Peripheral venous pressure as a predictor of central venous pressure during orthotopic liver transplantation

STUDY OBJECTIVE: To assess the reliability of peripheral venous pressure (PVP) as a predictor of central venous pressure (CVP) in the setting of rapidly fluctuating hemodynamics during orthotopic liver transplant surgery. DESIGN: Prospective clinical trial. SETTING: UCLA Medical Center, main operating room-liver transplant surgery. PATIENTS: Nine adult patients with liver failure undergoing orthotopic liver transplant surgery. INTERVENTIONS: A pulmonary artery catheter and a 20-g antecubital peripheral intravenous catheter dedicated to measuring PVP were placed in all patients after standard general endotracheal anesthesia induction and institution of mechanical ventilation. MEASUREMENTS: Peripheral venous pressure and CVP were recorded every 5 minutes and/or during predetermined, well-defined surgical events (skin incision, venovenous bypass initiation, portal vein anastamosis, 5 minute post graft reperfusion, abdominal closure). Pulmonary artery pressure and cardiac output (via thermodilution) were recorded every 15 and 30 minutes, respectively. MAIN RESULTS: Peripheral venous pressure (mean +/- SD) was 11.0 +/- 4.5 mmHg vs a CVP of 9.5 +/- 5.0; the two measurements differed by an average of 1.5 +/- 1.6 mmHg. Peripheral venous pressure correlated highly with CVP in every patient, and the overall correlation among all nine patients calculated using a random-effects regression model was r = 0.95 (P < 0.0001). A Bland-Altman analysis used to determine the accuracy of PVP in comparison to CVP yielded a bias of -1.5 mmHg and a precision of +/-3.1 mm Hg. CONCLUSION: Our study confirms that PVP correlates with CVP even under adverse hemodynamic conditions in patients undergoing liver transplantation.     

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.     

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.     

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.     

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.     

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 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.     

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.     

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.     

Cuff-occluded rate of rise of peripheral venous pressure: a new, highly sensitive technique for monitoring blood volume status during hemorrhage and resuscitation

We investigated the cuff-occluded rate of rise of peripheral venous pressure (CORRP)--a new, nearly noninvasive peripheral hemodynamic monitoring parameter--in dogs subjected to hemorrhage and resuscitation. Twelve adult mongrel dogs under general anesthesia were subjected to hemorrhage of 30% of their estimated total blood volume (TBV) for 30 minutes; after this time the extracted blood was reinfused. Arterial pressure (AP), central venous pressure (CVP), pulmonary arterial pressure (PAP), cardiac output (CO), pulmonary venous pressure (PWP), heart rate, and CORRP were continuously monitored. A "clinically significant change" (CSC) in CORRP and CO was defined as a change that exceeded two standard deviations from the mean of five baseline measurements made before the onset of hemorrhage, whereas a CSC in PWP or CVP was conservatively defined as a change that exceeded 2 mm Hg from the average of five baseline measurements, and a CSC in PAP and AP was defined as a change that exceeded 3 mm Hg and 5 mm Hg, respectively from the average of the baseline measurements. There was no consistent change in heart rate during hemorrhage. Thus defined, a CSC in CORRP occurred after an average extraction of 9.2% +/- 4.7% TBV, whereas a CSC was not seen until an average loss of 16.5% +/- 8.1% TBV for AP, 21% +/- 13% TBV for PWP, 15.5% +/- 7% TBV for PAP, and 35% +/- 3% TBV for CVP. These average blood losses are all significantly different from the average blood loss required to effect a CSC in CORRP. The blood loss required to effect a CSC in CO averaged 9.7% +/- 6%. We conclude that in these anesthetized dogs, CORRP detected blood loss earlier than other commonly used hemodynamic parameters, including several invasive parameters such as CVP, PAP, and PWP; CORRP and CO were equivalent in their ability to detect early stages of blood loss.     

Iliac venous pressure estimates central venous pressure after laparotomy

Background

Central venous pressure (CVP) is traditionally obtained through subclavian or internal jugular central catheters; however, many patients who could benefit from CVP monitoring have only femoral lines. The accuracy of illiac venous pressure (IVP) as a measure of CVP is unknown, particularly following laparotomy.

Methods

This was a prospective, observational study. Patients who had both internal jugular or subclavian lines and femoral lines already in place were eligible for the study. Pressure measurements were taken from both lines in addition to measurement of bladder pressure, mean arterial pressure, and peak airway pressure. Data were evaluated using paired t-test, Bland-Altman analysis, and linear regression.

Results

Measurements were obtained from 40 patients, 26 of which had laparotomy. The mean difference between measurements was 2.2 mm Hg. There were no significant differences between patients who had laparotomy and nonsurgical patients (P = 0.93). Bland-Altman analysis revealed a bias of 1.63 ± 2.44 mm Hg. There was no correlation between IVP accuracy and bladder pressure, mean arterial pressure, or peak airway pressure.

