Introduction
The word cancer elicits dread in nearly everyone. Cancer accounts for considerable mortality and morbidity in both men and women (Kozier, 2004). Certain genes controlling growth and interactions with other normal cells are apparently abnormal in structure or regulation in cancer cells. Humans of all ages develop cancer, and a wide variety of organs are affected. The incidence of many cancers increases as the fourth to sixth power of age, so that as people live longer, many more will develop the disease. Apart from individual suffering, the economic burden to society is immense (Murray, et al, 2000).
Cancer is caused in all or almost all instances by mutation or by some other abnormal activation of cellular genes that control cell growth and cell mitosis. These abnormal genes are called oncogenes. Also present in all cells are antioncogenes, which suppress the activation of specific oncogenes. Therefore, loss of or inactivation of antioncogenes allows activation of oncogenes that lead to cancer (Guyton & Hall, 2000).
Cancer cells are characterized by three properties: (1) diminished or unrestrained control of growth; (2) invasion of local tissues; and (3) spread, or metastasis to other parts of the body. Cells of benign tumors also show diminished control of growth but do not invade local tissue or spread to other parts of the body (Murray, et al, 2000).
An abnormal cell mass that develops when controls of the cell cycle and cell division malfunction is called a neoplasm. However, not all neoplasms are cancerous. Benign neoplasms are strictly local affairs. They tend to be surrounded by a capsule, grow slowly, and seldom kill their hosts if they are removed before they compress vital organs. In contrast, malignant (cancerous) neoplasms are nonencapsulated masses that grow more relentlessly and may become killers. Their cells resemble immature cells, and they invade their surroundings rather than pushing them aside, as reflected in the name cancer from the Latin word for “crab.” Malignant cells also tend to spread via the blood to distant parts of the body, where they form new masses. This last capability is called metastasis (Marieb 2004).
Genetic aspects of cancer are probably receiving the greatest current attention among genetic abnormalities. Some cancers are caused by oncogenes, genes which are carried in the genomes of cancer cells and are responsible for producing their malignant properties. These genes are derived by somatic mutation from closely related proto-oncogenes, which are normal genes that control their growth. Over 100 oncogenes have been described (Ganong, 2001).
Obviously, the initiation of mitosis and normal cell division depends on the orderly occurrence of events during what has come to be called the cell cycle. There is intense interesting the biochemical machinery that produces mitosis, in part because of the obvious possibility of its relation to cancer. When DNA is damaged, entry into mitosis is inhibited, giving the cell time to repair the DNA; failure to repair damaged DNA leads to cancer. The cell cycle is regulated by proteins called cyclins and cyclin-dependent protein kinases, which phosphorylate other proteins (Ganong, 2001).
Cell replication involves not only DNA polymerase but a special reverse transcriptinase that synthesizes the short repeats of DNA that characterize the ends (telomeres) of chromosomes. Cells with high telomerase activity, which includes most cancer cells, can in theory keep multiplying indefinitely (Ganong, 2001).
The impact of critical care on the outcome of cancer patients is not yet well evaluated. The prognosis of cancer patients who become critically ill and need intensive care is poor, with mortality rates of 40% to 80%. The discrepant results of past studies may be due to differences in the types and stages of cancers included, patients’ comorbid conditions, and the effectiveness of therapies for underlying cancer and nonmalignant conditions (Hsieh, 2006).
Rationale for the measurement of blood gases in the cancer patient who has become acutely ill
There are four good reasons why nurses must obtain blood gases in a critically ill cancer patient: 1) to assess the oxygenation capacity of the lungs for diagnostic reasons, 2) to assess the oxygen pressure in the blood for therapeutic reasons, 3) to assess respiratory adequacy, and 4) to assess acid-base status.
Blood gases are drawn from an artery with a small needle attached to a syringe. This syringe contains a small amount of heparin which prevents clotting of the blood. The sample is obtained from the radial artery at the wrist if it is possible. In situations where repeated samples are needed, an “arterial line” (a small catheter left inside the artery) is what is utilized. In newborns, the samples would be obtained through an umbilical artery catheter. In some cases where the radial pulse is unobtainable (blood pressure less than 60 systolic) the blood gases sample is usually obtained from the femoral artery in the groin of the patient.
