It has been exactly one week since Emily underwent her first chemotherapy treatment. She was feeling great for the first two days and then on the third day the chemo side effects came on in full force – nausea, vomiting, extreme fatigue, etc. Emily has emergency meds for the nausea, but they make her very sleepy so she mostly only uses them at night. Perhaps inspired by the Olympic Games currently underway in London, Emily has been sleeping like a true gold medal champion, logging 13 – 15 hours a night. Miles wakes Emily up around 2AM each night to feed her Saltine crackers so that she doesn’t wake up sick from an empty stomach. How adorable and dedicated is that?! For more adorableness check out the photo below…
The next seven day period is the time that Emily’s white blood cell count will be at its lowest point. This is called Nadir and is when Emily’s immune system is most susceptible to sickness and infection. Their apartment is being kept in pristine state of cleanliness with visitors going in and out of the apartment kept to a minimum. Emily doesn’t have time to deal with pesky germs when there is cancer to kick!
What Is Nadir?
When discussing chemotherapy side effects often you will hear the word nadir, mainly in reference to the low points of white blood cell and platelet counts.
Chemotherapy not only affects the rapidly dividing cancer cells but also some of the body’s normal cells, particularly cells that divide rapidly such as, the hair, the lining of the mouth, the lining of the intestinal tract and the white blood cells and platelets.
In the bone marrow, the spongy inner core of the larger bones in the body is where blood cells are made. There are very immature cells, called stem cells, from which the various types of blood cells develop. These stem cells do not reproduce quickly and are less likely to be affected by chemotherapy. As cells are maturing there are certain phases in which they divide faster. It is during these times that the cells are most sensitive to chemotherapy. The more mature cells can continue to become fully mature cells for several days after chemotherapy is given. When these cells live out their life span, the circulating supply is depleted and the blood counts fall to a low point, the nadir.
Emerging from the Nadir and Returning to Normal
The blood counts will return to normal within three to four weeks, after the body’s feedback system has told the stem cells in the bone marrow to increase production of new cells. If chemotherapy is given at the time that the stem cells in the bone marrow are increasing their production this could cause permanent bone marrow damage. The timing of chemotherapy cycles takes this process into account.
The nadir time is usually about 10 days after treatment, although this may vary depending on the drugs given. The concern during the nadir time is that the body’s first line of defense against infection, white blood cells (WBC) and the platelets, which help to clot the blood, are low leaving a person more susceptible to infection and bleeding. The next dose of chemotherapy is given only after a person’s blood counts have left the nadir and recovered to a safe level.