Berkenstadt H, Friedman Z, Preisman S, Keidan I, Livingstone D, Perel A
Department of Anesthesiology and Intensive Care, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Hashomer, 52621 Israel.
Br J Anaesth. 2005 Jun;94(6):721-6. doi: 10.1093/bja/aei116. Epub 2005 Mar 11.
Similarly to systolic pressure variation (SPV), pulse pressure variation (PPV) and stroke volume variation (SVV) derived from arterial pulse contour analysis have been shown to reflect fluid responsiveness in ventilated patients. However, unlike the SPV, both PPV and SVV have not been validated during extreme hypovolaemia. The aim of the present study was to examine whether these newly introduced variables respond to gradual hypovolaemia like the SPV by increasing gradually with each step of the haemorrhage even during extreme hypovolaemia.
SPV, SVV and PPV were measured in 8 dogs following initial volume loading (10% of the estimated blood volume administered as colloid solution), 5 steps of graded haemorrhage, each consisting of 10% of the estimated blood volume, followed by retransfusion of the shed blood.
The correlations of the SVV, SPV and PPV to the stroke volume (SV) throughout the study were -0.89, -0.91 and -0.91, respectively. Correlations of the CVP and the global end-diastolic volume (GEDV) of the heart chambers to the SV were 0.79 and 0.95, respectively. The SPV correlated significantly with both the PPV and the SVV (r=0.97 and 0.93 respectively). However, the PPV increased by more than 400% at 50% haemorrhage compared with increases of 200% and 120% for the SVV and %SPV, respectively.
This study demonstrates that the present algorithm used for the calculation of the SVV and the formula used to calculate the PPV, perform well over a wide range of preload states including severe hypovolaemia. However, the PPV changes more than the SPV and SVV. This may be due to the changing relation of the SV to the pulse pressure when the filling of the aorta is greatly decreased.
与收缩压变异（SPV）类似，通过动脉脉搏轮廓分析得出的脉压变异（PPV）和每搏量变异（SVV）已被证明可反映通气患者的液体反应性。然而，与SPV不同，PPV和SVV在极重度低血容量期间尚未得到验证。本研究的目的是检验这些新引入的变量在极重度低血容量期间是否像SPV一样，随着出血的每一步逐渐降低而逐渐增加，从而对逐渐降低的血容量做出反应。
对8只犬进行测量，初始容量负荷（以胶体溶液给予估计血容量的10%）后，分5步进行分级出血，每步出血量为估计血容量的10%，随后回输所失血液，测量其SPV、SVV和PPV。
在整个研究过程中，SVV、SPV和PPV与每搏量（SV）的相关性分别为-0.89、-0.91和-0.91。中心静脉压（CVP）和心腔的全心舒张末期容积（GEDV）与SV的相关性分别为0.79和0.95。SPV与PPV和SVV均显著相关（r分别为=0.97和0.93）。然而，与SVV和%SPV分别增加200%和120%相比，PPV在出血50%时增加超过400%。
本研究表明，目前用于计算SVV的算法及用于计算PPV的公式，在包括严重低血容量在内的广泛前负荷状态下表现良好。然而，PPV的变化比SPV和SVV更大。这可能是由于主动脉充盈大幅减少时SV与脉压的关系发生了变化。
