Blood saving protocol in elective total knee arthroplasty

The American Journal of Surgery 187 (2004) 261–267

Review

Blood saving protocol in elective total knee arthroplasty Nikolaos Kourtzis, M.D., Dimitrios Pafilas, M.D.*, Georgios Kasimatis, M.D. Department of Orthopedics, General Prefectural Hospital of Aegion, Ano Voulomeno, 25 100 Aegion, Greece Manuscript received June 25, 2002; revised manuscript January 11, 2003

Abstract 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. © 2004 Excerpta Medica, Inc. All rights reserved. Keywords: Knee; Arthroplasty; Autologous; Transfusion; Erythropoietin; Hemodilution

Blood loss tends to be significant and unpredictable in many orthopedic procedures because of the nature of the tissues and the inability to cauterize or coagulate bleeding bony surfaces [1]. Total knee arthroplasty (TKA) is a bloody major operation where transfusion of a considerable amount of allogeneic blood is common practice. However, blood transfusion is far from being considered a zero risk procedure. Instead, it is well established that its application bears a variety of serious complications (Table 1) [2– 6]. Blood screening measures cope only with specific bloodborne diseases of high morbidity and mortality, whose risk of transmission have significantly reduced albeit not eliminated [7]. However, there still remain known infectious factors (and numerous others not yet discovered) for which no screening is performed, Creutzfeldt-Jakob disease being a recent example [5]. Allogeneic blood transfusion should therefore be considered as a transplantation of cellular and soluble compounds (immunoglobulins, hormones, cytokines) of the donor, causing profound and prolonged alterations in the recipient’s immune function [4], thus justifying the growing interest about their safety. * Corresponding author. Tel.: ⫹30-69457-08065. E-mail address: [email protected]

Dealing with blood transfusion complications has substantial financial consequences [8], which superimpose on the overall cost needed to organize blood donation (blood donor selection, collection, screening, storage, transportation and transfusion of allogeneic blood). On account of the abovementioned safety problems and the pressures for hospitalization cost decrease, there has been a growing interest towards policies to avoid allogeneic blood transfusion. Current efforts [1,9,10] focus on (a) preoperative red blood cell mass expansion with utilization of recombinant human erythropoietin; (b) various forms of autologous blood transfusion (preoperative autologous donation, acute normovolemic hemodilution, intraoperative [cell saving device], and postoperative [closed wound drainage system] blood collection and reinfusion); (c) intraoperative and postoperative blood loss reduction due to meticulous hemostasis (modified surgical techniques, tourniquet use, electrocautery, Argon beam coagulation, local hemostatic agents and surgical glues such as Gelfoam and Surgicel), blood volume expanders (crystalloid, colloid solutions), drugs (having direct or indirect hemostatic action), controlled hypotension, and postoperative systemic analgesia; (d) development of transfusion guidelines (overcoming the undue fear when encountering a low hematocrit and

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Table 1 Serious complications after allogeneic blood transfusion Blood-borne diseases (viral, bacterial, parasitic, prion-related) Transfusion reactions (fever, hypersensitivity reactions—allergies, hemolysis, fluid overload, transfusion acute lung injury) Alloimmunization of blood cells and proteins Immunomodulation (immunosuppression, graft versus host disease, suppression of hemopoiesis, cancer recurrence, activation of latent viruses) Higher incidence (⫻ 7–10) of postoperative infections, more consecutive febrile days and antibiotic consumption, longer hospitalization Wound healing inhibition Life-threatening ABO incompatibility due to transfusion errors

decrease of the threshold under which transfusion is considered necessary—“transfusion trigger”); and (e) red blood cell substitutes or temporary oxygen carriers (perfluorocarbons) that are currently under research. Taking into account that every method mentioned above presents both advantages and disadvantages and that, most times, no single method can cope with the problem efficiently enough, we established a protocol, which combines methods. The aim was to achieve an efficient, easily applicable and of minimal risk way to eliminate allogeneic blood transfusions. Consequently, orthopedic surgeons, who rarely use alternatives to perioperative allogeneic transfusion could more easily adopt it.

