Saturday, August 31, 2013

Living Related Kidney Transplants I

Two sisters prepare for surgery on the same day. The older one is completely healthy, but her sibling, four years junior, developed kidney disease from IgA nephropathy, inflammation of the kidney. She has been on dialysis for four years, and today may be her big day: she is going to get a transplant from her big sister. After thorough screening of both siblings, the surgeons prepare to take out the kidney from the healthy sister. A hand-assisted laparoscopic procedure, the surgeon uses small ports and cameras as well as a larger port that allows a hand to help dissect out the important vascular and urologic structures. Kidney harvesting is a longer procedure than kidney transplant, and this takes us past lunchtime. My job as an anesthesiologist is to keep the kidney as hydrated and well-perfused as I can. As soon as they clamp the vessels and take out the donor kidney, they put it on ice and close up the incision. Kidneys are the most resilient organ to be transplanted, but still, once its blood supply is cut off, we're on the clock.

After bringing the donor to recovery, I go see the recipient and reassure her that her sister is doing well. We bring her back to the same room, induce general anesthesia, place an arterial and central line, and start the surgery. Even though the kidney belongs to her sister, we blunt any immunologic response by giving steroids, diphenhydramine, tylenol, and her first dose of immunosuppressants as the organ is going in. We want to do everything we can to optimize the new kidney's function and minimize the risk of rejection. We keep the blood pressures high, hydrate her fully, and measure urine carefully. At the end of the surgery, by the time we wake her up and bring her to recovery, her new kidney is making lots of urine. We hope that she won't need dialysis again for a long, long time.

Friday, August 30, 2013

Sedation

A patient with lung cancer has recurrent pleural effusions. He has had two chest tubes placed at outside hospitals to drain the fluid around his lung, but each time the chest tube is removed, the fluid reaccumulates and his symptoms of shortness of breath return. Ultimately, he is scheduled for a placement of a permanent chest tube called a Pleurex catheter which will allow him to drain the pleural effusions at home. While the initial chest tubes are placed with local anesthesia and surgeon-determined sedation, the Pleurex catheter is scheduled for anesthesiologist-delivered sedation which we call monitored anesthesia care even though the surgical procedure is not so different.

Many procedures are done with sedation ordered by a non-anesthesiologist. Nurses can administer medications for colonoscopy ordered by a gastroenterologist, reduction of a disclocation ordered by an emergency physician, or a chest tube placement ordered by a surgeon. And even though the medications they use are identical to the medications I use, sedation by an anesthesiologist is different. My sole concern is the patient's comfort and safety. The proceduralist doesn't have to worry about the vital signs, the patient's level of sleepiness, and the actual procedure simultaneously; I simplify his responsibilities so he doesn't have to multitask. I'm also extremely familiar with common sedation medications like fentanyl, midazolam, and propofol, and I have tricks up my sleeve like ketamine, alfentanil, and dexmedetomidine if the clinical situation requires something more complex. But of course, scheduling an operating room and an anesthesiologist for a case with sedation uses a lot more resources.

In comparing his prior chest tube experiences with the pleurex catheter experience, the patient thought there was a complete black-and-white difference. At the outside hospital, he was uncomfortable, did not feel that the proceduralist was listening, and did not get adequate sedation. When we did his pleurex catheter in the operating room, he was snoozing lightly, woke up immediately, and completely satisfied. He shook my hand in the recovery room and assured me that if he had to get something with sedation in the future, he hoped he would have an anesthesiologist.

