Friday, March 02, 2012

Pain and Anesthesia II

Some of the hardest patients to anesthetize for surgery are those with chronic pain. Similar to the patients I saw on my acute pain rotation, these patients take a whopping amount of opiates, and their bodies are tolerant and resistant to them. And yet, as anesthesiologists, we are asked to ready these patients for a surgery where skin, muscle, tissues, and bones are cut and rearranged, and then to wake them up afterwards with minimal discomfort. This is a challenging if not impossible situation.

I had a patient who was taking handfuls of Vicodin a day and needed a hip replacement. He refused a spinal or epidural, but we tried our best to use as many pain adjuncts as we could. We gave large amounts of opiates: 500mcg of fentanyl, 4mg of hydromorphone. We used ketamine as an adjunct. We ran the patient on a lidocaine drip during the surgery. We avoided acetaminophen given the amount of Vicodin he was taking preoperatively. With all of this, we achieved a satisfactory and yet suboptimal post-operative status. The patient was sleepy and snoring - side effects from all the pain medicines. Yet when you woke him to examine his hip and leg, he was in excruciating pain. When you left, he went back to snoring. Sometimes this behavior is interpreted as patients seeking pain medicines, but its not the case. As patients take more and more opiates, the therapeutic window - that is, the sweet spot where they get analgesia but don't have overwhelming side effects - gets smaller and smaller. Sometimes it disappears so that the patient is either "snowed" (sedated, asleep from the opiates) or in severe pain. It's a challenge, but we do as much as we can to tide patients through comfortably and safely.

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