Vessels in the Brain

I recently had two cases of craniotomies for resection of vascular lesions in the brain; one was an arteriovenous malformation, and the second was clipping of an aneurysm. The image above shows a cross-section of the brain with an extraordinarily large AVM in the parietal lobe. In an arteriovenous malformation, the artery connects directly to a vein without an intervening capillary network. They present with strokes, seizures, headaches, and focal neurologic deficits.

An aneurysm in the brain is a weakening or abnormality of an arterial blood vessel that creates a so-called "ticking time-bomb." Abrupt increases in blood pressure can cause the aneurysm to burst, leading to a devastating hemorrhagic stroke. A tenth of patients die before reaching the hospital, and only a third have a "good outcome" after treatment.

The anesthesia for both these cases is incredibly delicate. Resections of AVMs can be a bloodbath. Not only do we have to be ready for a large-volume resuscitation, but we also have to consider various tricks to rescue the patient: for example, if the surgeon simply cannot control the bleeding, we can consider adenosine, which stops the heart for thirty seconds. Hopefully the surgeon can get physical hemostasis while the heart stops beating. For the cerebral aneurysm, we do everything we can to avoid spikes in blood pressure. An inadvertent increase in blood pressure can burst the aneurysm and stroke or kill the patient. We induce anesthesia with a generous dose of pain medication so that intubation and placement of lines do not disturb the blood pressure. We pay extra vigilance when the neurosurgeons place the head in pins to avoid a sympathetic surge. We tolerate more hypotension because that is less risky. And we tiptoe around the patient superstitiously.

In the next few months, I expect to do more and more neurosurgical anesthesia, and here, I realize, the details in anesthesia can make the difference between life and death.

Both images are in the public domain, from Wikipedia.

Tahoe

I wrote about this last year and probably will again next year, but this last weekend was our yearly resident retreat in Lake Tahoe. It is a really wonderful gesture of appreciation from the program for our hard work. And with a growing focus on resident well-being, having a stress-free weekend hosted by the program really helps us escape the day-to-day resident grind. In anesthesia, we don't see our peers and colleagues as much, and late night bonding in the cabins or up on the slopes is a wonderful way for us to get to know the rest of the program. And, much as we try to avoid it, the anesthesia stories that crop up become a very practical list of tips, tricks, pitfalls, and ideas that we learn from. We stayed in gorgeous cabins, had delicious meals, skied gorgeous slopes, and shrugged off the weariness of resident hours in winter.

Image shown under GNU Free Documentation License, from Wikipedia.

Epilepsy

A middle-aged gentleman presents with seizures starting about a decade ago. Despite trying different cocktails of antiepileptics, the seizures are never fully controlled, and the side effects become intolerable. MRI is grossly normal. Continuous EEG captures some of the seizure activity and localize it to the temporal lobe for a presumed diagnosis of mesial temporal lobe sclerosis. However, because imaging is underwhelming, a decision is made by a multidisciplinary group of neurologists and neurosurgeons to proceed with invasive intracranial monitoring prior to temporal lobe resection. They want to be completely sure of the origin of the seizures before removing part of the brain. But invasive epilepsy monitoring is not a benign procedure either. After taking off the skull, the neurosurgeon works closely with the epilepsy specialists to place electrodes directly onto the surface of the brain. These electrodes are more sensitive and specific in localizing seizure foci than surface electrodes placed on the skin. Watching the surgeons work and the neurologists test the leads reminds me how incredible some things we do are.

EEG image shown under Creative Commons Attribution Share-Alike License.

Length of Training

I recently watched a beautiful documentary, Jiro Dreams of Sushi, about one of the best sushi restaurants in the world. The master chef, Jiro, has dedicated his entire life to learning the art and craft of sushi. The documentary examines his life, his values, how he distinguishes his sushi-making, how he selects his fish, how he trains his apprentices, his personality, and his accomplishments.

I mention this on this blog because of an amazing fact. In Jiro's restaurant, sushi apprentices prepare food for an entire decade before they are allowed to make one dish: tamago or egg. Ten years of training before one is good enough to craft the simplest dish! This is dedication, a true lifelong study to become the world's best. And maybe that's what residency is like. If a sushi apprentice has to spend ten years descaling fish, massaging octopus, and cooking rice, perhaps it makes sense that medical training is as long as it is. It really takes years of practice, experience, obsessive-compulsive perfectionism, and commitment to become a master at something.

Image shown under Fair Use, from Wikipedia.

