by I. Douglas McLaren, MD
On a Friday morning about a month ago, I cut the ulnar aspect of my right little finger at the base on a piece of sharp glass. There was lots of blood so I assumed that I may have severed the digital artery. The outer aspect of the finger was numb and I guessed that I’d sliced the nerve as well. I quickly wrapped it up and later in the day at work consulted a surgical colleague, a hand surgeon, who confirmed that the artery and nerve were disrupted but that the tendons were okay. He kindly agreed to explore the wound in the OR at 8:00 am the next morning, under local.
I duly arrived the next day just before eight, feeling a little trepidation, but ready to jump on the OR table. I was tired, having been woken for the second time at 4:00 am to come in to start anesthesia for a patient for liver transplantation. Luckily for me that case was suddenly canceled at 5:00 am. I bumped into the surgical orthopedic resident who told me that his boss had decided that it was probably better to do the procedure under a Bier block. I didn’t like the sound of that much, having expected a pure local, but I thought well, that’s better than a brachial plexus block or a general. I immediately went off to round up a colleague to administer intravenous regional anesthesia.
As I was paging my friend I recalled the name of the famous German doctor, August Karl Gustav Bier, who gave the first deliberate spinal anesthetic, and who pioneered intravenous procaine analgesia in 1908, nearly 90 years ago. Apparently, the Bier block did not become popular until much later when Holmes of Oxford substituted the more powerful lidocaine for procaine in 1963. I found the regional cart and drew up my usual Bier block local anesthetic mixture into a 50 cc syringe. This stronger-than-normal solution consisted of 35 cc 0.5% lidocaine, and 15 cc 1.0% lidocaine, making a total of 325 mg in 50 cc. I was fully aware that this cocktail of 0.65% lidocaine was stronger than the standard 50 cc of 0.5% holding 250 mg. Previous experience of imperfect patient analgesia in the past had prompted me to try slightly more powerful solutions.
Armed with my syringe, I returned to the OR, lay on the table and asked my resident colleague to place a 20 gauge cannula in a vein on the dorsum of the afflicted hand, which he did with his tremulous hand. I elevated my arm whilst the nurse located the correct double-cuffed tourniquet and fittings. The chief surgeon found an Esmarch bandage (Johann Friedrich von Esmarch, 1832-1908, professor of surgery in University of Kiel, Germany), and I asked them to exsanguinate the limb by stretching the latex as tightly as possible. This done, the lower and then the upper tourniquet cuff were inflated to 250 mm Hg, and then finally, the lower cuff released. The initial Esmarch bandage wrap around my naked wound was uncomfortable for a moment, but the rest felt fine. When I used to give Bier’s blocks for Colle’s fractures in the old days (using 0.2% bupivacaine), I would elevate the patient’s arm and then press on the brachial artery for five minutes instead of inflicting a painful Esmarch exsanguination. It usually worked pretty well.
Next, I lowered my arm and my colleague slowly injected the contents of the big syringe (50 cc) through the cannula into my hand and arm veins, watching carefully for any extravasation which might sabotage the block. I suggested that he might squeeze my forearm proximal to the cannula, first to keep the local anesthetic downstream near my fingers initially to help ensure a good block, and second to act as a second safety tourniquet in case the proper double tourniquet above was leaky. My hand and arm began to feel cold and tingly, and then weak. The tingling continued for quite a while as the cannula was removed and the arm was prepped with iodine. The wound still felt slightly painful as the area was cleaned but I could tell that the intensity of the block was still increasing, even after 15 minutes. By this stage I had lost the sense of position of the arm, as it was actually lying flat on a table in a lead hand, but felt as if it was flexed 90° at the elbow.
The operation commenced and the surgeons started using the microscope to reconnect the digital nerve. Meanwhile, an anesthesiology staff colleague took over for my resident. My friend immediately chided the departed resident for not starting an IV in the contralateral arm, and then berated me when I told him that I had asked the resident not to start one. My blood pressure and pulse rate remained stable at 120/75 mm Hg and 55 b.p.m., respectively. The blocked arm continued to send me various strange tingling sensations and mild electric shocks, and I had a great urge to move it, but successfully resisted the temptation.
After 35 minutes of tourniquet time, I became more aware of a diffusely painful achy discomfort in the region of the upper part of my right arm. At 45 minutes I asked my colleague to change the pressure from the upper tourniquet cuff to the lower one. This was done in two stages. First, the lower cuff was inflated with the upper still inflated, and then after a few minutes the upper cuff was deflated. This maneuver brought about great symptomatic relief and I had no further tourniquet discomfort for the rest of the case. Having reconnected the nerve, the chief surgeon informed me that the severed digital artery was twice as big as normal and that because of this he would attempt to reanastomose the two ends with the aid of the microscope, which he did.
As I lay still on the OR table talking to my colleague, I felt vaguely detached. I wondered if my systemic lidocaine level was affording me a measure of drowsiness. Some mild sacroiliac pain was relieved by flexing my left leg at the hip and knee. I thought to myself that perhaps I should have put a pillow under my lumbar spine at the start of the proceedings. Standard adjuvant sedation and analgesia was of course unavailable to me as I had, foolishly, elected to shun the usual IV at the beginning of the ordeal.
