5 Tips about the routine labs

I remember wondering why hematology was the first topic of clinical medicine during the didactic year of my program. Now I know why... A complete blood cell count (CBC) has been ordered on virtually every patient. The CBC gives you a quick inside look on a patient's energy status, infection status, and immune status. In addition to the CBC, a basic metabolic panel and urinalysis are the other two fundamental orders completing the lab trifecta. Conditions like anemia, infection and UTI are fairly easy to detect based on these labs. Here are 5 tips I have learned in the clinical setting regarding these labs that you might not know:

1. Hemoglobin and hematocrit are often elevated in smokers because the body is trying to churn out more RBCs in the face of chronic hypoxemia.

2. When the urine is negative for RBCs but positive for blood, think rhabdo. Muscle wasting of rhabdomyolysis releases myoglobin which yields positive blood but negative RBCs.

3. If the UA yields > 50 squamous cells, it is a dirty catch. Repeat the urinalysis.

4. A high BUN should raise suspicion of either a real volume depletion (most likely a GI bleed) or a perceived volume depletion. Recall a high BUN:Crt ratio (>20:1) is indicative of pre-renal failure.

5. Pay attention to potassium in patients with suspected diabetic ketoacidosis. Levels may be normal or elevated at initial presentation because the cells are spilling K+ into the blood in favor of absorbing H+. 

The Not So Easy Way Out

When I started a blog about the clinical year of PA school, I envisioned that I would be posting every week about all my new experiences. As it turns out, I needed a little time away to gain the necessary perspective on the clinical phase of PA school. I'll start with a common question I receive from 1st year PA students: Is the clinical year easier than the didactic year? 

The better question is why are we so curious about the “easy” part? Think back to your PA school interview when you were arguably the most ambitious about the challenging, complicated, and intellectually stimulating aspects of medicine. There is no arguing that the didactic year is mentally and emotionally exhausting but through all this hard work we sometimes lose sight of why we wanted to be physician assistants in the first place. It wasn’t for the least challenging path. 

The clinical year is so different than the didactic year that a comparison is not warranted. With the right mental approach, the clinical year is very rewarding. All the studying, classes, and clinical skills labs are put to work. It’s a taste of the career that you have ahead of you. Enjoying the satisfaction of completing your first twelve hour shift, realizing that proper documentation helps you remember the 8am patient when the clock strikes 6pm, getting frustrated that you still have to calculate the pediatric dose for ibuprofen with a calculator while your preceptor just knows it. And by the time you get your sea legs, it is time to move on to ski legs… if you catch my drift. Embrace the challenge of the clinical year. Make the most of working extra hours instead of complaining about it. Instead of getting frustrated when a preceptor practices differently than how you were taught, question it, research it, and move on. 

The practicing world of medicine works a lot differently than multiple choice exams. There is often more than one answer to a clinical problem. This can be frustrating for students at first but just be patient with the process. And to answer the question posed by many PA students about the clinical year...

Try your hardest to avoid the easy way out. 

AEIOU TIPS

These ten letters represent a mnemonic to ensure a thorough differential diagnosis, or a set of disease processes to consider when making a diagnosis. I cannot take full credit for this mnemonic as it was introduced to me by my dad, Dr. Grabert. It has served me well when interviewing patients and when I get stuck on exams. Traditionally, new PA students organize the body by systems. There is no fault in this approach, however AEIOU TIPS can expand your knowledge by approaching the body in terms of disease processes rather than anatomical relationships. 

A—Anoxia - We all know that oxygen deprivation (i.e. anoxia) is potentially fatal. One such anoxic condition is a pulmonary embolism (a.k.a. "PE"). These patients can often present with very vague complaints such as shortness of breath or tachycardia. Always keep this condition on your radar. You’ll save a life someday!

E—Endocrine - If you feel weak in understanding this body system, join the club. It has a thousand moving parts and generally ends with a lab value you must interpret. Understand that a primary disorder means that an extra-pituitary structure is the source of the problem. A secondary disorder means that the stimulating gland (usually the pituitary) is the source of the problem

I—Infectious - I didn’t realized just how specialized infectious disease was until I started PA school. It is a monster literally and figuratively. Don’t forget that not everything that is infectious is bacterial. If a person is really sick, suspect a virus. If a person is really, really, really sick, suspect a bacteria. 

O—Opiates - This word keys you to remember drug interactions. This becomes more prevalent in the later stages of the didactic year when you study pharmacology. But always remember that studying medicine really does mean studying “medicine.” Opiates most serious side effect is decreasing respiratory drive; they also cause constipation.

U—Urea - What’s the problem with urea? Well nothing, so long as it ends up in the urine and not backed up into the blood (i.e uremia). The kidneys are beyond extremely important to the body’s homeostasis because of their effect on electrolyte balance which ultimately controls blood pressure. Sometimes I feel like they are the real powerhouse and the brain gets all the credit. You will be studying electrolytes until you are exhausted enough to crave a Gatorade. Remember this fun mnemonic: a banana is like a cell. If you throw table salt (i.e. sodium) at a banana it won’t penetrate the peel, right? In other words, sodium likes to remain outside of the cell while potassium remains inside the cell (i.e. banana).

