Sunday, April 8, 2012

Neutropenia and Febrile Neutropenia (what is she talking about??)

copyright universal pictures animal house

One hundred point four, One hundred point four.....
Repeat over and over in your best Dean Wormer voice (when he tells Blutarsky his grade point average in the movie Animal House is:   "Zero point Zero").

Repeat after me: 100.4, 100.4, 100.4

Here's my take on the white blood cell (not that you asked!!):
The job of the white blood cell is to protect the body by fighting off infections that threaten it.  There are different types of white blood cells (see below), but basically "The Navy Seal" (or creme de la creme) of white blood cells, and also the most prevalent, is the neutrophil.  Neutrophils sense bacteria/infection or a "foreign invader" and they are the "first responders" on the scene.  They divebomb to the site of infection and gobble up all of the bacteria.  A Navy Seal would consider their mission a success and go off to do other great things.  A neutrophil gobbles up the "infection or invader" and then basically feels its' work is done and dies off.   The neutrophil is a selfless hero!!

When we are healthy and feeling well, we take the neutrophil for granted.  We have plenty of them, they do their job and we don't care about them.  When you are getting chemotherapy, you realize the importance of neutrophils, and you will ask about them every time you have your blood drawn.  You will tell your family and friends all about them too.  People will start refusing to sit next to you at dinner parties, because you now spend hours waxing on about the virtue of the neutrophil : )   Some Republicans will get lured into sitting next to you at a dinner party, thinking that you are talking about Newt Gingrich, when in reality you are talking about Neut-rophils (very lame attempt at humor, I know!).  They will disappear when they realize that you are talking about a white blood cell and not a pasty old white guy.  But, I digress!!

Have you ever used a soup bone?  Think of that area in the middle of the bone.  We humans have  tissue in the middle of most of our large bones called the bone marrow.  Millions of white blood cells, red blood cells and platelets are made here.  The large bones:   your sternum, skull, pelvis, long bones of your legs (femur and humerus).

 New white blood cells are constantly being made, as old ones are dying off.  These are what we call "rapidly dividing" cells.   The emphasis on this post is fever and low white blood cell counts so we will save more talk about platelets and red blood cells for another post.

We have gazillions of infection fighting white blood cells.  If someone near you coughs or is sick, your white blood cells/neutrophils gear up to protect the body.

When we give you chemo, it affects the bone marrow, so we wipe out large amounts of white cells, so your body's defense system doesn't protect you like it should.  You have fewer troops to fight the enemy.

The good news:  chemo kills rapidly dividing cells.  Cancer cells are rapidly dividing cells.  They are big, unorganized, not shaped like normal cells and they proliferate like rabbits.  They grow fast and out of control.  So,  chemotherapy kills cancer cells.....good, that is our goal.

The bad news:  chemo kills rapidly dividing cells.  There are some healthy "normal" cells that also come under the "rapidly dividing" category.  Your white blood cells, red blood cells, platelets in the bone marrow.  Also your hair follicles, the lining of your mouth, throat, GI tract.  These are all rapidly dividing cells.  Chemo kills these too.  On the positive side, new cells are always being produced.  On the negative side of things, the chemo killing off your healthy rapidly dividing cells are why you experience side effects like hair loss, mouth and throat sores, nausea, vomiting, diarrhea.  Until the reinforcement new cells arrive, you have to deal with the side effects (your doctors and nurses will tell you what you can do to tolerate most of these side effects). 

When we give you chemo, we don't wipe out the white blood cells (or red cells or platelets) the very first day.  Usually the bone marrow starts to be affected a few days after chemo is given.  But the time of maximum impact to the bone marrow is about 7 to 14 days after your chemo dose.   This is called the nadir.  This is usually when you feel like an 18 wheeler has run over your body.  This is also when you are more prone to getting infections because your white blood cell count can be really low. 

Since your white blood cells fight infection, when they are low in numbers they have a harder time or may be unable to fight off the infection/invaders.  So, we tell patients to be especially careful 7 to 14 days after chemo as they will have fewer white blood cells and they will be more susceptible to infection at that time.