Methods Sixty-one patients (group A) entered the protocol over the past 3 years (February 1998 to October 2001) and the results were compared with the ones obtained retrospectively from a consecutive series of 58 patients (group B) who were operated on in the past (October 1994 to November 1997) before the use of any blood saving technique. Patients operated on between November 1997 and February 1998 were not included, because this was the period when the knowledge from literature was put into practice and the final form of the protocol were progressively built up. Group A and B were comparable in age, sex and hematological values (before intervention) and their demographic details are shown in Table 2. The Aegion protocol consists of the methods shown in Table 3. Each patient belonging to group A received 10,000 IU (150 IU/kg) of human recombinant erythropoietin daily subcutaneously for 5 days preoperatively and 3 days postoperatively, in addition to 300 mg of elemental iron (as ferrum sulphate) orally plus 1 mg folic acid orally, for 5 days preoperatively until discharge. Mild acute normovolemic hemodilution was performed 1 hour preoperatively to all group A patients. This is defined as collection of 1 blood unit (500 mL) in standard bags

Table 2 Demographics

Men Women Total Mean age, years (range) Mean preoperative Hb (range) Mean preoperative Hct (range)

Group A

Group B

12 49 61 70.63 (57–80) 13.64 (9.7–15) 40.91 (30.6–44.9)

10 48 58 69.67 (57–83) 13.81 (11.8–16.8) 41.96 (36.3–50.2)

Hb ⫽ hemoglobin; Hct ⫽ hematocrit.

containing anticoagulant, which was labeled and stored in the recovery room fridge (4°C to 7°C) for later utilization, while the patients received 2 L of crystalloid solutions (Ringers’ Lactate) and 500 mL of colloid solutions (hydroxy-ethyl-amylo 6% in a NaCl solution—HAES-steril) before the beginning of the operation. Intraoperatively, the patients received approximately another 2 L of crystalloid solutions (Ringers’ Lactate), while all vital circulatory and respiratory parameters were continuously monitored. All patients received combined lumbar subarachnoid and epidural anaesthesia. All patients were operated on by the senior author (K.N.) and a standard surgical procedure was used. The operation was completed under tourniquet use, without intraoperative deflation to control hemostasis and with standard use of a bone tap for the occlusion of the femoral canal, all these contributing to minimal blood loss. Upon completion of the operation, an autologous blood transfusion device was inserted through the wound to drain the blood. As soon as the device was full (maximum 600 mL) or 5 hours after the operation was completed (whichever occurred first) the device was removed, and after 30 minutes’ wait this nonelaborated blood was then reinfused to the patients through a standard transfusion filter (40 ␮m). Thereupon the patients received their predonated autologous blood unit (the one given during the normovolemic hemodilution preoperatively), usually by the time blood loss rate in the drainages had been reduced. Postoperatively epidural analgesia was maintained through a continuous infusion device for 48 hours. AntiTable 3 Aegion protocol Aegion protocol

Group A

Group B

Perioperative use of human recombinant erythropoietin plus iron and folic acid Mild acute normovolemic hemodilution Surgical technique (tourniquet use, meticulous hemostasis) Postoperative blood salvage and autologous transfusion using a closed-wound drainage system Decreased transfusion triggers (hematocrit critical levels required for transfusion)

Yes

No

Yes Yes

No Yes

Yes

No

⬃21–22

⬃26–27

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Table 5 Number of patients receiving transfusions

Table 4 Exclusion criteria Excluding criteria

Method concerned

Uncontrolled hypertension Hemoglobin ⬎15 g/dL Chronic obstructive pulmonary disease Heart failure Severe cardiovascular disease Recent myocardial infarction Recent stroke Liver failure Renal failure Known hypersensitivity to a drug or its vehicles History of deep vein thrombosis Contraindication for antithromboembolic prophylaxis Primary hematologic disease—malignancy

EPO EPO ANH ANH EPO ANH, EPO ANH, EPO ANH, EPO ANH Fe, EPO EPO EPO EPO

ANH ⫽ acute normovolemic hemodilution, EPO ⫽ erythropoietin.

