Bier Block - This Dog Can Still Hunt

Yak - photo by JoAnn Sturman

Scott Sturman MD

With the advent of ultrasound guided brachial plexus blocks, the indications for Bier Block have waned in recent years.  The technique, however, remains useful for cases lasting between 20 and 60 minutes where MAC anesthesia is inadequate, brachial plexus blocks are impractical, or one wishes to avoid general anesthesia.  The most common problems–a leaking tourniquet, inconsistent analgesia, and tourniquet pain– can be avoided with a few Tricks of the Trade.

Generous IV sedation and prophylactic labetalol given at the first of the case will preempt sudden blood pressure elevations which may cause leaking from an otherwise well functioning tourniquet.

Faster onset and a more reliable analgesia can be obtained by forceful injection of 50 cc 0.5% lidocaine solution.  Placing a finger over a prominent vein and noting its distention insures a “pressurized” block and a well functioning tourniquet.

Tourniquet cycling and propofol-ketamine infusions are useful for dealing with tourniquet pain and extending the time patients can tolerate the tourniquet. 

Ketamine-Propofol Drips

Yak on Shishapangma Trek - photo by JoAnn Sturman

Scott Sturman MD

What can be done to enhance IV sedation for patients who do not tolerated tourniquet pain or require inordinately large doses of propofol?  Perhaps there is another all-too-often propofol shortage in the hospital.  A propofol-ketamine drip is effective under these circumstances.

The mixture ratio varies depending upon the patient, but for the most part, a 2mg propofol/1mg ketamine concoction works well.  As with many patients it is helpful to begin sedation with the standard midazolam 2mg along with fentanyl 100ug.  Begin a loading dose for the propofol-ketamine infusion at 30-40 cc per hour, then titrate the rate downward for the desired effect.  Doses will be considerably less than with the standard propofol technique.

Ketamine makes some patients salivate, so glycopyrrolate 0.2 mg should be given at the beginning of the case.  Interestingly, ketamine is now being used to treat depression in some patient populations, so don’t be surprised at at the conclusion of a case when your patient remarks, “Thanks, doc.  Could we do that again?”