Intraoperative Code

An 80 year old debilitated patient with heart disease, congestive heart failure, chronic obstructive pulmonary disease, and diabetes presents to an outside hospital with progressive weakness, fevers, hypotension, and tachycardia. An MRI of the spine shows an epidural abscess, infection of the area outside the spinal cord. He is intubated, started on antibiotics and vasopressors, and transferred to Stanford.

He goes to the operating room for an extensive multilevel spine surgery. I was not the anesthesiologist for this procedure so I don't know all the details. As the day progressed, the patient's blood pressure became lower and lower, requiring a constant infusion of phenylephrine. Near the end of the case, his heart stopped. His EKG was a flatline - asystole. The surgeons started chest compressions and the anesthesiologist ran the code. After several rounds of epinephrine and commencement of inhaled nitric oxide, the patient's heart returned. I was called to provide additional assistance. We brought the patient down to CT scan, concerned about a pulmonary embolism, but didn't find a massive saddle embolus. On transesophageal echocardiogram, the right ventricle was stunned, but we didn't know the cause. Despite active investigation, we didn't know why the cardiac arrest happened.

I write this post because we want to know the cause of a cardiac arrest, but rarely find a single certain etiology. When something this serious happens, we want to pinpoint what happened, both for the patient's treatment and for our peace of mind. Was this something we could have prevented or avoided? Was it inevitable? Did we miss something? Are we treating the patient appropriately?

Talking to many anesthesiologists, however, I began to realize such answers are rare. We memorize a mnemonic about the causes of cardiac arrest, but more often then not, the cause seems to be multifactorial. Here, an older patient with a significant cardiac history presents with a severe, overwhelming infection. He progresses to hemodynamic collapse and respiratory failure, requiring ventilatory support, vasopressors, and ICU admission. He was probably dehydrated at the beginning of the case, and may have been underresuscitated. Decompressing the epidural abscess may have released toxins into the bloodstream. The heart may have taken a hit. His immobility in the ICU may have made him prone to pulmonary embolism. Bleeding from an extensive case decreased his reserve. And one of these many triggers tipped him over the edge. The further I go in medicine, the more I realize this is how body and disease interact. Most critical events happen as an accumulation of small injuries suffered, not as a single event. We don't necessarily learn this in medical school, that life happens to be a little messier than textbooks.

The Spine

My current rotation is focused on anesthesia for spine surgeries. Our active neurosurgical and orthopedic groups have a busy service at Stanford. Although spine surgeries are similar to other general anesthetics, they have their own specific anesthetic concerns. Many patients undergo spine surgery because of chronic pain. One of my patients has a pain regimen that would widen the eyes of any practitioner: a daily dose of 600mg of morphine and 100mg of methadone, as well as muscle relaxants. Anesthetizing this patient and selecting opiates to achieve a smooth and comfortable wake-up is a real challenge. Yet after two large vials of sufentanil, a couple vials of dilaudid, a generous dose of ketamine, and some lidocaine, the patient woke up smoothly. Other patients with cervical spine problems can be difficult to intubate, requiring recognition, planning, and facility with advanced airway devices. The spine is quite vascular and spine surgeries (especially tumor resections) can bleed a lot. Because surgery near the spinal cord can lead to changes in neurologic function, spine surgeries are often done with neuromonitoring. We have to understand how our anesthetics change an EEG, EMG, and somatosensory potentials. Lastly, spine surgeries are often done on the back, and having patients on their stomach for hours has its own risks including blindness. So hopefully this month will give me an opportunity to learn and refine anesthesia for this aspect of neurologic surgery.

Image is in the public domain, from Wikipedia.

Strange

Sometimes, we run into circumstances we can't easily explain. I was recently scheduled for a straightforward spine surgery in an elderly woman. As I looked over her chart, I felt she was ready for surgery. Her blood tests the day before were perfectly normal. However, due to a fluke, on arrival on the day of surgery, she had her blood drawn again. Surprisingly, her liver function tests came back elevated. They went from normal to markedly abnormal within the span of sixteen hours. She had no changes in her health, symptoms, medications, alcohol intake, acetaminophen use, or exposures. We repeated the test and they were still abnormal. There was simply no explanation for the rapid rise in liver enzymes. As anesthesia can exacerbate hepatic injury and precipitate fulminant liver failure, we canceled the case. But this circumstance of unexpectedly changing lab results is unusual and I'm curious to see if we get any ultimate answers.

Orders of Magnitude

Image is from xkcd, drawn by Randall Munroe, shown under Creative Commons Attribution License.

