Category: Academic Day Seminars

ADS – Acid-base disorders

During EBM week, we learned that one of the most common reasons why learners motivate themselves to learn something that they don’t otherwise want to learn is a fear of failure or humiliation. Not that I didn’t want to learn this, as acid-base disorders was an area that weren’t touched upon in the undergrad curriculum (except for one lecture in the renal elective), but Dr. Brown’s lecturing style certainly motivates one to do the pre-readings and do them well.

I won’t go over WHAT was taught as I feel that I have a good grasp on what was covered and I just need to practice it – any patient who has labs drawn, or arterial blood gases done, I will try to evaluate them and see if there is an acid-base disorder. I have a good idea of what causes each of the disorders, and how that will influence drug therapy – example is a metabolic acidosis where replenishment of bicarb is necessary… but bicarbonate is reconstituted in a bag of NS…which has 154 mEq/L. Not nice!

Normal pCO2 = 40 mm Hg
Normal HCO3 = 24 mm Hg (21-28)
Normal anion gap = 10 (8-12)… ADJUST NORMAL down by 2 for every 10 g/L drop in serum albumin (N = 42-46 g/L)

One pearl I must record though is that potassium usually follows blood pH changes due to shunting of potassium (a cation) into or out of the cell to maintain ion balance.
– As pH DECREASES in acidemia, potassium INCREASES
– As pH INCREASES in alkalemia, potassium DECREASES

I’m more a systems kind of person and I like a systematic way of evaluating anything. For that reason, I found acid-base disorders to be easy to wrap my head around. As long as I have the labs, the blood pH is the main anchor and will let me determine whether it is an acidemia or alkalemia. The corroborating signs, symptoms, and labwork will allow me to confirm that the drug therapy for the appropriate diagnosis is the best for the patient.

ADS – Clinical pharmacokinetics approach to aminoglycoside and vancomycin dosing

I found myself repeating the old adage from 2nd year pharmacokinetics that Dr. Ensom said: “if you want the chicken to be finger lickin’ good, you have to use the Colonel’s recipe!” For the majority of patients, the “recipe”, i.e. dosing protocol will work just fine, but this session was mostly me trying to remember how the heck I even knew how to use those equations in The Kentucky Manual…anyway, here are some pertinent points I got from the morning’s session.

Aminoglycosides (Vd = 0.2-0.3 L/kg and t1/2 = 2 hours for adults);  – use the VCH dosing protocol for traditional or extended interval dosing. Do NOT use extended interval in: pregnancy, burns >20% BSA, pts on dialysis, or septic shock. Basically anyone who would have increased clearance such that the post-antibiotic effect will not extend to 24 hours.
To load or not to load? – YES, unless you are doing once-daily extended interval dosing.
When do you take a level? – before the 3rd dose within 30 mins, and 30 mins after the half-hour infusion (4th dose). No levels for extended interval dosing as the trough will be undetectable anyway.
How do you monitor for toxicities? – vestibular toxicity manifests in 1-2 weeks, so get audiology involved if you suspect it. Nephrotoxicity happens quicker.
Adjusting doses based on levels – if your patient’s renal function is stable, and their clinical course is stable, and they have received all their doses and are at steady state… you can use the “cheat” method for a peak level. For everything else, there’s Masterca- The Kentucky Manual. Also useful if the levels were not drawn correctly at the right time.

The “cheat” equation: New dose = old dose * (desired level/actual level) 