thromboembolic prophylaxis with low molecular weight heparin was given to all patients starting 1 day preoperatively till the 40th day postoperatively. Careful perioperative laboratory monitoring of full blood count, reticulocytes (only for group A patients, since due to the retrospective character of the study no such data was available for group B), iron and ferritin was performed starting on the fifth preoperative day till discharge. Regarding group B patients, measurements were done on the fifth preoperative day as part of the preoperative check (routine full blood count), before surgery (data extracted from the records of the anesthetic department) and postoperatively till discharge. Monitoring of the patient’s vital parameters during the operation was thorough, ensuring the safety of the protocol. Finally, perioperative blood losses from the wound were also measured, and in cases that allogeneic blood was given the units were also recorded. Taking into account each patient’s particular health profile, clinical status, hemoglobin level, rate of its decrease postoperatively, blood loss, and response to hemopoiesis (reticulocyte levels), we set personalized limits for allogeneic blood transfusion. Thus, overcoming our previous insecurity, otherwise healthy patients were transfused at hemoglobin levels below 7 to 8 (which correspond to hematocrit levels of 21 to 24). It was prerequisite for all the patients who entered the protocol that they could well tolerate its particular methods, especially utilization of recombinant human erythropoietin and hemodilution. Therefore, patients presenting with the conditions of Table 4 were excluded.

Patients transfused

Units/patient

0 1 2 3 4 5 Mean units unit units units units units Group A 56 Group B 8

3 14

2 20

9

5

2

SD

n

0.11 (7/61) 0.41 61 1.91 (111/58) 1.27 58

group B patients were transfused with allogeneic blood and 111 units were consumed (mean 1.91 unit per patient; Table 5). Consequently, a quite significant reduction of 94% in the allogeneic transfusions was achieved (P ⬍0.001, MannWhitney test; Fig. 1). Group A patients who received no allogeneic blood had the highest average hematocrit and hemoglobin values throughout the study, even when compared with group B patients who received allogeneic blood (Fig. 2), with apparent implications in patient well being, mobilization, and recovery. Massive stimulation of erythropoiesis was observed at most 6 days after starting administration of erythropoietin, the reticulocyte levels becoming normal 2 weeks after discontinuation (Fig. 3). A transient increase of the platelets’ count in group A patients was observed 2 weeks postoperatively, which however occurred in group B patients too (Fig. 4). In isolated cases where the platelets increased significantly, they did not exceed 1 ⫻106/␮L, and the patients remained asymptomatic. The count eventually returned to normal values within 1.5 months after the operation, and we noted no relevant complication. There has been no complication related to the methods of the protocol, except for the gastrointestinal discomfort of orally ingested iron. We noticed no hypertensive encephalopathy. We had no increase in the incidence of thrombotic

Results Only 5 patients belonging in group A finally needed allogeneic blood transfusion, receiving a total number of 7 units (mean 0.11 units per patient). On the other hand, 50

Fig. 1. Only 5 group A patients did receive allogeneic blood (7 units in total), while 50 group B patients were transfused with 111 units. The reduction in transfusion rate was 94%.

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Fig. 4. There was a transient increase of the platelets 2 weeks postoperatively, which, however, was observed in both groups and did not exceed 1 ⫻ 106/␮L.

application of the protocol requires cooperation between the anesthesiologists and the orthopedics, as well as the contribution of the nursing personnel. Comments

Fig. 2. Group A patients who eventually did not receive any allogeneic blood (crooked line with rectangles) had the highest average (A) hematocrit values and (B) hemoglobin values throughout the study, even when compared with group B patients who were transfused with allogeneic blood.

vascular events, since we had only one symptomatic vascular event in each group. Being strict in the maximum of 5-hour elapsed time after the end of the operation, we had no febrile reactions or any other complications after transfusion of blood salvaged from the wound. Success in the

Fig. 3. Massive stimulation of erythropoiesis was observed at most 6 days after starting administration of erythropoietin, the reticulocytes’ levels becoming normal 2 weeks after discontinuation. By the first postoperative day already an increased red blood cell production phase of the bone marrow is obvious.

