Survival of autotransfused red cells. 51Cr studies in 10 knee arthroplasty patients

Autologous blood transfusion following total knee arthroplasty: is it always necessary?

A retrospective study of 85 patients undergoing primary total knee replacement (TKR), who also received autologous blood transfusion (ABT) to compensate for the perioperative blood loss. In our series 16.4% of the patients needed allogenic blood transfusion. Of the remaining 83.4% only 49.5% received autologous transfusion. Autologous transfusion was withheld in 34.1% of cases either because the blood volume was inadequate or because the collection time exceeded the recommended time limit. The mean haemoglobin (Hb) level with or without autologous transfusion was 10 g, raising the question of the necessity of using autologous transfusion in primary total TKR.

Coagulation parameters after retransfusion of unwashed blood

Postoperative blood salvage reduces the risk of allogenic transfusion in patients undergoing elective total joint arthroplasty. We measured the concentrations of coagulation parameters after autotransfusion of unwashed shed blood in 22 patients having elective joint arthroplasty and compared them with patients without retransfusion. Twenty-two patients with a total hip or knee arthroplasty received a mean of 611.4 mL unwashed but filtered shed blood. No complications were observed during or after the reinfusion of salvaged blood. Levels of D-dimer and fibrinogen increased significantly over time after retransfusion (P < .0001). Comparison of the autotransfused group with the 25 patients without reinfused shed blood showed no significant difference in fibrinogen concentration between the 2 groups in the postoperative course but a significant difference with increased D-dimer concentrations in the autotransfused group (P < .001).

Blood saving protocol in elective total knee arthroplasty

BACKGROUND

To eliminate the need for allogeneic blood transfusion in patients undergoing elective total knee arthroplasty, we established and tried a protocol of combined methods, which is characterized by effectiveness, ease in application, and safety. It is based on perioperative administration of human recombinant erythropoietin plus iron and folic acid, mild acute normovolemic hemodilution, meticulous surgical technique, postoperative blood salvage through a closed-wound drainage system, and lower transfusion triggers.

DATA SOURCES

Sixty-one patients entered the protocol, and the results were retrospectively compared with the ones obtained from 58 consecutive patients who were operated on in the past before the use of any blood saving technique.

CONCLUSIONS

Only 5 patients of those who entered the protocol finally needed allogeneic blood transfusion, receiving a total number of 7 units, which is remarkable when compared with the 50 patients before the application of the protocol who required 111 units. Consequently, the utilization of allogeneic blood was reduced by 94%, a statistically quite significant result (P <0,001). We believe the protocol should be included in orthopedic surgeons' alternatives for blood saving in elective total knee arthroplasty.

Erythrocyte viability in blood salvaged during total joint arthroplasty with cement

BACKGROUND

Erythrocyte salvage, the collection of a patient's blood shed from the surgical wound, is one aspect of blood management. Previous investigators have examined salvaged blood for content; however, to our knowledge, none have examined the viability of erythrocytes after exposure to the chemical and thermal reactions produced by motorized instruments and polymethylmethacrylate during surgery. The purpose of this study was to determine the viability of salvaged erythrocytes from patients undergoing primary total joint arthroplasty with cement.

METHODS

Erythrocyte viability studies were performed on specimens from three subjects with use of a double isotope-labeling technique employing chromium-51 and technetium-99m. With use of a fresh blood specimen obtained prior to surgery and a specimen of salvaged blood that had been recycled, washed, and filtered with use of the Cell Saver, the viability of the Cell-Saver-processed erythrocytes, labeled with chromium-51, was calculated on the basis of the technetium-99m-labeled red blood-cell mass.

RESULTS

The mean erythrocyte viability (and standard deviation) in blood salvaged with use of the Cell Saver was 88.0% +/- 3.8%. The standard of the American Association of Blood Banks for minimum erythrocyte viability in adequately cross-matched allogeneic blood or predeposited autologous blood is 70%.

CONCLUSIONS

The high rate of viability of the erythrocytes in this study shows that the Cell Saver is a valuable adjunct to other blood management techniques for patients having total joint arthroplasty. We believe that the very high mean rate of erythrocyte viability and the extremely small standard deviation in our three subjects, as compared with the standards of the American Association of Blood Banks, made additional study subjects unnecessary.

Global blood management in orthopaedic surgery

Blood loss tends to be significant in many orthopaedic procedures because of the nature of the tissues and the inability to cauterize or coagulate bleeding bony surfaces. Regional hypotensive anesthesia has been useful in reducing blood loss particularly for joint replacement. A spectrum of measures is available to retrieve autologous blood and reinfuse it. The loop consists of predeposit autologous blood, preoperative hemodilution, intraoperative and postoperative red cell retrieval, and reinfusion. The safety of autologous blood has been accepted universally, but the measures to preserve it must be used judiciously to avoid excessive cost and, most importantly, ensure patient safety.