T—Trauma can affect any part of the body but traumatic brain injuries are by far the most extensively covered in PA school. The three major types are based on where they occur relative to the meninges (i.e. membranes that surround the brain). Think of the anatomy when assessing these injuries. 1) Epidural hemorrhages occur closest to the skull and a direct blow to the head is a likely culprit. 2) Subdural hemorrhages occur a little deeper and involve vessels that “bridge” between membranes. 3) Subarachnoid hemorrhages are very close to the brain, thus the brain can easily sense the “worst headache” ever.

I—Inflammatory/Immune -  The immune system, when properly regulated is our body’s saving grace. However, when the immune system begins to attack its own tissues (i.e. autoimmune disease), the prognosis can get quite complex. There is a diverse set of lab values that pertain to autoimmune diseases and they are rather complex. Two common markers that suggest an autoimmune process might be occurring include erythrocyte sedimentation rate (ESR) and C-Reactive Protein (CRP). 

P—Psych - Psychological disease processes often take a backseat to other physiological causes. Psychological health can not be forgotten and psychological drugs are very commonly prescribed. It is important to understand psychological drugs and their effect on neurotransmitters such as serotonin, dopamine, and norepinephrine. Dopamine is interesting in that it can viewed on a spectrum. Too much dopamine results in schizophrenia and too little dopamine results in Parkinson’s disease. This concept is especially important when studying antipsychotic drugs. 

S—Seizures serve as the buzzword in the AEIOU TIPS mnemonic, but it is meant to prompt you for neurological causes of disease. The neurological exam is so difficult because there are so many neurological pathways and functions. I mean, it is the brain we’re talking about. I really wish I knew more about the homunculus before PA school. See the image below and pay special attention to the legs. They hang off the side like they are dangling their feet in the water. In reality, they are dangling in the blood flow of the anterior cerebral artery. This might seem like foreign language right now, but this association is crucial when localizing the site of cerebrovascular accidents. 

Image retrieved from Huang, J. (2013). Overview of Cerebral Function: Figure 2. Merck Manuals.  http://www.merckmanuals.com/professional/neurologic_disorders/
function_and_dysfunction_of_the_cerebral_lobes/overview_of_cerebral_function.html

PA Team

The previous post underscored the importance of trusting yourself, but a good PA student also learns how to trust their peers. Teamwork is a major reason that PAs are so successful as a group. They are willing to leave their ego at the door to keep the patient’s best interests in mind. You might forget about this concept when that certain classmate or professor or preceptor starts to get on your nerves. Success depends on a diversity of interpersonal relations. In other words, the more personalities you are exposed to, the more prepared you will be to deal with a variety of personalities in the future. This will help you become more effective at problem solving and less fixated on “that person” that annoys you. As annoying as it might be, try to be open-minded with group projects in the didactic year. Inevitably, someone else will teach you something valuable. Finally, remember that everyone probably wants control of the situation and you’re not the only one in the group anymore that is a type-A personality.

Another group activity that causes added stress in PA school is finding the right study group. I always like to say, find those that are on your “wavelength.” Some people will talk over your head (big waves) or respond so fast (high frequency) that you can’t even process the information. Others will get so caught up on the minutia (lots of peaks and valleys) that the clinical relevance is lost. It may take some trial and error, but you’ll eventually just know when you are studying with people that are on your wavelength. And at the end of the day, there’s nothing wrong with studying by yourself. The group study sessions are just a way to lay it all out on the table and see if you can gather some useful information that you may have overlooked. 

Up next… Ten things I wish I knew before I started PA school.

Popular is Not Always the Answer

A majority of physician assistant programs are organized with one year of didactic (i.e. classroom) training followed by 12-15 months of clinical rotations. As I culminate my didactic phase of PA school, I am inspired to offer some words of wisdom to current and future PA students. The didactic phase is extremely challenging but it is well-designed. 

My first piece of advice is to trust yourself. This sounds commonsense but it is easy to get caught up in what everyone else is doing and forget about yourself. You have a unique background that got you accepted to PA school. No one else can even compare to your background, remember that. With that being said, it is important to continue what got you to PA school. There is no reason to dramatically change your study habits or buy into all the anxious chatter that occurs in the lecture halls before class. You will feel compelled to study the same way as your classmates because it is the popular thing to do. Breaking news for you, this is just an illusion. Trust yourself. This means trusting your preparation and your intuition. Physician assistant studies, like most advanced disciplines, is simply a new framework of organizing information. You’ve heard of pancreas, insulin, diabetes, hemoglobin, etc. Now you must re-organize this in your brain, not in someone else’s. Don’t worry about grades, just pass. Everyone in PA school is used to receiving a lot of As. However, often times the difference between an A and a B in PA School is added stress. Is it worth it?

“If you compare yourself to others, you may become vain and bitter, for always there will be greater and lesser persons than yourself.”  -excerpt from Max Ehrmann’s Desiderata