The Golden Rule

Physicians are supposed to be impartial. We ought to approach each patient as if she were our own mother (or grandmother or daughter). We should treat our patients without judgment; although we attend to each person individually (and take into account her personal desires, preferences, beliefs, and decisions), we should not treat patients differently based on our feelings toward them. I was taught long ago that if I had a patient who was in jail or charged with a crime, I should not inquire too much into their offense (so long as its not medically necessary) because I don't want to color my subjective perception of the patient.

This is a long preface to address the opposite circumstance. Recently, one of my coresidents had a family member who needed surgery. We talked about who we'd want as their anesthesiologist and surgeon, and to a greater degree, pondered how we would provide that anesthetic. Would I change my anesthesia if my patient were rich or famous or a friend? A couple things here - we are advised not to treat our loved ones. Taking on multiple roles and assuming a patient-doctor relationship with someone we are close to is a bad idea. It creates conflict, interpersonal tension, and provider bias. We also try to treat "VIP" patients just as we would anyone else.

But is this really the case? I think it's hard to know until we are put in that situation. For example, there are multiple ways of doing an anesthetic. I can achieve the same outcome with a completely intravenous anesthetic and an inhaled anesthetic. The intravenous anesthetic has a lower risk of nausea but a potentially higher risk of awareness and increased cost and labor. Would I prefer one technique over another if my patient were a family member? There are also monitors with no proven benefit; for example, we occasionally use an intraoperative EEG to assess depth of anesthesia, but the device has never proven to be superior to current standards of measuring anesthetic depth, and the cost is not insignificant. But would I add it on to the care of a patient who was particularly rich or famous? I'd like to think that sort of thing wouldn't affect me, but I cannot say until I find myself in that situation.

Open

The value is not in content. We like to think that what we create and what we write is what is important, but it's not. For hundreds of years, copyright law protected content, and only now are we beginning to see that influence is what's important. It's the perception, the reception, the reading of, digesting of, and interpretation of the content which is important.

What I mean is this. Social media - Facebook, Twitter, Google+ - has created the phenomenon of "reposting" content. It used to occur in the form of chain e-mails - back in the AOL days, you'd see a joke you thought funny and forward it to your friends. A decade later, we started talking about "viral" videos, videos that picked up momentum in a seemingly unreal fashion. Now, when we find things we like, we repost it, retweet it, plus it. And this, it seems, is the goal of a lot of content out there. Authors want their work to be rebroadcasted; they want the audience, the influence, the interpretation of their content.

As with most things, scientists are slow adopters. We still protect our content with lock, key, and lawsuit. We have to pay to get access to certain journals, and the fees aren't cheap; downloading an article may cost as much as a fancy dinner. As residents, our institutions provide us access to major journals, and for private practice physicians, medical groups (like the American Medical Association or American Society of Anesthesiologists) grant access to their particular publications. But why do we do this?

The content does not need protection; the content needs distribution. If a breakthrough in science occurs, you want more people to read it, not fewer. Spreading information speeds innovation, progress, experimentation. It helps patient care, levels the playing field of academic, private, and rural medicine, and provides ongoing learning. It makes no sense to me that journals are not open-access. Cloistering information is a thing of the past. Imagine if medical studies spread wildfire like cat pictures on the Internet. Each morning, over coffee, you read the articles your colleagues identify as most important; you "like" some of them, and pretty soon, the most relevant research is the most read. Currently, the process moves like molasses; an article's "relevance" is measured by how often it's cited, a process that manifests over decades. When I rifle through junk mail and find a journal, I don't know which articles matter or which my peers are most excited about.

This post was indeed spurred by the death of Aaron Swartz, a prodigious programmer and Internet activist. He was arrested for downloading academic journals from JSTOR; although charges from JSTOR were dropped, the government continued to pursue the lawsuit. He committed suicide recently, a big loss of the innovator who coauthored RSS 1.0, campaigned for a free and open Internet, and founded multiple companies. He was charged with downloading academic journals with the intent of distributing them. This may be a crime, but was it morally reprehensible? What value do academic journals have but to be read, and understood, and built upon? Research is not funded by the $40 I pay for that one article I really want. But research is inspired by and dependent upon those giants that come before us, whose shoulders we crouch upon today.

Dreams

Most residents, I'm sure, dream about work. It occupies so much of our waking day that it cannot help but intrude upon our sleep. Sometimes when we are on call, this creates an indiscernible amalgam of patients, images, decisions, communications that blend reality with imagination. In dreams, I have seen lab values, made diagnoses, realized new things about patients, and I will be the first to say that sleep deprivation puts (real life) patients in danger. This, fortunately, is being addressed with more reasonable work hour periods and does not pose such a problem in anesthesia where patient care occurs in concentrated defined periods of time.