Wednesday, August 28, 2013

Carbon Footprint

I've always been bothered by the environmental impact of the medical system. So much stuff is used in a hospital that the carbon footprint generated must be enormous. The contribution by anesthesiology is not insignificant. As I've become more comfortable with the medical side of anesthesia, I've started thinking a little bit about the systems issues and trying to reduce waste. Reducing waste not only helps with cost effectiveness and the bottom line, but it also helps reduce our environmental impact. For example, anesthesia produces a lot of waste gas which contributes to the greenhouse effect. When I can, I try to reduce my fresh gas flow and reduce the resultant nitrous oxide and fluorinated ethers released into the environment. I no longer draw up medications that may be required in an urgent but not emergent situation. I know I can have them ready in thirty seconds so I don't waste the medication, money, time, and equipment to prepare them if I don't expect to use them. I try to recycle the ridiculous amount of plastic waste we generate. Being conscientious about these things is an important habit for physicians to acquire because all this waste will add up, and some day we may be forced to limit our carbon footprint. Perhaps one person won't make a world of difference, but if expanded to a global scale, small changes in our practice which have no bearing on patient care may translate into substantial gains.

Monday, August 26, 2013

The Thoracic Epidural


For me, the thoracic epidural is one of the most challenging procedures. Although I feel quite proficient with lumbar epidurals in the low back used for labor, lower abdominal surgeries, and lower extremity procedures, the mid-back thoracic epidural is much more tricky. We use thoracic epidurals for surgeries involving the upper abdomen and chest. Although video-assisted thorascopic surgery is not too painful, open thoracotomies for large lung or mediastinal procedures have a tough post-operative course and the epidural helps a lot. Not only does an epidural reduce pain, allow patients to take deeper breaths, minimize IV opiates, and smooth the intraoperative anesthetic, but it also improves surgical outcomes for procedures like Ivor-Lewis esophagectomies. The problem is placing them. The spine anatomy at the thoracic level is more challenging than the spine at the lumbar level. The spaces to place the needle are smaller and the spinous processes are steeper so there is little room for error in the approach. Thus, there are several different techniques in entering the space which also makes it harder for residents to master. Out of all the routine procedures performed by an anesthesiologist, I find this the toughest.

Image is in the public domain, from Wikipedia.

Sunday, August 25, 2013

Unanticipated

For me, the most useful predictor of whether someone will be a difficult intubation is whether he was a difficult intubation in the past. If I trust the proceduralist (or if I had previously intubated the patient), then I usually assume the airway has not changed significantly and the past experience will be replicated. Recently, however, I found that this is not always the case.

I am called to intubate a patient in the emergency department with altered mental status of unclear etiology. He is completely obtunded and unarousable. Because he cannot protect his airway - that is, he is at risk for aspirating and choking - we place a breathing tube. This is easy and there are no problems. Five hours later, I am called to the intensive care unit for a stat airway, and I am surprised to see it's the same patient. He awoke and began to undergo alcohol withdrawal. Confused and violent, he pulled out his endotracheal tube with the balloon still inflated. He was hoarse and the ICU team wanted to sedate him and secure the airway again. This time, when I looked, everything was swollen. His vocal cords were large and edematous, his airway was angry and inflamed. I couldn't intubate him with a regular laryngoscope like I did several hours ago, and eventually had to call for a video laryngoscope to aid me.

Similarly, airways change in the operating room. For many of our thoracic surgery patients, we start by placing a single lumen endotracheal tube which facilitates bronchoscopy. When the surgeons begin the thoracic portion of the surgery, however, they want the single lumen tube changed to a double lumen endotracheal tube. Even if placing the single tube initially was easy, sometimes I find it much more difficult to get a good view and place a stiff, large double lumen endotracheal tube. These experiences remind me to approach each intubation with caution, even if I expect things to go smoothly and easily.

Friday, August 23, 2013

Whimsy

Halfway through the graveyard shift, when I started blinking to solidify shapes and sizes, the dull buzz in my head began to crescendo into an ache, a roar. My skull, an empty room, provoked yawn after yawn, a tireless seizure that echoed behind my formless mask. Beeping pulsed, machines whirred, the pulse oximeter marched fearlessly, and still the surgeons worked. But as if an occult hand conducted, my body acted in reflex. My eyes flicked up with the click and whirr of the blood pressure cuff, and my fingers pushed a well measured aliquot of phenylephrine. An aberrant beat and I scan the cardiogram. My left forearm sees and airway and mimes a motion my right arm could never hope to do. My index finger flicks a catheter off the IV hub. This is the dance at midnight, twenty hours into my shift. The clockwork, the machinery, the reflexes, the instinct play on.

