Blood loss in total knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Surgical Outcomes
• Patient Blood Management

Background:

• Standard protocols for total knee arthroplasty (TKA) often include measures like intraoperative tourniquet deflation, suction drainage, and immediate continuous passive motion (CPM).
• Concerns exist that these TKA interventions may increase patient morbidity, including blood loss and transfusion requirements.

Purpose of the Study:

• To evaluate the impact of intraoperative tourniquet deflation, suction drainage, and immediate continuous passive motion (CPM) on blood loss and transfusion necessity following primary total knee arthroplasty (TKA).

Main Methods:

• A prospective study of 112 primary TKAs performed using a standard protocol.
• Inclusion of intraoperative tourniquet deflation before closure, suction drains for 24-48 hours, and immediate CPM for a mean of seven days.
• Serial hematocrit (Hct) measurements were taken, and blood loss was calculated, with transfusion rates analyzed.

Main Results:

• Total calculated blood loss averaged 794 ml, higher in cemented vs. uncemented prostheses and males vs. females.
• Thirty-eight percent of patients required transfusion (mean 2.2 units).
• The drop in hematocrit was similar between transfused and non-transfused groups, indicating transfusion need was linked to preoperative Hct, not intraoperative/postoperative blood loss.

Conclusions:

• Intraoperative tourniquet deflation, suction drainage, and immediate CPM are safe and do not significantly increase blood loss or transfusion requirements in TKA.
• Preoperative hematocrit is the primary determinant for transfusion necessity after TKA, rather than intraoperative or postoperative blood loss.
• Standard TKA protocols incorporating these measures can be safely implemented without compromising patient blood management.