Oncologic Emergencies

Abstract

FigureUntil early in the first decade of the 21st century, patients often required admission to the ICU for management of classic oncologic emergencies—that is, superior vena cava (SVC) syndrome, tumor lysis syndrome (TLS), and malignant spinal cord compression (SCC). However, with the advent of preventive strategies and early detection of impending signs and symptoms, management of these classic emergent conditions has transitioned to the outpatient setting and/or on an oncology or medical-surgical unit.1 Currently, oncology patients in the ICU are more commonly admitted for emergencies that include cardiac and respiratory failure, life-threatening hemorrhagic events and coagulopathies, and sepsis. Like the classic oncologic emergencies, these conditions are the result of the cancer itself and/or the treatment. Nurses must be able to address the physical, emotional, and spiritual needs of the patient experiencing a life-threatening event in addition to coping with a cancer diagnosis. Admission to the ICU may have special meaning for patients and families, who once again are confronted with their own mortality and all the associated fears. The experienced critical care nurse recognizes the importance of preparing the patient and family for a highly technical and overwhelming environment, helping them navigate the unfamiliar system, and advocating for treatment options consistent with patient and family goals of care. Some cancer patients begin treatment and soon decide that the burden of their treatment's adverse effects is more than they are able to tolerate. For them, ”quality of life” is more important than “quantity of life.” These oncology patients are best cared for on oncology or medical-surgical units, or in their own homes with supportive care, rather than in the ICU. Other patients, who have very specific goals they are working toward, such as a child's graduation, a wedding, or the birth of a grandchild, may require ICU admission to meet those goals. The ICU serves as a bridge to get them to that goal. Finally, there are some patients who want “everything done,” despite the adverse effects they must endure or the unlikelihood of survival. These patients may require more than one admission to the ICU to try to proceed with additional treatment options. Oncology and critical care nurses work closely together to help these patients and family members understand the balance of treatment benefit and burden. A conceptual framework that is useful in guiding nursing practice for this cancer patient population is Ferrell's quality-of-life model,2 composed of four equally important domains: physical, psychological, social, and spiritual well-being. This framework reminds us of the importance of treating the whole person, not only the patient's physical well-being, and assists with the delicate balance of treatment benefit and burden. Classic Oncologic Emergencies Nearly a decade ago, many patients with cancer were admitted to the ICU for classic conditions defined as metabolic emergencies—TLS, syndrome of inappropriate antidiuretic hormone, and hypercalcemia of malignancy—and structural emergencies—SVC syndrome and malignant SCC. Because oncology teams have learned to anticipate and recognize these emergent conditions with certain types of cancer, they are usually diagnosed early and can be managed on the oncology or medical-surgical unit. Metabolic oncologic emergencies are common problems in advanced-stage malignancies and aggressive hematologic malignancies, respectively.3 Hypercalcemia occurs in 10 to 30 percent of patients with metastatic disease. TLS is associated with leukemias and lymphomas.1 A high index of suspicion for both hypercalcemia and TLS will help in prophylactic treatment and recognition of early signs and symptoms. For example, the use of bisphosphonates for patients with skeletal metastases has helped control calcium levels, preventing unnecessary hospitalizations for malignant hypercalcemia. Anticipation and prevention of TLS in at-risk patients, such as those with large tumor burden, have reduced the need for admission to the ICU.3 Superior vena cava syndrome occurs most commonly in patients with vascular access devices. Malignant SCC occurs in 2.5 to 6 percent of patients with cancer, particularly those with breast, lung, or prostate malignancies.1 Again, early recognition of signs and symptoms and early intervention can prevent progression to a life-threatening emergency.REGAN DEMSHAR, RN, MSN (left); is an Advanced Practice Nurse at the University Hospitals Case Medical Center and Seidman Cancer Center; RACHEL VANEK, MSN, ACNP-BC, is a Nurse Practitioner in the ICU at University Hospitals Case Medical Center; and POLLY MAZANEC, PHD, ACNP-BC, AOCN (right) is an Assistant Professor at the Frances Payne Bolton School of Nursing at Case Western Reserve UniversityFor example, oncology patients presenting with new-onset back pain, worsening at night with