Thursday, August 22, 2013

Smoking

Most of our thoracic surgery cases are a result of smoking. One of the most common indications for lobectomy is lung cancer, a direct consequence of longstanding tobacco use. The smoking history also makes the surgeries higher risk because they cause comorbidities such as COPD, cardiovascular disease, and hypertension. Yet despite this, the addictive nature of tobacco and its psychological dependence is overwhelming; I've had one patient who we took for resection of her lung cancer who adamantly refused to give up her smokes. This habit has devastating health consequences and a significant societal cost.

As a physician who doesn't have any family or friends who smoke, it's hard for me to understand why it still exists. I certainly come from one end of the spectrum, who abhors cigarettes, who has seen patients suffer and die from its consequences, who can't fathom why anyone would even want to smoke. But I stand firm. To me, there aren't any redeeming factors about tobacco; there's certainly no medical justification. The cost, for individual patients, society, health care systems, and the government, is not only exorbitant, but also avoidable. If we are really serious about improving health care and reducing the cost of medicine in this country, we need to address the epidemic of smoking.

Image is in the public domain, from Wikipedia.

Tuesday, August 20, 2013

Supervision

Last night on call, I was carrying the airway pager and was paged to supervise a critical care fellow for some intubations in the intensive care unit. ICU fellows come from many different specialties and those who come from non-anesthesia residencies have to get experience managing the airway. Although they often do rotations in the operating rooms, they also have to get comfortable with intubating critically ill patients in the unit which is much harder than those coming in for elective surgery. While I am ultimately responsible for the airway overnight, I try to give fellows the opportunity to intubate when its appropriate.

The experience gives me some insight into what it's like to be an attending. It's tough. There's an overwhelming urge to step in and do the procedure, but I have to restrain myself as long as I know I can rescue an airway if necessary. Even though I talk the fellow through the procedure, I note details that could be improved and have to figure out which should be mentioned immediately and which should be given as feedback after the procedure is done. I have to become comfortable with seeing an intubation from the outside and troubleshooting without holding the blade in my hand. In the supervising role, I have to multitask by not only guiding the fellow through the airway, but managing medications, vital signs, and external factors as well. It was a really educational night, not just for the fellow, but for me as well.

Sunday, August 18, 2013

Lies, Damned Lies, and...

Statistics can be very tricky to interpret. In the news, in medicine, and in research, statistics are often bent to convey an interpretation of the data. I used to think that data was pure and unadulterated, but in a world where persuasion is everything, this is not the case. For example, consider a very rare cancer that happens in one in a million people. Say a new medication reduced that occurrence to one in two million people. Proponents of that medicine will claim that it halves the rate of the cancer, which is true. But opponents of the drug may say that it reduces the rate of cancer from 0.0001% to 0.00005%, which is also true. But the first statement makes it look like a much bigger difference than the second statement. This is one simple way that the reporting of statistics can be used to bias readers. A recent xkcd comic highlighted that for me.

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

Friday, August 16, 2013

Insurance and Primary Care

Everyone should have primary care. Everybody should be able to see a doctor, get routine check-ups, have their chronic diseases managed and treated, afford medications, receive vaccinations, get prenatal care, undergo appropriate screening tests, and get patient education about their health, illnesses, preventive care, goals, and medicines. Primary care is the foundation for a healthy society.

But how is insurance involved? Insurance is a transfer of the risk of a loss from one entity to another in exchange for payment. It is used to hedge against the risk of a contingent, uncertain loss. When we buy car insurance, homeowner's insurance, or life insurance, we hedge against the risk of an accident. When we buy health insurance, we hedge against the small risk that we will need expensive care - that an injury will land us in the emergency department, a new cancer will require cutting-edge chemotherapy, or an illness will require a brief hospitalization.

