Critical care issues in the patient with hematologic malignancy

Tumour lysis syndrome: implications for cancer therapy

The tumour lysis syndrome (TLS) is a group of metabolic abnormalities caused by rapid and unexpected release of cellular components into the circulation as a result of massive destruction of rapidly proliferating malignant cells. It usually develops in patients with hematologic malignancies like acute lymphoid leukemia, non-Hodgkin and Burkitt's lymphoma after initiation of chemotherapy or may, rarely, occur spontaneously. Though TLS is seldom observed in relation to solid tumours, there have been reports of connections with examples such as lung, liver, breast, gastric carcinomas. The clinical manifestations of TLS include hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia. These indications if untreated lead to life-threatening complications such as acute renal failure, cardiac arrhythmias, seizures, and eventually death due to multiorgan failure. Therefore early detection of TLS is of vital importance. This can be accomplished by identification of high risk patients, implementation of suitable prophylactic measures and monitoring of the electrolyte levels in patients undergoing chemotherapy.

Tumor lysis syndrome in elderly

The majority of cancers occur in adults over the age of 65, with about 70% of all cancer deaths in this population. Tumor lysis syndrome (TLS) is a complication of hematological and others malignancies, caused by massive tumor cell lysis due to chemotherapy, immunotherapy, radiotherapy. TLS can determine an alteration of the body's normal homeostatic mechanisms and cause hyperuricemia, hyperkaliemia, hyperphosphatemia, hypocalcaemia and uremia. Aggressive fluid administration has been recommended in all patients presumed to be at risk of this syndrome. Hyperkaliemia has to be correct with hypertonic glucose, resins and dialysis. Initial treatment of hyperphosphatemia includes phosphate binders. The cornerstone of prevention and treatment of hyperuricemia includes both inhibiting the formation of uric acid as well as increasing its renal clearance through urinary alkalinization, allopurinol, rasburicase. Conventional management to prevent acute renal failure consists of intravenous hydration, diuretic therapy and urinary alkalinization. The management of TLS in elderly patients is often complicated by the renal and the heart senescence and by the presence of multiple co morbid conditions, polypharmacy and difficulties with adherence to complex medication and dietary regimens.

[The patient with leukemia in the intensive care unit]

Patients with leukemia are prone to critical illness at some time during their disease and their therapy that requires critical care. A number of these patients will have the opportunity to receive curative treatment and have an excellent probability of long-term remission if supported through a crisis. Complications that cause critical illness can be categorized as related to disease or those caused by therapy. The present review is focused on the description of the types of complications requiring intensive care, on specific aspects of the application of critical-care techniques, on organization of the intensive care unit in the context of leukemia and on ethical considerations.

Treatment by design in leukemia, a meeting report, Philadelphia, Pennsylvania, December 2002

Novel approaches have been designed to treat leukemia based on our understanding of the genetic and biochemical lesions present in different malignancies. This meeting report summarizes some of the recent advances in leukemia treatment. Based on the discoveries of cellular oncogenes, chromosomal translocations, monoclonal antibodies, multidrug resistance pumps, signal transduction pathways, genomics/proteonomic approaches to clinical diagnosis and mutations in biochemical pathways, clinicians and basic scientists have been able to identify the particular genetic mutations and signal transduction pathways involved as well as design more appropriate treatments for the leukemia patient. This meeting report discusses these exciting new therapies and the results obtained from ongoing clinical trials. Furthermore, rational approaches to treat complications of tumor lysis syndrome by administration of the recombinant urate oxidase protein, also known as rasburicase, which corrects the biochemical defect present in humans, were discussed. Clearly, over the past 25 years, molecular biology and biotechnology has provided the hematologist/oncologist novel bullets in their arsenal that will allow treatment by design in leukemia.

Elitek-rasburicase: an effective means to prevent and treat hyperuricemia associated with tumor lysis syndrome, a Meeting Report, Dallas, Texas, January 2002

Renal precipitation of uric acid associated with tumor lysis syndrome (TLS) is a major complication in the management of leukemia, lymphoma, and other drug-sensitive cancers. Management of hyperuricema has historically consisted of administration of allopurinol, hydration, alkalinization to maintain pH between 7.0 and 7.3, and in some cases diuresis. Allopurinol, a xanthine analogue, blocks xanthine oxidase and formation of uric acid. Urate oxidase converts uric acid to allantoin, which is 5-10 times more soluble than uric acid. Homo sapiens cannot express urate oxidase because of a nonsense mutation. Urate oxidase was initially purified from Aspergillus flavus fungus. Treatment with this nonrecombinant product had been effective in preventing renal precipitation of uric acid in cancer patients, but was associated with a relatively high frequency of allergic reactions. This enzyme was recently cloned from A. flavus and is now manufactured as a recombinant protein. Clinical trials have shown this drug to be more effective than allopurinol for prevention and treatment of hyperuricemia in leukemia and lymphoma patients. This drug has been approved in Europe as well as the US and several clinical trials are in progress to further determine its clinical utility in other patient subsets. The purpose of this meeting was to discuss usefulness of recombinant urate oxidase, also known as rasburicase, Fasturtec, and Elitek, for the management of TLS in certain cancer patients.

Oncologic emergencies in the patient with lymphoma

OBJECTIVES

To provide a brief overview of the oncologic emergencies most commonly occurring in lymphoma patients.

DATA SOURCES

Published articles, research studies, and reference books.

CONCLUSIONS

As a result of their malignancy and the treatments they receive, lymphoma patients are at an increased risk for the development of the following oncologic emergencies: superior vena cava syndrome, cardiac tamponade, sepsis, acute tumor lysis syndrome, and increased intracranial pressure. If not recognized and treated quickly, these complications can be deadly. With appropriate medical and nursing management, these emergencies either can be prevented or their complications minimized.

IMPLICATIONS FOR NURSING PRACTICE

An awareness of which patients are at risk for these complications and the pathophysiology of each emergency will assist nurses in the implementation of treatment measures.

Haematological patients transferred to the intensive care unit: what ICU nurses need to know

This article will consider the nursing care and treatment required by haematology patients when transferred to an intensive care unit (ICU). Background information on types of haematological malignancies, treatment for and survival from these diseases will be presented. This will be followed by considering some of the complications that may lead to admission to ICU including tumour lysis syndrome, infections, disseminated intravascular coagulation and haemorrhage and the side-effects of treatment itself. Specialist needs of these patients when in an ICU will be addressed and the patients' experience of the disease will be discussed to enable ICU nurses to offer the best standard of care possible for such patients.

Critical care of the patient with hematologic malignancy

Patients with leukemia, lymphoma, or multiple myeloma are prone to critical illness because of the diffuse nature of their disease and the disruption of protective mechanisms. Despite high morbidity rates, a number of these patients have an excellent probability of long-term remission if supported through a crisis. Complications that cause critical illness can be categorized as related to disease or those caused by therapy. Those with unique features or management strategies for the hematologic malignancy patient and are included in this discussion include: leukostasis, disseminated intravascular coagulation, tumor lysis syndrome, respiratory failure, and typhlitis. A case study of an acutely ill, newly diagnosed patient with several of these oncologic emergencies is used to exemplify typical clinical finds and management strategies.