Update on erythropoiesis-stimulating agents.

Erythropoiesis-stimulating agents (ESAs) have long been approved for the management of anaemia in a variety of clinical settings. Subsequently, a number of clinical trials were undertaken in which the haemoglobin end points were targeted to be maintained at normal or high-normal ranges, in an attempt to demonstrate improvements in long-term survival. For patients undergoing spine surgery, patients with cancer chemotherapy-induced anaemia and those with chronic kidney disease, adverse outcomes in these clinical trials were found, including death, thrombosis and/or cardiovascular events. Informed choice by patients for risks of ESA therapy as well as for blood transfusion should be part of the consent process for management of anaemia. Despite current regulations restricting ESA use, these agents are an effective treatment of anaemia, particularly for those who would be transfusion dependent without ESA therapy.