What is Post-TKA “Cognitive Dysfunction”
A post-operative short-term mild decline of cognitive capacity can be a disturbing complication of TKA
A disturbing complication of TKA is the postoperative short-term mild decline of cognitive capacity. Memory functions and analytical functions of the brain are reduced. Cognitive functionality recovers in the majority of patients within a week to 6 months. It may range from very mild to quite noticeable. In one scientific study it was found:
- 41% of TKA patients suffered from Cognitive dysfunction 1 week after surgery.
- This rate was reduced to 15% three months after surgery.
Many surgeons believe this phenomenon is a side-effect of anesthesia. They implicate drugs used, oxygen levels in the blood, and the blood pressure during surgery. However, scientific studies suggest post-TKA Cognitive Dysfunction may actually be the result of the use of pneumatic tourniquets.
- It has been shown that incomplete squeezing of the blood away from the limb before inflating the pneumatic cuff leaves about one third to one half of the blood in the limb. This blood coagulates (clots) during the time of surgery.
- When the tourniquet is deflated at the end of surgery clots travel to the lungs and in some patients to the brain. It results in small brain infarcts that can be identified by magnetic imaging (MRI) of the brain.
Incomplete removal of blood from the leg prior to the inflation of the pneumatic tourniquet (leaving behind blood to clot) may be the cause of post-TKA Cognitive Dysfunction. HemaClear® exsanguinates 95% of blood during its application (as opposed to 45% with gravity and 67% when Esmarch Bandage is used). This may lead to thinking that patients treated with HemaClear® are at far less risk of developing clots and Cognitive Deficit after TKA. A clinical study is underway to validate this.