Marjon Borgert

11 General introduction and outline of the thesis GENERAL INTRODUCTION Intensive care The intensive care unit (ICU) is a highly complex environment. This complexity is due to the multitude of technologies in use, the many di erent medications being administered, the complexity of illnesses being treated, and the wide range of ICU professionals who work together there, often under emergency circumstances. In such complex environments, adverse events are more likely to occur. Because the tolerance of critically ill patients to such events is low, patient safety is an important issue in the ICU. 1-3 ‘To err is human’ In 1999, the Institute of Medicine (IOM) released its report ‘To Err is Human: Building a Safer Health System’. Since then, the issue of patient safety has become increasingly important. This report stated that around 44,000 to 98,000 patients die in hospitals in the United States every year due to preventable medical errors. 4 The report has had an enormous impact on awareness of patient safety issues worldwide, and has led to an increase in the number of research projects being conducted on patient safety around the world. 5 Patient safety research applies outcomes of safety science to achieve reliable health care delivery systems; it also minimizes the incidence and impact of, and maximizes recovery from, adverse events. 6 Adverse events are injuries that occur as a result of health care delivery itself rather than the underlying disease 7 , and are seen as a serious problem that must be prevented. How de ning patient safety has changed over time Only a few decades ago, complications in hospitals were seen to be an inevitable consequence of medical interventions. 8 This has changed over the years, and some types of complications have come to be seen as unacceptable, and as potentially preventable adverse events. For example, hospital-acquired infections (HAIs) were once seen as unavoidable complications. Due to a better understanding of themechanisms of infectious disease transmission and of how to prevent HAIs, we now see these infections as unacceptable complications. 9 Over the years, even more complications have become preventable - including falls, pressure ulcers, catheter-related urinary tract infections, and venous thromboembolism - and are now seen as unacceptable events. Due to the continuous improvement of medical interventions and surgical techniques and the growing concerns for patient safety, the number of unacceptable events might be even larger in future. 10 Vincent and Amalberti state that patient safety can be seen as a ‘constantly moving target’. 10 According to Vincent, patient safety is therefore de ned as