Qualitative and quantitative analysis of post-operative drainage: pilot study

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Clinical Pathology

Background:

• Surgical drains are commonly used to monitor postoperative blood loss after orthopedic procedures.
• Accurate assessment of blood loss is crucial for patient management and transfusion decisions.
• Existing methods may overestimate actual blood loss due to the composition of drained fluid over time.

Purpose of the Study:

• To evaluate the composition of fluid drained via Redon drains after total knee arthroplasty (TKA) and primary hip arthroplasty (THA).
• To determine if early Redon drain removal is a viable option by analyzing drained fluid composition.
• To compare drained fluid composition with preoperative and postoperative blood samples to accurately assess blood loss.

Main Methods:

• A monocentric prospective study involving 25 patients undergoing TKA or THA for osteoarthritis.
• Analysis of Redon drain fluid volume and composition using sedimentation studies.
• Qualitative analysis of drained fluid content.
• Collection of preoperative and postoperative blood samples for comparison.

Main Results:

• Decreased sedimentation volumes and protein levels were observed in drained fluid compared to blood samples for both TKA and THA.
• Fluid drained on postoperative days 2 and 3 was identified as a mixture of blood and serum.
• Fluid drained on postoperative day 1 primarily consisted of blood.

Conclusions:

• Postoperative blood loss measured by Redon drains may be overestimated, particularly after the first postoperative day.
• The composition of drained fluid changes from pure blood to a blood-serum mixture.
• These findings support the consideration of early Redon drain withdrawal to improve accuracy in blood loss assessment.