Oncologic Emergencies – 5 – Leukostasis

Oncologic Emergencies PART – 5

(All the articles published in past are available at www.shyamhemoncclinic.com/blog/)

Question:  Last time we discussed Fever in a case of Neutropenia – Febrile neutropenia. Very important to know for our readers. Since number of cancer patients under treatment has dramatically increased, you may come across some of these patients in your practice too. You may be their first contact person in case of fever. THIS FEVER IS NOT TO BE TREATED LIKE ANY OTHER FEVER. THIS IS A POTENTIAL EMERGENCY. Remember to start intravenous antibiotics urgently, even before waiting for blood test results. Even if the patient looks stable, this is is an emergency. He/She may become unstable in next few hours, if not treated timely. See the discussion points from last time for details. Note the option of oral antibiotics in emergency, if for some reason, intravenous antibiotics is not practically possible.

Ans: Thank you for reemphasizing. Considering the number of cancer patients on rise, FEBRILE NEUTROPENIA IS LIKELY TO BE THE MOST COMMON ONCOLOGIC EMERGENCY THAT ANY DOCTOR WILL SEE IN HIS LIFETIME. Hence it is very important to know basic practical aspects about this emergency.

Que: What is the next important emergency?

Ans: Well every emergency is important! Since every life saved is precious.

But let us discuss very high blood counts (wbc, platelet, red cell). We discussed low counts last time!

LEUKOSTASIS is the term used for effects of very high WBC. Extremely high wbc count is most commonly seen in acute leukemia, or chronic leukemia. Leukostasis is generally a risk of acute myeloid leukemia, however it can happen in chronic leukemia too. It is much less common in acute lymphoid leukemia, even with much higher counts, such as in range of even about 10 lac.

Similar to other diseases, there is no absolute number above which leukostasis happens. However broadly, one can say that in case of acute myeloid leukemia, WBC count above 50 to 100,000 especially with absolute blast count above 50,000, there is risk. And higher the count, higher the risk.

These are generally newly diagnosed patients, hence presenting to a non oncologist doctor. They generally have nonspecific symptoms, frequently mild e.g. fatigue, bodyaches, some with mild headaches, blurred vision, mild dyspnea, mild hypoxia, low grade fever; occasionally more severe symptoms like lethargy, confusion, severe dyspnea. Many are asymptomatic as well with very high wbc counts. For some patients, first sign is an intracranial bleeding.

Thus, it is not possible to diagnose this clinically. However when you see a patient who has unexplained symptoms or “just looks ill”, you ask for basic blood work up. And it shows this very high wbc count. At this point, it is important you remember this potential condition, and that it is a potential emergency. Even if the patient “looks ok”.  This risk is Real!

This has happened with me. Early in my practice years, I remember two such patients of acute myeloid leukemia. Both were detected to have high wbc count with high blast percentage on Friday. Both out of town patients. In both cases, physicians felt that over the weekend, they need not be sent to us, as work up will not happen and unnecessary cost will incur for admission. And that “patient is very stable”.  Both these patients died before Monday, very likely from intracranial bleeding.

Unfortunately, this continues to happen, although less frequently now. As there is more awareness, and we are lot more emphatic about admitting such patients right away, even if it is weekend, holiday anything!

So, all you need to remember is that if there is a patient with very high wbc count, advise urgent referral to any hematologist or oncologist. Do not wait for symptoms. If your pathologist is confident that this is not ACUTE leukemia, then a delayed referral and outpatient consultation may be appropriate. Simple rule to detect acute leukemia (especially one which requires urgent admission) is: ONE WHOSE WBC COUNT and PLATELET COUNT ARE ABOUT THE SAME!

Once admitted, treatment for LEUKOSTASIS includes intravenous hydration, medicines to reduce wbc count quickly (such as hydroxyrea, ara-c), and if available APHERESIS, other supportive care. Chemotherapy for AML may be started for someone who is already diagnosed and there is no need to wait for any other reason.

Apheresis procedure is same as is done for making a Single Donor Platelet. Same machine too! Only difference is we change the setting to remove white cells instead of platelets. This is the most effective and most rapid treatment. Now this is much more widely available, at least in larger cities, with good blood banks. We frequently initiate this life saving procedure even at night.

February 13th 2020. Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 079 26754001. Diplomate American Board of Oncology and Hematology. Ahmedabad. drchiragashah@gmail.com