THE RATIO OF EXTERNAL AND CALCULATED BLOOD LOSS IN ARTHROPLASTY OF LARGE JOINTS OF THE LOWER EXTREMITY Lebed M.L., Kirpichenko M.G., Shamburova A.S., Sandakova I.N., Bocharova Yu.S., Popova V.S., Karmanova M.M., Fesenko M.A., Golub I.E.

Irkutsk Scientific Center of Surgery and Traumatology,

Irkutsk State Medical University, Irkutsk, Russia

Total arthroplasty of big joints of the lower extremities (hip and knee joints) presents a complex technologic intervention for the locomotor system, with inevitable severe damages of tissues in the surgery site [1]. One of the expected consequences of surgical invasion is perisurgical blood loss, which reaches 1,000-1,500 ml for knee joint replacement and requires for donor hemotransfusion for 3.5-18.5 % of patients according to the literature data [2-7]. The similar situation is related to hip joint arthroplasty, with total volume of bleeding of 1,000-1,350 ml, and transfusion requirement in 5.4-26.2 % [5, 8].

Negative effects of hemotransfusion are well known. Transfusion of donor blood components is associated with possible transfusion responses, the risk of hemotransmissive infectious complications, and with the risk of volumetric overload of the cardiovascular system, periprosthetic infection, increasing hospital stay and mortality [9-15]. It is not surprisingly that transfusions highly increase the use of resources and general costs of treatment [16].

Besides sparing surgical techniques, the volume of perisurgical blood loss can be decreased with methods for reduction of blood flow in the intervention site (controlled systemic hypotension, pneumatic tourniquet) which influence on system of regulation of aggregate state of the blood (fibrinolysis inhibitors, warming of patient), and optimal postsurgical position of the knee joint [1, 3, 15, 17, 18].

Estimation of frequency of blood transfusion, and identification of patients with high risk of hemotransfusion are critical for development of a strategy for blood loss reduction [6].

For orthopedic interventions, the risk factors of blood transfusion are older age, low presurgical level of hemoglobin, high anesthesiological risk, and high volume of hemorrhagic drainage [19].

Objective − basing on a comparison of the volume of external perioperative blood loss and a decrease in blood hemoglobin concentration in patients after arthroplasty of large joints of the lower extremities, to conclude the effect of hidden blood loss on the development of postoperative anemia.

MATERIALS AND METHODS

The data of 609 patients were used. They received planned surgery in Irkutsk Scientific Center of Surgery and Traumatology. Three groups of clinical follow-up were formed in compliance with surgery volume. The comparative characteristics of number of patients, age and gender composition, and basic physical status are presented in the table 1. All statistical results are presented as the median (M), 25th and 75th percentiles (P₂₅ and P₇₅). According to our opinion, precise description of results allows more informative description of structure of data.

Table1

Characteristics of groups of clinical follow-up

Groups	Group 1	Group 2	Group 3
Intervention volume	Primary total knee joint replacement	Primary total hip joint replacement	Revision hip joint arthroplasty
n	224	355	30
Age, years	65 (60; 70)	62 (54; 68)	61 (56; 63)
Men/women	40 / 184	14 2/ 213	14 / 16
Basic physical status according to ASA	3 (3; 3)	3 (3; 3)	3 (3; 3)

All interventions were conducted in conditions of subarachnoid anesthesia with bupivacaine. The pneumatic tourniquet was used to decrease the volume of perisurgical blood loss during knee joint replacement. Moreover, in absence of contraindications, all patients received infusion of tranexamic acid (10 mg/kg) 20 minutes before incision in hip joint arthroplasty, and 10 minutes before tourniquet removal in knee arthroplasty [20, 21]. Before surgery, and on the days 1, 3 and 5, all patients received laboratory examination with estimation of blood hemoglobin level. Also the following values were considered: perisurgical external blood loss (during intervention and in the first day after it), the rate of transfusion of donor blood components, and reinfusion of autological drained blood. The volume of circulating blood was 70 ml per kg of body mass [22]. The calculated total blood loss was determined according to a degree of a decrease in hemoglobin level with consideration of hemotransfusion, similar with technique by Good L. et al. [23]. The level of hemoglobin in one dose of packed red blood cells was 43 g [24]. All calculations were conducted with Microsoft Excel.

