Interpreting lab results suck! Really, it does.
It is complicated and dry. For example, there is hyponatremia, which basically means low salt levels in the blood.
But then, there is:
- spurious hyponatremia
- isotonic hyponatremia
- hypertonic hyponatremia
- hypotonic hyponatremia.
And then to make it even more confusing, there is:
- hypervolemic hypotonic hyponatremia
- hypovolemic hypotonic hyponatremia
- euvolemic hypotonic hyponatremia.
Confused yet? I certainly am. I was lost at “hyponatremia.”
And that is just the beginning of interpreting lab results. There is hypernatremia, hypokalemia, hyperkalemia, hypo… You get the idea. And each of them is as bad and confusing. I needed help with interpreting labs because there is no way I am going to memorize it all.
That is why I really had to get the book, Clinician’s Guide to Laboratory Medicine, by Dr. Samir Desai. (He is one of the authors of books I have already reviewed: Success in Medical School, Success on the Wards, and The Successful Match. Basically, he is known to write quality books.) The book is over 250 pages long and can easily fit into your coat pocket. I guess that is why the word “pocket” is on the front cover.
Clinician’s Guide to Laboratory Medicine has really good reviews. In fact, every single review I have read has been positive (except for the complaints about the small print). But did it live up to my lofty expectations? Read more to find out.
Contents of the Book
With all of my book reviews, I would like to start out with the table of contents. In a way, by glancing at the table of contents, you can get an idea of what the book is about and what it will cover.
Chapter 1 – Electrolytes and Acid-Base
Chapter 2 – Hematology
Chapter 3 – Nephrology
Chapter 4 – Neurology
Chapter 5 – Endocrinology
Chapter 6 – Gastroenterology
Chapter 7 – Pulmonary
Chapter 8 – Cardiology
Chapter 9 – Rheumatology
My Thoughts on Clinician’s Guide to Laboratory Medicine
In this case, the table of contents does not do justice to what the book will cover. Basically, the book will help you interpret almost any lab values. It will cover whatever you have learned in medical school, and beyond! It will cover whatever can be measured from head to toe.
So let’s go back to the example about hyponatremia.
Once you turn to the section on hyponatremia, you will first see a chart listing the types of hyponatremia (spurious, isotonic, hypotonic, and hypertonic) and the causes of each. It is ok if you do not yet know what each type means, because they are explained later on.
After the chart, you will see the steps to assess which type it is.
Step 1: Consider spurious hyponatremia.
So this step explains that spurious hyponatremia could be due to:
- drip arm hyponatremia — when serum Na+ is measured from sample taken upstream from IV infusion on hypotonic fluid
- dead space hyponatremia — when blood is taken from central venous line without regard of the dead space
It will tell you what you should do next. And if it is ruled out, proceed to …
Step 2: Measure the serum osmolality.
I am not going to give away this whole section. But based upon the serum osmolality, you can determine if the hyponatremia is hypertonic, isotonic, or hypotonic.
Let’s pretend that the patient has hypotonic hyponatremia. Most cases are hypotonic anyways.
That will bring us to …
Step 5: Assess the patient’s volume status.
You will then come across another chart. It turns out that hypotonic hyponatremia has three types: hypovolemic, hypervolemic, and euvolemic. Next to each type, the chart has the physical findings that correlate to each type.
Let’s say the patient has peripheral edema and elevated jugular venous pressure. This means that he will have hypervolemic hypotonic hyponatremia.
It goes on to explain the possible causes: chronic heart failure, cirrhosis, etc.
And if the cause is unclear, you can get the sodium level of the urine. And based on the results, you can have a better idea what the cause is.
When I typed this all out, I realized how much information it really took to arrive at hypervolemic hypotonic hyponatremia. It basically took me a third of the article to reach that conclusion. But in the book, all this information only took up a total of 2 – 3 pages. Again, the book is over 250 pages long. So just imagine how much information is packed inside this little book.
And if you think this is good stuff, you can get all of this for each lab marker. It will show you:
- causes of each type
- steps to take to determine the type and causes
Basically, with this book, you will have everything you need on how to interpret lab values.
So what is my final verdict?
I highly recommend this book for any medical student, resident, and attending. The only downside to the book is the small font. But other then that, I really have no complaints.
Now if the publisher can turn Clinician’s Guide to Laboratory Medicine from a book into an application for a smart phone or tablet, I think this will really be a winner.
Disclaimer: I received a copy of the book from the publisher for me to review. Do keep in mind that it will not influence my opinion of the book. If the book is good, I will write a good review. If the book is not so great, my review will reflect that.
This review is part of The Only Medical School Books You Will Ever Need series. Click on the link if you want to avoid wasting money on useless textbooks.