tailieunhanh - Essential Guide to Acute Care - part 7

Nếu đây là dưới một giá trị quan trọng, tiếp tục kết quả hyperfiltration trong xơ cứng cầu thận tiến bộ, mà cuối cùng dẫn đến mất ống thận. Mất ống thận tiếp tục gây ra hyperfiltration hơn cho đến khi kết quả suy thận. Điều này đã được gọi là lý thuyết hyperfiltration suy thận và giải thích lý do tại sao tiến bộ | 124 Chapter 7 nephrons. If this is below a critical value continued hyperfiltration results in progressive glomerular sclerosis which eventually leads to nephron loss. Continued nephron loss causes more hyperfiltration until renal failure results. This has been termed the hyperfiltration theory of renal failure and explains why progressive renal failure is sometimes observed after apparent recovery from ArF 7 . How to manage ARF Early action saves kidneys. A simple system for managing ARF involves five steps 1 Treat hyperkalaemia if present see Box 2 Correct hypovolaemia and establish an effective circulating volume 3 Treat hypoperfusion 4 Exclude obstruction 5 Stop nephrotoxins and treat the underlying cause involve an expert . The history observations and drug chart usually reveal the cause of ARF. Lifethreatening hyperkalaemia above l should be treated first. The next step is to treat hypovolaemia discussed in Chapter 5 . After that some patients may be euvolaemic but still have a blood pressure too low to adequately perfuse their kidneys . in severe sepsis or cardiogenic shock . Antihypertensive medication should be stopped and consideration should be given to the use of vaso-active drugs. A sample of urine should be sent for analysis and the patient catheterised in order to accurately measure urine output. Ideally a urine sample should be obtained before catheterisation as Box Treatment of hyperkalaemia Double-check with the laboratory that the sample was not haemolysed. Attach a cardiac monitor to the patient. Give 10 ml of 10 calcium chloride . slow bolus for cardiac protection. Give 50 ml of 50 dextrose . 10 U of actrapid insulin is added if the patient is unlikely to mount an adequate insulin response . Monitor capillary glucose measurements. Check serum K 1-h later. If serum K still high give another 50 ml of 50 dextrose . If serum K still high give 100 ml of sodium bicarbonate . Salbutamol nebulisers can also be added.