Textbook of Medical-Surgical Nursing 3e

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Unit 3   Applying concepts from the nursing process

chemotherapy are troublesome for some patients. To minimise discomfort, some antiemetic medications are necessary for the first week at home after chemotherapy. Relaxation techniques, acupressure and imagery can also help to decrease stimuli contributing to symptoms (Dribble et al., 2007). Altering the patient’s diet to include small frequent meals, non-spicy foods and comfort foods may reduce the frequency or severity of these symptoms. Although the epithelium that lines the oral cavity quickly renews itself, its rapid rate of proliferation makes it suscep- tible to the effects of chemotherapy. As a result, stomatitis and anorexia are common. The entire gastrointestinal tract is susceptible to mucositis (inflammation of the mucosal lining), and diarrhoea can often result. Antimetabolites and anti­tumour antibiotics are the major culprits in mucositis, diarrhoea and other gastrointestinal symptoms. Haematopoietic system.  Most chemotherapeutic agents cause myelosuppression (depression of bone marrow func- tion), resulting in decreased production of blood cells. Myelosuppression decreases the number of WBCs (leucopenia), red blood cells (anaemia), and platelets (thrombocytopenia) and increases the risk for infection and bleeding. Depression of these cells is the usual reason for limiting the dose of the chemotherapeutic agents. Myelosuppression is predictable, and patients usually reach their nadir counts (point at which blood counts are lowest) 7 to 14 days after chemotherapy has been administered. At this time nurses anticipate associated toxicities, especially febrile neutropenia (fever associated with neutrophil count less than 1.0 × 10 9 /L. Monitoring blood cell counts frequently is essential, as is protecting the patient from infection and injury, particularly while the blood cell counts are depressed (Duong & Loh, 2006; Nirenberg et al., 2006). Other agents, called colony-stimulating factors (granulo- cyte colony-stimulating factor [G-CSF], granulocytemacro- phage colony-stimulating factor [GM-CSF], and erythropoietin [EPO]), can be administered after chemotherapy. G-CSF and GM-CSF stimulate the bone marrow to produce WBCs, especially neutrophils, at an accelerated rate, thus decreasing the duration of neutropenia. The colony-stimulating factors decrease the episodes of infection and the need for anti­ biotics and allow for timelier cycling of chemotherapy with less need to reduce the dosage. EPO stimulates red blood cell production, thus decreasing the symptoms of chronic administered anaemia. Interleukin 11 (IL-11) stimulates the production of platelets and can be used to prevent and treat thrombocyto­penia but has had limited use because of toxici- ties such as fatigue, oedema, arrhythmias and syncope (Burcat & McAdams, 2007; Hurter & Bush, 2007; Nirenberg et al., 2006). Renal system.  Chemotherapeutic agents can damage the kidneys because of their direct effects during excretion and the accumulation of end products after cell lysis. Cisplatin, metho­ trexate and mitomycin are particularly toxic to the kidneys. Rapid tumour cell lysis after chemotherapy results in increased urinary excretion of uric acid, which can cause renal damage. In addition, intracellular contents are released into the circula- tion, resulting in excessive levels of potassium and phosphates (hyperkalaemia and hyperphosphataemia) and diminished levels of calcium (hypocalcaemia). (See later discussion of tumour lysis syndrome.)

a reaction along with other predisposing risk factors such as pre-existing allergic reactions to food, blood products and other medications. Emergency medication and resuscitation equipment should be easily accessible. The usual chemotherapy hypersensitivity reaction is cat- egorised as a type I immediate, immunoglobulin E mediated reaction. Type I hypersensitivity reactions may present as a local reaction and then rapidly progress to systemic ana­phylaxis, or the initial presentation may be an acute life-threatening anaphylaxis. Symptoms include generalised itching with local- ised or generalised urticaria; flushing of the face, hands or feet; chest tightness; agitation; nausea and vomiting; dyspnoea and bronchospasm; difficulty speaking; feeling of impending doom; and hypotension (Gobel, 2005; Wilkes & Barton-Burke, 2007). The medication should be discontinued immediately and emergency procedures initiated. Many institutions have developed specific protocols for responding to hypersensitiv- ity reactions including standing orders for administration of emergency medications (de Lemos, 2006). See Chapter 48 for further discussion of allergic reactions. For some chemotherapeutic agents, especially if they are essential in the treatment plan, desensitisation procedures may be possible, and the patient is retreated with the agent at reduced dosages or slower infusion rates. Premedication regimes including corticosteroids, histamine-1 and histamine-2 antagonists, and antipyretics are routinely pre-administered for certain chemotherapy agents to prevent or minimise potential reactions. Doxorubicin or daunorubicin can create localised allergic reactions referred to as flare reaction. Patients typically experi­ ence a hot, flushed sensation with urticaria and pruritis. The nurse must confirm that the reaction is indeed a flare and not an extravasation. The infusion can be temporarily discontin- ued and restarted at a slower infusion rate after consultation with the doctor and IV administration of hydrocortisone. Toxicity Toxicity associated with chemotherapy can be acute or chronic. Cells with rapid growth rates (e.g. epithelium, bone marrow, hair follicles, sperm) are very susceptible to damage, and various body systems may be affected as well. Gastrointestinal system.  Nausea and vomiting are one of the most common side effects of chemotherapy and may persist for up to 24 to 48 hours after its administration. The vomiting centres in the brain are stimulated by: (1) activation of the receptors found in the chemoreceptor trigger zone (CTZ) of the medulla; (2) stimulation of peripheral autonomic pathways (gastrointestinal tract and pharynx); (3) stimulation of the vestibular pathways (inner ear imbalances, labyrinth input); (4) cognitive stimulation (central nervous system disease, anticipatory nausea and vomiting); and (5) a combination of these factors. Medications that can decrease nausea and vomiting include serotonin blockers, such as ondansetron and dolasetron, which block serotonin receptors of the gastrointestinal tract and CTZ, and dopaminergic blockers, such as metoclo­ pramide (Maxalon), which block dopamine receptors of the CTZ. Phenothiazines, sedatives, corticosteroids and histamines are used in combination with serotonin blockers with the more emetogenic chemotherapeutic regimes. Delayed nausea and vomiting that occurs later than 48 to 72 hours after