Also called as Water Pills as this group of drugs lower the blood pressure by excreting excess water and sodium. Originally Diuretics enhance the rate of urine excretion - diuresis. These drugs are prescribed for the treatment of hypertension, (High blood pressure), Congestive Heart Failure (CHF) and Edema, a condition in which excess fluid is accumulated in the body tissues.
Even caffeine, alcohol and some fruit extracts and juices like that of cranberry juice have mild diuretic effect.
Types of Diuretics
Loop type diuretics:
Sometimes a combination of the diuretics like hydrochlorothiazide and triamterene is also prescribed.
Edema previously known as hydropsy is a condition where the soft tissue is swollen because of the accumulation of interstitial fluid. Abnormal accumulation of the interstitial fluid presents a noticeable swollen appearance in various areas of the body. The fluid moves from the vascular region to the interstitial region because of preexisting conditions. The distribution of edema in different areas of the body is an effective diagnostic factor to identify various underlying conditions. Edema is broadly classified in to two categories, localized and generalized respectively.
Localized edema is predominantly caused because of the obstruction caused in the lymphatic or venous system. In some cases these edemas can be fatal as they induce conditions such as deep vein thrombosis and allergic reactions like angioedema. Angioedema is also known as non-pitting edema. Localized edema can also occur due to neoplasm and also because of inflammation associated with infections.
Generalized edema is caused because of impaired cardiac or renal function. Fluid retention and increase in the concentration of sodium may result in the swelling of various body parts. This type of edema can also occur because prolonged sitting or standing in one position. The sodium retention associated with renal impairment is generally caused because of vasoconstriction. In conditions such as cirrhosis of the liver, the edema is generally noticed in the peritoneal region which is referred to as ascites. Edema associated with cardiac impairment is usually associated with the right side of the heart and the left side impairment leads to pulmonary edema. Shortness of breath is often associated with edema.
Clinical manifestations and causes associated with edema
Edema (oedema) occurs because of various preexisting health conditions. Any variation in the vital parameters of the body such as fluid imbalance, venous pressure fluctuations and lymphatic impairments lead to edema. Protein insufficiency and hepatic disease increases the occurrence of edema. Many women experience episodes of edema during pregnancy. This happens because of increased fluid distribution to nourish the developing child and mother at the same time. Some forms of edema also occur because of increased capillary permeability. Conditions such as vasculitis and post-anoxic encephalopathy cause increased capillary permeability.
Pitting edema is also one if the important types of edema which occurs in some people who wear tight outfits. The regions covered by the tight clothing generally swells up and after a certain period of time, the tissue returns to the normal appearance. In addition to the conditions mentioned, edema is also caused because of certain drugs. Drugs which block the calcium channels, corticosteroids, birth control pills and antidepressants predominantly induce the onset of edema.
Edema requires medical attention as it may lead to many other complications. The complications associated with edema are swelling with pain, stretched skin with dryness, formation of scarred tissue, and risk of skin ulcers and decreased elasticity of the arteries, veins and muscles.
Diagnosis and Treatment of Edema
Diagnosis of edema is done by identifying the underlying causes associated with it. Complete biochemical analysis is done to identify the factors such as hyperthyroidism, protein insufficiency and fluid electrolyte ratios. Pregnant women are generally advised to avoid standing for prolonged period of time especially during the last trimester of their pregnancy. Patients suffering from consistent edemas are advised to keep in an elevated position with some support. Loose and comfortable clothing is also recommended as it helps in the uniform blood circulation.
Treatment for edema includes dietary restriction of sodium flowed by the administration of diuretics. Diuretics are predominantly used in conditions such as lymphedema, renal disease and obstruction in the venous flow. Since edema is also associated with weight loss, the administration of diuretics has to be reduced once the patient reaches optimal weight.
Abdominal fluid accumulation
Abdominal fluid accumulation indicates the onset of a medical condition called ascites. Ascetic fluid is a pale yellow colored fluid. The predominant accumulation of ascetic fluid occurs in the region of peritoneum. Ascetic fluid has many sources. However the most significant source is the liver. One of the major causes for ascites is liver cirrhosis.
Causes for accumulation of ascetic fluid
The factors contributing to liver cirrhosis are associated with portal hypertension and edema caused because of tissue fluid imbalance or infection. The formation of ascetic fluid is also associated with the decrease in albumin levels. Albumin levels are decreased in portal hypertension conditions. Another significant factor that leads to accumulation of ascetic or abdominal fluid is the underlying condition of kidney failure caused due to excess salt and water retention. In addition, ascetic fluid accumulation is also caused because of underlying conditions such as neoplasm, congestive heart failure and infectious diseases such as tuberculosis. Ascetic conditions are classified into transudative and exudative types based on the protein estimation of the respective ascetic fluid. The comparative analysis of protein in the ascetic fluid is based on the albumin levels in the ascetic fluid when compared to serum albumin. This comparative analysis is also called as serum ascites albumin gradient.
Symptoms of abdominal fluid accumulation
Ascetic symptoms are associated with abdominal pain and discomfort. In some cases the ascetic condition is initially asymptomatic which progresses into a symptomatic condition. Shortness of breath occurs because of pleural effusion which is caused by the pressure on diaphragm because of the abdominal fluid rise. Apart from these other symptoms are nausea, anorexia, and bloating and flank pain.
Conditions associated with abdominal fluid accumulation such as ascites are diagnosed using laboratory analysis. Laboratory tests such as ascetic fluid protein estimation, albumin analysis, amylase, lactose dehydrogenase and triglyceride values are taken into consideration. These values help in the determination of underlying conditions which may be responsible for the accumulation of ascetic fluid in the abdominal cavity.
Microbiological analysis such as Gram's stain, acid fast stain and also cultures of both routine bacteriology and for Mycobacterium is done to diagnose the condition due to of infectious diseases. In the case of tuberculosis, the ascetic fluid tends to appear chylous or milky in nature. This because of the presence of thoracic or interstitial fluid. The serum ascites albumin gradient values are taken into consideration to determine the cause of ascites because of bacterial peritonitis, Pancreatitis, Vasculitis and portal hypertension. High albumin gradients or transudative gradients generally occur in unclear etiologies such as occult cirrhosis and portal hypertension. Hepatic vein thrombosis and liver cirrhosis related ascites is generally diagnosed by biopsy and radiological methods.
Treatment of abdominal fluid accumulation
Ascites is treated according to fluid electrolyte monitoring. The patient is prescribed a restricted salt diet in order to avoid edema. In cases of low sodium levels, the salt restriction may be increased to 1.5 l instead of 1. Diuretics are generally prescribed in the case of ascites. The research pertaining to the use of aquaretics for the excretion of electrolyte free water is still underway for the approval.
Therapeutic paracentesis is administered on a regular basis to treat refractive ascites. The most effective method for reducing the portal pressure in patients with ascites and under diuretics is the administration of trans jugular intrahepatic portosystemic shunt also known as TIPS. This is a radiological procedure used in patients suffering from refractive ascites; this technique may be performed either in conscious state or by administering general anesthesia.
Bibliography / Reference
Collection of Pages - Last revised Date: March 21, 2019