At 70 minutes the surgeons had reanastomosed the digital artery and called for tourniquet deflation! At this point, I piped up to suggest that perhaps the cuff might be released in stages. This was my own personal practice, as I thought that several cycles of very brief deflation and then reinflation slowed the efflux and therefore the peak systemic blood levels of both local anesthetic and acidotic metabolites from the ischemic limb. I was also privately bearing in mind that I had received, albeit by my own doing, the relatively hefty dose of 325 mg of lidocaine—me being a modest 70 kg—and that I had no IV running if something went amiss. However, both my good colleague and my friendly chief surgeon remarked that they didn’t believe that such a practice made any difference whatsoever, and so down came the tourniquet once and for all. Now ensued the most interesting part of the whole experience.
As the tourniquet pressure fell to zero, I started a mental stop watch and imagined a hypoxemic, hypercarbemic tide of red-cell tinged, lidocaine-flavored sludge being washed centrally up my arm, into the right heart, on through the lungs, and out into the systemic circulation. At approximately 15 seconds post-tourniquet deflation (PTD), I remarked on a distinctly garlic-like taste in the mouth, followed at 20 seconds by a rushing sensation in the ears and a general wooziness, which was not particularly pleasant. I could hear the chief surgeon saying that sounds might seem louder to me. At 45 seconds PTD the fuzzy/drunken/anxious feeling had intensified and I tried to concentrate by relating my experiences to my colleagues to counteract the nasty lightheaded feeling. At the same time, I was aware of a salvo of PVC-type palpitations, which were also rather unpleasant, and I began thinking that I was sliding downhill toward unconsciousness and seizures. Funny, I thought lidocaine was a treatment for PVCs? I fought off the feeling that I was going to pass out by concentrating on a spot on the ceiling and by talking to my colleague. Surely they must notice that I look strange or something, but there was no ECG connected to register all the PVCs. It was only when the pulse rate on the pulse oximeter increased from 55 to 85 and the blood pressure rose from 120/75 to 150/80 that it was obvious to the others that the arm contents had been truly noxious.
While this very unpleasant portion of the case ran its course, the surgeons commented that the reanastomosed artery had filled very nicely. They then injected 1% lidocaine into the wound and sutured the skin together. The suturing did hurt a bit but I was actually pleased to concentrate on the discomfort to avoid slipping into oblivion. I remember thinking that it was interesting that I could feel some pain as the stitches went in minutes after the tourniquet had been released, as I had read that analgesia remained after a Bier’s block for a short period of time. As the minutes passed, I willed my liver to metabolize the remaining lidocaine, and gradually, over ten minutes, the CNS symptoms subsided and I didn’t seize or arrest. The little finger was carefully wrapped, padded and splinted in 30° of flexion to protect the anastomoses.
As I sat up slowly and carefully on the edge of the OR table, I noted that an area around the my right bicipital aponeurosis ached markedly, presumably due to 70 minutes of tourniquet pressure. This took two days to disappear. I thanked the chief surgeon, who told me to wear the anti-extension splint for a month. I still felt fuzzy but managed to walk back to the coffee lounge with my faculty colleague. I thanked him as well and we went over the case, drawing the following points and conclusions before I drove myself into town to meet my wife.
Lessons to Be Learned: The Five Ts
Point 1. Timing - It is better for patient, surgeon and anesthesiologist to have the appropriate type of anesthesia decided and agreed upon in reasonable time before the procedure.
Point 2. Two IVs - One small IV is optimally placed near the operative site for the Bier block. A second IV placed in a different limb is mandatory for three reasons: a) to provide sedatives and analgesics as necessary to keep the patient comfortable—the patient may experience discomfort from the operative site, the tourniquet, or just from lying still on the OR table; b) give benzodiazepines prophylactically to raise the patient’s seizure threshold in case of local anesthetic CNS toxicity; and (c) in case general anesthesia or cardiorespiratory resuscitation is required.
Point 3. Tourniquet - Local anesthetic may remain in the limb for a long time after infusion and may cause unpleasant side effects on reperfusion. It seems prudent then, to release the tourniquet in stages, i.e., deflate and inflate again rapidly, then pause two or three times in an attempt to reduce peak blood levels, both of local anesthetic and anaerobic metabolites.
Point 4. Toxicity - Both preservative-free lidocaine 0.5% and prilocaine 0.5% usually provide a sufficient block with good exanguination, and is safer. Stronger lidocaine solutions although within usual mg per kg dosage guidelines may cause toxic side effects even 60 minutes after infusion. Previously popular 0.2% bupivicaine should not be used due to its cardiac toxicity.
Point 5. Transport - Even in the absence of usual intravenous sedation and analgesia, inadvertent CNS side effects of local anesthetics make it seem sensible to insist on a designated driver postoperatively.
—Author's Note: Fortunately, one month later, my wound is healing nicely and sensation is returning to the affected portion of my pinky.