Vancomycin (Vd = 0.6-0.8 L/kg and t1/2 = 4-6 hours for adults) – use the VCH/PHC dosing protocol.
To load or not to load? – YES…although in the course of doing the literature search for my project, I found that the evidence of a loading dose is not very extensive, but if a patient’s bacteremic, or they have meningitis, you wouldn’t deny them a load, right?
When do you take a level? – I thought this was cut and dry, before the 4th dose then use the cheat equation above to adjust the dose. HOWEVER, Dr. Loh presented an interesting case where one would have to improvise. A level may not even be warranted for an otherwise healthy patient who may not get vanco past 7 days. Post-levels are usually not indicated, and only reserved for unique cases such as in the case of renal failure or burns, or unstable clinical status warranting calculation of individual PK parameters.
In the setting of fulminant renal failure, it might be advisable to give a “mini-load” for the patient if a suboptimal dose was given in Emerg. After that, a random vanco level may be the best option just to see how the patient is clearing the drug.
If a load was given in Emerg, technically you could take a level pre-3rd dose assuming that the patient’s clinical status has remained stable. – the half-life of vanco is 4-6 hours, so steady state should be reached in 20-30 hours… assuming q12h dosing, that would fall within before the 3rd dose.
How do you monitor for toxicities? – there are some that are dose-related, i.e. red man syndrome and ototoxicity, and some that are not, such as nephrotoxicity (but really…vanco is not that nephrotoxic, one would be more worried about the other medications on board that may be nephrotoxic). NEUTROPENIA actually occurs in 1-10% of patients (as per Lexicomp) but it only manifests after 1-2 weeks of treatment.

Overall, I feel more confident than when I walked in that morning in terms of my ability to evaluate a patient’s AMG or vancomycin regimen. I also learned that sometimes you may have to improvise and think clinically to solve dosing issues – but that’s why we are on the ward! If everything were perfectly protocolized, physicians wouldn’t need us!

ADS – Community-acquired and hospital-acquired pneumonia

I quite enjoyed this session. Going back to Dr. Nishi’s session on an intro to ID, where she kept saying that for undergraduates, we are trained to treat ID as a cookie cutter system. Cellulitis gets cephalexin or cefazolin, full stop! However, real life is never that black and white, and this session revealed that. Dr. Brown introduced a case where the medical resident asks you what is good to treat someone with fever and cough. This was a good session to follow the morning one as we got into the mindset of first asking if there was an infection or not. It was a bit like a general workup. Vitals, ROS, med Hx, conditions, labs, and HPI. Once we were convinced it was a pneumonia, it turned to a roundtable discussion where we each had to provide a regimen and defend it! In total there were almost 30 regimens. After, we went through each and every choice, and the pros and cons of each regimen.

This was a great reminder of what to consider when recommending a medication (or not) for an ID patient. Definitely not cookie cutter. It also made us recall knowledge from the bugs and drugs table from undergrad, along with more up to date antibiograms. 

The process was repeated, albeit abridged, for HAP and VAP. The main point I got was that >48 hours exposure to the hospital setting or health care setting coupled with S/S suggestive of pneumonia increases your suspicion of HAP. In addition, there is much to keep in mind including if they had surgery and what type of surgery they had, prior exposure to broad spectrum ABX…kind of like a regular workup! The biggest pearl I got was that generally, double covering for Gram-negatives is not necessary. This encouraged me to think beyond the guidelines, while also thinking about the usual hospital bugs you’d be worried about such as Enterobacteriaceae, Acinetobacter, and MRSA pneumonia.

This session provided a good framework by which to approach other types of infection I will encounter, including UTIs, intraabdominal infections, meningitis, and others.

ADS – Introduction to Infectious Diseases

I’m writing this on public transit so I don’t forget most of the things (it’s amazing what you think you retain right after but then lose shortly thereafter!). Here are some of the more pertinent points I got from today’s morning session:

– Always be skeptical of a specimen: when it was obtained, where the sample was taken from, and (where I think I’d miss the most) how the sample was obtained. Harking back to my hospital rotation, I know that I’d skip to the C&S.

– The white blood cell count (and sometimes the temperature) can be deceiving: but a fever and leukocytosis indicate infection, I cry! It was a good reminder that there are multiple causes for these signs.

– Source control is sometimes the most important way to treat an infected patient: it’s great that you treat an intraabdominal abscess with cipro and metronidazole, but antibiotics don’t penetrate that well into abscesses. It shows how medicine and pharmacy can work together.

– The fundamental question is “does my patient have an infection?”: Again, it was good to build upon undergraduate knowledge and it gave me some tools to critically assess the culture, physical findings, and antibiotic choice that may be on board already. Just because an organism grows (and sometimes heavily) on a C&S does not mean that organism is causing the infection.

