Not long ago I worked in a SNF (Skilled Nursing Facility). It's the type of place people go when they are not sick enough to stay in the hospital and not well enough to live at home.
A part of my job there involved responding to laboratory reports recieved from the laboratory center via fax.
One day, after doing my first rounds and recieving report I checked the fax for these lab reports. I noticed a report for a particular patient in the stack of papers, it was for a BMP (Base Metabolic Panel, or Electrolyte Panel) and the results were listed as "Pending"
This is not a rare occurance. Sometimes if lab results aren't complete, it's nice to get a notice that they're still working on it, that they haven't been missed or forgotten.
Later on that evening I checked the fax machine again and there was another lab report for the same patient. The report still was marked "Pending".
It is a bit weird to have a rutiene lab take that long, esspecially when all the other labs that were collected at the exact same time as this one had already come back.
The patient was alert and verbally responsive throughout the evening, participating in self care and complaining of only chronic pain.
Early in the morning, the CNA providing care in the room saw the patient become unresponstive and stop breathing. A pulse could not be felt. We started CPR and called 911. The patient was taken to the hospital in cardiac arrest.
I spent a lot of the rest of the morning calling people and documenting what had happened.
The whole event was unanticipated and upsetting, esspecially when I heard the fax machine printing out another set of papers.
They were lab results for the patient who had just been sent out...
And they were still "Pending".
I later learned that the lab had reiceved the blood, and it had been processed, but the level of pottassium in the sample was so high that they did not accept it as an accurate reading. They called later in the day to say they were sending out another phlebotimist to collect another sample because the pottassium level was abnormally high.
Pottassium is a mineral like salt, when it desolves in water it becomes an ion refered to as K+ (or K) it is primarily an intracellular ion involved in many processes including glucose transportation accross the cellular membrane and muscle function.
Low levels of K (hypokalemia) can occur during diuretic therapy in "pottassium wasting diuretics".
Hypokalemia is also associated with certian endocrine disorders: in diabetic patients, high levels of glucose are also associated with low levels of pottassium. In Cushing's Syndrome (when the adrenal gland is releasing too much of the steroid hormones cortisol and ACTH) the cells are put into "energy storing mode". Which causes conversion of glucose to storable forms of energy such as glycogen or fat, this also lowers the pottassium level as the glucose must be transported inside a cell in order for it to take place.
High levels of pottassium (Hyperkalemia) occur when a patient with renal problems is recieving a special kind of diuretic called a "pottassium sparing diuretic" or alternatively is recieving a supplemental pottassium vitamin at too high a dose.
It is also associated with hypoglycemia in diabetes and in Addisons disease-when the adrenal gland is releasing too little of the steroid-hormone cortisol or ACTH, causing the cells to be in energy consumption mode-this condition leads to low glucose levels and (...you guessed it) hyperkalemia.
People with Addison's disease will need to take steroid replacement drugs long term, unfortunately long term steroid replacement is associated with
Cushing's Syndrome
:(
There is a very narrow therapeutic range for pottassium (3.5-5.0 mEq/L), so a patient with a blood pottassium level of 7 mEq/L has a critical value for that lab. People with critical values for pottassium are in extreme danger of suffering from life-threatening arrythmias.
Now, it is possible to get a false critical value. Sometimes if a blood sample sat out too long the blood cells lyse (break apart) and all the intracellular pottassium gets mixed up with the extracellular pottassium, making the overall reading to be higher. When this happens, another sample needs to be collected.
Hypokalemia causes the heart to repolarize very, very slowly. This means that the T wave (the beginning of repolarization) will be flat and there will be another wave between it and the P wave of the next PQRST complex. This new wave is called the 'U' wave. If the patient does not recieve supplemental K via pills or a diluted dose IV, Torsades de Pointes will develop (a particular type of V Tach)
Hyperkalemia causes the heart to take a long time depolarize, resulting in flat P waves, a wide QRS complex and peeked T waves. Eventually this will also deteriorate into V Tach and V Fib, if its not dialized.
Pottassium is an importiant lab to monitor. If you have a high or low reading (even if you think its false) its importiant to communicate it. I'm not even being dramatic when I say its a matter of life and death. The worst that would have happened in an innacurate lab draw is the patient got sent to the hospital and monitored closely until the pottassium level was verified.
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