On a first glance, it's not clear why insurance is involved in primary care. Perhaps an analogy with other types of insurance would be car insurance covering oil changes or homeowner's insurance covering roof maintenance. If something is supposed to be routine, then it's not the type of contingent, uncertain event covered by insurance.

But perhaps here is the reason why insurance companies are invested in primary care. If patients get their routine health screening, manage their hypertension, diabetes, cholesterol, and pain, and become educated about taking care and control of their health, then the risk of these catastrophic events is hopefully mitigated. By keeping everyone healthy, there may be fewer injuries and illnesses, and perhaps those that do happen will be less severe. Perhaps in an ideal world, everyone would get primary care, and insurance would be a separate distinct entity.

Tuesday, August 13, 2013

Bronchial Blockers

Several days ago, I wrote a post on the use of double lumen tubes to achieve lung isolation. The other deice we occasionally use for lung surgeries is something called a bronchial blocker. With a normal endotracheal breathing tube in place, we can insert a long, thin, balloon tipped catheter down into one of the mainstem bronchi. If we inflate the balloon, that side will not be ventilated, allowing a surgeon to work. There are many different advantages and disadvantages to using a bronchial blocker over an endotracheal tube, and the thoracic anesthesia rotation is our primary time to learn and familiarize ourselves with these devices.

In the diagram shown above, an endotracheal tube with an inflated balloon is positioned above the carina or first branchpoint of the lungs. A flexible fiberoptic bronchoscope in solid black is introduced down to the tube to hine light down the right mainstem bronchus. The bronchial blocker also passes through the tube and is guided (either mechanically or by a lasso) down that right side. When the balloon is in the right place, the camera should see the images shown. It's pretty satisfying to look over the drapes into the surgical side and see the successful deflation of the operative lung.

Image is in the public domain, from openi.nlm.nih.gov.

Sunday, August 11, 2013

How Far Do You Go?

A gentleman with bipolar disorder intentionally walks into traffic and is hit by a high speed vehicle. Rushed to the hospital, he's found to have multiple injuries including an aortic injury, pelvic fracture, lumbar spine fracture, and fractures of one arm and both legs. Because of his aortic injury, he is emergently taken to the cath lab for placement of a thoracic aortic graft. While the procedure goes smoothly, his initial labs from the emergency department give us pause. His INR, a measure of coagulability, is over 4, dramatically elevated. His platelets are bordering on 100,000 the limit where most would do elective surgery. The cardiac anesthesia team starts transfusing fresh frozen plasma, platelets, as well as blood. We don't know why his lab values are so abnormal - whether he is taking warfarin or if he has liver dysfunction or if it's something else - but we treat empirically given his multiple injuries.

His care is then transferred to me from the cardiac anesthesia team. The orthopedic surgeons begin fixing an open fracture. Hemodynamically, requiring only intermittent boluses of low dose pressors. His INR has trended down to 2.4, closer to normal, but the platelets have plummeted to 50,000 with an unclear cause. Ideas of heparin-induced thrombocytopenia or dilutional coagulopathy cross my mind as I pour in more blood products. He's cold at 34.5 degrees Celsius, which doesn't help the bleeding. And most of all, we don't know what other medical problems the patient has, why his liver seems to be failing, what other medications he was on.

As the anesthesiologist, I am consulted by the surgery intensive care team, the spine service, and the orthopedic surgeons about whether they should proceed with further surgeries. Once the open fracture is fixed, they would like to fixate the pelvis, stabilize the lumbar spine burst fracture, and work on the arm. They would like to do these procedures within 48 hours, but they don't have to be done now. How do I weigh the risks and benefits of proceeding or sending him to the ICU for workup and stabilization before further surgeries?

