Thursday, April 17, 2014

Ultrasound


The ultrasound machine is part of every anesthesiologist's armamentarium. We most commonly use it for putting in central venous access, scanning the internal jugular or femoral veins. But ultrasound can also be a tool for placing difficult IVs or arterial lines, evaluating the heart (both transthoracic and transesophageal), and placing nerve blocks. Thus, my month on regional anesthesia taught me a lot about ultrasound.

Most physicians can get away with a rudimentary understanding of the physics, machine, and computing algorithms. However, to successfully do nerve blocks, anesthesiologists need more than a superficial understanding of ultrasound. Our targets are millimeters wide but can be several centimeters deep. They are surrounded by critical structures and can be tricky to visualize. The goal is to see the needle tip at every moment as it reaches the target. This seems easy, but getting the needle, ultrasound beam, and target aligned in one view is an incredibly challenging technical skill to learn.

Ultrasound taught my hand fine, miniscule movements. When I first started, I thought I made small adjustments, but I was moving the probe millimeters at a time - a reasonable action if I were placing a central line into a jugular vein, but ineffective in locating a bundle of peripheral nerves. But over the four weeks, I developed better judgment in directing my needle at the right angle and trajectory and better muscle memory in adjusting the ultrasound beam to catch the needle and target at once.

Furthermore, I gained a deeper understanding of ultrasound physics and mechanics. Though it sounds dry, it helped me understand how to select the correct probe and orientation for each block. The more challenging aspect was learning how to adjust the machine's algorithms in displaying the data. Sometimes when visualization is poor, changing how the ultrasound waves are interpreted can make a needle or target more apparent. As a medical student, I was intimidated by how many knobs and dials the ultrasound machine had; now I have a reasonable understanding of what they do and how to use them.

Monday, April 14, 2014

Anatomy


For most medical students, the brachial plexus is a nightmare. The nerves from the cervical and upper thoracic spine that give sensation to the arm seem to have no rhyme or reason. They branch, connect, intertwine, and split off seemingly randomly, and for most of us, it is an exercise in memorization and then prompt amnesia.

I had thought myself free of the brachial plexus. But unfortunately, understanding the sensory innervation of the arm is essential to the regional anesthesiologist. The anesthetic plan differs whether the surgeon is working on the index finger versus the pinky, the wrist versus the elbow versus the shoulder. Performing a successful nerve block requires an understanding of which nerves need to be anesthetized and how to get to those nerves. Sometimes we have to block the roots as they come out, sometimes we block the divisions. We also have to understand the nearby anatomic structures to avoid crucial vessels and guide our needle. Which muscle layers overlie the nerves? How is each division situated in relation to the artery?

We don't learn most of this in our general anesthesia rotations. Although we study it for our tests, our month on regional anesthesia is the opportunity to apply this theoretical knowledge of anatomy into practice. Over the month, I saw different anatomic variants of the normal. I recognized how other factors - trauma, obesity, swelling, positioning affect the difficulty of the block. This month has helped me place anatomy into a clinical context. Of course, relearning brachial plexus anatomy was just the beginning; I had to pull out my notes on innervation of the leg, the lumbar plexus, the abdominal nerves, and other factoids from the first year of medical school.

Image shown under Creative Commons Attribution Share-Alike License, from Wikipedia.

Sunday, April 13, 2014

Regional Anesthesia

I spent the last month on my regional anesthesia rotation, our immersion into nerve blocks. I'm one of the last residents in my year to do regional anesthesia. Although I got the usual pre-rotation jitters starting something completely new, I quickly got the hang of it and had a great month. Nerve blocks are primarily used for orthopedic surgeries, though we do them for a wide variety of procedures, from nephrectomies to mastectomies to open hysterectomies. Some are done specifically for post-operative pain, like a femoral nerve block for knee replacements. Others are intended to be the primary anesthetic, such as numbing an entire arm for wrist surgery. Although much of the focus of the rotation was becoming proficient in the procedures, regional anesthesia has many other facets that encompass systems based practice, operating room efficiency, understanding surgical requirements, and managing patient follow-up.

The concept of regional anesthesia is simple. If the surgery is localized to a specific area innervated by specific nerves, then blocking those nerves with local anesthesia will be sufficient for the surgery (or for post-operative pain management). It requires much less amount of medicine than the surgeon infiltrating local anesthesia indiscriminately. And it may make general anesthesia unnecessary. Thus, a good sense of anatomy and peripheral nerves is all a regional anesthesiologist needs to devise a plan of action.

