Sodium, Potassium, and Urea - Case Study Example

Sodium, Potassium and Urea Case Study Diagnosis This is a case of primary hyperaldosteronism or Conn’s Syndrome. History Young Patient presents withgeneralized muscle weakness which is only related with hypertension and there is no family history given for hypertension. Patient is female and too young so it is unlikely that she has any chance of essential hypertension .So it is important to relate his weakness and hypertension and take them together. Signs and Symptoms on GPE Conn’s Syndrome is mostly seen asymptomatically or presents with only few symptoms and is seen in a young patient mostly. The patient in our case study is 30 years old so that favors the initial diagnosis of Conn’s syndrome. Patient presents with Weakness of muscles. Generalized muscle weakness should always be related with the levels of calcium in the body. In Conn’s syndrome there is hypokalemic metabolic alkalosis which causes low ionized leading to muscular weakness which is also present in this patient. Details of hypokalemic metabolic alkalosis will be explained later. The patient also presents with hypertension. Most of the times (95% of cases) the cause of hypertension in unknown and it is also called as essential hypertension. However, hypertension can be secondary to some other reasons and that seems to be the primary case here. It is due to excessive secretion of aldosterone which cause increase levels of rennin and hence cause salt and water retentions(Davidson Medicine 2010 p 778) Detail of this discussion would also follow in discussion of pathogensis. Lab Results There are three lab results that were given in this case, level of Sodium (146mmol/L), Potassium (2.1mmol/L) and Urea (7.2 mmol/L) . Levels of potassium seem to be low and patient has hypokalemic where level of sodium is at the higher levels and is not actually raised too much and urea is also slightly on the higher side. These lab findings when correlated to the clinical history are a sure finding that are seen in patients of Conn’s Syndrome because of excessive salt and water retention (Kumar and Clark 2011 p657). Pathogenesis It is important to differentiate secondary hyperaldosteronism caused by excessive rennin from primary hyperaldosteronism which can be caused by adrenal hyperplasia or primary adenoma of adrenal gland and since our patient has a short history he most likely to have cons syndrome or adenoma. Due to this there would be excessive secretion of aldosterone which would act in the distal tubule of kidney. This would cause absorption of sodium and loss of potassium ion. Hypokalemia can cause metabolic alkalosis which can cause muscle weakness and might even cause tetany in extreme cases. Increase of sodium would also mean more absorption of sodium ions as well and hence this would dilute the intravascular compartment causing hypertension. However extreme of hypertension crisis is rarely seen in these conditions. This can also present as polyuria due to increase in the intravascular compartment and secondary to tubular damage producing nephrogenic diabetes insipidus (Davidson Medicine 2010 p 778). There can be some other minor pathogenic pathways like activation of mineralocorticoid receptor pathway in the distal nephron even with low concentration of aldosterone but they are very rare to be discussed. Further Lab Diagnosis The initial tests should always have been done for the electrolyte levels as they were rightly done. After the initial suspicion of Conn’s Disease the levels of rennin and aldosterone need to be checked. The Aldosterone:Renin ratio (ARR) is the primary screening test for most of the patients who have any suspicion of this diseases. Abnormal ratio doesn’t confirm the diagnosis and should even further be evaluated. There is a word of caution in this. All hypertensive medicine actually changes this ratio so they need to be stopped before getting this test for atleast 2 weeks. Even if the hypertensive ratio is important than only those with minimum effect to this ratio like alpha blockers should be given. It might also be supported with oral potassium as hypokalemic can disturb the level of these hormones. Suppression and stimulation tests are next in line. Levels of aldosterone are either suppressed by infusion of 0.9% saline infusion which needs to be 2L in span of 4 hours. Stimulation test is seen by giving captopril and abnormal levels indicate towards our initial diagnosis. CT scan or MRI can also be effective in treatment. False positive results because of non functional adrenal gland and false negative test because of insufficient resolution are seen as well and should be kept in mind. In required, adrenal vein catheterization can also be done. Creatinine Clearance Test Introduction Glomerular filtration forms a major basic underlying mechanism of renal functioning. Any glomerular