This is a tough question because there are too many unknowns. The patient had already been through about eight hours of anesthesia and undergone a major aortic procedure. Could we get him through one more surgery? In the end, I advised that given his dropping platelets without a clear reason, his elevated INR, his temperature, and his multiple transfusions, that we get him to the ICU. There are a lot of risks with an unstable pelvis and unstable spine, but I felt that a night in the ICU could stabilize him. I was worried that his kidneys took a hit during the cath lab procedure, that his liver may be failing from unrecognized injury or hypotensive episodes, and that we didn't know his mental status. These hard decisions, trying to weigh a lot of unknowns, make intensive care medicine very challenging.

Saturday, August 10, 2013

Double Lumen Tubes

How do you isolate the lungs? What techniques are there to inflate one lung and deflate the other so that a surgeon can work yet a patient can be oxygenated and ventilated? Well, one easy way is to push a normal endotracheal breathing tube too far down into the lungs so it becomes endobronchial. If you manage to get it into the side you want to ventilate, then you can breathe for that lung while allowing the other lung to deflate.

But the double lumen tube provides a much more sophisticated solution. One lumen acts as a normal endotracheal tube; it has a cuff that inflates within the trachea and an outlet below that cuff to allow positive pressure ventilation. But it also has a second lumen whose tip ends up in one of the mainstem bronchi. This has a second balloon and an opening to allow ventilation of just that lung. Most commonly we use left sided double lumen tubes because the anatomy of the right lung can be tricky to navigate (because the right upper lobe takes off very proximally). Most people get confused, but we can use a left sided tube for surgeries on either lung. If the surgeon needs the right lung deflated, we simply use the endobronchial lumen in the left mainstem to ventilate the lung. If the surgeon needs the left lung deflated, we raise both balloons and ventilate the tracheal lumen which will go down the right lung.

These tubes happen to be very large and so placing them requires a little more care and finesse than a normal intubation. And slight movements of the tube can cause us to lose the isolation, so we have to be vigilant and facile with the fiberoptic bronchoscope to check our position and adjust the tube positioning. Although its a labor intensive process, it's fun and challenges us to use a wide range of skills and knowledge.

Double lumen tube shown under GNU Free Documentation License, from Wikipedia.

Thursday, August 08, 2013

Thoracic Anesthesia

Currently I'm on a thoracic anesthesia rotation. We don't have a huge volume of thoracic surgery cases so this rotation is our primary opportunity to learn techniques and intricacies specific to lung surgeries. Most surgeries fall into three categories. First, a surgeon may need to look at and operate on the airways such as dilation for bronchial mainstem stenosis. The anesthetic challenges are inducing and maintaining anesthesia and gas exchange as well as sharing the airway with the proceduralist. Second, a surgeon may need to operate on the lungs to resect a lesion like cancer. Unfortunately, patients with lung cancer are often smokers and have poor lungs and other comorbidities to begin with. Lastly, a surgeon may need to operate within the thoracic cavity to resect a mass like a thymoma. Our main concern here is to isolate the lungs so that we can deflate one to allow the surgeon access while maintaining adequate oxygenation, ventilation, and anesthetic depth.

These unique surgeries share a vital organ and the space it inhabits. Over this month, I will gain a much deeper knowledge of the pulmonary anatomy and physiology, techniques in thoracic epidural pain control, devices to allow lung isolation, and management of the airway and ventilator in high risk patients.

Wednesday, August 07, 2013

Pain, Medicine, and Meaning

Doctors can get easily carried away with diagnoses, tests, treatments, and diseases. Ultimately, however, most of us go into the profession to relieve suffering, to help patients achieve the most they can. Pain clinic was a good reminder of this, where our focus was less on disease and treatments but more on the symptoms and how to ameliorate them. We let our oncologist colleagues deal with the metastatic cancer, our neurosurgeons evaluate for the spine procedure, our rheumatologists manage the immunosuppressants. Our job was to validate the patient's pain and figure out how to manage it and help them improve their function. Perhaps this is medicine at its heart.

Image is in the public domain, from Wikipedia.