We check your white blood cell counts frequently during chemo.  We know that we are going to drop your white blood cell counts with chemo, so we have to have your white blood cells/neutrophils at a certain safe level to start with in order to safely give you your chemo.  If they are too low, we are going to have to hold your chemo that day.  This can get frustrating for cancer patients.  You get yourself mentally geared up for the next cycle, only to be turned away that week and told to come back later.  It would be dangerous for us to treat you that day, because we know that your neutrophil count is already too low.  If we drop it lower (which we will) and it becomes REALLY low, it could become life threatening. A Low neutrophil count is called "neutropenia".

Some patients get postponed for several weeks until their "counts" come up.  Others return to normal in a few days.  It all depends on the type of chemo, the number of treatments you have already have and just some people's bone marrow recovers more quickly than others.

When we draw your blood and your blood counts come back, we calculate the Absolute Neutrophil Count to determine whether it is safe to give you treatment or not. 

This from ChemoCare.  "Normal Adult Values on a "CBC" or Complete Blood Count with "types" of white blood cells."  This shows you the breakdown of white blood cell types, including our hero the neutrophil:
White Blood Cell Total4-11 k/ul

"One measure of risk is the absolute neutrophil count (ANC). The ANC is calculated by multiplying the total white blood count by the percent of neutrophils (also called segmented neutrophils, segs, polymorphoneucleated cells or PMNs, polys)
Total white blood count x % neutrophils* = ANC
* Neutrophils may be reported as segs & bands (a band is slightly less mature form of a seg). In this case add the % of segs to the % of bands then multiply by the total number of white blood cells.
(% segs + % bands) x Total white blood count = ANC

Risk of Infection based on Absolute Neutrophil Count (ANC)
ANC greater than 1500No increased risk of infection
ANC 1000-1500Slight increase in risk of infection
ANC 500-1000Moderate increase in risk of infection
ANC 100-500High risk of infection
ANC less than 100Extremely high risk of infection"

Usually we hold chemo if your ANC is less than 1000, but it all depends on the type of chemo regimen we are giving you.  Also, for transplant patients there are other rules and that will be in a later post on transplant.

What does this mean for you????   If you have a low level of neutrophils AND you have a fever you  have "febrile neutropenia", and are at risk of developing what could be a life threatening infection.  Infection is our biggest concern with anyone on chemo. 

So, if you have a temperature of 100.4, you need to call your cancer team/doctor on call, and come in to be admitted to the hospital.  You may not have an infection, but we are going to check your counts, cover you with antibiotics or antifungal drugs or both, and we are going to culture you to see if you have an infection or not. We are going to watch you like a hawk to keep you safe.  You may never actually get an infection, but the admission to the hospital is necessary to keep you safe.

If you have a temperature of 100.4, please don't screw around.  If it happens at 2 in the morning, PLEASE don't wait until the clinic opens at 7 a.m. to get help.  GET INTO AN EMERGENCY ROOM, IDENTIFY YOURSELF AS A CANCER PATIENT RECEIVING CHEMO TO ANYONE WHO WILL LISTEN.  Most likely they will put you in a protective room, do a fever workup and will get a dose of IV antibiotics into you ASAP and then they will transfer you to the inpatient cancer unit.

Some hospitals use 100.4, some 100.5 as their cutoffs for fever.  Bottom line, Temp of 100.4, get moving.  There are different levels of risk for neutrophil count and how high your fever is that decides whether you get treated outpatient or inpatient.  The National Comprehensive Cancer Network [NCCN] has guidelines or algorithms that most hospitals use to treat cancer patients with these issues.

Did I write all of this to scare the bejesus out of you?  No.  This is the one thing we never joke about with cancer patients.

Just remember one other very important thing.  All this yapping about rapidly dividing cells yada, yada, yada.  Just like the other side effects of chemo....all of this is temporary and will return to normal again one day.

So....if you are chilled, check your temperature.  If your temperature is 100.3, check it again in a few minutes.  If your white count is really low, pack a bag, call your doctor and make plans for someone to drive you to the hospital. 

P.S.  No rectal thermometer use if you are a cancer patient (phew, right?). 

More precautions to take in a later post, as you are probably fast asleep after reading this one!!

Here's a link to a calculator, so you can figure out your own ANC from your lab report if you want to:

Other reference links for this post:

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