This was a great primer (full of clinical pearls that I will update with in Nuggets of Knowledge) to my upcoming ID/AMS rotation, which I am really looking forward to. It allowed me to rustle through the depths of 2nd year knowledge, and should prove to be a good background by which to base further learning from.

ADS – Introduction to Clinical Patient Workup and Therapeutic Thought Process

The process. You hear about it before you enter residency, perhaps when you’re shadowing a current resident or clinical pharmacist. As we all enter and progress through our respective residency journeys, we will learn to embrace it, hone it, respect it, live and die by it, and eventually become Jedi Masters (if Tila’s analogy holds up) of clinical pharmacy…hopefully. My hospital OEE was at Vancouver General, so some of what I heard was kindly gone over in the first 2 days of rotation before they shunted us to the wards, but for me, repetition sometimes breeds learning, so it was great to hear it once more. Now, repeat after me: “The drug and dose are wrong until proven otherwise. The drug and dose are wrong until proven otherwise…”

I found myself restless these past few days, I wanted to get in there and start honing that process, becoming painfully aware of my ignorance, and start climbing that residency mountain. Today, we went over the proper process of working up a patient, the first step in that mountain. This was by far (personally), the most engaged I was this week. Here are some things that jumped out at me, and which I will strive to be more aware of in the coming future:
– Always have a plan B, C, D, etc: as Sue emphasized, the team will almost always choose and implement your plan A. So when plan A goes south and they look to you as the pharmacist, you’ll have a plan. I guess this was drilled into our heads in undergrad as well, but in the hospital setting it becomes way more pertinent as situations can change on a dime, and time is literally money (admission lengths) and life.
– If a drug is stopped or just “hanging about”, why is that? Investigate! Challenge your own knowledge!: not to be the Medication Police For Physicians, but to make sure one doesn’t miss a DTP.
– Labs “upon admission” means upon admission to hospital from HOME, not upon transfer: in the sample case, the patient was transferred from Prince Rupert Hospital (PRH) to VGH. For the sake of getting a baseline for the context of the conditions that are treated, labs upon admission to PRH are more appropriate for comparison’s sake.
– As pharmacists, we don’t diagnose, but anticipating the diagnostics that will be conducted and how to interpret them is a tool in one’s arsenal to monitor drug therapy and to always be ready for what happens: I immediately thought about my upcoming Emerg rotation in January…previously asking ED pharmacists about their role, they said that anticipating the differential diagnoses, and what to monitor for given the possible diagnostics that may be performed. What would one expect? What would prompt a change in drug therapy?

I definitely will look back at the session before Clinical Orientation starts up on July 24th. Before then, there’s Drug Distribution, a project week, and the UBC didactic week to look forward to…

ADS – Safety with Parenteral Medications

Today’s (June 15th) ADS was on a topic that, for the vast majority, was not touched upon in the undergraduate curriculum, but is very important for hospital practice. For the 4 years of pharmacy school, we got to know PO medications very well, and we would learn IV dosing and pharmacokinetic considerations, e.g. IV medications have 100% bioavailability, and unless you’re talking about a fluoroquinolone, PO meds don’t have (virtually) 100% bioavailability. However, some hospital-specific concerns that I would not have previously considered, and an approach for pharmacists when faced with a question specific to parenteral medications were discussed today. Here are the ones that struck me the most:
– Questions you should always ask a nurse who is inquiring about Y-site/piggyback compatibility, or how much/how fast to give a drug: 
Central or peripheral line? – concentration of drug is dependent on that.
Location of the patient? – logistically, only certain meds or certain concentrations may be delivered on certain wards, such as ICU or BMT.
IV intermittent or continuous infusion? – sometimes, the type of drug precludes asking this question.
– Drugs that are inherently irritating to vasculature are more irritating in areas of the body with slower blood flow: this is intuitive as one would think that if a drug has more time to hang around a section of vasculature, it has more time to irritate the vessels! It would certainly prompt me to rethink, or at least, more closely monitor a patient who is given an irritating medication such as acyclovir or vancomycin via a peripheral site.
– Different disease statements warrant different kinds of lines: my preconception was that it was dependent on patient-specific factors that didn’t have to do with disease states. For example, tunneled central venous catheters (CVC) have a triple lumen which allows the administration of 3 drugs (which may all be incompatible) at the same time, and BMT or hemodialysis patients are best suited for those. On the other hand, IVADs (or PortaCaths), which are implanted into the patient’s body just under the skin, have only a double lumen and are best suited for cancer treatment, or other chronic disease requiring intermittent IV treatment.

