INTRODUCTION

Cardiopulmonary bypass (CPB) started in the fifties with progressive advances through the last forty years. The average blood loss per patient is about 1000 ml. (4 units of packed RBC) for adult patient undergoing open-heart surgery. ₁ Because of scant resources we raised the question of using all the blood volume available in the pump, infusing it back to the patient immediately post bypass. Using a hemoconcentrator circuit in the pump allowed us to reduce that volume to acceptable levels that can be tolerated by the patient in both adult and pediatric age groups. The only added cost was that of the collecting bag a "Y" connector.

MATERIALS AND METHODS

Thirteen consecutive patients were subjected to open-heart surgery at King
Faisal Specialist Hospital and Research Center (KFSH&RC) using the modified
CPB circuit (fig.1). The average age was 28 (0.5-70 years). The average
age weight was 42 (4.8-77 kg). Hemoglobin before CPB averaged 111 (86-150
gm/L). There were 8 patients not transfused any banked blood at all (60%).
The average volume transfused to the other 5 patients was 650 (75-1375 ml).
All recovered blood from the pump averaged 292 mL. (100-600 mL). The
hemoglobin of this recovered blood was 162 (125-212 gm/L). There was no
mortality in this study. Hemoglobin on discharge home was 106 (84-150
gm/L). In the subgroup of 8 patient not requiring any banked blood
transfusion, the hemoglobin before CPB was 119 (86-150 gm/L), and on
discharge home, it was 101 (84-132 gm/L), and the average recovered volume
was 338 (100-600 ml) will hemoglobin of 154 (125-205 gm/L). (Table-1)

Figure 1

TECHNICAL ASPECTS

All patient undergoing CPB for open heart procedures at KFSH&RC are
operated upon using the roller pump, membrane oxygenator, blood cardioplegia
(warm then cold with last shot warm) via antegrade and retrograde routes,
with moderate hypothermia (30-32oC) and a hemoconcentrator.

As in the illustration (Fig.1), we added a small reservoir bag on the
hemoconcentrator loop just beyond the hemoconcentrator with a sideway "Y"
connector to return the blood to the venous reservoir.

Figure 2

DISCUSSION

Different strategies to reduce blood and blood products transfusion as to avoid the well known morbidity and mortality associated with that. ₂ Algorithm use Intra-operatively has decreased blood transfusion in cardiac surgery,₃ demonstrating that physicians’ transfusion practice was significantly altered by the use of a transfusion algorithm with on-site coagulation data, independent of surgical blood losses. Also the algorithm was an effective physician education tool. In this study the non-transfusion rate improved up to 60 % in the “ most conservative “ algorithm group. At KFSH & RC, the rate of banked blood non-transfusion rate for patients undergoing CPB is about 10 % 1.One centre investigated CABG procedures and reported non-transfusion rates up to 49-65 %.₄ Multicenter study in 41 hospitals reported their experience using Aprotonin in all types of cardiac surgery in 671 patients.₅ There was a non-transfusion rate of 13 % with average of 2 units RBC per patient (maximum 65 units in one patient). Other studies revealed a wide range 21-75% for non--transfusion rates._{6 7 8} As demonstrated above, we managed to improve our non-transfusion rate up to 60 %, but this is surely to be verified in a larger patient population with a control group.

At this stage, it is realized that the cost of such modification is nominal
compared to the potential benefits to our limited resources and definitely
to reduce any other associated morbidities in patients undergoing CPB.

CONCLUSION

The potential benefits outweigh the risk and the nominal increase in cost
for such modification and if this is verified at a larger scale controlled
study, it may be recommended for routine application in CPB.