ONS Connect - March 2008 - (Page 22)

fivEMiNUTEiNSErviCE AS Seen In tHe OncOlOgy nursing FOrum Recognize Hepatic Sinusoidal Obstruction Syndrome in Patients With Cancer [By Pamela Oestreicher, PhD, ONS Scientific Writer] H epatic sinusoidal obstruction syndrome (SOS), a serious complication that can occur following either allogeneic or autologous hematopoietic stem cell transplantation (HSCT), was described by Tracy Krimmel, MSN, AOCN®, APRN-BC, and Loretta A. Williams, PhD, RN, in the January 2008 issue of the Oncology Nursing Forum. Hepatic SOS develops early in the transplantation process, usually by day 35, and, in its severe form, can have a mortality rate as high as 67%. The incidence of hepatic SOS can be as high as 70%, depending on factors such as the condi- tioning regimen used and hepatic function prior to transplantation. Although the pathogenesis of hepatic SOS is not understood, it is thought to begin with injury to the hepatic venules. The vascular inflammatory process leads to deposits of fibrin in the portal vessels, causing obstruction. The sinusoids become dilated and hepatocytes become necrotic when collagen accumulates in the sinusoids and venules. Injury to the sinusoidal endothelial cells and the hepatocytes in zone 3 of the liver, located around the central veins, is an important initial event in hepatic SOS. Hepatocytes in zone 3 contain high concentrations of cytochrome P450, an enzyme that metabolizes many chemotherapeutic agents, including busulfan (Myleran®, GlaxoSmithKline) and metabolites of cyclophosphamide. Inability to effectively metabolize those chemotherapeutic agents increases liver damage. These events lead to widespread disruption of liver function. risk factors Cytotoxic agents implicated in the development of hepatic SOS include busulfan, a common conditioning agent used in HSCT, and gemtuzumab ozogamycin (Mylotarg ®, Wyeth Pharmaceuticals), an anti-CD33 monoclonal antibody. Risk factors for hepatic SOS include • Karnofsky score less than 90% • Age older than 20 years • History of liver disease • Intensive conditioning regimen • Fungal infection • Elevated aspirate aminotransferase at the start of HSCT • Previous abdominal radiation • Female gender • Advanced malignancy • Prior exposure to amphotericin B • Total number of days on broad-spectrum antibiotics • Total number of days with fever before HSCT. key Definitions Conditioning regimen: provides immunosuppression to prevent rejection of the transplanted graft; traditionally achieved by delivering maximally tolerated doses of multiple chemotherapeutic agents with nonoverlapping toxicities, with or without radiation Hematopoietic stem cell transplantation: IV infusion of autologous (selfdonor) or allogeneic (non–self-donor) stem cells collected from bone marrow, peripheral blood, or umbilical cord blood to reestablish hematopoietic function in patients with damaged or defective bone marrow or immune systems Hepatic sinusoidal obstruction syndrome: a toxic injury to sinusoidal endothelial cells causing a cascade of events, including compromised blood flow to centrilobular hepatocytes, fibrosis, and obstruction of hepatic blood flow; also known as veno-occlusive disease of the liver Hepatocytes: functional cells of the liver that are supported by reticuloendothelial cells Sinusoids: the vascular spaces that separate individual plates of hepatocytes; blood from the hepatic and portal veins combine in the sinusoids and drain into the central venules. “Five-Minute In-Service” is a monthly feature that offers readers a concise recap of a full-length article published in the Clinical Journal of Oncology Nursing or Oncology Nursing Forum (ONF). This edition summarizes “Hepatic Sinusoidal Obstruction Syndrome Following Hematopoeitic Stem Cell Transplantation” by Tracy Krimmel, MSN, AOCN®, APRN-BC, and Loretta A. Williams, PhD, RN, which is featured in the January 2008 issue of ONF. Questions regarding the information presented in this Five-Minute In-Service should be directed to the ONF editor at ONFEditor@ons.org. Photocopying of this article for educational purposes and group discussion is permitted. 22 ONS CONNECT March 2008

Table of Contents Feed for the Digital Edition of ONS Connect - March 2008

ONS Connect - March 2008 Contents Editor's Note Just In From Then to Now A Year in the Life—Month Three Web Connect Capitol Connection Notice Nursing Now Recognize Hepatic Sinusoidal Obstruction Syndrome in Patients With Cancer Caregiver Care Elasticity of Cells May Help Researchers to Identify Cancer Calendar of Events ONS Congress Your Thoughts and Comments Are a Valued Decision-Making Resource Staying On Top

ONS Connect - March 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.