Secondary Causes of Aplastic Anemia (Pediatric Nursing)

00:00 Now that we've discussed Fanconi anemia as a genetic cause of aplastic anemia, let's look at some of the other causes of aplastic anemia.

00:08 The first is medications.

00:09 These can be toxic to the bone marrow and can damage the pluripotent hematopoeitic stem cells before they differentiate to committed stem cells.

00:18 The onset of drug-induced aplastic anemia is variable and can be insidious.

00:23 This can occur days after the initiation of the medication up to months after the start of a new drug.

00:28 The average time is about 6 1/2 weeks after starting a medication.

00:33 It typically starts with neutropenia which is the low white blood cells followed by thrombocytopenia which is low platelets.

00:40 Finally anemia develops and this happens slowly due to that longer lifespan of the red blood cell.

00:46 Clinical features of drug-induced aplastic anemia depend on the degree to which each cell line is suppressed.

00:52 Medication-induced aplastic anemia is one of the few life threatening reactions to medications.

00:59 Common drug classes include cytotoxic chemotherapy We know this is a medication but this is also a toxin.

01:06 Chemotherapy is effective in killing off cancerous cells but the chemical sometimes ends up harming the healthy stem cells found in the bone marrow.

01:13 In fact, chemotherapy can cause blood cell counts to fall in the first week after starting treatment.

01:19 This reduces the number of red cells, white cells and platelets in the body.

01:23 Thankfully this reduction is usually temporary and it should improve after the chemotherapy has been successfully completed.

01:30 The next is certain medications that we used to treat rheumatoid arthritis, and certain antibiotics.

01:36 To stop the aplastic anemia caused by a medication, the patient will need to stop the medication, if able.

01:42 Remember this isn't always possible especially if the medication is being used to manage a serious condition.

01:48 The patient can also receive a blood transfusion to replace the components of the blood that are not being made by the marrow.

01:54 The prognosis is similar when caused by medications as when aplastic anemia is idiopathic.

01:59 These patients usually respond well to immunosuppressive therapy and stem cell transplantation.

02:05 Aplastic anemia can also be caused by viral infections.

02:08 It is thought of as a response to the persistent inflammatory feedback to the hematopoietis system which makes it difficult for the bone marrow to function normally.

02:17 Viruses that have been linked to the development of aplastic anemia include hepatitis, the Epstein-Barr virus and cytomegalovirus.

02:25 In addition, Parvovirus B19 and HIV have also been linked.

02:30 Both the virus in itself can ensue this immune response and this can have a tremendous impact on the hematopoeitic process resulting in aplastic anemia.

02:40 How about aplastic anemia in pregnancy? Well a woman who has aplastic anemia prior to becoming pregnant will typically have a worsening of her symptoms during her pregnancy and some women will develop aplastic anemia while pregnant which is thought of as a sort of autoimmune reaction.

02:55 There is significant maternal and neonatal morbidity and mortality in patients with aplastic anemia These women have complicated obstetric and anaesthetic management and will likely be managed by a high risk maternal fetal medicine specialist These women are at high risk for hemorrhage due their thrombocytopenia and up to 75% of these patients require a blood transfusion during or after delivery.

03:21 The platelet count can also be too low to perform a safe cesarean delivery.

03:26 Due to their neutropenic state, these women are at an increased risk for infections and sepsis.

03:32 Aplastic anemia is managed in the same way as a non-pregnant patient although there are some additional potential risks.

03:39 And immunosuppressants, this can interfere with breastfeeding and these women may need to formula feed their babies.

03:45 They can also receive blood transfusions and stem cell transplant.

03:50 Chemotherapy is unique as it fits into the medication category and it also fits into the toxin category because it's a cellularly toxic medication.

03:58 Some patients with cancer will also receive radiation therapy and this can also damage the healthy cells in the bone marrow.

04:04 This usually improves once the therapy is completed.

04:08 Certain chemicals including pesticides, insecticides and benzene which is an ingredient in gasoline have been implicated and causing aplastic anemia.

04:17 With elimination of the exposure to these chemicals, aplastic anemia usually resolves.