There is a growing tendency to consider the practice of allogeneic transfusion as unacceptable where there can be equivalent alternatives. Bearing that in mind, we searched for such an option that would minimize or even eliminate allogeneic blood transfusion for every single patient, irrespectively of the total blood loss, that would be easily applicable and of minimal risk. Since postoperative blood loss in the drains is unpredictable and varies over a wide range (300 mL to 1,850 mL in our department), the surgeon should always have extra options in case of a considerable postoperative hematocrit drop, even if the preoperative hematocrit is within the “safe” range. We thought therefore the combination of methods would be very useful. Before the application of the protocol, low postoperative hematocrits along with slow restoration to normal levels were recorded in all patients undergoing total knee arthroplasty, even though they did receive allogeneic blood at the same time. This observation is consistent with an erythropoietic dysfunction due to the age of the patients [11], the operation itself [12], and the transfusion of allogeneic blood [6]. Acute blood loss is indeed the main stimulus for erythropoiesis, yet a latent phase intervenes resulting in 3 to 6 days for erythroid hyperplasia to appear and 7 to 10 days before the erythropoietic response is maximal [13]. The use of erythropoietin overcomes this delay in erythropoiesis immediately postoperatively and constitutes a reliable and safe way to compensate for blood loss after elective major surgery (Fig. 3). Use of erythropoietin is well established as safe and its side effects are comparable with that of the placebo [9,14]. The doses of erythropoietin and the duration of treatment vary greatly among studies. Prevailing trends [9,15] are (a)

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for scheduled surgery after 3 weeks’ time, 600 IU/kg subcutaneously daily in 4 doses (preoperative days ⫺21, ⫺14, ⫺7, and 0), that is 16 ampoules of 10,000 IU erythropoietin for a 70 kg patient; (b) for scheduled surgery in less than 3 weeks’ time, 300 IU/kg subcutaneously daily in 15 doses (from preoperative day ⫺10 to postoperative day ⫹4), that is, 30 ampoules of 10,000 IU erythropoietin for a 70 kg patient. The subcutaneous route seems to be most preferable route of administration. In this protocol we suggest daily administration of 10,000 IU erythropoietin (150 IU/kg) subcutaneously for 8 days, starting 5 days before and for 3 days after surgery, thus for a 70 kg patient we need only a total of 8 ampoules of 10,000 IU erythropoietin. As a result, not only a short preoperative preparation period is required, but there is a 50% reduction in the number of the ampoules as well. This is justified by the fact that erythropoietin was not used as a single treatment, but as a part in a combination of methods only contributing to blood loss management. Furthermore, our goal was not to reach a preoperative high hematocrit value (to make us feel comfortable in the setting of perioperative blood loss), but rather to stimulate erythropoiesis in order to be in a phase of increased erythrocyte production by the first postoperative day already (Fig. 3). This agrees with the bibliographic data showing maximum response of reticulocytes within 1 week after administration of erythropoietin [16]. Immediately postoperatively, blood loss was compensated with the autologous blood transfusion using the wound drainage system and the reinfusion of the blood taken during the acute normovolemic hemodilution. Bearing in mind the above, we gave erythropoietin even to patients with preoperative hemoglobin over 13 g/dL (an excluding level in other blood saving methods), since its action would be virtually apparent postoperatively, after the hematocrit fall (and consequently of blood viscosity) owing to perioperative losses. On account of this, we now believe the exclusion criteria listed in Table 4 could become more flexible, without any impact on its safety. Maximum action of erythropoietin is achieved when patients’ iron stores are adequate [14,13], therefore we decided to give the patients iron together with folic acid. Owing to the complications of parenteral administration of iron that can be even life-threatening [16] and in order to enable patients to receive treatment at home, the oral route was considered best: 300 mg of elemental iron plus 1 mg of folic acid were administered daily. Implementation of preoperative autologous donation in various intervals before surgery is difficult, it is associated with increased overall transfusion rates [17], and is not cost effective for the total of the patients applied [18]. More importantly, excluding criteria shown in Table 4 must be strict and concern a high percentage of total knee arthroplasty candidates (preexisting anemia, cardiorespiratory diseases, elderly patients). In view of the above and since a lot of patients show little interest and simply do not comply with such a protocol, we

