Please note: In any event, the values of pressure and model selection in the Model Selection Guide are to be used as reference.
Please note: In any event, the values of pressure and model selection in the Model Selection Guide are to be used as reference.
No. HemaClear® is a sterile single-use device that is removed by cutting when the procedure ends. Therefore, it cannot be re-used or re-sterilized.
There are many studies on use or no use of tourniquets in TKA. The frequently used end points are:
Blood loss
Pain
Mobility and strength
The studies all show higher intra-operative blood loss, but no significant overall difference in haemoglobin drop and need for transfusion
Less thigh pain when tourniquet is not used
Better mobility and quad strength when tourniquet is not used.
On the other hand, there is this study from J Arthroplasty that shows deeper cement penetration when tourniquet is used.
Please note that all of these studies were done with pneumatic tourniquets, not HemaClear.
I believe that if a study is done with HC vs. no tourniquet or a three-way study (no tourniquet/Pneumatic tourniquet/HemaClear) there will be advantages found for HemaClear.
As a policy, we do not recommend using HemaClear to surgeons who are not using tourniquets. We do remind them that patients in which they do use a tourniquet (e.g. haemophiliacs, anaemic, Jehovah Witnesses etc.) or in cases where they use a tourniquet “only” during cementation, it is better for the patient to use HemaClear.
BTW, the XL model is used in the upper thigh in almost all adults. Its upper BP pressure is also 160 mm Hg and it is essentially a “one size fits all adults”.
0.5% lidocaine = 0.5 gram in 100 cc = 500 mg. so 20 cc of 0.5% lidocaine = 100 mg = safe dose used often in emergency medicine for cardiac premature beats. This is how much you need for forearm Bier Block. For upper arm Bier Block with pneumatic cuff (no tight stockinet) you need 50-60 cc of 0.5% lidocaine which is 250-300 mg. This is overdose and not safe. May cause seizures and even cardiac arrest. As such, it is customary to wait at least 30-40 minutes after lidocaine injection for upper arm tourniquets before releasing the tourniquet to allow for it to be absorbed into the tissues.
We assume that at least 30 cc of lidocaine is needed for upper arm HemaClear placement (less is needed because the veins are compressed by the HemaClear stockinet). This is 150 mg which is the upper level of safety. If more than this is injected, the 30-40 minutes delay is also needed with HemaClear.
Now what does “slow” pressure release means?
When tourniquet pressure is released slowly, first the tourniquet pressure reaches the systolic level and blood starts to flow INTO the arm. Venous outflow remains zero until the venous pressure increases above the tourniquet pressure. At this point there is a lot of blood in the limb and when the tourniquet pressure is further released a gush of venous blood is exiting the limb into central circulation, not only with lidocaine, but also with Lactate, CO2, H2, K+ etc. Not very good for the heart.