lying down, should be urgently evaluated with magnetic resonance imaging and started on high-dose corticosteroids to reduce vasogenic edema in the spinal cord.1,4 Radiation therapy remains the mainstay of treatment of SCC. Surgery may be indicated in patients who have a life expectancy of three months or more and who are at risk for paraplegia.5 Research has shown that those who have surgery and radiation compared with radiation alone are more likely to remain ambulatory, improving quality of life.5 Table 1 lists the classic oncologic emergencies, the types of cancer associated with these conditions, late signs and symptoms, and appropriate interventions. More recently, oncology patient admissions or transfers to the ICU are usually due to life-threatening emergencies such as respiratory or cardiac compromise, bleeding emergencies, sepsis, and hemodynamic instability. These conditions are seen in patients with other chronic illnesses as well as those with cancer. Some of the care provided in the ICU is standard practice for system failure, but there are considerations unique to oncology in each of these emergent conditions. In many instances, the best care is to treat the cancer as well as the presenting problem.Table 1Case Study Mrs. S was admitted to the oncology floor for neutropenia following initial chemotherapy for stage IV breast cancer with metastasis to the lung. She is a 62-year-old librarian who continues to work part-time while receiving her chemotherapy. She lives with her husband of 40 years and has two grown children who live nearby. Since admission to the floor, she reported shortness of breath and was unable to lie flat. Vital signs reflected a fever of 38.9 C, blood pressure 126/40 mm Hg, heart rate 106 beats per minute, respiratory rate 34 breaths per minute, and SaO2 of 88% on 2 L of oxygen. Physical examination revealed bilateral basilar lung crackles, and 2+ lower extremity edema. Respiratory distress worsened over the first 24 hours post-admission. Her goal of care at this time was to continue aggressive chemotherapy. She was hoping to be able to see her first grandchild born in three months. Respiratory Emergencies Respiratory failure is a common clinical complication of oncology patients who are undergoing treatment or who have progressive or metastatic disease to the lung. Patients may require transfer to the ICU to reverse the respiratory failure. There has been significant improvement in outcomes for patients with cancer admitted to the ICU for respiratory failure. In 1979, Snow et al6 reviewed 180 patients with cancer admitted to the ICU requiring mechanical ventilation. They found that 26 percent survived to extubation and that mortality was related to advancing organ dysfunction. Since that time, the management of patients with respiratory failure has improved survival rates. In 2005, Soares et al7 evaluated 463 patients with cancer who required mechanical ventilation in the ICU. The reasons for mechanical ventilation included respiratory failure, sepsis, airway obstruction, pulmonary embolism (PE), and cardiopulmonary arrest. The team found that 50 percent survived to leave the ICU. Not surprisingly the results showed that the severity of organ failure, poor performance status prior to the current crisis, and older age correlated with mortality.7 Respiratory failure in patients with cancer can stem from a number of causes. For example, primary brain tumors or metastatic disease to the brain, encephalopathy from liver metastasis, or paraneoplastic syndromes associated with selected malignancies can lead to centrally mediated respiratory failure. Examples of lung and chest wall conditions that may be found in patients with cancer include pneumonia, radiation injury, toxic effect of chemotherapy, and malignant effusions. Airway obstruction from primary or metastatic disease can lead to respiratory failure by impeding gas flow to the gas exchange units in the lung. Vascular disorders are also common in patients with cancer. Deep venous thrombosis and subsequent PE can lead to severe hypoxemia and death.8 Respiratory failure is classified as either hypoxemic or hypercapnic. Some patients may present with a mix of both low oxygen tensions and elevated carbon dioxide levels. Treatment differs on the basis of type and underlying cause. Reversal of the underlying cause while supporting the respiratory functions of the body is the general aim. The following are examples of common causes of respiratory failure in the cancer patient. Pneumonia Pneumonia, an infection of the lung parenchyma, is seen often in patients with cancer. Pneumonia may occur as a result of the malignancy or the treatment. Patients with cancer have an impaired immune response, increasing their susceptibility to opportunistic organisms. Those with lung malignancies may develop an obstructive pneumonia behind the malignancy. Patients who are neutropenic from chemotherapy are at increased risk of bacterial pneumonia from