Volume 5 Supplement 6

Autumn Scientific Meeting of the Association of Cardiothoracic Anaesthetists

Open Access

Retrograde autologous priming of the cardiopulmonary bypass circuit - effective and safe blood conservation

  • S Balachandran1,
  • MH Cross1,
  • S Karthikeyan1,
  • AK Mulpur1,
  • SD Hansbro1 and
  • M Nazir1
Critical Care20015(Suppl 6):3

https://doi.org/10.1186/cc980

Published: 4 January 2001

Introduction

Many patients require a blood transfusion after cardiac surgery. Dilution of the patient's blood with the pump prime may contribute to this need. Retrograde autologous priming (RAP) of the cardiopulmonary bypass (CPB) circuit reduces CPB prime volume, and hence haemodilution [1]. The purpose of the present study was to compare RAP of the CPB circuit with normal priming in reducing both the percentage of patients requiring homologous blood and the volume of blood transfused. The incidence of complications was noted.

Patients and methods

After ethics approval and informed consent, 84 patients undergoing primary coronary artery surgery were recruited. Patients were randomized into control and RAP groups. Acute normovolaemic haemodilution (ANH) was performed as appropriate, aiming for a minimum haematocrit during CPB of 20%. The incidence of perioperative myocardial infarction was monitored by troponin T concentrations and new electrocardiographic changes. Haematocrit below 18% while on CPB and below 24% during the postoperative period were used as triggers for blood transfusion. All data were analyzed using the appropriate statistical tests; P < 0.05 was considered statistically significant.

Results

The groups were matched for age, weight, New York Heart Association classification and preoperative haematological data. There was a significant difference in homologous blood transfusion between the two groups. The percentage of patients receiving homologous blood was 47.5% in the control group versus 20.0% in the RAP group (P = 0.009). The mean volume of homologous blood transfused was 296.7 ml in the control group versus 81.9 ml in the RAP group. Table 1 shows various parameters and their significance between these two groups.
Table 1

Variables measured

 

Control

RAP

P

ANH donation (ml)

446.4

628.3

0.015

RAP volume removed (ml)

-

788.8

-

Oxygenator reservoir volume at 30 min (ml)

1133.8

640.0

< 0.001

Preoperative haematocrit (%)

43.1

43.0

NS

Haematocrit on CPB (%)

23.8

24.6

NS

Haematocrit on admission to the ICU (%)

27.0

28.8

0.040

Haematocrit at discharge (%)

31.7

33.5

0.030

Homologous blood transfusion (%)

47.5

20

0.009

Homologous blood transfusion per patient (ml)

296.7

81.9

0.003

Postoperative troponin T > 1 μg/l (%)

10

12.5

NS

Q-wave myocardial infarction (%)

2.5

2.5

NS

ICU, intensive care unit; NS, not significant.

Discussion

The present results indicate that reducing the CPB prime and haemodilution by means of RAP of the CPB circuit is a safe and effective means of reducing homologous blood transfusion. We found no significant adverse effects.

Authors’ Affiliations

(1)
The Yorkshire Heart Centre, Leeds General Infirmary

References

  1. Cromer MJ, Wollk DR: A minimal priming technique that allows for a higher circulating haemoglobin on cardiopulmonary bypass. Perfusion. 1998, 13: 311-313.View ArticlePubMedGoogle Scholar

Copyright

© BioMed Central Ltd on behalf of the copyright holder 2000

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