Conclusions

IVP is an adequate measure of CVP, even in surgical patients who have had recent laparotomy. Measurement of IVP to guide resuscitation is encouraged in patients who have only femoral venous catheter access.     

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.     

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.     

Impact of portal venous pressure on regeneration and graft damage after living-donor liver transplantation.

Several reports claim that portal hypertension after living-donor liver transplantation (LDLT) adversely affects graft function, but few have assessed the impact of portal venous pressure (PVP) on graft regeneration. We divided 32 adult LDLT recipients based on mean PVP during the 1st 3 days after LDLT into a group with a PVP > or = 20 mm of Hg (H Group; n = 17), and a group with a PVP < 20 mm of Hg (L Group; n = 15). Outcome in the H Group was poorer than in the L Group (58.8 vs. 92.9% at 1 year). Peak peripheral hepatocyte growth factor (HGF) during the 1st 2 weeks was higher in the H Group (L: 1,730 pg/mL, H: 3,696 pg/mL; P < .01), whereas peak portal vascular endothelial growth factor (VEGF) level during the 1st week was higher in the L Group (L: 433 pg/mL, H: 92 pg/mL; P < .05). Graft volume (GV) / standard liver volume (SLV) was higher in the H Group (L / H, at 2, 3, and 4 weeks, and at 3 months: 1.02 / 1.24, .916 / 1.16, .98 / 1.27, and .94 / 1.29, respectively; P < .05). Peak serum aspartate aminotransferase, bilirubin levels, and international normalized ratio after LDLT were significantly higher in the H Group, as was mean ascitic fluid volume. In conclusion, early postoperative PVP elevation to 20 mm of Hg or more was associated with rapid graft hypertrophy, higher peripheral blood HGF levels, and lower portal VEGF levels; and with a poor outcome, graft dysfunction with hyperbilirubinemia, coagulopathy, and severe ascites. Adequate liver regeneration requires an adequate increase in portal venous pressure and flow reflected by clearance of HGF and elevated VEGF levels.     

Pressure measurements during cardiac surgery--internal jugular vs central venous

Although central venous pressure (CVP) is a valuable guide and measurement during cardiac surgery anesthesia, there are many occasions however, when the time consumed in inserting a peripheral catheter, defeats the actual purpose. The purpose of this study was to compare central venous pressure and internal jugular veins pressure, and to see whether the jugular veins pressures were a reliable guide to central venous pressure monitoring. Simultaneous measurements of the internal jugular (both left and right side) and right atrial venous pressures were made in 70 patients undergoing cardiac surgery both at times when the chests were closed and when they were opened. After induction of anesthesia, a 16 gauge catheter was inserted into the internal jugular vein on each side of the neck, and another catheter was passed into the right atrium. Then the CVP and internal jugular veins were measured six times during anesthesia and postoperatively. A good correlation was found between pressures of right and left internal jugular veins with that of CVP both at times when the chests were closed and when they were opened. It is concluded that left and right internal jugular vein pressures are reliable guides to central venous pressures during anesthesia in cardiac surgery.     

Induction of anesthesia with propofol injected through a central venous catheter

We compared propofol injected through a central venous catheter with that through a peripheral cannula from the standpoint of injection pain, induction time and hemodynamic changes. Thirty-nine patients about to receive abdominal surgery, who had central venous catheters inserted via the subclavian vein, were included in this study. General anesthesia was induced with a loading dose of propofol 1 mg.kg-1 followed by an infusion of 10 mg.kg-1.hr-1 into the central vein without carrier intravenous fluid (group A, n = 13), the peripheral vein without carrier intravenous fluid (group B, n = 13) or the peripheral vein with rapid infusion of acetated Ringer's solution (group C, n = 13). After endotracheal intubation, anesthesia was maintained with propofol 4 mg.kg-1.hr-1. The incidence of injection pain was 53% in group B and 76% in group C, whereas none of the patients in group A felt discomfort or pain during propofol injection. The mean induction time was significantly shorter in group A (43 +/- 12 sec) than group B (66 +/- 16 sec) or group C (57 +/- 11 sec). There were no differences between each group in hemodynamic changes during induction of anesthesia. Propofol injection via central venous catheter can avoid the injection pain and shorten the induction time.     

Changes in portal venous pressure in the early phase after living donor liver transplantation: pathogenesis and clinical implications