Thursday, April 10, 2014

Pre-op Clinic

Pre-op clinic, a requirement for all anesthesiology residents, is a strange and fascinating creature. We don't particularly like it, since most of us went into anesthesia to avoid clinic. And at first, it seems exceedingly easy. The vast majority of patients, having gone through the surgeon's office, are appropriate candidates for getting anesthesia and surgery. The pre-op visit assures that nothing is missed, that the patient receives all their instructions and education, and that labs and studies are reviewed. Practically, it means that 90% of the visits are very routine, and for anesthesiology residents, it can be a little tedious.

However, having done it every year of my residency, I've noticed that it's changed over time. As an intern, I was quite apprehensive about everything; I ran all my patients in detail by my attending, and I learned a lot. Gradually, I've done a week or two of pre-op clinic each year, and now at the end of residency, I feel quite independent. Perhaps I'll give my attending a one-liner for complex patients, but for the most part, I operate autonomously. Having done anesthesia for pretty much every surgery, I can tell a patient exactly what to expect; some need epidurals, double lumen tubes, arterial lines, blood transfusions, or avoidance of general anesthesia.

I also appreciate the nuances much more now. What happens when a patient has severe multiple sclerosis? Myasthenia gravis? End stage COPD? Fresh cardiac stents? Instead of defaulting on my attending's judgment, I now have a good sense of what I'd do as the anesthesiologist and can formulate a reasonable plan. Although clinic is not my favorite activity, at least I have a better grasp of its finer points.

Monday, April 07, 2014

Sorry for the Gap in Blogs!

Like anything, residency comes in ebbs and flows. Some months, especially for new rotations, are busier and more exhausting. Even if I don't spend that much time in the hospital, new rotations can be mentally and emotionally exhausting. It's strange because I don't work as long hours or as many days as I did in internship, I feel like I have more things competing for my time. Perhaps it is this strange phenomenon where getting a little free time paradoxically makes me more busy than if I had no free time at all. This is true talking to older attendings who, during their residencies, gave up all hope of a life outside the hospital. By setting such expectations, all their hours were focused on medicine, but this was considered a necessary sacrifice. Now, I have an inkling of freedom, and I want to cultivate all these extracurricular interests. I dabble in a few, and suddenly, I have grossly overestimated what I can do, and I'm frantically scrabbling to prioritize, salvage, do, play, and sleep. In any case, I know that my life is much easier than it was in internship, but I'm finding it tougher to blog consistently. This next month won't be any better as I'm starting in the cardiovascular ICU, a notoriously busy month. I'll still be blogging about last months activities, though, on my regional anesthesia rotation.

Thursday, April 03, 2014

Electroconvulsive Therapy

If you look back far enough in this blog, you'll find older posts on electroconvulsive therapy. I was recently assigned to provide anesthesia for ECT treatments. We provide a short several-minute anesthetic while a psychiatrist induces a seizure in a patient with severe refractory depression. When I first did ECT anesthetics, I followed the recipe without a good sense of all the steps. I was overwhelmed with such a brief yet involved anesthetic and depended quite a bit on my attending. This time around, at the end of my residency, it was a completely different feel. I felt completely independent and relaxed. I not only understood all the components of the anesthetic recipe - ondansetron, ketorolac, remifentanil, etomidate, hyperventilation - but I knew why they were chosen and what alternatives I had. I knew the crazy physiologic derangements that come with electroconvulsive therapy and how to treat the bradycardia, tachycardia, hypertension, inadequate seizure, and status epilepticus that could happen. To me, this was an epiphany to show me how much I've learned in the last few years of residency.

Tuesday, April 01, 2014

OR Management

I have to say, after two weeks trying to run the board and learning about principles of surgery center management, I don't find it as fun as direct patient care. Management is a frustrating business. I'm constantly trying to negotiate with surgeons and nurses about optimizing the flow of the surgeries. Changes which should be easy take much longer to happen. Implementing a new policy involves so much red tape. I move mountains to make things happen, and at the end of the day, it saves half an hour. When something goes wrong, the buck stops with me, and I have to fix it, whether it is an emergency or an inconvenience. I went into medicine to take care of patients, not systems.

Nevertheless, it was a really enlightening and educational experience. It taught me to be aware of the surgery center as a whole. By the end of the rotation, I knew what was going on in each room; I knew which surgeons and anesthesiologists were where, which rooms had delays, which rooms were moving fast. I knew where my resources were if something went wrong. I had a good grasp of how to make things happen. I became a better leader. I learned about my management and communication skills. And I got a keen awareness of the things that matter in our medical system to administrators. I learned where our inefficiencies lie, where we can make improvements. I have a little better sense of why the American health care system is so broken. I know how gargantuan a task it is to fix it.

