 patients were recorded. Mean CVP was 4.8 ± 2.9 mmHg and mean PVP was 6.9 ± 3.1 mmHg ( P <0.0001). The bias was −2.1 ± 1.1 mmHg (95% CI: −2.3 to −1.9). When adjusted by the average bias of −2 mmHg, PVP predicted a CVP≤5 mmHg with a sensitivity and a specificity of 93% and 87%, respectively.
Conclusion: Routine insertion of a CVC should be discussed in patients without expected surgical difficulties. Thus, PVP monitoring may suffice to estimate CVP in uncomplicated cases.     

Effect of body temperature on peripheral venous pressure measurements and its agreement with central venous pressure in neurosurgical patients

Previous studies suggest a correlation of central venous pressure (CVP) with peripheral venous pressure (PVP) in different clinical settings. The effect of body temperature on PVP and its agreement with CVP in patients under general anesthesia are investigated in this study. Fifteen American Society of Anesthesiologists I-II patients undergoing elective craniotomy were included in the study. CVP, PVP, and core (Tc) and peripheral (Tp) temperatures were monitored throughout the study. A total of 950 simultaneous measurements of CVP, PVP, Tc, and Tp from 15 subjects were recorded at 5-minute intervals. The measurements were divided into low- and high-Tc and -Tp groups by medians as cutoff points. Bland-Altman assessment for agreement was used for CVP and PVP in all groups. PVP measurements were within range of +/-2 mm Hg of CVP values in 94% of the measurements. Considering all measurements, mean bias was 0.064 mm Hg (95% confidence interval -0.018-0.146). Corrected bias for repeated measurements was 0.173 +/- 3.567 mm Hg (mean +/- SD(corrected)). All of the measurements were within mean +/- 2 SD of bias, which means that PVP and CVP are interchangeable in our setting. As all the measurements were within 1 SD of bias when Tc was > or = 35.8 degrees C, even a better agreement of PVP and CVP was evident. The effect of peripheral hypothermia was not as prominent as core hypothermia. PVP measurement may be a noninvasive alternative for estimating CVP. Body temperature affects the agreement of CVP and PVP, which deteriorates at lower temperatures.     

The effect of the prone position on venous pressure and blood loss during lumbar laminectomy.

STUDY OBJECTIVE: To determine the effects of three different prone support systems (Andrews spinal surgery frame, Cloward surgical saddle, and longitudinal bolsters) on inferior vena cava (IVC) and superior vena cava (SVC) pressures; the validity of measuring central venous pressure (CVP) for the determination of ideal positioning of the patient; and the relationship among frame type, blood loss, and hemodynamic measurements. DESIGN: Prospective, randomized study of the hemodynamic effects of the prone position. SETTING: Inpatient surgery at a university hospital (regional spinal cord injury treatment center). PATIENTS: Eighteen patients free of significant coexisting disease (ASA physical status I and II) undergoing elective lumbar laminectomy. INTERVENTIONS: Patients were assigned to one of three support frames and measurement of SVC pressure, IVC pressure, and mean arterial pressures (MAP) were obtained supine, prone, and after repositioning. These pressures and measured blood loss were obtained every 15 minutes during the surgical laminectomy portion of the procedure. MEASUREMENTS AND MAIN RESULTS: Patients positioned on the Andrews frame had decreased mean SVC and IVC pressures from 8.7 mmHg and 8.4 mmHg in the supine position to 3.3 mmHg and 1.8 mmHg in the prone position, respectively (p less than 0.001). Prone position CVP also was significantly lower in the Andrews group compared with that in the other two groups (p less than 0.001). Repositioning efforts did not significantly decrease CVP. Blood loss was higher in the Cloward group (1,150 +/- 989 ml) than in the Andrews (245 +/- 283 ml) and bolsters (262 +/- 188 ml) groups (p less than 0.02). CONCLUSIONS: Increased blood loss was not associated with increased SVC or IVC pressure, nor was there any significant correlation between any demographic or hemodynamic variable and blood loss. There was no evidence that CVP is useful in determining the ideal prone position in patients undergoing lumbar laminectomy.     