both typical and atypical organisms. They are prone to Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Klebsiella pneumoniae, as well as opportunistic organisms and fungi.8 In addition, most patients with cancer have comorbid conditions, such as chronic obstructive pulmonary disease, which puts them at an additional risk of pneumonia. Pneumonia can present with the usual signs and symptoms of fever, cough, sputum, hypoxemia, and shortness of breath, or with vague, ill-defined symptoms such as fatigue and nausea with few diagnostic findings. Prompt recognition and initiation of antibiotics aimed at the most likely organism may improve outcomes.8 Cultures of sputum and blood should be sent before administration of antibiotics. Supplemental oxygen and the use of noninvasive ventilation if needed have been shown to improve mortality in the critically ill patient with cancer.9 High morbidity and in-hospital mortality rates of 55 percent to 83 percent are associated with patients with cancer who require mechanical ventilation.10 Venous Thromboembolism Venous thromboembolism (VTE) includes deep vein thrombosis and pulmonary embolism. VTE must be included in the differential diagnosis of patients with cancer who present with sudden-onset shortness of breath and unexplained hypoxemia. Although postoperative patients are at greatest risk of PE, patients with malignancy have a fourfold increase in the risk of VTE.11 Risk may be higher due to the type of cancer diagnosis. For example, mucin-secreting tumors, such as pancreatic or gastric cancer, lung cancers, and acute promyelocytic leukemia are associated with an increased risk of clot development.12 Computed tomographic pulmonary angiography is the “gold standard” for the evaluation of PE.13 Patient selection for thrombolytic therapy, anticoagulation, and inferior vena cava (IVC) filter can be complicated because of other clinical conditions, such as treatment-associated myelosuppression, that may coexist with the malignancy. Patients with uncomplicated VTEs are usually cared for on the oncology or medical-surgical units. The treatment of VTE includes initial anticoagulation with unfractionated heparin, a low molecular weight heparin, or a pentasaccharide. The use of weight-based unfractionated heparin is effective in achieving appropriate levels of anticoagulation for most patients. Low molecular weight heparins are also effective for short-term and long-term anticoagulation. Treatment may be complicated in patients who are at risk of bleeding due to multiple metastatic sites, low platelet counts, heparin-induced thrombocytopenia, and thrombosis. The evidence supports continued long-term use of anticoagulation after the first incidence of VTE in the patient with cancer.12 Complicated management of VTE may require ICU admission. The use of thrombolysis is reserved for patients with extensive deep vein thromboses or large PEs, secondary to the high risk of bleeding with this therapy. Careful selection of patients appropriate for thrombolysis should include those with severe right heart failure secondary to vascular obstruction.12 If a patient is at high risk of bleeding or PE, the placement of an IVC filter may be considered.14 The patient's life expectancy and disease stage should be considered. Placement of an IVC filter does not prolong life and has been associated with poor outcomes.14 Lower-extremity swelling, migration of the filter, and vessel injury may occur as a result of IVC filter placement.15 Therefore, this option should be reserved for patients in whom the risk of anticoagulant therapy outweighs the benefit and is consistent with patient goals of care. Acute Lung Injury/Acute Respiratory Distress Syndrome Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS), are defined by a partial pressure of arterial oxygen to fraction of inspired oxygen of less than 300 and less than 200, respectively, in the setting of bilateral noncardiogenic infiltrates.16 Recent data estimate 190,000 cases annually with 74,000 deaths associated with this syndrome.16 The risk of developing ALI and ARDS is related to the presence of a predisposing condition such as aspiration, pneumonia, sepsis, multiple transfusions, or pancreatitis. The hallmark pathological finding is increased permeability of the alveolar-capillary membranes with resultant flooding of the alveolus and subsequent hypoxemia. Patients with cancer, especially those who have any of the aforementioned risk factors, are at risk of ALI and ARDS.8 The mainstay of therapy for ALI and ARDS is to correct the underlying process while supporting the patient and preventing complications such as secondary infections, thromboembolic disease, gastrointestinal bleeding, and malnutrition. Recent advances in targeting mechanical ventilation tidal volumes to 6 mL/kg of ideal body weight along with fluid management strategies have improved survival rates.17,18 Pulmonary Toxicity Associated With Chemotherapy and Radiation The toxic