The blood gases sample is corked off immediately to prevent exposure to room air, and placed in ice. The site of the arterial puncture is kept under pressure for about ten minutes in order to prevent formation of a hematoma or a semisolid mass of blood in the tissues.
The blood gases sample is placed in a machine that measures the pH, partial pressure of oxygen (PaO2), and carbon dioxide (PaCO2). Usually the hemoglobin is measured in another machine. These are the “measured values,” from which other values are calculated. “Controls” (solutions of known pH) are used to insure the accuracy of the measurements of blood gases of the patient.
Readings for the blood gases may need to be adjusted for the patient’s temperature. Oxygen, carbon dioxide, and pH are all affected by a change in the temperature of the patient. The machine is calibrated for measurements on a patient with a temperature of 37.0 centigrade.
Electrolyte imbalances and common cardiac consequences in the acutely ill cancer patient
The human body will try to restore any imbalance by itself, but if a person has an overwhelming acute or a chronic (long term) problem, there may be a need for medical intervention, such as being given concentrated, pure O2 or, in extreme cases, being put on a respirator to gain additional oxygen. If a patient is on continuing oxygen therapy, health care professionals may order blood gas tests to monitor the effectiveness of that therapy.
Electrolytes are chemicals in the body that regulate important physiological functions. Examples of electrolytes are sodium, chloride, magnesium, potassium and calcium. Electrolyte imbalance causes a variety of symptoms that can be severe.
The types of fluid and electrolyte imbalances that are observed in a client with cancer depend on the type and progression of the cancer. All electrolyte imbalances can occur in the client with cancer and are caused by anatomical distortion and functional impairment from tumor growth and tumor-caused metabolic and endocrine abnormality. In addition, clients with cancer are at risk for fluid and electrolyte imbalances related to the side effects of their chemotherapeutic and radiological treatments (Potter & Perry, 2004).
Electrolyte imbalance is commonly caused by loss of body fluids through prolonged vomiting, diarrhea, sweating, or high fever. All of these may be side effects of chemotherapy treatment. The kidneys play a critical role in regulating electrolytes. They control the levels of chloride in your blood and “flush out” potassium, magnesium and sodium. Therefore, a disturbance in blood levels of these electrolytes may be related to kidney function.
A high level of calcium in the blood, called hypercalcemia, may become a medical emergency. Hypercalcemia is a common metabolic complication of cancer. Hypercalcemia resulting from cancer is particularly common in conjunction with breast cancer, lung cancer or multiple myeloma and often results from the destruction of bone due to bone metastases.
About 20% of hypercalcemic patients have bone metastases that produce the hypercalcemia by eroding bone – local osteolytic hypercalcemia (Ganong, 2001). There is evidence that this erosion is produced by prostaglandins from the tumor. The hypercalcemia in the remaining 80% of the patients appears to be due to elevated circulating levels of PTHrP (humoral hypercalcemia of malignancy).
Extracellular fluid calcium ion concentration normally remains tightly controlled within a few percentage points of its normal. In increased calcium concentration or hypercalcemia, there is a depression of neuromuscular excitability and can lead to cardiac arrhythmias (Guyton & Hall, 2000). The tumors responsible for the hypersecretion include cancers of the breast, kidney, ovary and skin (Ganong, 2001).
Role of the ward nurse in the transfer of an acutely deteriorating cancer patient to the critical care unit
There is a growing body of nursing literature that examines the variety of complications facing cancer patients requiring intensive care intervention (Alfafara & Hedges, 1996). Critical care nurses may not understand or agree with rationale behind critical care unit admissions for some patients with cancers. They may be considered to have a poorer prognosis than patients without malignancies. Prognosis and survival for a cancer patient requiring critical care interventions are influenced by various clinical variables. Cancer patients with significant organ insufficiency and multisystem dysfunction are least likely to survive critical illness. Tumor characteristics, such as location, cell type, and metastatic potential, affect prognosis. Phase of illness–diagnosis, treatment, remission, recurrence, or progression–has a direct effect upon prognosis.
