Hematology/Oncology Emergencies, An Issue of Emergency Medicine Clinics of North America (eBook)

John C. Perkins (Autor)

eBook Download: PDF | EPUB

2014 | 1. Auflage
100 Seiten
Elsevier Health Sciences (Verlag)
978-0-323-32029-0 (ISBN)

Infos

This issue of Emergency Medicine Clinics edited by Drs. John Perkins and and Jonathan Davis focuses on emergencies related to Hematology/Oncology and covers topics such as: Oncologic Mechanical Emergencies, Neutropenic Fever, Oncologic Metabolic Emergencies, Acute Leukemias, Pediatric Oncologic Emergencies, Chemotherapeutic Medications and their Emergent Complications, Anemia, Thrombotic Microangiopathies (TTP, HUS, HELLP), Congenital Bleeding Disorders, Acquired Bleeding Disorders and Antithrombotic agents, Sickle Cell Disease, and more!

Textauszug

Oncologic Mechanical Emergencies

Umar A. Khan, MD, Carl B. Shanholtz, MD and Michael T. McCurdy, MD∗[e-mail],     Division of Pulmonary and Critical Care, University of Maryland School of Medicine, 110 South Paca Street, 2nd Floor, Baltimore, MD 21201, USA

∗Corresponding author.

Prevalence of cancer and its various related complications continues to rise. Increasingly these life-threatening complications are initially managed in the emergency department, making a prompt and accurate diagnosis crucial to effectively institute the proper treatment and establish goals of care. The following oncologic emergencies are reviewed in this article: pericardial tamponade, superior vena cava syndrome, brain metastasis, malignant spinal cord compression, and hyperviscosity syndrome.

Keywords

Pericardial tamponade

Superior vena cava syndrome

Brain metastasis

Metastatic spinal cord compression

Hyperviscosity syndrome

Key points

• Diagnosing an oncologic emergency requires a high degree of suspicion in patients with a known or suspected malignancy.

• Echocardiography is the modality of choice to diagnose pericardial tamponade, and prompt pericardiocentesis can reverse the hemodynamic effects of tamponade.

• Radiation and systemic corticosteroids are the treatments of choice for SVC syndrome, however establishing tissue diagnosis is recommended prior to starting the treatment.

• Prompt imaging can establish the diagnosis of brain metastasis as well as malignant spinal cord compression. Systemic corticosteroids and radiation therapy remain the mainstay in the emergency department setting.

• Hyperviscosity is frequently seen in paraproteinemias and plasmapheresis can prevent potentially life threatening complications.

Oncologic emergencies represent a wide spectrum of disorders either resulting from the progression of a known malignancy or presenting as the initial manifestation of a previously undiagnosed malignancy (Fig. 1). Patients might not show characteristic signs and symptoms, so a high degree of suspicion for malignancy-related complications is crucial, especially in patients with known malignancy. With the prevalence of cancer on the increase, patients presenting with cancer-related emergencies as their initial manifestations of malignancy are also expected to increase.1 Because these are life-threatening conditions, prompt recognition can markedly reduce morbidity and mortality in the short-term and affect prognosis in the long-term. In addition, if the patient’s clinical condition permits, prognosis and life expectancy should be discussed and the goals of care should be explored during initial evaluation. The conditions discussed in this article are often early manifestations of disease; therefore, the treatment provided in the emergency department (ED) plays a significant role in the management of these patients.

Fig. 1 Two-dimensional echocardiographic image of pericardial tamponade showing diastolic right atrial (large arrows) and right ventricular indentation (small arrows) in the subcostal window.

Pericardial tamponade

Twenty percent to 34% of patients who have cancer have pericardial involvement.2,3 The most common primary malignancy involving the pericardium is lung cancer, followed by breast and esophageal cancers.4 Although malignant pericardial effusion is the most common manifestation of pericardial involvement, the most serious complication is pericardial tamponade. Pericardial tamponade is an increase in intrapericardial pressure that impairs intracardiac filling and cardiac output, necessitating emergent intervention.

