Mr. Drummond Is A 72-Year-Old Male Postoperatively

Mr Drummond Is A 72 Year Old Male Who Is 2 Days Postoperative For A B

Mr. Drummond is a 72-year-old male who is 2 days postoperative for a bowel obstruction. His urine output over the last 4 hours is less than 100 ml per hour. The MD has ordered Normal Saline IV at 200 ml per hour.

Question 1: The nephron being the functional unit of the kidney, list the three main functions the nephron is responsible for.

Question 2: The MD orders the following diagnostic and laboratory tests: kidney, ureter, and bladder roentgenography (KUB), intravenous pyelography, creatinine and blood urea nitrogen (BUN). Explain how each one can help in the diagnosis of kidney disease.

Question 3: Mr. Drummond has an elevated BUN and creatinine. The MD orders a creatinine clearance. Explain how this is done and what information it will give you to help diagnose Mr. Drummond’s renal problem.

Paper For Above instruction

The nephron, as the fundamental functional unit of the kidney, plays a crucial role in maintaining the body's internal environment through its specialized functions. These functions include filtration, reabsorption, and secretion. First, filtration occurs at the glomerulus, where blood plasma is filtered into Bowman's capsule, allowing water, ions, and small molecules to pass through while larger molecules and cells are retained within the bloodstream. Second, reabsorption takes place primarily in the proximal convoluted tubule, loop of Henle, distal tubule, and collecting duct, where essential substances such as glucose, sodium, and water are reabsorbed back into the bloodstream, ensuring homeostasis. Third, secretion involves the transfer of waste products and excess ions from the blood into the tubular fluid, facilitating their elimination through urine. The nephron’s coordinated functions thus regulate fluid and electrolyte balance, remove waste products, and regulate blood pressure and pH.

The diagnostic tests ordered—KUB (kidney, ureter, and bladder radiography), intravenous pyelography (IVP), creatinine, and blood urea nitrogen (BUN)—each provide specific insights into kidney health. The KUB is a plain X-ray that visualizes the size, shape, and position of the kidneys, ureters, and bladder, helping identify obstructions, calculi, or structural abnormalities. IVP involves injecting contrast dye and taking sequential X-rays to visualize the urinary tract in detail, assessing for obstructions, kidney size, and anatomy; it also evaluates the renal collecting system and the presence of any masses or blockages. Creatinine and BUN are blood tests measuring waste products filtered by the kidneys; elevated levels suggest impaired renal function, with BUN also influenced by hydration status and protein intake. Together, these tests help define whether kidney damage is structural or functional and identify potential causes.

In cases of elevated BUN and creatinine, calculating creatinine clearance offers a more precise assessment of renal function. This test estimates the glomerular filtration rate (GFR), indicating how effectively the kidneys are filtering blood. To determine creatinine clearance, a 24-hour urine collection is performed alongside a blood sample for serum creatinine measurement. The amount of creatinine excreted in the urine is measured and used to compute the clearance rate using a specific formula. This calculation takes into account the urine volume, urine creatinine concentration, serum creatinine, and collection duration. The resulting value provides a quantitative measure of GFR, which is crucial for diagnosing the severity of renal impairment, staging chronic kidney disease, and monitoring the progression or response to treatment. A reduced creatinine clearance signifies decreased kidney function, helping clinicians determine appropriate interventions and management strategies.

Understanding the functions of the nephron, interpreting diagnostic imaging, and calculating creatinine clearance are integral to diagnosing and managing renal diseases. These assessments assist in early detection, guiding treatment decisions, and improving patient outcomes, particularly in postoperative patients like Mr. Drummond who are at risk for renal compromise due to fluid imbalance and other factors.

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