tailieunhanh - Essential Guide to Acute Care - part 2

Oxy được mô tả bởi Joseph Priestley vào năm 1777 và đã trở thành một trong các loại thuốc được sử dụng phổ biến nhất trong thực hành y tế. Tuy nhiên, liệu pháp oxy thường được mô tả không chính xác, | CHAPTER 2 Oxygen therapy By the end of this chapter you will be able to Prescribe oxygen therapy Understand the different devices used to deliver oxygen Understand the reasons why PaCO2 rises Know the limitations of pulse oximetry Understand the principle of oxygen delivery Apply this to your clinical practice Myths about oxygen Oxygen was described by Joseph Priestley in 1777 and has become one of the most commonly used drugs in medical practice. Yet oxygen therapy is often described inaccurately prescribed variably and understood little. In 2000 we carried out two surveys of oxygen therapy. The first looked at oxygen prescriptions for post-operative patients in a large district general hospital in the UK. It found that there were several dozen ways used to prescribe oxygen and that the prescriptions were rarely followed. The second asked 50 qualified medical and nursing staff working in acute areas about oxygen masks and the concentration of oxygen delivered by each 1 . They were also asked which mask was most appropriate for a range of clinical situations. The answers revealed that many staff could not name the different types of oxygen mask the difference between oxygen flow and concentration was poorly understood one third chose a 28 Venturi mask for an unwell asthmatic and very few staff understood that PaCO2 rises most commonly due to reasons that have nothing to do with oxygen therapy. Misunderstanding of oxygen therapy is widespread and the result is that many patients are treated suboptimally. Yet oxygen is a drug with a correct concentration and side effects. Hypoxaemia and hypoxia Hypoxaemia is defined as the reduction below normal levels of oxygen in arterial blood - a PaO2 of less than kPa 60 mmHg or oxygen saturations less than 93 . The normal range for arterial blood oxygen is 11-14kPa 85-105 mmHg which reduces in old age. Hypoxia is the reduction below 14 Oxygen therapy 15 normal levels of oxygen in the tissues and leads to organ damage. .