effects of chest wall radiation therapy and/or selected chemotherapeutic agents on the lung parenchyma may be the precipitating factor in respiratory failure. These toxic effects can result in mild to severe hypoxemia. Radiation therapy can cause structural changes in the lung tissue that predispose patients to respiratory failure. Table 2 lists key chemotherapeutic agents that can cause lung injury. The diagnosis of treatment-induced toxicity is one of exclusion of other causes for the respiratory failure and often is made via open lung biopsy. Stopping the offending agent is essential, and supportive care along with systemic corticosteroids is indicated.8Table 2Case Study Continued… Mrs. S was seen by the Rapid Response Team and found to have hypoxemic respiratory failure due to pneumonia. Her chest radiograph had bilateral lower lobe infiltrates. She was transferred to the ICU, and a sputum culture was sent. She was quickly started on broad-spectrum antimicrobials, and her sputum culture grew methicillin-resistant S. aureus. She was started on continuous positive airway pressure, and over 48 hours her oxygen needs improved; she was tapered to a nasal cannula. Mrs. S improved following ICU support for respiratory failure related to pneumonia and was transferred back to the oncology floor to review treatment plans for metastatic breast cancer. The oncology team worked closely with Mrs. S, changing her chemotherapy regimen to one with less risk for neutropenia, reducing the potential for infection. She lived for six more months, working three of those months and retiring with a large community reception. She felt well enough during her remaining months to work on a legacy photo album for her new granddaughter with her daughter and family. Survival of this emergent condition had a positive impact on her physical, social, psychological, and spiritual well-being. Ventilatory Modalities Over the past decade, emphasis has focused on appropriate admissions and transfers of patients with cancer to the ICU for intervention. Predictors for survival include cancer in remission, good performance status at onset of critical illness, absence of comorbidities, immune suppression less than seven days in length, correctable reason for ICU admission, and the absence of a fungal infection.18 No one specific scoring tool can be used to best prognosticate patients with cancer who are critically ill.18 When deciding which ventilatory modality to employ in the patient with respiratory failure, Soares et al10 make several recommendations on the basis of analysis of studies from 1999 to 2009 evaluating prognosis in oncology patients requiring respiratory support in the ICU. They recommend the use of noninvasive positive pressure ventilation (NIPPV) in nonpalliative care patients with cancer who require more than supplemental oxygen while the underlying condition is diagnosed and treated. Conditions such as cardiogenic pulmonary edema, pneumonia, and to some degree hypercapnic respiratory failure from conditions such as chronic obstructive pulmonary disease respond well to noninvasive ventilation. Fluid overload secondary to renal failure, patients with sepsis who require vasopressors, and those patients whose respiratory failure is from an unknown cause, do not fare as well with NIPPV and should be considered for mechanical ventilation early.18 NIPPV should also not be used for a prolonged period of time.10 In an attempt to identify the characteristics that are predictive of death in patients with cancer who required mechanical ventilation, another study by Soares et al7 found advanced age, multisystem organ failure, and lower performance status were associated with higher mortality. The use of various scoring systems may be helpful when attempting to identify those patients at higher risk of death, but the ideal tool for evaluating the risk for patients with cancer has yet to be developed.18 The APACHE II tool uses key clinical data to score illness severity but has been found to underestimate mortality in patients with cancer.19 The APACHE II tool is administered early in the ICU admission, but the acuity of patients with cancer is at its lowest at this time. The intensive care mortality model attempts to incorporate oncologic variables (i.e., presence of intracranial mass effect, allogeneic bone marrow transplantation, and recurrent or progressive cancer) for better prognostication.20 It is administered 72 hours after admission, when patients with cancer demonstrate their highest acuity. Shelton et al18 recommend that regardless of the instrument used to help predict ICU outcomes, ongoing assessment by intensivists in conjunction with oncologists and patients or their proxies should be used as the gold standard for decision making. Adapted from AACN Advanced Critical Care 2011;22:337-348. This is Part 1 of a 2-Part Article. Part 2 will cover cardiac emergencies, hemorrhagic and coagulopathic emer gencies, and another case study.