We all finished the session by going through a few real-life cases where Pharmacy is consulted regarding physical characteristics of IV medications. It reinforced the process that pharmacists must go through when assessing compatibility and suitability of different IV medications, and definitely made me feel more comfortable in navigating the many different resources that are available. In the toolbox of problem solving, the special considerations that we must take into account when assessing IV drug therapy will definitely be applied to patients in future clinical rotations, and may also be applied during my Drug Distribution rotation starting next week.

ADS – Patient Assessment by the Head to Toe Method

Today we had a seminar presented by Dr. Kanji and Dr. Leung on a systematic approach to patient assessment. The head to toe approach was touched upon over the 4 years of pharmacy school now and again in a couple of structured tutorials, and during my institutional OEE rotation at VGH, but it was valuable for me to hear and reflect upon the important points in an “all-in-one” session.

Specifically, I found it provided me with a more complete toolkit for approaching the sample case for workup for Friday’s ADS on Clinical Therapeutic Workup and Therapeutic Thought Process. Here are some new, more in-depth bits of knowledge that made me go “huh..that’s interesting!” and prompted me to reflect upon previous cases encountered in the institutional setting, and will better equip me to apply these to my patients in the near future:
– The Glasgow Coma Score (GCS) is a measure of patient responsiveness comprised of 3 axes: eyes, verbal, and motor. When I was on my OEE rotation, the GCS was always reported as just a single number. Although I had to look it up back then, this presentation reinforced that point.
– The Mini Mental Status Exam (MMSE) is REALLY easy to mess up on…if you’re in a high-pressure situation, unfamiliar environment, etc…so it’s important to keep that in mind when assessing a patient. What is their baseline at home? What other things may influence the findings? I’m sure I’ll see much more of it during my Psychiatry rotation later on.
– Psyc assessments: I’m not really a mnemonic type of learner, so it was interesting to see what you should be looking for in that format, but it prompted me to develop my own “flow” as to how, systematically, I should be assessing mental signs and symptoms in a patient.
– Heart sounds: This was really an “a-ha” moment for me – in all the patients I encountered on my hospital OEE rotation, I always read “S3 and S4 sounds absent” or some variation. However, today I learned about the adventitious heart sounds. The S3 heart sound can be NORMAL for a patient <30 yo, but it can be pathologic in CHF or a ventricular septal defect (VSD). The S4 heart sound can be NORMAL for a patient <20 yo, but it can be pathologic in hypertension, MI, ischemia, or aortic stenosis. On the other hand, murmurs have a LOT of descriptors for them, depending on timing, radiation, intensity…the list goes on. These points will help me understand better what may be going on in a cardiology patient, or may help me monitor therapy for a cardiovascular condition.
– For hepatic function, most of this material was new to me. We didn’t get a lot of instruction on this area of assessment in undergrad so it was valuable to have the information to digest and apply. There will be a future ADS on Liver (Function) Tests…which Dr. Leung mentioned is kind of a misnomer, as some of the tests (such as LDH and ALP) are not reflective of liver function. Conversely, PTT (prothrombin is synthesized in the liver) and albumin are more reflective of liver function. Bottom line: be wary, and one needs to treat the patient, and not the level!
– The remainder of the systems that were covered, namely, renal, lytes, MSK, heme, endo, and derm – were covered in undergrad, and most of the information was not new to all of us. However, it was valuable to reinforce those ideas again, and it gives us a good framework by which to start developing the thought process and integrate all lab and physical findings into case presentations, which can help formulate recommendations.

Overall, I think that when evaluating a patient with a given condition, the head to toe method is a systematic approach to ensure that nothing is missed in my assessment, and that it flows logically into a monitoring plan for any recommendations that I may make in terms of drug therapy.