Care plans should reflect achievable goals and outcomes. Ward nurses need to evaluate outcomes of nursing actions and be alert for signs that goals are being met. Adequate time should be allowed to teach each nursing approach to a problem. Multidisciplinary collaboration remains essential in the provision of nursing care services.
After years of neglect, care at the end of life is receiving increasing attention and concern. When end of life is near, the patient is suffering the effects of a progressive and mortal illness, and is coping not only with bodily symptoms, but also with the existential crisis of approaching death (Cole, 2003).
Although the imperative of care is providing optimal symptom relief and alleviation of suffering, there is clear evidence in the current medical literature that there is a failure in doing this. Despite wide dissemination of pain management guidelines, many patients with cancer continue to suffer not only from pain, but also from other troubling symptoms and interpersonal scenarios in their final days.
The most effective approach to providing better care in patients with other diseases has been the use of clinical practice guidelines based on the delivery of evidence-based medicine. The ethical and professional challenge to do so is as important as the obligation to cure (Cole, 2003).
Ward nurses spends more time with the patient than does any other discipline and is, therefore, in the best position to detect subtle changes that may indicate impending treatment-related complications. The critical care nurse is vigilant in monitoring the patient’s dynamic physiologic responses to life-threatening problems (Alfafara & Hedges, 1996).
End-of-life care is defined as “the active, total care of patients whose disease is not responsive to curative treatment.” The philosophy of this care is to attain maximal quality of life through control of the myriad physical, psychological, social, and spiritual distress of the patient and family (Cole, 2003).
Physical symptoms in a cancer patient other than pain often contribute to suffering near the end of life. In addition to pain, the most common symptoms in the terminal stages of an illness such as cancer or acquired immunodeficiency syndrome are fatigue, anorexia, cachexia, nausea, vomiting, constipation, delirium and dyspnea.
Management involves a diagnostic evaluation for the cause of each symptom when possible, treatment of the identified cause when reasonable, and concomitant treatment of the symptom using nonpharmacologic and adjunctive pharmacologic measures (Alexander, 2001).
Although pain is commonly associated with end-of-life distress, other physical symptoms often contribute to the suffering of terminally ill patients. In patients who have cancer, fatigue and anorexia rank as the top two reasons for emotional and physical distress, with pain ranked third. Nausea, constipation, altered mental state (e.g., delirium) and dyspnea are the next most common symptoms (Alexander, 2001).
Potential benefits of critical care for the patient with cancer must be weighed against burdens that may be associated with such treatment. Of particular concern is emerging evidence of physical and psychological suffering among critical care unit patients, including patients with cancer and other malignancies.
A prospective study of symptom experience self-reported in real-time by cancer patients treated in a medical critical care units, including patients and nonsurvivors receiving mechanical ventilation, revealed that distressing symptoms such as pain, discomfort, dyspnea, depression, and anxiety were prevalent, often at high levels of severity (Cole, 2003).
Symptom burden is relevant in critical care unit decision making, although expert palliative care can be expected to improve patient and family comfort and should be integrated into treatment plans for all critically ill patients-especially those, such as patients with cancer, who remain at high risk for hospital death. Financial and other burdens for families of such patients may be significant (Cole, 2003).
The patient should be encouraged by the ward nurse to make appropriate arrangements for personal matters. These include updating his or her will, thinking about end-of-life care and advance directives, and discussing these with an appropriate surrogate. All of these discussions should be both compassionate and culturally sensitive. Above all, the patient should be allowed to express their reaction to the situation (Cole, 2003).
A patient has a greater chance for survival if an acute life-threatening crisis occurs early in the diagnostic phase rather than following disease progression. Clear communication of the patient’s diagnosis, prognosis, and treatment goal will facilitate the nurse’s understanding of the need for ICU treatment for a patient with cancer (Alfafara & Hedges, 1996).
The ward nurse’s knowledge of treatment-related side effects and toxicities will assist in predicting the development of critical crises. Pancytopenia results from many chemotherapeutic regimens and can lead to life-threatening bleeding and/or sepsis. Metabolic derangements, anaphylactic reactions to drugs, and long-term damage to organ systems contribute to the likelihood a cancer patient undergoing treatment may require intensive care intervention (Alfafara & Hedges, 1996).