disease tends to decrease the rate of this process of filtration hereby impairing the clearance of body fluids. Creatinine clearance test focuses on this rate of filtration, and its efficacy and it also helps detect renal vascular anomalies which may be evident in the form of filtration anomalies. Creatinine is a chemical substance with maximum clearance rate in a human kidney (almost equal to the Glomerular Filtration Rate) and therefore it is used as a standard in measuring the renal clearance. Methods and Materials In this test, the Glomerular Filtration Rate abbreviated as GFR is measured with the help of already provided standard values. Two samples are provided each for a normal person and a person with chronic renal disease. The urine samples of both persons are pre-diluted up to 21 times. Jaffe’s reaction is the most common method used to estimate the clearance where the sample gives a red color with alkaline picrate solution. Readings are taken and analyzed against a standard curve drawn earlier. Now the values are compared. Results Results thus obtained are tabulated below: Renal Function-Creatinine Clearance Test H2O (ml.) Standard (ml.) Concentration (mmol/L) 1.0 0 0 0.8 0.2 200 0.6 0.4 400 0.4 0.6 600 0.2 0.8 800 0 1.0 1000 Creatinine Clearance-Absorbance at 500nm Sample Reading 0 0 200 0.33 400 0.483 600 0.595 800 0.835 1000 1.636 U1 0.797 U2 0.372 P1 0.112 P2 0.648 Keeping in mind the standard values and comparing the results obtained from the samples of the three patients, the following conclusions have been reached and the results interpreted. Calculations Creatinine is calculated from the following formula; Creatinine Clearance = * mL/min Where, U=urine creatinine conc. umol/L P= plasma creatinine umol/L V= volume of urine passed in given time in mls. T=time of collection in min. Also, Urine volume for Patient 1= 1000mL/24 hrs. Patient 2=3000mL/24 hrs. Deriving the value of y from the graph as y=0.0016x p1x=0.112/0.0016 Concentration = 70micro-moles/L p2x=0.648/0.0016 Concentration = 405 micro-moles/L U1x= (0.797*21)/0.0016 Concentration = 10460.62 micro-moles/L. U2x= (0.372*21)/0.0016 Concentration = 4882.5 micro-moles/L Clearance Calculations: P1= (10460.62/70) * (1000/1440) =103.77mls/min P2 = (4882.5/405) * (3000/1440) = 25.11mls/min The normal creatinine clearance level is 120mls/min in a healthy and young person. Discussion Creatinine Clearance Test is employed both with diagnostic aims and for monitoring the follow up of a treatment, i.e. therapeutic aims. In patents of chronic renal failure or congestive cardiac disease, abnormalities in clearance values are suspected due to impaired renal function. It is then that the doctor advises a Creatinine Clearance Test. Inability to clear creatinine properly by the glomeruli lead to an increased blood creatinine levels. For that matter both the blood and urine samples are taken for the test. The creatinine clearance of patient 1 is observed to be 103.77mls/min, which is slightly below the normal creatinine clearance level of 120mls/min.The results conclude that patient 1 shows a normal renal function. On the other hand, the creatinine clearance level of patient 2 at 25.11mls/min is significantly below the normal level. This signifies the chronic renal failure in patient 2. Conclusion Patient 1 has values for both serum and urine creatinine within normal ranges. On the other hand, the values are abnormal for patient 2 hinting towards malfunctioning glomerular apparatus and impaired GFR. Questions 1. What protein would not be detected by dipsticks? And how would you detect it? Bence Jones proteins or light chains of Gamma Globulins are the proteins which cannot be detected by dipsticks. These proteins especially in low concentrations avoid detection by a dipstick and need special tests for detection. Some of these tests include the technique of urine electrophoresis and a specific antibody test on a urine sample mid-stream (patient.co.uk 2001). 2. What are the factors predisposing to renal stone formation? Some of the risk factors or predisposing factors according to Umm.edu (2012) behind renal stone formation are listed below; Age and gender Obesity Lifestyle Geographical differences Weight gain Ethnicity Family history Medical conditions Medications, etc. 3. What other markers can be used to measure GFR? Markers used to estimate the GFR are varied. These include both the indigenous and external substances. The indigenous substances include urea and creatinine whereas the exogenous substances include insulin, non-radiolabeled contrast medium, radiolabelled compounds and iothalamate. However, an ideal marker would compromise an indigenous substance which is completely filtered and neither absorbed nor secreted (Sirwal et al. 2004). Glucose Tolerance Test Report Introduction Glucose is the most important monosaccharide present in blood and performs