Sunday, August 04, 2013

Pain Clinic

The last month on chronic pain clinic taught me many important lessons. Chronic pain is extremely prevalent and can have a crippling effect on a patient's well-being. There is an epidemic of opioid use, billions of dollars lost due to disability, and a wealth of questions we have yet to answer. The pain medicine physician's primary goal is not to eliminate pain but to maximize functionality, to manage their pain in medical, psychological, and physical ways so that the person can return to a job, taking care of a family, enjoying life. Many diagnoses are chronic illnesses, pain syndromes that someone will live with for the rest of her life, and managing that is not easy when patients want to be completely "cured." Being a well-rounded pain doctor requires an intimate knowledge of anatomy, pharmacology, and psychology.

Although I really enjoyed my month on pain, I also don't think it's the perfect subspecialty for me. I liked clinic hours but didn't particularly like clinic. I enjoyed being a proceduralist but didn't see myself doing those procedures for the rest of my career. Some patient interactions were very satisfying, but many didn't resound with me. I gained a lot of knowledge, but saw how that knowledge would aid me in the operating room and intensive care unit. This experience will make me a better anesthesiologist and a better intensivist.

Saturday, August 03, 2013

Misuse, Abuse, and Diversion

Many physicians are concerned about prescribing high doses of long-term opiates because of the potential for misuse, abuse, and diversion. After talking to many patients, I think opiates are a little different than many other medications because patients think they can manage their dose without physician input. If a patient takes her blood pressure at home and it's elevated, she isn't likely to take an additional lisinopril or metoprolol. But if a patient has an exacerbation of his back pain, he might pop an extra oxycodone to tide him through. Misuse of drugs like this can lead to early refills, running out of pills, and physician distress.

Why do we get distressed? Because worse than misuse - which can hopefully be cleared up with better education and communication between the physician and patient - we worry about abuse and diversion. Because opiates have a euphoric effect, patients can take them for non-medical reasons, for the "high." This gives these medications a street value, and some people divert drugs by selling medications intended only for themselves. Not only can abuse and diversion be medically dangerous and physically harmful, but it's illegal. Worry about prescription drug abuse erodes patient-doctor trust. It piques the curiosity of the DEA and contributes to a massive societal problem. 

There are tools we have to flag aberrant behaviors. We use urine drug screens and check to see what prescriptions are filled, who wrote them, where they are filled, how many tablets were given, and how many were used. The majority of patients are reliable, using their medications appropriately, and pose no problems. But there's always the fear that one patient will get us in trouble, and with our licenses on the line, it's no wonder that chronic opiate use scares us. Furthermore, recent epidemiology studies show that as opiate prescription rises, opiate related emergency visits and deaths continue to rise. This is a big problem with health care in the U.S.

Thursday, August 01, 2013

The Science of Pain

While the clinical facet of pain is very important, I have also been fascinated by the philosophical and scientific questions surrounding pain. Why do we have pain? How is pain adaptive? How does pain shape who we are? How and why do disease states transform pain from an adaptive response to a maladaptive one? How does the brain and nervous system change when someone has chronic pain? How and why does taking too much pain medication end up worsening pain? This question refers to medication overuse headache where headache treatments used inappropriately start triggering headaches as well as how opiates can cause hyperalgesia and heighten pain experiences. What is the relationship between pain and identity? Is there a way to objectively measure someone's pain experience? Is childbirth really "the worst pain most women experience" and how do you prove that? Why do different types of pain feel different; why do some things feel like an electrical shock, burning, ache, pressure, or stab?

Even though most of these questions aren't directly related to medicine, I'm really curious about them. I used to think of pain as a very simple system, but the more I delve in, the more complexity I find. It's not as simple as giving an opiate and blocking signal transmission. From capsaicin (what makes spicy things spicy) to cognitive-behavioral therapy, there are so many ways of intervening with the pain experience that work on chemicals, receptors, neurons, networks, systems, and behaviors. There is so much we don't know, and much we're only beginning to uncover. Philosophers and scientists have been struggling with these core questions for centuries, and I can see now why they are so captivating.