A ward nurse incharge of a critically ill cancer patient should take a holistic approach to the patient and family impacted by cancer. An oncology nurse is often involved with the patient and family throughout the entire continuum of cancer from diagnosis, through treatment, remission, recurrence, and, eventually, death.
Cancer nursing interventions differ according to the phase of illness. Over time, the nurse develops a strong therapeutic relationship with the patient and the family. Serving as a patient/family advocate, the oncology nurse coordinates care with other members of the health care team and ensures that the patient and family have an active role in decision making (Alfafara & Hedges, 1996).
The focus of critical care nursing is to provide highly technologic care to patients with single or multisystem crises. The core knowledge of critical care nursing includes mechanical ventilation; hemodynamic, cardiac and respiratory monitoring; electrocardiogram (ECG) interpretation; and advanced cardiac life support.
The critical care nurse interacts with the patient/family during a specific point in the illness–often an acute life-threatening illness. Initially, a high priority of the critical care nurse is to stabilize the patient’s physiologic crises. Once the patient is stabilized, the critical care unit nurse may then address the biopsychosocial implications of the life-threatening event (Alfafara & Hedges, 1996).
Neurological assessment in the acutely ill cancer patient
Upon performing a neurological assessment of the critically ill cancer patient, complications are found. Neurologic complications occur frequently in patients with cancer. After routine chemotherapy, these complications are the most common reason for hospitalization of these patients.
Brain metastases are the most prevalent complication in cancer patients, affecting 20 to 40 percent of cancer patients and typically presenting as headache, altered mental status or focal weakness. Other common metastatic complications are epidural spinal cord compression and leptomeningeal metastases (Newton, 1999).
Cord compression can be a medical emergency, and the rapid institution of high-dose corticosteroid therapy, radiation therapy or surgical decompression is often necessary to preserve neurologic function. Leptomeningeal metastases should be suspected when a patient presents with neurologic dysfunction in more than one site (Newton, 1999).
Metabolic encephalopathy is the common nonmetastatic cause of altered mental status in cancer patients. Cerebrovascular complications such as stroke or hemorrhage can occur in a variety of tumor-related conditions, including direct invasion, coagulation disorders, chemotherapy side effects and nonbacterial thrombotic endocarditis (Newton, 1999).
Issues concerning the withdrawal of acute treatment in the person with cancer
Terminal restlessness affects a large proportion of patients with cancer at the end of life. It has many different risk factors, presentations, and causes. Management consists of keen assessment, identification and reversal of the causes, and treatment by a combination of pharmacological, environmental, and spiritual interventions (Blanchette, 2005).
In the patient with advanced cancer, terminal restlessness severely affects quality of life and creates additional burden upon family members. It is important for acute care clinical nurses to be educated about the numerous causes of terminal restlessness in the hospitalized adult patient with cancer. The focus is comfort and symptom management strategies. Recognizing and managing terminal restlessness empower nurses to help their patients achieve a peaceful death and to help decrease unnecessary distress for grieving loved ones (Blanchette, 2005).
Cancer-related fatigue is a complex and multifactorial phenomenon that is likely due to a variety of causes and contributing factors. The exact mechanisms involved in its pathophysiology are unknown. It may be a sequela of the malignancy itself, caused by multimodal cancer treatment, or secondary to treatment-related anemia. Cancer-related fatigue has known contributory physiologic factors, including cachexia, deconditioning, and high levels of certain cytokines such as interleukin-1, interleukin-6, and tumor necrosis factor-[alpha]. Psychosocial factors contributing to fatigue include anxiety, depression, and insomnia (Mock, 2004).
Common electrolyte imbalances that contribute to terminal restlessness are hyponatremia, hypercalcemia, hyperglycemia, and hypoglycemia. The most frequent contributors are hyponatremia and hypercalcemia. Low sodium may result from the disease process (for example, small cell lung cancer) or from side effects of diuretics (Blanchette, 2005).
Until recently, medical advice for patients undergoing treatment for cancer was to obtain additional rest and avoid activities that are physically challenging. Currently, the use of exercise as an adjunct therapy for cancer treatment-related symptoms has gained favor in oncology rehabilitation as a promising intervention.
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