The study corresponds to Helsinki Declare − Ethical Principles for Medical Research with Human Subjects, 2000, and the Rules for Clinical Practice in the Russian Federation confirmed by the Order by Health Ministry of Russia on June 19, 2003, No. 266.

RESULTS AND DISCUSSION

Owing to improvement in surgical technique and the system for anesthesia provision, arthroplasty operations are efficient and quite safe for treatment of injuries and diseases of big joints of the lower extremities.

A typical patient admitted for planned primary arthroplasty of knee and hip joints is a woman, age of 62-65, with idiopathic deforming arthrosis of degree 3, with concurrent somatic pathology, with class III of physical status stratification of ASA. A locomotor system pathology significantly limits the physical activity of the patient, and promotes obesity in adherence to common type of nutrition. In these conditions, the final result of treatment highly depends on compensatory potential of the body, which allows successful mobilization of functional reserves to pass through multiple consequences of surgical trauma, and subsequent early movement activation. One of the key factors of successful rehabilitation is oxygen capacity of the blood. Therefore, maintenance of safe interval of qualitative and quantitative characteristics of blood system, with routine control and correction, is obligatory direction of perisurgical therapy (the term blood management is used in English language literature).

External blood loss in arthroplasty of big joints of the lower extremities and in the short term postsurgical period is simply to calculate (the table 2).

Table 2

External blood loss in arthroplasty of large joints of lower extremities

Groups

Group 1

Group 2

Group 3

Surgical blood loss

(50; 100)

200

(100; 250)

475

(350; 700)

% CBV

1.0

(0.9; 1.8)

3.4

(2.2; 4.9)

7.4

(5.6; 14.9)

Drained discharge in 1st day after surgery

240

(150; 350)

150

(100; 200)

160

(126; 234)

% CBV

4.3

(2.9; 6.6)

2.6

(1.7; 3.8)

3.0

(2.2; 3.8)

External perisurgical blood loss (intrasurgical + 1st day after surgery)

308

(225; 453)

350

(250; 470)

718

(450; 988)

% CBV

5.9

(4.1; 8.9)

6.1

(4.8; 8.6)

10.9

(7.7; 19.3)

Knee joint replacement (the group 1) is commonly performed with pneumatic tourniquet. Correspondingly, the volume of intrasurgical hemorrhage is minimal and, as a rule, is within the limits of measurement errors. For hip joint surgery, application of tourniquet is impossible, and revision endoprosthetics has some specific technical features, which influence on blood loss indices in groups 2 and 3.

The total external perisurgical blood loss in primary arthroplasty of the lower extremities rarely achieves 10 % of total circulating blood, and, seemingly, it does not suppose transfusion of donor blood components. However, it is impossible to refuse from transfusion (the table 3).

Table 3

Transfusion of blood components in arthroplasty of large joints of lower extremities

Groups

Group 1

Group 2

Group 3

Amount of patients with transfusion of donor packed red blood cells, n (%)

(4.5 %)

(8.7 %)

(36.7 %)

Volume of transfusion of donor packed red blood cells, ml

312

(300; 343)

310

(297; 332)

320

(307; 345)

Amount of patients with transfusion of donor fresh frozen plasma, n (%)

(8.1%)

(11.0%)

(46.7%)

Volume of transfusion of donor fresh frozen plasma, ml

330

(310; 558)

300

(280; 575)

510

(468; 598)

Amount of patients with transfusion of donor blood components

(9.4 %)

(13.8 %)

(46.7 %)

Amount of patients with reinfusion of autologous drained blood, n (%)

(13.9 %)

(4.8 %)

(3.3 %)

Volume of reinfusion of autologous drained blood, ml

450

(375; 600)

400

(300; 500)

450

Our results correspond to other authors' data concerning requirement for hemotransfusion for patients after lower extremity arthroplasty. As for transfusion of erythrocytic components, our rate of transfusion is close to the lower limit indicated in the literature.

