1Department of Anaesthesiology and 2Department of Cardiac Surgery, Ludwig-Maximilians-University, Großhadern University Hospital, Marchioninistr. 15, D-81377 Munich, Germany*Corresponding author
Accepted for publication: September 12, 2001
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Abstract |
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Methods. SVV and SPV were determined before and after volume loading with colloids in 20 mechanically ventilated patients.
Results. SVV and SPV decreased significantly after volume loading and were correlated (r=0.89; P<0.001). Changes in SVV and changes in SPV as a result of volume loading were also significantly correlated (r=0.85; P<0.005). Changes in SVV correlated significantly with changes in stroke volume index (SVI) (r=0.67; P<0.005) as did changes in SPV (r=0.56; P<0.05). SVV determined before volume loading correlated significantly with changes in SVI (R=0.67; P <0.005). Using receiver operating characteristics curves, the area under the curve was statistically greater for SVV (0.824; 95% confidence interval: [CI] 0.641.0) and SPV (0.81; CI: 0.621.0) than for central venous pressure (0.451; CI: 0.170.74).
Conclusions. Monitoring of SVV enables real-time prediction and monitoring of the left ventricular response to preload enhancement in patients after cardiac surgery and is helpful for guiding volume therapy.
Br J Anaesth 2002; 88: 1246
Keywords: heart, left ventricular preload; heart, left ventricular response; heart, systolic pressure variation; heart, central venous pressure; measurement techniques, pulse contour analysis; monitoring, haemodynamic
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Introduction |
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We investigated the relation between SVV and the haemodynamic response of the left ventricle to volume loading compared with the SPV determined off-line in 20 mechanically ventilated patients after cardiac surgery using cardiopulmonary bypass.
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Methods and results |
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For the off-line calculation of SPV, we recorded the digitalized trace of the arterial pulse wave on a computer connected to the haemodynamic monitor. We used the same individual time window of 30 s divided into four periods of 7.5 s, which was analysed for the corresponding value of SVV and determined the highest and lowest value of systolic arterial pressure to calculate SPV.
Drug therapy was not changed within the study period. After recording of central venous pressure, thermodilution SVI and SVV, and a recording of the arterial pressure curve trace for later determination of SPV, volume loading was performed over 10 min using 3.5% oxypolygelatine 20 ml x body mass index (mean 548 ml). The measurements were then repeated.
Statistical analysis of the data was performed on a standard personal computer using SPSS for Windows 10.0 run under Windows NT. All variables are expressed as mean (SD). Correlation of haemodynamic variables and their changes were assessed using Pearsons correlation. Receiver operating characteristics (ROC) curves were calculated with varying discriminating thresholds for each variable to assess the ability to predict volume responsiveness.6
All patients tolerated the study treatment well. Overall, the thermodilution SVI increased from 40 (9) ml m2 to 50 (9) ml m2, whereas SVV decreased from 23 (7) to 11 (3)%, and SPV from 16 (7) to 6 (3) mm Hg. Central venous pressure increased significantly from 7 (2) to 10 (3) mm Hg. Linear regression analysis of SVV and SPV is shown in Figure 019F1A (R=0.89; P<0.001). Changes (%) in SVV (SVV) and SPV (
SPV) as a result of volume loading correlated significantly (R=0.85; P<0.005). Comparison of
SVV and
SPV using a BlandAltman plot is shown in Figure 019F1B.7 Changes in thermodilution SVI (
SVI) correlated significantly with
SVV (R=0.67; P<0.005) and
SPV (R=0.56; P<0.05). To investigate the ability of each variable to predict volume responsiveness,
SVI was correlated with values of SVV determined before volume loading (r=0.67; P<0.005), as well as with values of SPV before volume loading (r=0.60; P<0.01). ROC curves for central venous pressure, SPV and SVV were generated with varying discriminating thresholds for each variable. Patients were classified as responders to volume loading if the increase in SVI was >15% (n=13), or as non-responders (n=7), according to Stetz et al.8 When comparing the areas under the ROC curves, the area for SVV (0.83; 95% confidence intervals [CI]: 0.641.0) and SPV (0.81; CI: 0.621.0) did not differ significantly, whereas the area for central venous pressure (0.42; CI: 0.170.74) was significantly smaller (P<0.001).
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Comment |
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References |
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2 Perel A, Pizov R, Cotev S. Systolic blood pressure variation is a sensitive indicator of hypovolemia in ventilated dogs subjected to graded hemorrhage. Anesthesiology 1987; 67: 498502[ISI][Medline]
3 Tavernier B, Makhotine O, Lebuffe G, et al. Systolic pressure variation as a guide to fluid therapy in patients with sepsis-induced hypotension. Anesthesiology 1998; 89: 131321[ISI][Medline]
4 Goedje O, Hoeke K, Lichtwarck-Aschoff M, et al. Continuous cardiac output by femoral arterial thermodilution calibrated pulse contour analysis: comparison with pulmonary arterial thermodilution. Crit Care Med 1999; 27: 240712[ISI][Medline]
5 Berkenstadt C, Margalit N, Hadani M, et al. Stroke volume variation as a predictor of fluid responsiveness in patients undergoing brain surgery. Anesth Analg 2001; 92: 9849
6 Hanley JA, McNeil BJ. A method of comparing the areas under receiver operating characteristic curves derived from the same cases. Radiology 1983; 148: 83943[Abstract]
7 Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; 1: 30710[ISI][Medline]
8 Stetz CW, Miller RG, Kelly GE, Raffin TA. Reliability of the thermodilution method in the determination of cardiac output in clinical practice. Am Rev Respir Dis 1982; 26: 10014
9 Sonnenblick EH, Strobeck JE. Current concepts in cardiology: Derived indexes of ventricular and myocardial function. N Engl J Med 1977; 296: 97882[ISI][Medline]
10 Michard F, Boussat S, Chemla D, et al. Relation between respiratory changes in arterial pulse pressure and fluid responsiveness in septic patients with acute circulatory failure. Am J Respir Crit Care Med 2000; 162: 1348