Knee Surg Relat Res.  2017 Mar;29(1):52-56. 10.5792/ksrr.16.038.

Optimal Timing for Hemoglobin Concentration Determination after Total Knee Arthroplasty: Day 1 versus Day 2

• Khalfaoui
• Godavitarne C
• Wilkinson

• KMID: 2371534
• DOI: http://doi.org/10.5792/ksrr.16.038

Abstract

PURPOSE
Postoperative hemoglobin (Hb) determination remains an essential parameter for quantifying blood loss following total knee replacement (TKR) surgery and guiding transfusion practice. In this study we aimed to ascertain the optimal timing for Hb determination postoperatively and assess its relationship to serum hematocrit (Hct).
MATERIALS AND METHODS
This was a retrospective cohort analysis of 61 consecutive patients undergoing preoperative, day 1 and day 2 Hb and Hct concentration determination following TKR surgery. This was a single centre study in the United Kingdom.
RESULTS
The mean fall in Hb concentration at day 1 was 2.9 g/dL in comparison to 3.3 g/dL at day 2. This indicated a significant difference of 0.39 g/dL (p=0.023). A total of 5 patients required blood transfusions following day 2 Hb determination. Postoperative Hct values varied in close relation with the Hb concentration with no significant differences demonstrated. Our study reveals a significant change between day 1 and day 2 Hb concentrations following TKR surgery, with no significant differing information provided through Hct determination.
CONCLUSIONS
Our results support the use of delayed routine testing at day 2 following surgery as it is likely to more accurately reflect ongoing hidden blood loss into the joint cavity and within soft tissue planes.

Keyword

Knee; Arthroplasty; Blood loss; Hemoglobin; Hematocrit

MeSH Terms

Arthroplasty
Arthroplasty, Replacement, Knee*
Blood Transfusion
Cohort Studies
Great Britain
Hematocrit
Humans
Joints
Knee
Retrospective Studies