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Severe and morbid obesity and transfusional risk in total knee arthroplasty: An observational study

Montserrat Tió1, Misericordia Basora1, Jose Rios2

  • 1Department of Anesthesiology, Hospital Clinic, Barcelona, Spain.

The Knee
|July 22, 2018
PubMed

Insights

Severe and morbid obesity (Class II-III) does not increase blood loss or red blood cell (RBC) transfusion needs during total knee arthroplasty (TKA). Obese patients had higher estimated blood volume, balancing similar RBC losses compared to non-obese individuals.

Area of Science:

  • Orthopedic Surgery
  • Obesity Research
  • Transfusion Medicine

Background:

  • Severe and morbid obesity (Class II-III) presents challenges in total knee arthroplasty (TKA).
  • The impact of body mass index (BMI) on blood loss and red blood cell (RBC) transfusion during TKA remains unclear.
  • This study aimed to investigate blood loss and transfusion requirements in severely and morbidly obese patients undergoing TKA.

Purpose of the Study:

  • To determine blood loss in severe and morbidly obese patients undergoing TKA.
  • To assess red blood cell (RBC) transfusion needs in these patients.
  • To compare outcomes between non-obese, obese Class I, and obese Class II-III patients undergoing TKA.

Main Methods:

  • Retrospective analysis of patients undergoing TKA.
  • Obesity classification based on World Health Organization (WHO) guidelines.
  • Estimation of blood loss using formulas for lost red-cell mass and percentage of lost blood volume.
  • Recording of perioperative hemoglobin levels and optimization treatments.

Main Results:

  • A total of 922 patients were included: 35.90% obese Class I, 18.76% obese Class II-III.
  • Estimated blood volume (EBV) was significantly higher in obese Class II-III patients (5030 ± 464 ml) compared to non-obese (4390 ± 470 ml) and obese Class I (4736 ± 423 ml) patients (P < 0.001).
  • Global estimated blood volume lost showed no significant differences between groups, but the percentage of lost blood volume was lower in obese Class II-III patients (29.65%) (P < 0.005).
  • Transfusion rates were 12.7% (non-obese), 12.1% (obese Class I), and 6.4% (obese Class II-III) (P = 0.062), with a predicted negative transfusion risk for Class II-III patients.

Conclusions:

  • Severely and morbidly obese patients (Class II-III) undergoing primary TKA do not experience greater blood loss.
  • These patients do not have higher red blood cell (RBC) transfusion needs compared to non-obese and obese Class I individuals.
  • Higher estimated blood volume in obese Class II-III patients may compensate for similar RBC losses, leading to comparable or lower transfusion rates.
Abstract

Keywords:
ArthroplastyBlood lossBlood transfusionBody mass indexKneeObesity

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