Last night, I had a dream of a patient in intensive care I had seen before. It was continuity of care, and the patient's evolving clinical story played out. Yet when I woke up, I couldn't figure out whether it was a patient I knew from my ICU rotations or from prior dreams. That strange haze of deja vu makes our dreams so vulnerable to interpretation as reality. It was fascinating for those of us who wonder about the biology of dreaming and terrifying for those of us who have to care for patients.

I also had a period of lucid dreaming, that is, dreaming where I knew I was in a dream. I could control the dream too, and what else would I do but go raid some candy jars? (Dreams are so odd sometimes). In the middle of this dream, I wondered about an experiment to see if glucose levels in the blood change when someone dreams of eating candy. The dreams I have...maybe I'm getting too much sleep.

Image of the Cheshire Cat is in the public domain, from Wikipedia.

Book Review: The Power and the Glory

I recently reread Graham Greene's famous The Power and the Glory, one of my favorite novels. Set in the Mexican state of Tabasco in the 1930s, it describes the struggle between church and state. The main character is an unnamed Roman Catholic whiskey priest facing persecution by the government. Its themes are incredibly powerful and moving, and especially for me, I found the question of duty compelling. The whiskey priest is an immoral drunk, a poor example of religion, and yet he is the only church in the state. Despite his many sins and faults, his sense of duty never wavers. He gives himself entirely to his religion, almost like what physicians do in residency. He is the resident who, after 29 hours of being up in the hospital, responds to a page without fail because that is his duty, the right thing to do. For us, practicing in the House of God, the patient is that sacrifice, and we are the crucible. What does it mean to have such a sense of obligation? What kind of person would be unfailing? How do the people - the patients, the peasants - view such a whiskey priest, such a resident? Even though the story is about a world far from what I know, a world completely different than what we live in today, the themes still resonate strongly.

Image shown under Fair Use, from Wikipedia.

Obsolete

How time changes things. I remember how important the encyclopedia was while growing up. While thumbing through pages to get to the article I was to research, other fascinating topics would wayside me. Sprawled on the floor with volumes open, I would read and read and read. Then I remember picking up a CD - Encarta '95 - and finding two bookshelves' worth compiled onto one small disc. Fifteen years later, all that information is available within seconds from Google and Wikipedia. Rather than an expert writing an entry, users create millions of peer-reviewed articles, free on the Internet. The knowledge base refines over time as a dynamic system which reflects the evolving world. We still get easily sidetracked from one page to another, but the experience of and access to learning and research has changed so much. Now I don't even know what to do with old encyclopedia volumes; they've become completely obsolete. They are akin to the travel agent or dinosaur - some strange, mythical creature of the past.

Image of encyclopedias is in the public domain, and ironically, from Wikipedia.

Vets

It is easy to make generalizations about the veteran patient population. Most of the patients who present for surgery are over 60, and nearly all of them have hypertension, hyperlipidemia, diabetes, COPD, and arthritis or degenerative joint disease. Looking back through my pre-operative notecards, 90% of them start with "HTN HL DM" as the first line under the past medical history. The veteran population also struggles with substance use; virtually every patient has a smoking and drinking history, many use marijuana, and a good number use illicit drugs. Psychiatric disease and medications are common. Obesity is a big problem; when I'm at the VA, a "normal sized" patient is 90kg (nearly 200lbs) and I don't break a sweat until someone exceeds 120kg (260lbs). All of these characteristics are quite different than the patients I see at Stanford and Valley.

Why is this the case? There may be some positive to take from it - perhaps the VA is so good at primary care that everyone gets plugged into the system and is appropriately diagnosed and treated for hypertension, hyperlipidemia, and diabetes. But perhaps the preventive care does not start early enough; maybe vets could avoid these chronic diseases if they saw a physician earlier. Some service-related conditions like PTSD can exacerbate non-service-related conditions like hypertension. It is important for us to understand why this population is so homogeneous yet different than the community in order for us to address their particular health care needs.

