Blood Chemistry Labs

MPKH, BSN, RN · Jan 30, 2016

Well I'd look at the trend and check what treatment/medications the patient is on, as well as the patient's diagnosis and history before calling the physician.

General rule of thumb is if the lab value is tending towards the normal (or the patient's norm), or the patient is already receiving treatment/medication for the abnormal lab value, there is no real need to call the doctor. To me, that's like calling the doctor for normal vital signs value...it's not needed.

Secondly, if the patient has a diagnosis or comorbidity that will directly affect a lab value, it might not be necessary to call the doctor, unless the lab values are not trending towards normal (or patient's baseline) or the labs don't reflect that the treatment is working.

A patient in end stage kidney failure will have sky high creatinine and very poor GFR, . A patient who came in with hyponatremia will have low sodium levels, and those who come in with rhabdomyolosis will have a high CK. A patient with chronic anemia will be low on the hgb, and a septic patient will have high WBC.

You do call if a lab value deviates significantly from the normal (or patient's own baseline), or if the lab value is critically high or low. You will rely on your judgement and critical thinking, and will be better as you gain more experience on when to or when not to call the doctor regarding lab values.

As for your situation...a potassium of 3.3 is consider normal (on the low side, but still within normal range), but a mag level of 1.5 is outside the low end of normal for mag levels. Thus the nurse called the doctor for the mag and not the potassium.

Oh, and as you gain more experience, you will become familiar with the normal range of values for the common labs.

jadelpn, LPN, EMT-B · Jan 30, 2016

All of the labs as a whole provide a bigger picture overall on what is happening with a patient.

When you receive a lab report, the highs and lows are "flagged" which means that they should be reported. (and some list "normal" ranges--which can vary slightly by facility)

It is good practice to find out if a practitioner wants all lab results when they come in, (not just the flagged variety) so that any plan of care can be altered asap.

And always use your resources. Your charge nurse can be a second set of eyes as far as if the practitioner doesn't necessarily want lab results until they round, except for the flagged variety.

There's also a critical high system in most hospitals. The lab calls with these, speaks directly to the nurse, and protocol is usually the MD is notified within a time frame, and don't forget to document same. With or without new orders, but ask "what is it you would like me to do with this INR of 10?"

KelRN215, BSN, RN · Jan 30, 2016

It depends on what's going on with the patient. On many units, 3.3 isn't a K+ level that you would do anything about. When I did a clinical in cardiac surgery, they wanted everyone's K+ in the 4 range so just about everyone was on supplements though. People in the outside world walk around with K+ levels of 3.3 and are fine. Mine was 3.1 before I started on supplements.

A sodium level of 133 can be a big deal in one patient but expected in another. If you have a patient in SIADH or Cerebral Salt Wasting, you'd expect hyponatremia and 133 may be your goal for him. If you have a patient in DI and a sodium level of 133, that should tell you something. Either they're over-antidiuresed, fluid overloaded or, if in the immediate post-op/post brain trauma period, they may be entering into the second phase of tri-phasic diabetes insipidus- temporary SIADH- in which case the treatment needs to change immediately. Some drugs can cause hyponatremia and, if asymptomatic, treatment may not be warranted. I've seen kids on Trileptal with sodiums in the 120s on no sodium supps.

PT/PTT- depends if the patient is on anticoagulants. You want the PTT to be elevated for a patient on heparin. A patient who is not anticoagulated with the same elevated PTT would be cause for concern.

WBC- we don't even call panic values to the MD for oncology patients with no WBC count if they're admitted with neutropenia. ANC was 0 yesterday, it's still 0 today, that's why the patient is here. I once had a lab call me to notify me of a WBC count of 3,000. Nothing to be done about that in an oncology patient on active chemo. For another patient, that may indicate a problem.

BUN/Creatinine- there is no such thing as a low value that warrants notifying the MD for either. Elevated levels, again, it depends what's going on with the patient. A creatinine of 1.5 in a patient with ESRD due for dialysis is nothing to write home about but that same creatinine may mean something for a patient on nephrotoxic drugs whose creatinine was 0.6 yesterday.

So, unless you get a call from the lab with a panic value and policy mandates that you notify the provider, there aren't really any hard and fast rules. A hemoglobin of 8 in a post-op patient may indicate a problem but for oncology patient, we don't even transfuse until it's less than 7. You have to look at the whole picture.