Blood loss in total knee arthroplasty: an analysis of risk factors.
The amount of blood loss in a primary cemented total knee arthroplasty (TKA) seems to vary in different reported studies. We carried out a prospective study to determine the factors affecting the peri-operative blood loss, hidden blood loss and blood transfusion requirements in a primary cemented total knee arthroplasty. The factors analysed were gender, diagnosis, tourniquet time and body mass index (BMI). We included a total of 66 consecutive patients who underwent primary TKA by a single surgeon (A.M). There was significantly more peri-operative blood loss in male patients than in females (p=0.001, Student's t test). The patients with rheumatoid arthritis did not show any statistical difference in peri-operative blood loss compared with that in patients with osteoarthritis. The tourniquet time and the surgical time showed a positive correlation with peri-operative blood loss. The BMI did not show any correlation with peri-operative blood loss. The incidence of blood transfusion was significantly higher in patients with rheumatoid knees as their pre-operative haemoglobin value was low. The amount of hidden blood loss in our series was 38%. We concluded that gender and tourniquet time plays a role in blood loss in TKA, but diagnosis (advanced osteoarthritis [OA] or rheumatoid arthritis (RA) does not. The blood transfusion depends on both pre-operative haemoglobin value and intra-operative blood loss. The post-operative transfusion trigger can be brought to 8.0 g% in a haemodynamically stable patient.
Trauma and Orthopaedics, Bombay Hospital and Postgraduate Institute, Mumbai, India. nporth@ntlworld.com
Narayana
N
Prasad
Vinod
V
Padmanabhan
Arun
A
Mullaji
D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000601:surgery; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D016063:Blood Loss, Surgical / Q000503:physiopathology / Q000517:prevention & control*; D001803:Blood Transfusion; D001843:Bone Cements; D002484:Cementation / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D019106:Postoperative Hemorrhage / Q000503:physiopathology / Q000517:prevention & control*; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D014111:Tourniquets
D001843:Bone Cements