Respiratory Physiology and the Impact of Different Modes of Ventilation on the Photoplethysmographic Waveform

The photoplethysmographic waveform sits at the core of the most used, and arguably the most important, clinical monitor, the pulse oximeter. Interestingly, the pulse oximeter was discovered while examining an artifact during the development of a noninvasive cardiac output monitor. This article will explore the response of the pulse oximeter waveform to various modes of ventilation. Modern digital signal processing is allowing for a re-examination of this ubiquitous signal. The effect of ventilation on the photoplethysmographic waveform has long been thought of as a source of artifact. The primary goal of this article is to improve the understanding of the underlying physiology responsible for the observed phenomena, thereby encouraging the utilization of this understanding to develop new methods of patient monitoring. The reader will be presented with a review of respiratory physiology followed by numerous examples of the impact of ventilation on the photoplethysmographic waveform

Non invasive prenatal testing for single gene disorders:Exploring the ethics

Non-invasive prenatal testing for single gene disorders is now clearly on the horizon. This new technology offers obvious clinical benefits such as safe testing early in pregnancy. Before widespread implementation, it is important to consider the possible ethical implications. Four hypothetical scenarios are presented that highlight how ethical ideals of respect for autonomy, privacy and fairness may come into play when offering non-invasive prenatal testing for single gene disorders. The first scenario illustrates the moral case for using these tests for ‘information only', identifying a potential conflict between larger numbers of women seeking the benefits of the test and the wider social impact of funding tests that do not offer immediate clinical benefit. The second scenario shows how the simplicity and safety of non-invasive prenatal testing could lead to more autonomous decision-making and, conversely, how this could also lead to increased pressure on women to take up testing. In the third scenario we show how, unless strong safeguards are put in place, offering non-invasive prenatal testing could be subject to routinisation with informed consent undermined and that woman who are newly diagnosed as carriers may be particularly vulnerable. The final scenario introduces the possibility of a conflict of the moral rights of a woman and her partner through testing for single gene disorders. This analysis informs our understanding of the potential impacts of non-invasive prenatal testing for single gene disorders on clinical practice and has implications for future policy and guidelines for prenatal care

Patient Safety in the Cardiac Operating Room: Human Factors and Teamwork: A Scientific Study from the American Heart Association

The cardiac surgical operating room (OR) is a complex environment in which highly trained subspecialists interact with each other using sophisticated equipment to care for patients with severe cardiac disease and significant comorbidities. Thousands of patient lives have been saved or significantly improved with the advent of modern cardiac surgery. Indeed, both mortality and morbidity for coronary artery bypass surgery have decreased during the past decade. Nonetheless, the highly skilled and dedicated personnel in cardiac ORs are human and will make errors. Refined techniques, advanced technologies, and enhanced coordination of care have led to significant improvements in cardiac surgery outcomes

Misunderstandings Concerning Genetics Among Patients Confronting Genetic Disease

Critical questions arise about misunderstandings of genetics. We interviewed for 2 h each, 64 individuals who had or were at risk for Huntington's disease (HD), breast cancer or Alpha‐1 antitrypsin deficiency. These individuals revealed various misunderstandings that can affect coping, and testing, treatment and reproductive decisions. A therapeutic misconception about testing appeared: that testing would be helpful in and of itself. Many believed they could control genetic disorders (even HD), yet these beliefs were often incorrect, and could impede coping, testing, and treatment. Misunderstandings about statistics and genetics often fueled each other, and reflected denial, and desires for hope and control. Emotional needs can thus outweigh understandings of genetics and statistics, and providers’ input. Individuals often maintained non‐scientific beliefs, though embarrassed by these. These data have implications for care, and public and professional education. Misunderstandings’ persistence, despite realization of their inaccuracy, suggests that providers need to address not just cognitive facts, but underlying emotional issues