Friday, December 30, 2016

WILTIMS #514-5: Let's call it a night

The past few "days" have actually been part of my week of night-call during this sub-I. So, instead of working from 7am to between 4:30 and 6pm, I come in at 5pm and leave at around 6am. Night shifts are typically pretty mellow. There is usually only a senior resident, an intern, and sometimes a sub-I like me, so the number of patients we each cover is roughly double that of weekday day-shifts. But, as most patients and attending physicians sleep through the night (there are exceptions to both), normally there isn't much to do but say "hi" to each patient and write an abbreviated note on each. If all's quiet(never say this word in a hospital) and your pager is set to one of the more obnoxious rings, then you might even be able to find a comfy chair and nod off for a few hours.

On my first night of the shift, this was not the case. We admitted six patients all while one of the patient's I was supposed to be watching overnight slowly but steadily spiralled into septic shock. It's telling as to how surprising this development was by the fact that I was the one to whom this patient was assigned. Very quickly, however, my senior resident took charge and the management of this patient turned into a full team effort. By morning, when no one had slept all night, we finally called in the PICU (pediatric intensive care unit) team to come take this patient to their unit.

Thankfully that was not a typical night and things mellowed out a bit on the subsequent nights.

Saturday: Tonight we had a nice little medical mystery walk into our ER. A 3-4 year old girl* was brought into the emergency department because, though she seemed perfectly healthy, some routine labs that her primary care doctor has ordered came back with some disturbing results. According to the results they brought in, she had severe pancytopenia (pan = all, cyto = cell, penia = too few, pancytopenia = having low counts in red blood cells, white blood cells, and platelets all at the same time). Pancytopenia is always scary in kids because it's almost always caused by only two things: aplastic anemia, which isn't great; or leukemia, which is worse. I was one of the two people in the room as we explained the possible prognoses to the family. But, thankfully, this kid had none of the above.

It turned out that the patient's mother had a habit of requesting a course of corticosteroids from their pediatrician every time the kid got a cold. "Her cough always sounds horrible and just never goes away unless she gets the steroids," the mom said. A short round of high-dose steroids is sometimes prescribed for a severe or stubborn asthma exacerbation, but the side-effects are significant so we try to avoid that when possible. One of the ways we use corticosteroids is to suppress the immune system, since often it is the immune system's over-response that causes most of the discomfort of being sick. At the same time, viruses can sometimes falsely lower the white blood cell count (and other counts to a lesser degree) by pulling cells out of the blood and into tissues. But, as IL on Saturday, if you use steroids while fighting off a virus, the two effects can compound and give results that would otherwise look like leukemia.

SundayIL: Differentiation syndrome is a rare, but not unheard of, complication to treatment for acute promyelocytic leukemia (APML). APML is caused by a type of precursor white blood cell that stalls during its maturation and builds up in huge numbers. There is a great, almost miraculous cure to this specific form of leukemia achieved by giving a drug that forces the aberrantly paused cell lines to continue on their way to becoming mature cells. The cancer just melts away. Rarely though, this sudden release of immune cells can cause a potentially severe bout of havoc similar to an allergic reaction, called differentiation syndrome.

*As usual, some or all details have been changed to preserve patient anonymity.

Tuesday, December 27, 2016

WILTIMS #512-3: Dosing, ordering, staging and grading

Thursday: Don't underdose pain meds in children. We have a tendency to look at kids as being small and feeble and are reticent to giving then the full dose of pain medications, even after adjusting the dose for their weight. But that's just silly! We wouldn't give them less antibiotics than recommended just because they're small and cute, so why would we make them suffer when it's perfectly safe to give them proper pain coverage? It happens all the time though, so we have to be vigilant and follow the evidence.

ThursdayIL: The enzyme asparaginase, which is used as an adjunct cancer therapy, can be produced both in E. coli, our typical enzyme-mass-producing organism of choice, and Erwinia chrysanthemi (recently renamed as Dickeya dadantii), a bacterium otherwise only known as an infectious agent to plants. If a patient is allergic to the E. coli variety, they get asparaginase-Erwinia.