BACKGROUND: Although living-donor liver transplantation (LDLT) has been accepted for adult populations, the occurrence and pathogenesis of small-for-size syndrome remain highly controversial. METHODS: Portal venous pressure (PVP) was measured in 79 cases of LDLT from anhepatic phase to day 14. PVP was monitored through a catheter inserted via the inferior mesenteric vein. In a separate series of seven cases of adult LDLT, the splenic artery was ligated following arterial reperfusion. RESULTS: For days 2 to 4 and 9 to 11, recipients of small-for-size graft (<0.8% of body weight) displayed significantly higher PVP than recipients of larger grafts. The 13 patients with elevated mean PVP (>or=20 mm Hg) early in the first week (days 0-4) demonstrated significantly worse survival (84.5% vs. 38.5% at 6 months; P < 0.01), but this was not applicable to elevated mean PVP late in the first week (days 5-7). Elevated PVP early in the first week was also associated with higher incidence of bacteremia, cholestasis, prolonged prothrombin time, and ascites. Splenic artery ligation (SAL) immediately reduced PVP from 10 to 20 mm Hg (median, 16 mm Hg) to 9 to 13 mm Hg (median, 11 mm Hg; P = 0.02). Posttransplant PVP was significantly lower in SAL patients than in non-SAL patients from days 2 to 7 despite small graft size. Early PVP in SAL patients was consistently below 20 mm Hg, and survival was significantly better than in non-SAL patients with high early PVP (P < 0.01). CONCLUSION: Elevated PVP in the early phase is strongly associated with poor patient survival attributable, at least in part, to small-for-size graft. Further elucidation of the pathogenesis behind this phenomenon and efforts to modify PVP will be key to improving results.     

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.     

Right ventricular end-diastolic volume index as a predictor of preload status in patients with low right ventricular ejection fraction during orthotopic liver transplantation

OBJECTIVE: The objective of this study was to compare the accuracy of 2 variables: pulmonary artery occlusion pressure (PAOP) and right ventricular end diastolic volume index (RVEDVI) as predictors of the hemodynamic response to fluid challenge as well as definition of the overall correlation between RVEDVI and change in PAOP, right ventricular ejection fraction (RVEF), central venous pressure (CVP), and determination of the right ventricular function during orthotopic liver transplantation. MATERIALS AND METHODS: A modified pulmonary artery catheter equipped with a fast response thermistor was used to determine RVEF, allowing calculation of RVEF end-diastolic volume index (EDVI, as the ratio of stroke index [SI] to EF). The above-mentioned hemodynamic measures were taken in 4 phases: T0, after induction of anesthesia; T1, during anhepatic phase; T2, 30' after graft reperfusion; and T3, at the end of surgery. RESULTS: The variation of the REF value was 36 +/- 4% and 39 +/- 6%. Linear regression analysis showed a significant correlation between RVEDVI (range, 133 +/- 33-145 +/- 40 mL/m(2)) and stroke volume index (SVI) in each phase (r(2) = 0.49, P < .01; r(2) = 0.57, P < .01) at T0 and T1, respectively, and at T2 and T3 (r(2) = 0.51, P < .01; r(2) = 0.44, P < .01), respectively. No significant variations in the linear regression analysis between RVEDVI, PAOP, CVP, and RVEF were observed. No relationship was found between PAOP (range, 10 +/- 2-6 +/- 2 mm Hg) and SVI. CONCLUSION: RVEDVI may be the best clinical estimate of right ventricular preload. In fact, minor changes of RVEF have been recorded, confirming that RV function was not altered during uncomplicated orthotopic liver transplantation.     

Effects of Posture and Prolonged Pneumoperitoneum on Hemodynamic Parameters during Laparoscopy

BACKGROUND: The present prospective study was designed to evaluate hemodynamic changes associated with head-down positioning and prolonged pneumoperitoneum during totally endoscopic robot-assisted radical prostatectomy. METHODS: Ten American Society of Anesthesiologists (ASA) physical status I-III patients undergoing totally endoscopic robot-assisted radical prostatectomy were enrolled in the study. Invasive hemodynamic parameters were measured by transpulmonary arterial thermodilution using the PiCCO system with a femoral artery catheter. Cardiac index (CI), heart rate (HR), mean arterial pressure (MAP), systemic vascular resistance index (SVRI), intrathoracic blood volume (ITBV), and central venous pressure (CVP) were recorded with the patient in the supine position, after head-down tilt, intraoperatively after 30 min, 1 h, 2 h, 3 h, and 4 h of pneumoperitoneum at an insufflation pressure of 12 mmHg, after deflation still with head-down positioning, and finally, with the patient in the supine position. RESULTS: Placing the patient in the Trendelenburg (head-down) position caused a significant increase in CVP (from 9.9 +/- 3.4 to 15.1 +/- 2.3 mmHg), whereas all other hemodynamic parameters remained nearly unaffected. The induction of pneumoperitoneum resulted in a significant increase in MAP (from 74.9 +/- 12.9 to 95.4 +/- 11.9 mmHg). No other parameter was affected. Even at 4 h of pneumoperitoneum only mild hemodynamic changes were observed. After release of the pneumoperitoneum with the patient still in the head-down position, HR (49.0 +/- 4 versus 63.9 +/- 12.4 min(-1)) and after placing the patient in the supine position, CI (2.4 +/- 0.2 versus 3.3 +/- 0.7 l min(-1 )m(-2)) increased significantly, whereas CVP returned to baseline values. CONCLUSIONS: Patients undergoing totally endoscopic radical prostatectomy with 4 h of pneumoperitoneum in the Trendelenburg position experienced no significant hemodynamic depression during posture and pneumoperitoneum.