Monday, March 31, 2014

The Order of Cases

Here's a very simple operating room scheduling question. If you have several short cases and one long complex case, how do you order them? If you start with the long case, you can tackle the difficult, challenging surgery first. If additional resources are needed; for example, if the surgeon got into trouble, it's easier to deal with that during the daytime than the nighttime. But leading with the complex case means that if it is cancelled for any reason, then there's a big gap that will be hard to fill. If the case is unpredictable in timing, there could be a big delay for the subsequent patients. The opposite, to start with the predictable short cases and follow with the long case gives more predictability to the day, but it means the surgeon might be tired when he needs to be most attentive. Staff who work on shifts such as nurses, and in some cases, anesthesiologists, may change half-way through the long case if it starts in the afternoon.

In reality, there doesn't seem to be any steadfast rule about booking cases. Sometimes, surgeon preferences are honored. Sometimes, patient preferences are acknowledged. But when things get canceled, delayed, or changed, we start thinking about how to make this process a little more efficient.

Saturday, March 29, 2014

Room Utilization

The scarcest resources in a surgery center are the operating rooms themselves. Surgeons are always itching to operate, patients want their elective cases done, and you can hire more anesthesiologists and nurses. But rooms are a fixed resource. That's why room utilization is such an important concept in operating room management. After you determine how long each room is going to be open for, you have to fill those rooms with cases. If those cases finish early, the room is under-utilized, and staff expecting to work will have nothing to do. If those cases finish late, the room is over-utilized, and you have to pay overtime and deal with staff morale. So the optimal utilization of rooms is a big deal.

Predicting utilization is really, really hard. Different specialties and different cases have varying levels of predictability. For example, a seasoned cataract surgeon can probably get her utilization optimized fairly easily. A general surgeon who only does large bowel resections will have trouble. Not only are bigger cases more variable in their timing, but they are also harder to slot into block time. That is, if a general surgeon is allocated 8 hours of block time in an operating room but has a 6 hour case, if he does not find a 2 hour case, he will under-utilize the room.

Predictability is important as well. A surgeon may vary on how long he takes to do a specific operation, and different surgeons will vary on how long they take to do that operation. Furthermore, this distribution of case duration is not a normal distribution on a bell curve; rather, most cases will cluster together but the average duration will be pulled up by a few outliers of very difficult or complicated surgeries (such as laparoscopic procedures that have to open). Other problems with this view of OR management is that utilization doesn't necessarily correlate with revenue; a cardiac surgeon may underutilize his block time but make a lot of money for the hospital; utilization shouldn't be a surrogate for optimization of profit.

The problem with utilization is that in order to optimize it, we might want to take away block time from a surgeon who is underutilizing his room and give it to a surgeon who is overutilizing it. This might encourage slow surgeons to remain slow, hoping to get more time, and fast surgeons to slow down, afraid they will lose their time. They may also alter their predictions of case durations; by predicting that they will be faster, they can book more cases. Optimizing utilization means we have to have the data to predict how long a case will take; however, there are thousands of different surgeries, and unless a particular procedure is done frequently (like cataracts or cystoscopy), there will be a lot of unknowns with infrequent surgeries.

All of these variables come into play in real life operating room management, and my two weeks as the ambulatory surgery scheduler gave me a glimpse into this strange world. In medicine, everything revolves around the patient, but in management, everything revolves around efficiency and money.

Thursday, March 27, 2014

Ergonomics

Hand-in-hand with the last post, I had an ergonomics evaluation as much of my musculoskeletal strain is from poor posture and mechanics. We spend so much of our time in front of computers, at workstations, doing repetitive motions, but we rarely think about how this affects our bodies. Especially when we are young, we are just unaware, and over time, the toll of tension adds up. I was thoroughly humbled by the ergonomics consultant. Now I adjust my anesthesia workstation first thing in the morning. I change the level of my keyboard, the height of my chair, the position of my monitor. I watch how I push gurneys, move patients, even hang up IV bags. After lifting thousands of one liter IV bags over my head, I've finally learned how to do it without over-exerting my trapezius muscles. So much of what I love about anesthesia is procedural, and ergonomics are important. I'm developing awareness of my posture during laryngoscopy, how I hold the ultrasound probe, how I access my medication cart. I wish I didn't have to think about these mundane aspects of everyday work, but if I don't, I regret it.