Active use of donor fresh frozen plasma (FFP) in all three groups is explained by realization of the program for blood loss correction on the basis of normalization of transcapillary exchange [25]. Predominance of volume of external postsurgical hemorrhage over intrasurgical one promoted higher requirement for reinfusion of autologic drained blood and a decrease in incidence of transfusion of donor blood components in the group 1 as compared to other groups. Most commonly, donor transfusion was used in the group 3 (46.7 %). It was associated with objective technical difficulties of surgical intervention. The indices of transfusion of donor blood components in patients of all three groups testify that only one dose (about 300 ml) of packed red blood cells was required for maintenance of oxygen capacity of the blood.

Indications for transfusion of donor blood components are regulated by the order of Health Ministry of Russia No. 183n "About confirmation of rules for clinical use of donor blood and (or) its components" [22], and medical technique "Replacement of blood loss in planned surgery" FS No. 2010/157, May 6, 2010 [25]. Therefore, after normalization of blood level of total protein, the key criterion of requirement for transfusion is a decrease in hemoglobin level below 70-80 g/l.

All intervention had the character of planning. It means the possibility of presurgical examination and preparation of patients for identification and compensation of concurrent chronic diseases, including chronic anemia in its diagnosis. However, there is an evident discordance between relatively low volume of presurgical external blood loss and requirement for hemotransfusion, which appears in some patients.

In pathogenesis of anemia, which is almost inevitable after extensive orthopedic interventions, hidden blood loss is s important as external hemorrhage. After suturing of a surgical wound, a hematoma appears in the intervention site even after scrutinous surgical hemostasis [26]. Gender, diagnosis, body mass index, a prescribed anticoagulant, management mode of tranexamic acid, and the use of active drainage are the factors of occult blood loss [27]. The degree of occult blood loss after arthroplasty of big joints of the lower extremities is comparable or higher than total external blood losses in the perisurgical period [23, 28, 29]. The findings of this issue vary significantly that can be associated with differences in surgical technique and use of blood saving techniques.

The mechanisms of occult blood loss include extravasation into tissues, residual blood in a joint, and hemolysis [29, 30]. Possibly, development of anemia after lower extremity arthroplasty is influenced by the aseptic inflammatory process, which appears after a surgical injury to tissues. However, there are only scare findings on this issue in literature [31].

In any case, it is difficult to determine contribution of each of the above-mentioned mechanisms, and, possibly, it is not required. It is worth to estimate the total effect of all links of pathogenesis of perisurgical anemia according to changes in oxygen capacity of the blood since transfusion strategy is oriented to maintenance of hemoglobin level higher than minimal one.

For this purpose, the index of calculated blood loss is efficient. It shows the volume of external hemorrhage, which corresponds to a decrease in hemoglobin level in absence of influence of other mechanisms of postsurgical anemia (the table 4).

Table 4

Ratio of calculated and external blood loss in arthroplasty of large joints of lower extremities

Blood loss values

Group 1

Group 2

Group 3

External blood loss (surgical + 1st day after surgery)

мл ml

308

(225; 453)

350

(250; 470)

718

(450; 988)

% CBV

5.9

(4.1; 8.9)

6.1

(4.8; 8.6)

10.9

(7.7; 19.3)

Calculated blood loss

1257

(977; 1605)

1117

(880; 1483)

1318

(915; 1806)

% CBV

23.0

(18.0; 29.7)

21.1

(16.1; 27.0)

24.8

(15; 32.4)

Ratio of calculated and external blood loss

3.6

(2.6; 5.2)

3.3

(2.2; 4.5)

1.9

(1.5; 2.7)

It is evident that calculated blood loss exceeds external perisurgical hemorrhage. In the groups of primary arthroplasty, this ratio is 2-5 (with the median about 3.5), and only 1.5-3 for revision arthroplasty (the median about 2). The size of the received multiplier certainly depends on some conditions, which include local features of anesthesia provision and surgical practice, and, therefore, it characterizes the clinical course with this feature.

CONCLUSION

The results of the study show that occult blood loss significantly exceeds the volume of external postsurgical hemorrhage and contributes to development of postsurgical anemia in patients with primary arthroplasty of big joints of the lower extremities. The identified features of the postsurgical period in patients with interventions for the locomotor system allow separating some groups of patients with high risk of transfusion procedures, and planning the material and technical provision for realization of medical activity.

Information on financing and conflict of interests

The study was conducted without sponsorship. The authors declare the absence of any clear and potential conflicts of interests relating to publication of this article.