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  • Meeting abstract
  • Open Access

Acute, normovolemic hemodilution: effects on systemic and splanchnic blood flows and oxygen metabolism

  • 1,
  • 1,
  • 1,
  • 1,
  • 1 and
  • 1
Critical Care20037 (Suppl 3) :P31

https://doi.org/10.1186/cc2227

  • Published:

Keywords

  • Cardiac Output
  • Fentanyl
  • Hemodynamic Stability
  • Hydroxyethylstarch
  • Exchange Blood

The impact of acute normovolemic hemodilution (HD) on splanchnic perfusion was evaluated in 21 anesthetized (fentanyl and vancuronium) mongrel dogs (16 ± 1 kg). They were randomized to controls (n = 7, no HD), moderate HD (hematocrit 25 ± 3%, n = 7) or severe HD (hematocrit 15 ± 3% ml/kg), through an isovolemic exchange of whole blood and 6% hydroxyethylstarch at a 20 ml/min rate, to the target hematocrit. The animals were followed 120 min after HD. Cardiac output (ml/min), portal vein blood flow (ml/min), portal vein-arterial CO2 gradient (mmHg) and PCO2 gap (gas tonometry, mmHg), and splanchnic perfusion were evaluated through portal vein blood flow and gas tonometry.

Results

Exchange blood volumes were 33.9 ± 3.3 and 61.5 ± 5.8 ml/kg for moderate HD and severe HD, respectively. Controls maintained a hematocrit of around 41% throughout the study. Arterial pressure remained stable for all animals.

Conclusion

Global and regional hemodynamic stability were maintained after moderate and severe HD. However, a moderate gastric mucosal acidosis was induced with a hematocrit of 15%, which may become relevant after major surgery or trauma.

Table 1

 

Baseline

HD0

HD30

HD60

HD120

Cardiac output

     

   Control

2.4 ± 0.2

2.4 ± 0.2

2.3 ± 0.2

2.3 ± 0.2

1.8 ± 0.2

   Moderate hemodilution

2.6 ± 0.4

3.6 ± 0.4

3.4 ± 0.5

2.8 ± 0.3

2.8 ± 0.3

   Severe hemodilution

2.3 ± 0.5

3.6 ± 0.5

3.2 ± 0.2

2.8 ± 0.2

2.4 ± 0.3

Portal vein blood flow

     

   Control

448 ± 31

450 ± 45

440 ± 47

419 ± 39

379 ± 23

   Moderate hemodilution

311 ± 55

438 ± 83

485 ±± 60

446 ± 55

436 ± 57

   Severe hemodilution

382 ± 61

454 ± 68

459 ± 56

445 ± 47

388 ± 51*

PVCO2 gap

     

   Control

3.9 ± 0. 9

4.7 ± 0.8

6.3 ± 1.1

5.4 ± 1.2

6.4 ± 1.9

   Moderate hemodilution

6.7 ± 1.5

6.0 ± 1.2

7.9 ± 1.6

7.7 ± 0.6

6.0 ± 0.7

   Severe hemodilution

4.6 ± 0.5

7.1 ± 1.0

7.4 ± 0.6

8.0 ± 1.2

9.9 ± 1.6

PCO2-gap

     

   Control

3.3 ± 2.8

4.3 ± 2.7

2.7 ± 2.4

5.3 ± 2.6

11.6 ±± 1.7

   Moderate hemodilution

4.4 ± 3.4

5.6 ± 2.6

4.6 ± 2.5

6.9 ± 2.7

9.6 ± 2.3

   Severe hemodilution

1.0 ± 2.2

7.9 ± 1.5

10.0 ± 1

12.0 ± 1.4

16.1 ± 2.9

Authors’ Affiliations

(1)
Heart Institute, InCor, and LIM11, University of São Paulo Medical School, São Paulo, SP, Brazil

Copyright

© BioMed Central Ltd 2003

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