Friday: It's frustrating not being able to put in orders as a sub-I. Of course, it makes sense legally and for patient safety. But as we are the pseudo-doctors in charge of our patients, when a nurse needs something for a patient, they page us, not the other residents who can actually write orders. So it ends up happening with frustrating frequency that we have a plan in place for some banal anticipated event that is delayed because I need to get an actual resident to switch away from whatever they are doing to open up my patient on the EMR (electronic medical record) to sign off on my orders. It seems like such a simple task, but since everyone else is usually taking care of sicker patients, my requests almost never take priority. Again, this is how it needs to be for many reasons, but that doesn't mean it's not frustrating.

FridayIL: The staging and grading of acute graft-vs-host disease (GVHD) is pretty complicated. Each involved organ system has four stages of involvement and then the grade is determined by either of two different systems that weigh the combinations of staging of each organ system. For example, both systems only allow for skin involvement in the lowest grade of the disease; even stage 1 involvement of the liver or gut automatically raises the grading. But if you have stage 4 involvement of any organ, then you are automatically grade 4.

I also learned a nice rule of thumb for pRBC (packed red blood cells) transfusion in severe iron deficiency anemia. You don't want to overload the heart and cause heart failure, so only transfuse at a rate less than or equal to the hemoglobin level (e.g. ≤4ml/kg/hr for a Hg of 4g/dL).

Saturday, December 24, 2016

WILTIMS #511: Enemy at the gates

Fever is a very scary thing in cancer kids. In normal kids, even though the technical cut-off for fever is 100.4°F (38.0°C), we aren't really all that concerned with an otherwise asymptomatic fever until it's consistently hovering a good deal higher than that (Reminder: please don't ignore your child's fever because of my silly blog; let your doctor make the call). But if you have no immune system, like kids receiving chemo or transplant meds, then your body has a really hard time producing the signals that lead to a fever. So, if one of these kids hits 100.4°, then it means that they are likely already quite ill, but not showing the typical signs yet. It's like if you're fighting a war and you have no more troops; just because you don't hear any gunfire, doesn't mean the enemy isn't advancing right to your door.

WednesdayIL: Though ECP does stand for emergency contraceptive pill (as I learned in my OB/GYN rotation), it quickly became apparent that that is not what the pediatric oncologist was talking about in regards to treating a young boy's graft-vs-host disease. In this case, it turns out, ECP stands for extracorporeal photopheresis, a method of essentially cleaning the patient's white blood cells. The idea is to remove some of the patient's blood, separate out the immune cells, and radiate them with UV light to make them invisible to the rest of the immune system before reinfusing them into the patient. This technique is used in patients with cutaneous T-cell lymphoma and some autoimmune diseases.

I also learned that you have to be careful with dosing methotrexate (a kind of chemotherapy) in patients in renal failure, with Down's syndrome, and patients who are "third-spacing." The first case is pretty simple; your kidneys filter out the toxic medicine after it circulates through the body. When the kidneys fail, the toxic stays around longer than usual and can do damage. With Down's patients, there is thought to be overexpression of some enzymes on the multiplied chromosome 21 that interfere with the drug metabolism resulting in higher levels of active drug in the blood stream.

The last one is a bit more complicated. "Third spacing" is when a patient is collecting unusual amounts of fluid outside of the two typical fluid "spaces" in the body (inside cells and in the blood stream). Instead the fluid pools in places like the abdominal cavity or the area around the lungs. But this fluid can still absorb chemicals like methotrexate, removing active drug from circulation, so the dosage required to get a typical effect is much higher. The problem is that we are usually also trying to eliminate this "third-spacing" so if you give large doses of the drug and then pull the unused drug back into the bloodstream from the extracellular spaces, then you've now overdosed the patient with medication they already had in their body.

Saturday, December 17, 2016

WILTIMS #510: A tale of two frequent fliers

On Tuesday, I got to meet two of the heme-onc floor's frequent fliers. Now in most areas of medicine, the term "frequent flier" has a starkly negative connotation. In the adult ER, it conjures images of alcoholics, drug users, and the mentally ill* and is usually accompanied with rolled eyes and a sigh. But in peds heme/onc, there are two prototypes, of which I got to meet one of each this week.

One is the "sickler", a kid with sickle cell anemia who is seen every few months with a new sickle cell crisis. These are very painful experiences that we can only do so much for. The main reasons the child is admitted to the hospital are so that we can monitor them as they receive high doses of our most powerful pain meds and to watch for any life threatening complications of the disease process.