Comparative utility of centrally versus peripherally transduced venous pressure monitoring in the perioperative period in spine surgery patients

Study ObjectiveTo compare central venous pressure (CVP) with peripheral venous pressure (PVP) monitoring during the intraoperative and postoperative periods in patients undergoing spine surgery.DesignProspective observational study.SettingUniversity-affiliated teaching hospital.Patients35 ASA physical status 1, 2, and 3 patients.InterventionsA peripheral catheter in the forearm or hand and a central catheter into the internal jugular vein were placed for PVP and CVP monitoring, respectively.MeasurementsCVP and PVP values were collected simultaneously and recorded electronically at 5-minute intervals throughout surgery and in the recovery room. The number of attempts for catheter placement, ease of use, maintenance, and interpretation were recorded. Patient comfort, frequency of complications, and cost were analyzed.Main resultsThe correlation coefficient between CVP and PVP was 0.650 in the operating room (P < 0.0001) and 0.388 in the recovery room (P < 0.0001). There was no difference between groups in number of attempts to place either catheter, maintenance, and interpretation with respect to PVP and CVP monitoring in the operating room. In the recovery room, the nurses reported a higher level of difficulty in interpretation of PVP than CVP, but no differences were noted in ease of maintenance. There were no complications related to either central or peripheral catheter placement. Patient comfort and cost efficiency were higher with a peripheral than a central catheter.ConclusionDuring clinically relevant conditions, there was limited correlation between PVP and CVP in the prone position during surgery and postoperatively in the recovery room.     

Cerebral venous sinus pressure in seated dogs: impact of PEEP, cervical venous compression, and abdominal compression

The authors studied the effects of positive end-expiratory pressure (10 cmH2O PEEP), abdominal compression, and neck compression on dural venous sinus pressure (VSP) in seated dogs. Abdominal compression increased the central venous pressure (CVP) as well as both the systemic arterial pressure and the cardiac output and thus may offer a useful substitute for an antigravity suit. Except when CVP was greater than 8 mmHg, there was little or no correlation between CVP and VSP. Moreover, each method increased VSP, but this effect was closely related to VSP prior to application of the method (pre-VSP). On comparing the VSP changes in relation to the pre-VSP levels when they were either above or below -1.0 mmHg, significant differences were noted in VSP increases, i.e., -0.4 +/- 1.3 (mean +/- SEM) and 4.3 +/- 1.2 mmHg by PEEP, 1.9 +/- 0.3 and 6.4 +/- 0.4 mmHg by abdominal compression, and 10.2 +/- 1.3 and 1.5 +/- 0.5 mmHg by neck compression, respectively. This indicates that PEEP and abdominal compression were more effective in increasing relatively highly negative pre-VSP (less than -1.0 mmHg), while neck compression greatly increased pre-VSP when it was at or above a slightly negative pressure (-1.0 mmHg). The authors conclude that a single application of any one of these three methods during sitting-position surgery may not be effective in increasing cerebral dural sinus pressure.     

Intraoperative fluid management during orthotopic liver transplantation

OBJECTIVE: To assess clinical safety of a low central venous pressure (CVP) fluid management strategy in patients undergoing liver transplantation. DESIGN: Retrospective record review comparing 2 transplant centers, one using the low CVP method and the other using the normal CVP method. SETTING: University-based, academic, tertiary care centers. PARTICIPANTS: Patients undergoing orthotopic cadaveric liver transplantation. INTERVENTIONS: Each center practiced according to its own standard of care. Center 1 maintained an intraoperative CVP <5 mmHg using fluid restriction, nitroglycerin, forced diuresis, and morphine. If pressors were required to maintain systolic arterial pressure >90 mmHg, phenylephrine or norepinephrine was used. At center 2, CVP was kept 7 to 10 mmHg and mean arterial pressure >75 mmHg with minimal use of vasoactive drugs. MEASUREMENTS and MAIN RESULTS: Data collected included United Network for Organ Sharing status, surgical technique, intraoperative transfusion rate, preoperative and peak postoperative creatinine, time spent in intensive care unit and hospital, incidence of death, and postoperative need for hemodialysis. Principal findings include an increased rate of transfusion in the normal CVP group but increased rates of postoperative renal failure (elevated creatinine and more frequent need for dialysis) and 30-day mortality in the low CVP group. CONCLUSIONS: Despite success in lowering blood transfusion requirements in liver resection patients, a low CVP should be avoided in patients undergoing liver transplantation.     