a number of functions inside a human body. After being obtained from carbohydrates in the diet, glucose enters the blood and takes part in a number of energy-related metabolic processes. Regulation of body glucose holds vital importance as any imbalance may lead to metabolic disorders such as Diabetes Mellitus (Steffes 2008). Therefore glucose metabolism is checked with the help of laboratory tests, one of which is a very sensitive Glucose Tolerance Test. Most common among these is the Oral Glucose Tolerance Test in which blood is drawn from the patient and glucose levels accessed. Oral glucose is given and readings of blood glucose are taken after a specific time interval (Nlm.nih.gov (2012)). Methods and Materials In this experiment, blood and urine samples were obtained from three patients and were analyzed for glucose levels. The blood samples taken were fasting samples while the urine samples were taken 2 hours after the patients were given a glucose load. These urine samples were analyzed using dipsticks. Basically, glucose is oxidized by glucose oxidase when it comes in contact with the atmospheric oxygen resulting in the production of gluconic acid and hydrogen peroxide. When a phenol reagent is present, hydrogen peroxide in the presence of peroxidase oxidizes 4-aminophenol and an intense red colored product is produced. Results The data obtained from both the blood and urine samples is tabulated below: Composition of Standards and Their Concentration Glc. Conc. (MMol./L) H2O (ml.) Glc. Standard (ml.) 0 1.0 0 5 0.9 0.1 10 0.8 0.2 15 0.7 0.3 20 0.6 0.4 25 0.5 0.5 Absorbance at 540nm of Standards of Varying Concentration Standard MMol/L Absorbance at 540 nm 0 0 5 0.124 10 0.3 15 0.586 20 0.794 25 1.010 Absorbance at 540nm of Blood Samples of Patients P1 fasting 0.12 P1 2 hrs. 0.194 P2 fasting 0.219 P2 2 hrs. 0.304 P3 fasting 0.340 P3 2 hrs. 0.576 Calculations From the graph: Y=0.04x Hence, P1 fasting x = 0.12/0.04 Glucose concentration=3 mmol/L P2 fasting x = 0.219/0.04 Glucose Concentration=5.475mmol/L P3 fasting x = 0.34/0.04 Glucose Concentration=8.5mmol/L P1 2 hrs x = 0.194/0.04 Glucose concentration=4.85 mmol/L P2 2 hrs x = 0.304/0.04 Glucose concentration=7.6 mmol/L P3 2 hrs x = 0.576/0.04 Glucose concentration=14.4 mmol/L Keeping in mind the standard values and comparing the results obtained from the samples of the three patients, the following conclusions have been reached and the results interpreted. Discussion Glucose metabolism plays a vital role in maintaining the body homeostasis. Owing to its importance, the regulation of the entire set of processes is tightly regulated. However, certain anomalies do occur owing to a number of reasons. A person is not labeled either as a diabetic or a non-diabetic. There exists a third category in between in which the disturbance is there but not to an extent as severe as full-blown Diabetes. Patient 1 has a glucose concentration of 4.85mmol/L in postprandial state which is under the normal range of 7.0 tolerance level. This shows that insulin production and consumption are normal. Patient 2 shows a little higher glucose concentration in postprandial state at 7.6mmol/L. This level of concentration directs towards the impaired tolerance level ranging 7.8-11.1mmol/L. Care is needed to properly tackle with the health issues that may arise and to reduce the chances of diabetes. Patient 3 has 14.4mmol/L glucose concentration after a glucose load 2hours. This falls in the low tolerance to glucose levels showing the possible existence of diabetes mellitus having low insulin levels. Conclusion Patient 1 has normal glucose levels in his bodies and his test results were in the normal range. Patient 2 had slightly impaired but not so much so that he could be labeled as a diabetic. The values for his samples indicate that he is glucose intolerant. However, patient 3 has values that lie clearly outside the normal range and above the threshold for Diabetes Mellitus, thus patient 3 is diabetic. Questions 1) What facts should be taken into account while interpreting the results of a Glucose Tolerance Test? A number of important facts need to be considered while interpreting the results of a GTT. Some of these include knowledge of the standard glucose values in blood and urine both at random and during fasting. Moreover, it should be noticed what the thresholds for Glucose Intolerance and DM are. Apart from these values, the patient should not be consuming caffeine or smoke on the morning of the test. No medication affecting the glucose levels must be taken. These and a number of other seemingly meager factors can greatly influence the readings of the test. 2) a. Why is measuring HbA1c a better guide to long term diabetic control than measuring just glucose? Glysolated Hemoglobin or HbA1c gives an estimate of the blood sugar levels over a period of 8 to 12 weeks (WHO.int 2011). It shows the amount of glucose attached to the hemoglobin in blood. Since RBCs containing Hb have an average lifespan of 120 days, the test for estimation of HbA1c gives the reading of around 120 days’ worth of sugar load in the body. Therefore, this test and HbA1c are much better guides to long term Diabetic control. b. how is HbA1c now used in the diagnosis of DM? While using fasting blood glucose levels, a lot of inconvenience is encountered. Moreover, daily variations in blood glucose levels are unavoidable. For that matter, nowadays, an average value is obtained for a given number of days in terms of HbA1c. it provides almost the same sensitivity and specificity as fasting glucose levels. 