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adopted an attractive alternative solution: that of acute normovolemic hemodilution [19,20]. The aim is to lose “diluted” blood postoperatively and to return the predeposited blood unit preferably after any major blood loss has ceased (usually within 6 hours upon completion of the operation) [20], or sooner if indicated by the patient’s clinical status. Therefore, the clinical importance is principally to protect patients who might have unpredictable or substantial blood losses [21], yet maintain perioperative hematocrit values that minimize the risks related to ischemia [22]. Another major advantage of acute normovolemic hemodilution is that patients are transfused with their own fresh and fully functional blood, which contains clotting factors and contributes to hemostasis [23]. Moreover, the procedure of hemodilution itself has a positive impact on platelets circulation [24] and activation-adhesion [25], thereby contributing in hemostasis even before the autologous transfusion. We chose “mild” hemodilution [26,27], that is, removal of only 1 blood unit instead of the 2 to 3 units removed in classic “severe” acute normovolemic hemodilution [19,28]. This is considered safer, is better tolerated by the patients, and excluding criteria of Table 4 could become more flexible, enabling even more patients to enter the protocol, especially those suffering from cardiovascular, pulmonary, renal, or liver diseases. Surgical technique plays of course major role in maintaining minimal blood loss. The operation was completed using a limb tourniquet without intraoperative deflation to control hemostasis [29]. We did no unnecessary soft tissue detachment respecting the surrounding tissues, synovial membrane was spared, and a bone tap for the occlusion of the femoral canal was used. It is of major importance that the patients lost virtually no blood intraoperatively and that in case hemostasis was inadequate, blood salvage compensated for the blood loss. Albeit the measures above, postoperative blood loss in wound drainages can be extensive. Using blood salvage devices, autologous blood was collected from the wound and reinfused to the patients [30]. This was fully functional whole blood [31], which would otherwise be wasted. Ideally, this should be done within 6 hours after collection in order to avoid any febrile reactions, bacterial contamination, visual thrombi formation, and clotting disorders [32]. For even better safety we set a 5-hour limit for reinfusion. We noticed no infection, clotting disorder, or any other complication including air embolism that could be associated with the method. Ultimately, blood transfusion practices in hospitals reflect primarily each physician’s point of view rather than an objective necessity for blood [33]. The experience with Jehovah’s Witness patients shows that their postoperative course is satisfactory, although their hematocrit remains low [34,35]. This questions older policies that suggested transfusion using the “30-10” rule [36]. It seems that surgeons should overcome their initial insecurity, particularly after experience is gained, and adopt a new transfusion trigger at

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hemoglobin levels of 7 to 8 g/dL for otherwise healthy patients undergoing orthopedic surgery [37]. One must always bear in mind that low hemoglobin level per se does not justify transfusion [38] and that multiple clinical along with hemodynamic parameters should be evaluated for every individual case [39]. If the patient’s general condition is compromised (eg, cardiovascular disease, pulmonary disease), using a higher transfusion threshold is recommended [40]. Therefore allogeneic transfusion should be done on patient-specific demand [10]. Lowering the transfusion trigger from 26 to 27, to 21 to 22 alone might explain the difference in transfusion rate between the two groups, at least for those patients transfused with 1 or 2 units, thus questioning the use of erythropoietin, normovolemic hemodilution, and blood salvage. However, it was the use of erythropoietin with its subsequent erythropoiesis which permitted such an approach, not to mention of course that in the early postoperative period, normovolemic hemodilution and blood salvage protected patients from any sudden hematocrit drop or hemodynamic instability. There may also be some criticism as to how much effect each measure has produced. We did not proceed in evaluating the corresponding contribution of each method to the final result. We believe that it is desirable for every surgeon not to risk when applying a new method, but to be within a secure zone with enough alternatives; since postoperative blood loss is unpredictable, every method should be employed as a safe way out of allogeneic transfusion, even for “borderline” patients. Finally, management of postoperative pain with continuous epidural anaesthesia not only controlled pain but further prevented blood losses, since pain-associated blood flow redistribution due to venous vasoconstriction was eliminated [13]. Moreover, mean arterial pressure was kept within normal limits as pain was controlled [13], resulting in blood loss reduction in the drains. Conclusions The ultimate goal of blood management in elective orthopedic surgery should be the elimination of any need for allogeneic blood transfusion. The study shows that allogeneic blood transfusion after total knee arthroplasty is no longer considered necessary during the postoperative period. In this way a valuable fluid, especially in countries where there is shortage of blood donors, is spared for cases where it is absolutely indicated. We believe the Aegion protocol should be included among orthopedic surgeons’ alternatives for blood saving in elective total knee arthroplasty. References [1] Sculco TP. Global blood management in orthopaedic surgery. Clin Orthop 1998;357:43–9.

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