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Critical Care

Open Access

Increased pulse pressure variations observed in a pulmonary experimental thromboembolism model

  • GA Westphal1, 2,
  • ARR Gonçalves1, 2,
  • A Bedin1, 2,
  • R Steglich1, 2,
  • E Silva1, 2 and
  • LF Poli de Figueiredo1, 2
Critical Care200711(Suppl 3):P8

Published: 19 June 2007


Pulmonary HypertensionMean Arterial PressureFluid ResponsivenessPulse Pressure VariationPulmonary Thromboembolism


Pulse pressure respiratory variation (PPV), which is the difference between the maximal and minimal arterial pulse pressure values after each positive-pressure breath, is largely used for early identification of hypovolemic status. Increased PPV observed in hypovolemia results from exaggerated respiratory variation in transpulmonary blood flow that results in corresponding left ventricular preload variations during respiratory cycles. Hence, any modulations that affect the left ventricular preload would influence PPV.


To test the hypothesis that PPV amplification observed in hypovolemia can also be detected after pulmonary thromboembolism obtained with central venous injection of blood cloth.


PPV was studied in five anesthetized and mechanically ventilated male rabbits weighing 1.6 ± 0.3 kg. The heart rate (HR) and mean arterial pressure (MAP) were monitored after central venous (jugular) and arterial (carotid) catheterization, and 1.5 ml/kg autologous blood cloth were injected slowly through the jugular catheter into the central circulation. The HR, MAP and PPV were registered before and after blood cloth injection and compared using the Student t test.


The HR did not change, but the MAP was significantly lowered as much as PPV significantly increased after cloth injection. See Table 1.

Table 1




P value


249 ± 50

295 ± 22.9



55 ± 4.2

21 ± 3.4



5.5 ± 1.8

30 ± 5.6



PPV amplification observed in hypovolemia can be also detected after pulmonary thromboembolism obtained with central venous injection of blood cloth. It is possible to conclude that pulmonary hypertension should be assumed as a limitation for cardiovascular fluid responsiveness determination by PPV.

Authors’ Affiliations

Division of Experimental Surgery, Joinville University (Univille) Medical School, Joinville, Brazil
Division of Applied Physiology, Heart Institute, InCor, University of São Paulo Medical School, São Paulo, Brazil


© BioMed Central Ltd 2007