But slowly, as these crises keep happening, these patients can become desensitized to the medications, requiring higher and higher doses and even becoming addicted. Meanwhile the team who used to be looked up to as a kind family trying to help, starts to be seen as an incompetent, rotating group of idiots who are refusing to treat their pain. At best, sicklers are quiet and patient as they suffer through their pain and our annoying bidaily questioning. At worst, they are bitter and uncooperative.† But they are all well-known to the entire hospital.

The second heme/onc frequent flier is the totally healthy cancer/transplant kid. Depending on the type of cancer, some kids need to come into the hospital to receive their treatment. Other kids had a bone marrow transplant to treat their cancer (and have practically no immune system now so as to stave off transplant rejection) and need to come in because they spiked a fever or had a positive growth on a surveillance culture. These kids are often totally 100% healthy but, because of our appropriately cautious guidelines to try to keep them that way, they sometimes get stuck in the hospital for a few days while we double check that they aren't getting sick.

We love these kids. They are adorable and energetic and just want to be outside of their boring rooms. They can often be found coloring at the nurses station or playing with toys in the hallway. Most kids in the hospital, even when they are starting to feel better, like to stay in their familiar room surrounded by family. Our hospital works very hard to make sure that a child's room is a safe space, where we won't do painful procedures, like lumbar punctures, if it can be avoided. But the frequent fliers know all the nurses and doctors and like to be roaming the halls and saying "hi" to everyone. I have never worked harder to prove that a kid didn't need to be on isolation precautions (and thus be confined to their room) than when one of these kids comes back in.

TuesdayIL: Rhodotorula mucilaginosa is a common environmental fungus that on rare occasions can grow in the blood of immunosuppressed patients.

*There is a good conversation to be had about how these medical demographic groups should not have a negative stigma associated to them. But, especially in the ER, the way our medical system is set up makes it very hard to find long-term placement and treatment for these groups, so they are usually just stabilized and sent home or back onto the street. The frustration with the system is the real negative influence here, but the patients are often treated as guilty by association.

†Note that these patients start falling into the same camp as the adult ER patients discussed above; patients who the system has failed and whom are at risk for the caregivers to misdirect their frustrations towards.

Friday, December 16, 2016

WILTIMS #508-509: Pediatric Heme/Onc

[Same old story: this post recounts days long past. I refuse to let this blog stay dead! "Once more unto the breach, dear friends, once more..."]

As hinted in my last post via my TodayILearned facts, the specific service I'm on for my pediatric sub-I is hematology, oncology, and transplant. This service is actually a lot of fun, with fantastic attending doctors, and dedicated nurse practitioners and nurses. But I was quickly reminded of the life and death realities of working in this field.

We recently had a teenager transferred to our service from general pediatrics. The kid came in with some vague symptoms that just weren't going away. All but cleared to go home, one last test, a bone scan, was done and to everyone's surprise it showed metastatic cancer. A biopsy was done which the medical staff knew was going to all but determine the kid's fate. Most childhood cancers are very treatable; some are not. It came back as Ewing's sarcoma which has a <10% survival rate. It was a sobering reminder that not all of our pediatric patients leave with happy endings.

ThursdayIL: Patients with suppressed immune systems (like cancer or transplant patients) must have their blood glucose carefully watched. Fungus loves high sugar levels and can thrive (and kill) if the immune system isn't there to fight it.

From: Nabil M. Elkassabany, M.D., et al. ; Green Plasma—Revisited.
Anesthesiology 2008;108(4):764-765.
Somewhat relatedly, if a patient has a bad reaction to a transfusion, the blood products may have been contaminated. But if the patient received several kinds of products, like red blood cells, plasma and platelets all at once, which is the most likely culprit? Units of platelets are far more likely to start growing bacteria or fungus for the simple reason that they don't need to be refrigerated.

Tangenting again, blood plasma is usually an orangish-yellow but occasionally a healthy person will donate green plasma. No, these are not Vulcans/Romulans in disguise; unusually high, but still completely safe, amounts of ceruloplasmin, a copper containing compound in blood, cause the color change.

FridayIL: The top four causes of death for pediatric patients with sickle cell disease are:
  1. Infection
  2. Splenic sequestration
  3. Acute chest syndrome
  4. Multi-organ failure
The vast majority of children with diagnosed sickle cell in the developed world will live well into adulthood. But these kids do often end up in the hospital once and awhile for pain management during sickle cell crises, and it's important for us to know which extreme tragic outcomes we must make sure don't happen on our watch.