Three decades ago, cancer and critical care were viewed as dichotomous terms. However, the paradigm has shifted, and today, cancer is viewed similarly to other chronic illnesses. Advance knowledge of the molecular basis of malignancy, identification of new therapeutic targets and advances in supportive care for these patients contributed to this shift in thought. Approximately 66% of patients newly diagnosed with cancer can expect to survive for more than five years,1 and as many as 17% will develop illnesses requiring critical care.2
Despite clear research supporting the beneficial effects of critical care for patients with cancer, remaining biases can impede optimal care. Literature describing outcomes of critical illness in patients with cancer have been published for decades with few variations in overall outcomes,2 but this article will cite data collected during the most recent decade. Reports often divide patients into two groups – those with hematologic malignancies and those with solid tumors. These two groups often experience different types of critical illnesses and various outcomes from specific interventions, although recent reports demonstrate little difference in outcomes if a patient is admitted for an acute illness. Patients with solid tumor malignancies demonstrate better overall survival rates from care in the intensive care unit (ICU). These statistics may be attributed to the amount of post-surgical intensive care required for these patients.3 It also is important to recognize the differences in outcomes when treating patients with an active malignant disease compared to those receiving adjuvant therapy directed at maintaining a remission or a disease-free state. In all critical illness, the presence of an active malignant disease negatively influences the patient's prognosis. A good prognostic variable is the application of critical care for management of a non-malignant complication such as acute myocardial infarction. A list of variables reported to influence outcomes in critical illness is included in Table 1.
The measure of success when addressing critical care interventions has been based on survival rates from high-intensity support therapies such as cardiopulmonary resuscitation (CPR), mechanical ventilation or dialysis. Recent studies commonly stratify survival based on generalized intensive care interventions and the utilization of mechanical ventilation. Mortality is measured at discharge from the ICU or the hospital and at a long-term point such as six months. Overall intensive care survival rates for patients with cancer are about 46% to 59%, 4-9 and six-month survival rates range from 0% to 44%.4,5,8,10 Variations in survival rates depend on the primary diagnosis and on the presence of specific clinical complications. Patients who have had allogeneic hematopoietic stem cell transplantation, late-stage metastatic malignancy or multi-organ failure have the poorest prognoses.3,5-7,10-12 This is not dissimilar to ICU outcomes for other chronic medical conditions.13,14 Universal critical illness scoring systems such as the Acute Physiology and Chronic Health Evaluation (APACHE) II have some benefit in predicting the survival rates of these patients. Oncologic critical care scoring systems such as the ICU Cancer Mortality (ICM) model account for hematologic toxicities and the effect of tumor masses, and they are better for predicting an individual's risk of death.15-17 Because mechanical ventilation is implemented as both a supportive short-term intervention and as a life-saving measure, survival rates for these patients vary from 18% to 76%.4-7, 10, 11, 18
Given the natural history of malignancy and therapies employed, often it is believed mistakenly that infection and bleeding are the most common etiologic mechanisms of critical illness. In fact, respiratory distress requiring intensive support is the most common critical illness and the most likely non-relapse cause of death.4, 11-13 If mechanical ventilation can be avoided with the application of supportive care or non-invasive ventilatory support, outcomes improve significantly. 13,19,20 Overall, immediate survival from mechanical ventilation is approximately 25%; however, other poor prognostic variables to be considered include mechanical ventilation for more than 14 days, sepsis or pneumonia as the rationale for ventilatory support, and arterial oxygen concentration less than 55 mm Hg on room air.12,13 Cardiovascular failure such as shock, neurological complications, renal failure and hepatic dysfunction are additional complications reported as primary reasons for critical care admission.3,6,8,11, 21 Oncologic emergencies due to the tumor or treatment are the cause of critical illness in approximately 20% of patients.4,11,17 Resources describing specific oncologic emergencies and the management of such situations are available in oncologic and critical care literature.22
The most important consideration for the management of emergent situations in patients with cancer is the phase of the disease trajectory.22,23 Patients who are newly diagnosed and who have not received definitive therapy for their malignancy almost always are treated aggressively. Many patients presenting with emergencies during the treatment phase are high-priority candidates for critical care support due to the reversibility of adverse effects. Patients are advised of potential adverse effects and assured that supportive measures can be provided to abrogate these effects. Decisions regarding the management of complications that occur with a progressive disease are the most challenging. At times, the clinical crisis may be reversed easily with a critical care intervention. For example, patients with pericardial effusion may benefit clinically and have improved quality of life if a pericardial catheter is placed to drain excess fluid. In this same setting, other interventions unlikely to alter either quality or quantity of life may not be recommended. Late effects of therapy that occur after the patient is cured effectively also have varying prognoses.
Each complication and patient circumstance is considered when making the decision to provide critical care. When medical or surgical complications occur during the treatment of malignant disease, the reversibility of the crisis is the first consideration. Then, the effect of the cancer illness on the complication or its treatment is factored into the decision to treat the complication aggressively. For example, a recently diagnosed patient who has an acute myocardial infarction in the midst of chemotherapy has an excellent chance of recovery without impeding quality of life; however, a patient with acute leukemia and prolonged neutropenia who experiences a bowel perforation may not be a surgical candidate because of the likelihood that the patient will not return to baseline health.
Patients with cancer have frequent fluctuations in their clinical condition requiring short periods of intensive care followed by periods of total independence. These clinical variations, which often mirror patients' therapies, have led some oncologic practices to implement an integrated level of critical or intermediate care within the oncology department. These systems reportedly improve the continuity of care and allow for specialized care in oncologic emergencies.24 Consulting or collaborating care with intensivists usually is standard. Oncology-dedicated ICUs are another option for large academic medical centers with large volumes of critically ill patients. Despite these options, the majority of critical care for patients with cancer is performed in a general critical care unit. Clinicians in these settings must be familiar with the patient's oncologic process and prognosis. They need to understand the necessity for highly aggressive therapies in order to reverse critical illnesses and appreciate the limits of these therapies.25 Critical care for patients with cancer is an essential component of developing innovative and highly effective therapies directed against cancer. If health professionals had been unwilling to pioneer new and toxic therapies directed against cancer during the last 30 years, care for cancer patients would not have progressed to its current level of success. Patients entrust their lives to oncologists and intensivists, and these healthcare professionals are obligated to weigh all the information available to provide appropriate patientcentered comprehensive care.
Cancer in the ICU: The Multiprofessional Approach
While every patient admitted to a critical care unit presents with unique challenges, the oncologic patient brings with him or her the opportunity to utilize one of the most diverse multiprofessional team approaches in critical care. Cancer knows no boundaries in regard to age, race or sex. The disease takes a toll not only on one’s physical health, but also can affect one’s body image, interpersonal relationships and financial resources. Because of the various challenges of the cancer patient, we must invite all necessary professionals to the team, including intensivists, nurses, pharmacists, respiratory therapists, physical therapists, nutritionists, pastors and others who will contribute to treatment. Keep in mind that a multiprofessional team may include those not always thought of in routine critical care. Massage therapists, music therapists or even visiting pets all can have therapeutic value.
As caregivers we must address our own biases and fears toward these diagnoses and understand that the outcomes for these patients have changed radically over the past several decades as exemplified in Brenda Shelton’s article “Critical Care of Cancer Patients.” The Right Care, Right Now™ philosophy rings true in these cases whether we are addressing a newly diagnosed patient or a patient experiencing complications secondary to ongoing treatment. As treatment options continue to expand and develop, we will need to implement outcome measurements and quality improvement.
– April Howard is the chair of the Society of Critical Care Medicine’s (SCCM) Nursing Section |