3) Other than Type 1 and Type 2, what other classifications of DM are there? Apart from these two types, there exist 2 further main types with their numerous subtypes of DM. these two more types are Gestational type of DM and other types such as due to exocrine pancreatic diseases, DM due to a number of genetic defects, drug or chemical induced, defects in insulin action genetically, endocrinopathies, etc. (endotext.org n.d.). 4) Write short notes on “artificial pancreas”. Artificial pancreas is a new technology still in progress whose main aim is to provide an artificially assisted supply of pancreas to maintain the metabolism of the body. Although the pancreas performs a number of exocrine and endocrine functions, preventing a body from glucose imbalance takes the lead and is therefore the focus of this innovation. Currently, three different designs are underway, through bioengineering, gene therapy and medical equipment. All of these have different principles of operation but have the same underlying aim. Liver Function Tests Introduction Liver is the major factory or store house of the body. It performs a number of screening functions. Liver produces a number of enzymes like amino-transferases of alanine and aspartate. These enzymes help filter blood. An anomaly of liver and irregularity in its function can lead to a variation in the amounts of blood aminotransferases’ levels. For that matter, Liver Function Tests are a reflection of functioning of a liver. LFTs are advised in patients with n suspected liver disease ranging from jaundice all the way to malignancy. Methods and Materials Samples of blood from two patients have been provided. A series of different tests are carried out with freshly prepared reagents to detect different chemical constituents of a sample. Albumin, total and conjugated bilirubin is so detected by noting down the peak absorbance of substances thus produced. Bilirubin after treatment produces azobilirubin which has an absorbance peak at 600 nm. Unconjugated bilirubin cannot be detected whereas the total bilirubin is detected by addition of caffeine-sodium benzoate or a similar acting agent. This reaction is allowed to continue for 10 min after which ascorbic acid is added. A standard control is prepared following the same steps but the temporal association of the reaction period and addition of ascorbic acid is different. It should be noted that a blank tube should be present for each sample. For the determination of alkaline phosphatase, different methods are used. Amino phenazone method was used in this scenario where 6 standard tubes were prepared by dilution of a 10mmol/L standard. Now 10 empty test tubes are taken and the reagents added. After incubation in a water bath for3 min, serum is added and the mixtures again incubated. At a wavelength of 520nm, a spectrophotometer then measures the absorbance of each tube contents after standards have been added to them. A graph is plotted and the amount of phenol liberated is measured. Results Data obtained from the tests is tabulated below; Liver Function Samples Patient 1 Patient 2 Total Protein (g/L) 70 68 Albumin (g/L) 38 40 AST (IU/L) 45 450 STD. = 20 vol. / ml Standards and Their Respective Concentrations H2O (ml) Standard (ml) Concentration (mmol/L) 1 0.0 0 0.9 0.1 0.2 0.8 0.2 0.4 0.7 0.3 0.6 0.6 0.4 0.8 0.5 0.5 1.0 Determination of Bilirubin Tube Absorbance at 600 nm Standard 0.413 P1 0.459 P2 0.042 Std.blank 0 P1 Blank (P1 Bl) 0 P2 Blank (P2 Bl) 0 Determination of Serum Alkaline Phosphatase Tube Absorbance at 520 nm Standard 0 (mmol/ L) 0 Standard 0.2 (mmol/ L) 0.176 Standard 0.4 (mmol/L) 0.372 Standard 0.6 (mmol/L) 0.553 Standard 0.8 (mmol/L) 0.763 Standard 1.0 (mmol/L) 0.964 P1 blank 0 P1 0.567 P2 blank 0 P2 0.541 Calculations For bilirubin; Absorbance test/Absorbance standard * 350 This implies; p1= 0.459/0.413 * 350 = 388.98 umol/L p2=0.042/0.413 * 350 = 35.59 umol/L For Alkaline Phosphatase; (Abs*1000/15)/Y P1= (0.567*1000/15)/0.964 = 39.21 IU/L P2= (0.541*1000/15)/0.964 = 37.41 IU/L Discussion Liver function tests, Bilirubin and Serum Alkaline Phosphatase levels show the basic physiology of liver function. Their abnormal