Peripheral venous pressure as a measure of venous compliance during pheochromocytoma resection

Venous pressures measured from peripheral venous catheters (PVP) closely estimate the central venous pressure (CVP) in surgical and critically ill patients. CVP is often used to estimate intravascular volume; however, fluctuations of CVP may also be induced by changes in venous tone caused by alpha-adrenergic catecholamine stimulation. We simultaneously monitored PVP, CVP, and mean arterial blood pressure during resection of pheochromocytoma in a 63-yr-old woman and found excellent correlation between the three pressure variables, suggesting that fluctuations of PVP reflect overall changes in vascular tone.     

Right ventricular end-diastolic volume monitoring after cardiac surgery.

INTRODUCTION: In the postoperative management of cardiac surgery patients, pulmonary capillary wedge pressure (PCWP) and central venous pressure (CVP) are the most commonly used parameters of preload. However, these pressure parameters are easily affected by ventricular compliance, positive end-expiratory pressure and other factors. The aim of this study was to evaluate whether right ventricular end-diastolic volume index (RVEDVI) reflects cardiac output or ventricular preload in patients after cardiac surgery during postoperative management. METHODS: We performed measurements in 31 patients postoperatively in the intensive care unit every 1 or 2 hours using a modified thermodilution catheter. RESULTS: There were 999 measured hemodynamic data sets and the measurement duration was 47 +/- 21 hours (mean +/- SD). RVEDVI was 119 +/- 32 ml/m(2), cardiac index (CI) was 2.7 +/- 0.7 L/min/m(2), and PCWP was 11 +/- 4 mmHg. A significant correlation was found between RVEDVI, CVP and CI in 15 of 31 patients, and between PCWP and CI in 4 of 22 patients. In 33% of cases, CVP showed a negative correlation with CI, whereas 7% showed a negative correlation between RVEDVI and CI. CONCLUSION: RVEDVI was a significant index during the postoperative management after cardiac surgery.     

The relationship between central venous pressure and pulmonary capillary wedge pressure during aortic surgery

Twenty-three ASA physical status II-III patients scheduled for elective abdominal aortic surgery were studied preoperatively with multiple unit gated acquisition angiography (MUGA) scan to determine the resting left ventricular and right ventricular ejection fractions (LVEF and RVEF respectively). Intraoperatively pulmonary capillary wedge pressure (PCWP) and central venous pressure (CVP) were measured in each patient at five different time periods in the horizontal, 24 degrees head up, and 24 degrees head down table tilt positions. The correlation between absolute values and changes in PCWP and CVP, and the degree to which preoperative knowledge of LVEF and RVEF predicted these correlations were examined. Resting LVEF ranged from 0.1 to 0.84. Thirteen of the 23 patients failed to show significant correlation (p less than 0.05) between the absolute values of PCWP and CVP either before and/or after aortic crossclamp. When the correlation coefficients from this analysis were ranked against LVEF, there was a weak but significant correlation before aortic crossclamp (r = 0.41), but not after. The correlation between a change in PCWP and a change in CVP was significant for the 23 patients at all time intervals, before and after aortic crossclamp. However, the prediction of a change of PCWP value from a known change of CVP value ranged in accuracy from +/- 3 mmHg to +/- 12.5 mmHg. The study suggests that if the filling pressures of both ventricles need to be assessed during aortic surgery, then the PCWP and CVP must be independently measured.(ABSTRACT TRUNCATED AT 250 WORDS)     

Optimal portal venous circulation for liver graft function after living-donor liver transplantation

BACKGROUND: Previous studies have shown poor outcome after living-donor liver transplantation (LDLT) as a result of excessive portal venous pressure (PVP), excessive portal venous flow (PVF), or inadequate PVF. We investigated optimal portal venous circulation for liver graft function after LDLT in adult recipients retrospectively. METHODS: Between June 2003 and November 2004, 28 adult patients underwent LDLT in our institution. We modulated PVP under 20 mmHg in these 28 cases by performing a splenectomy (n=4) or splenorenal shunt (n=1). The PVF and PVP were measured at the end of the operation. Compliance was calculated by dividing PVF by PVP. RESULTS: PVF and compliance showed a significant inverse correlation with peak billirubin levels after LDLT (r = -0.63: r=-0.60, P<0.01), and with peak international normalized ratio after LDLT (r=-0.41: r=-0.51, P<0.05). Compliance was higher in right-lobe graft with middle hepatic vein cases (148+/-27 ml/min/mmHg), and lower in left-lobe graft cases (119+/-50 ml/min/mmHg). CONCLUSIONS: Liver graft function was better when PVF and graft compliance were higher and PVP was maintained under 20 mmHg.     