Pathophysiology

Normally, the pericardial space contains up to 50 mL of fluid. However, cancerous cells can invade this space via direct invasion or through blood or lymphatic metastasis, leading to substantial malignant fluid accumulation. An acute increase of only 200 mL of fluid may cause a steep increase in intrapericardial pressure, impairment of cardiac filling, and hemodynamic compromise.5 However, patients with chronic pericardial disease can have stress relaxation, whereby, over the course of weeks or months, the pericardium may accommodate up to 2 L of fluid, without a significant increase in intrapericardial pressure.5

Signs and Symptoms

The presenting complaints associated with malignant pericardial effusions can be nonspecific, ranging from exertional dyspnea to tachycardia and chest pain. The classic Beck triad6 of muffled heart sounds, hypotension, and increased jugular venous pressure is seen in one-third of patients with rapidly accumulating effusions7 but is less common in patients with chronic effusions. Pulsus paradoxus (Box 1), characterized by a decrease in systolic blood pressure of more than 10 mm Hg with inspiration, is observed in up to 77% of patients with pericardial tamponade.6

Box 1   How to check pulsus paradoxus

1. Inflate blood pressure cuff until Korotkoff sounds are absent

2. Gradually deflate cuff, noting highest blood pressure when Korotkoff sounds appear intermittently (with expiration)

3. Continue to deflate cuff further and note blood pressure reading when Korotkoff sounds are audible during both inspiration and expiration

4. Difference between first and second reading of greater than 10 mm Hg is diagnostic of pulsus paradoxus

Diagnosis

Pericardial tamponade is usually diagnosed with echocardiography. Findings that help to differentiate pericardial effusion from cardiac tamponade are right atrial collapse in late diastole and right ventricular collapse in early diastole. Right atrial collapse is a more sensitive marker of pericardial tamponade, whereas right ventricular collapse is more specific.8 Doppler findings suggestive of increased intrapericardial pressure are changes of more than 30% in the mitral inflow velocities and more than 50% in the tricuspid inflow velocities. A respirophasic shift in the interventricular septum indicates that the right heart expands during inspiration at the expense of left heart filling.9

Other diagnostic modalities may also identify pericardial tamponade. Electrocardiographic findings suggestive of pericardial effusion and tamponade include low-amplitude waveforms and electrical alternans.4 On chest radiography, a sudden increase in the transverse cardiac diameter, termed a water bottle heart, suggests a rapidly accumulating pericardial effusion.7 Computed tomographic (CT) imaging can also aid in the diagnosis.8 Cardiac catheterization shows increased right-sided pressures and equalization of the right atrial, right ventricular, and pulmonary capillary wedge pressures.8,9

Management

Initial management with fluid resuscitation is appropriate in patients who seem to be hypovolemic and hemodynamically unstable. However, fluid administration could be detrimental to euvolemic or hypervolemic patients by increasing intracardiac pressure and thus compromising coronary perfusion pressure.8,9 The role of inotropes in the management of tamponade remains unclear.

The definitive treatment of acute pericardial tamponade is emergent pericardiocentesis. Preferably, this treatment is performed using ultrasound guidance. Almost half of malignant pericardial effusions may reaccumulate,10 and thus, placement of an indwelling catheter should be considered at the time of pericardiocentesis. A pericardial window can also provide long-term symptomatic relief in select cases.11,12 Patients with tamponade are dependent on preload as well as changes in the intrathoracic pressure. Procedures such as endotracheal intubation may further reduce preload and afterload both because of positive pressure and induction agents. Routine prophylactic intubation is not recommended for tamponade, because of the risk of cardiac arrest during or shortly after intubation. Careful consideration of the risks and benefits should be considered if intubation is contemplated.

Prognosis

Despite adequate treatment, the long-term prognosis for patients with malignant pericardial involvement remains poor. Median life expectancy is about 5 months after the diagnosis of a malignant pericardial effusion. Hemodynamic instability, dependence on pressors, and a higher volume of pericardial drainage are poor prognostic markers.13 Clinical features and management are summarized in Table 1.

Table 1

Cardiac tamponade key points

Beck's triad: Muffled heart...

Produkt-Details

• Erscheint lt. Verlag: 28.8.2014
• Sprache: englisch
• Themenwelt: Medizinische Fachgebiete ► Innere Medizin ► Hämatologie
• Themenwelt: Medizin / Pharmazie ► Medizinische Fachgebiete ► Notfallmedizin
• Themenwelt: Medizin / Pharmazie ► Medizinische Fachgebiete ► Onkologie
• ISBN-10: 0-323-32029-5 / 0323320295
• ISBN-13: 978-0-323-32029-0 / 9780323320290