values would show nonspecific liver disease which would indicate towards further investigations towards confirmation of diagnosis as they can be raised in several hepatic and extra hepatic diseases and are basically biomarkers of injury. It should be noted that proper cause should also be investigated along with the diagnosis and treatment of injury. The result of first patient (i.e. 388.98 umol/L) indicates more than normal bilirubin level (i.e. 20umol/L), due to which impaired liver functions can be observed (metabolic and excretory).Slightly increased Level of ALP also indicates cholestasis in patient 1.Moreover, the alkaline phophatase level of patient 1 is calculated at 39.21 IU/L, which is within the normal range of 30 to 90 IU/L which does not indicate any hazard. Patient 2 has a bilirubin level of 35.59 umol/L, that is slightly higher than the normal range of 20umol/L. This shows risk of impaired metabolic and excretory liver functions. Moreover, the alkaline phophatase level of patient 2 is calculated at 37.41 IU/L, which is within the normal range of 30 to 90 IU/L e any which does not indicate any hazard. Conclusion Patient 1 is suffering from haemolytic disease. Patient 2 is suffering from haemolysis. Questions 1. Jaundice is newborn is common. Why? Jaundice is newborn is also called as physiological jaundice of new born. The new born liver in premature and there is high level of red blood cells turn over initially for metabolism. New born have high level of red blood cells and when they can’t be metabolized by liver, they would start to precipitate as Bilirubin which would also cause the yellow discoloration of skin and sclera. This condition usually gets resolved in few days by itself due to the maturity in liver (Lippincott 2012) 2. Write short notes on Chronic Hepatitis. Chronic hepatitis is liver damage that is seen for prolong duration and would eventually lead to liver cirrhosis. It is caused by hepatitis B, C and D and is basically a persistent infection and damage to liver cells. It silent initially especially in case of hepatitis C and manifestation is seen at a very late stage. PCR is the most widely accepted clinical test that is done for confirmation of diagnosis. Treatment is by interferon or peg interferon or some anti viral medication but that is also seen in the initial phase of the disease and not effective at a later stage. 3. What is Gilberts Disease, explain? UDP Glucuronyl transferase deficiency causes this lifelong but mostly harmless disease. It is basically famililial unconjugated hyperbilirubinemia and increase in levels of bilirubin is seen after fasting or minor infections. It is lifelong but mostly harmless condition and has no clinical signs except might jaundice and slight abdominal pain and that too is seen in extreme conditions. 4. Why albumin and protein levels are are insensitive indicators of liver damage? Albumin and protein are not very sensitive for liver disease as their measurements can also change in certain other conditions as well especially those related to kidney. They might also have a problem in absorption from gut and hence their levels can’t be specified especially for liver and other causes should be looked into as well if there is any abnormal finding in their levels. Reference list: Unknown. (2013) [online] Available at: http://Lippincotts Illustrated Reviews Biochemistry, 5th Edition by Pamela C. Champe [Accessed: 15 Jan 2013]. Endotext.org (n.d.) Classification of Diabetes Mellitus - Chapter 4 : Diabetes And Carbohydrate Metabolism | Endocrinology | EndoText.org. [online] Available at: http://www.endotext.org/diabetes/diabetes4/diabetesframe4.htm [Accessed: 14 Jan 2013]. Nlm.nih.gov (2012) Glucose tolerance test: MedlinePlus Medical Encyclopedia. [online] Available at: http://www.nlm.nih.gov/medlineplus/ency/article/003466.htm [Accessed: 12 Jan 2013]. Steffes M (2008) [online] Available at: http://www.cdc.gov/nchs/data/nhanes/nhanes_07_08/OGTT_E_met_OGTT_ModP.pdf [Accessed: 12 Jan 2013]. Who.int (2013) Use of Glycated Haemoglobin (HbA1c) in the Diagnosis of Diabetes Mellitus Abbreviated Report of a WHO Consultation . [online] [Accessed: 14 Jan 2013]. Patient.co.uk (2001) Urine Dipstick Analysis | Doctor | Patient.co.uk. [online] Available at: http://www.patient.co.uk/doctor/Urine-Dipstick-Analysis.htm [Accessed: 14 Jan 2013]. Sirwal et al. (2004) [online] Available at: http://www.jkscience.org/archive/volume63/estimate.pdf [Accessed: 14 Jan 2013]. Umm.edu (2012) Kidney stones - Risk Factors. [online] Available at: http://www.umm.edu/patiented/articles/what_risk_factors_kidney_stones_000081_5.htm [Accessed: 14 Jan 2013]. Nicki R. Colledge, Brian R Walker, Stuart H Ralston. Davidson Principles and Practice of Medicine 21st edition. Anne Ballinger, Parveen Kumar and Micheal Clark. Essentials of Kumar anc Clark’s Clinical Medicine 5th edition. Read More