Both metformin and angiotensin converting enzyme inhibitors are excreted by the kidneys in urine

Metformin and angiotensin-converting enzyme inhibitors are also excreted in urine by the kidneys. Angiotensin-converting enzyme inhibitors are metabolized in the liver and eliminated by the kidneys. As a consequence, renal insufficiency may allow metabolites to accumulate throughout the body, impairing efficiency. Renal and peritoneal dialysis is prescribed in cases of intoxication. The treatment should be discontinued for Mary because she has ascites, which is another contraindication due to the fact that the drug is metabolized in the liver (Gustot & Moreau, 2010). On the other hand, metformin is cleared through the kidney in the urine unchanged; its accumulation can cause lactic acidosis. Hence the drugs should be replaced to prevent further accumulation.

Question 2

Edema is the accumulation of fluid in the interstitial space as opposed to the intravascular space. The oncotic pressure within the blood vessels plays a huge role in ensuring that the fluids remain within the vessels. The oncotic pressure is usually maintained by blood proteins and more so albumin. In the case of Mary, there is a low level of albumin in blood to maintain the oncotic pressure since most of it is lost through the kidneys. Secondly, there is reduced venous return due to the ascites hence leading to the pooling of blood in the peripheral blood vessels causing edema. Furthermore, the high sodium level of 180mmol/l as opposed to the normal 135-145mmol/l plays a role in the development of edema.

Question 3

The renin-angiotensin-aldosterone system (RAAS) plays a significant role in the regulation of blood pressure. The human body has a positive feedback mechanism when the blood pressure is low. The juxtaglomerular cells in the kidneys, produce renin upon sensing low blood pressure, the renin then converts angiotensinogen to angiotensin I in the liver. Angiotensin I is then converted into angiotensin II in the lungs (Laake & Bugge, 2010). Angiotensin II then acts on the renal tubules to hence the reabsorption of sodium, at the same time it triggers the release of antidiuretic hormone and aldosterone. The kidney disease, lead to the decreased production of renin which at the end of the day impairs electrolyte balancing. Normally the concentration of sodium in blood ranges from 135 to 145 mmol/l hence low, however, the kidney disease has led to over accumulation of the sodium to up to 180mmol/L. Similarly, due to the failing kidneys, there is over accumulation of potassium, normally the potassium levels are 3.6-5.2 mmol per liter.

Question 4

Normally, the kidneys eliminate the waste products from the body and other substances that the body does not need. However, in renal failure, there is damage to the glomerulus hence leading to the loss albumin and serum proteins. Low amounts of albumin in the blood has more effects on the healing process of the patient it affects the transportation of drugs. In most cases, drugs in blood are transported bound to albumin. Even the red blood cells are lost through the renal arteries that supply the nephrons hence lading to hematuria.

Question 5

Chronic kidney diseases cause many other systemic physiological disorders. Continued vomiting of blood form the upper gastrointestinal track will result in electrolyte imbalance in the body which will get worse owing to the fact that the kidney will not be able to regulate the changes. In addition, the patient is at the risk of developing anemia due to the chronic blood loss form the gastrointestinal track and hematuria from the kidneys.





References

Gustot, T. and Moreau, R. (2010) ‘Renal failure in cirrhosis’, in Ascites, Hyponatremia and Hepatorenal Syndrome: Progress in Treatment, pp. 112–121. doi: 10.1159/000318992.

Laake, J. H. and Bugge, J. F. (2010) ‘[Acute renal failure in critically ill patients].’, Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række, 130(2), pp. 158–61. doi: 10.4045/tidsskr.10.34549.