Inferior vena cava diameter and central venous pressure correlation during cardiac surgery

OBJECTIVE: The purpose of this study was to determine whether a relationship exists between the inferior vena cava diameter (IVCD) or the superior vena cava diameter (SVCD) measured at the point of entry into the right atrium using transesophageal echocardiography (TEE) and the central venous pressure (CVP) under different experimental conditions. DESIGN: Prospective study. SETTING: University hospital, single institution. PARTICIPANTS: Seventy patients undergoing elective cardiac surgery. Interventions: CVP, IVCD, and SVCD were measured in a 2-dimensional, long-axis midesophageal bicaval view at end-diastole with electrocardiographic synchronization. Data were recorded during suspended ventilation, before and after leg elevation, and at different levels of positive end-expiratory pressure (0, 5, and 10 cmH(2)O). MEASUREMENTS AND MAIN RESULTS: The relationship between IVCD and CVP had 2 portions: A first (CVP 11 mmHg) in which the correlation was poor (R = 0.272, p = 0.065). No correlation between SVCD and CVP was observed. CONCLUSION: A strong correlation between TEE-derived IVCD measured at the point of entry into the right atrium and CVP was observed in cardiac surgical patients when CVP was 相似文献   

Relationship between peripheral and central venous pressures in different patient positions, catheter sizes, and insertion sites

OBJECTIVE: To investigate the relationship between peripheral and central venous pressures in different patient positions (supine, prone, lithotomy, Trendelenburg, and Fowler), different catheter diameters (18 G and 20 G), and catheterization sites (dorsal hand and forearm) during surgical procedures. DESIGN: Prospective clinical study. SETTINGS: University hospital. PARTICIPANTS: Five hundred adult patients. INTERVENTIONS: Peripheral over-the-needle intravenous catheters were placed in the dorsal hand or forearm. Central venous catheters were inserted via the internal jugular or subclavian vein after induction of anesthesia. MEASUREMENTS and MAIN RESULTS: Simultaneous measurements of central and peripheral venous pressures were made during stable conditions at random time points in surgery; 1953 paired measurements were performed. Mean central venous pressure was 11 +/- 3.7 mmHg and peripheral venous pressure was 13 +/- 4 mmHg (p = 0.0001). The overall correlation between central venous and peripheral venous pressures was found to be statistically significant (r = 0.89, r(2) = 0.8, p = 0.0001). Mean difference between peripheral and central venous pressure was 2 +/- 1.8 mmHg. Ninety-five percent limits of agreement were 5.6 to -1.6 mmHg. CONCLUSION: It has been assumed that replacing central venous pressure by peripheral venous pressure would cause problems in clinical interpretation. If the validity of this data is confirmed by further studies, the authors suggest that central venous pressure could be estimated by using regression equations to compare the 2 methods.     

Comparison of peripheral and central venous pressures in critically Ill patients

We conducted a prospective study to determine the relationship between central (CVP) and peripheral (PVP) venous pressures in critically ill patients. CVP and PVP were measured on five different occasions in 20 critically ill patients in the intensive care unit. Results showed that the mean difference between PVP and CVP was 4.4 mmHg (95% CI = 3.7 to 5.0). However, PVP might be 1.9 mmHg below (95% CI = 0.7 to 3.1) or 10.6 mmHg above (95% CI = 9.4 to 11.8) the CVP. The mean difference between changes in PVP and corresponding changes in CVP was 0.3 mmHg (95% CI = -0.1 to 0.7). The actual change in PVP could be 3.0 mmHg below (95% CI = 2.3 to 3.7) or 3.6 mmHg above (95% CI = 2.9 to 4.3) the change in CVP. Overall, the direction of change in PVP (rise or drop) predicted a same direction of change in CVP with an accuracy of 78%. Changes in PVP > or = 2 mmHg predicted a change in same direction of CVP with an accuracy of 90%. The direction of changes in CVP > or = 2 mmHg were predicted by the direction of change in PVP with an accuracy of 91%. We conclude that PVP measurement does not give an accurate estimate of the absolute value of CVP in individual patients. However, as changes in PVP parallel, in direction, changes in CVP, serial measurements of PVP may have a value in determining volume status and guiding fluid therapy in critically ill patients.