Things Doctors Don't Know

Sometimes patients assume we know the entire spectrum of human health and disease. But - perhaps to public consternation - there is so much that physicians do not know, and a lot of this is probably surprising. The whole of medicine is too big, too vast, too complex, and ever-changing, and doctors choose what they want to become experts in. I can tell you the steps of a heart surgery, interpret a panel of laboratory tests, or tell someone they will die, but I know very little about nutrition. When I come home during the holidays and see non-medical family and friends, I inevitably get asked about this or that diet or supplement or exercise regimen. And despite being a doctor, I have no sage counsel on these topics; the extent that anesthesia involves diet on an everyday basis is to dictate when you have to stop eating or drinking before surgery. This shocks people, but it's entirely true. I had a brilliant wonderful mentor in medical school whose interest and expertise surrounded the primary care of a bariatric patient after they had gastric bypass surgery. She could tell you every little thing about nutrition, diet, supplements, and weight loss. She could tell you what psychological barriers these patients encounter, what screening they should get for preventative medicine, and what medications, vitamins, and nutrients were absorbed from what parts of the gastrointestinal tract. I could do none of this and probably will never be able to. But that's where she's focused her medical training, and consequently, she cannot do things I do on a daily basis: placing a breathing tube, responding to a multitrauma victim of a car accident, or inserting an IV into a three month old child.

Medicine is and has to be specialized. Long gone are the days of the giants who could do everything - manage a pregnant patient, deliver a child by C-section, resuscitate that child, care for him while he grew up, operate when he developed appendicitis, and manage his chronic illnesses as he grows old. And we must know our limits. I never give advice regarding nutrition. Or psychiatric illness. Or how to raise a child. We learn about those things in medical school, but being a doctor does not automatically make us authority. We seek to learn more, carving both depth and breadth of knowledge, but we will never know everything.

Comparing Hospitals

We are a society that loves comparing ourselves to our peers. Hospitals do not escape such scrutiny. Each year, the U.S. News World Report ranks hospitals, and hospitals love boasting about their rankings. It's good press, good for morale, and an affirmation of the work we do. But such ranking lists need to be taken with a boulder of salt. The task of comparing hospitals on performance in area as big as "cardiovascular medicine," "cancer," or "rehabilitation" is herculean if not impossible. There are too many factors in play. To imagine one can look at rates of complications, reputation, ability to perform high risk procedures, adherence to guidelines, cutting edge technology, and a dozen other factors and come up with a score is folly. Would you rather go to a hospital that follows national guidelines or to one that is cavalier and breaks rules yet achieves better outcomes? Would you rather go to a hospital that realistically says a surgery is too high risk or to a hospital willing to take that risk and operate? The presence of a few experts does not automatically elevate their department's quality of care. The reputation of an institution may have little bearing on how their patients do. Yet the U.S. News World Report tries to plug all these things into a magical formula to come out with a list. No doubt the institutions on the list are outstanding, but to think there is rhyme or reason to where they fall in the ranking is silly. The art and science of medicine cannot be quantified. We all strive to provide the best care, right care, humanistic care, and we should heed little to our society's love of comparing things.

Navigating Different Hospitals

One of the things I looked for in a residency program was the opportunity to go to different hospitals. Some programs are based solely at one hospital, which allows one to become intimately familiar with the institution, people, and culture. But I wanted to diversify my training, and coming back to the VA reminded me that this is an important aspect of residency. Although some inconveniences such as the administrative paperwork are frustrating, other inconveniences such as different equipment become opportunities for learning. The anesthesia machines at the VA are from a different vendor than those at Stanford, which encourages me to play around with them, explore the differences in capabilities and functions, and learn more about how they work. Different institutions have different drug shortages, which affects the anesthetic I provide. A temporary shortage of paralytic reversal changes my choice of muscle relaxant. Because the VA acquires dexmedetomidine at a lower price, we use it more often. Even small things like the types of IVs, the amount of space in the operating rooms, and the electronic medical record differ, forcing me to adapt and allowing me to determine what things I like best, which may become useful when I start thinking about practice later on.

Book Review

In keeping with yesterday's post, I recently read Lev Grossman's The Magicians, a novel often described as "Harry Potter for adults." For me, it comes short of that title, but was an engrossing (not intending to pun on the author's name) book. Although it presents a fantasy world with teenagers who attend a secret school of magic, it is much darker and more pessimistic. The characters who thought they would find complete satisfaction in a world of wizardry encounter only disappointment and unmet expectations. The book follows the course of the main characters as they finish school and enter the "real" world, so to speak. Although I loved the discovery of magic and the school itself, I lost interest in the subsequent plot. The characters were quite realistic but I did not connect deeply with any of them. I did, however, love the writing. The diction, syntax, and tone of the text was witty, brilliant, sarcastic, intellectual, and sublime. The book is worth a try for those looking for an elegantly-written dark urban fantasy.

Image shown under fair use, from Wikipedia.

Resolutions

This year's resolution is to read and write more. I've been frequenting the library much more and devouring books, both fanciful and serious. There's so much I want to learn about and explore. I hope that this year is a year of awakening, discovery, learning, and epiphany.

Image shown under Creative Commons Attribution Share-Alike License.