Renal Urology Alterations in Body Systems Lecture PDF

NURS 115 Pathophysiology Lecture 8 Alterations in Body Systems Renal / Urology Structure and function Urinary tract infections Glo...

NURS 115 Pathophysiology Lecture 8 Alterations in Body Systems Renal / Urology Structure and function Urinary tract infections Glomerular disorders Acute and chronic kidney injury Alterations in Renal function in children Week 10 26/10/2022 Dr. Manfred Mortell Assistant Professor Department of Nursing and Allied Health University of the Bahamas  Learning Outcomes The student will comprehend Renal and Urology system Structure and function Urinary tract infections Glomerular disorders Acute and chronic kidney injury Alterations in Renal function in children In addition to further review of the recommended Chapters 8/19/2022 NURS 115 Pathophysiology 2  Terminology Acute kidney injury (AKI) an abrupt reduction in kidney function with elevation of blood urea nitrogen and creatinine Acute tubular necrosis (ATN) most common cause of acute renal failure Afferent arteriole Transports blood into the glomerulus Analgesic nephropathy Kidney disease caused from high consumption of analgesic Azotemia Increased serum urea levels and frequently increased creatinine levels as well Chronic glomerulonephritis Glomerular diseases leading to chronic renal failure Chronic kidney disease (CKD) GFR < 60 mL/min/1.73 m2 Creatinine a waste product excreted in the urine Cystitis Inflammation of the bladder Diuretic Any agent that enhances the flow of urine End-stage kidney failure (ESKF) Irreversible total kidney failure Erythropoietin (EPO) A hormone made by the kidneys that stimulates erythropoiesis Glomerulus A tuft of capillaries that loop into the Bowmans Capsule Juxtaglomerular apparatus Cells which control renal blood flow, GFR and renin secretion Kidney Maintain homeostasis for solutes, body water, excretion of metabolic wastes, conserving nutrients and regulating acids and bases, secreting the hormones renin, erythropoietin, 1,25-dihydroxyvitamin D3 for the regulation of blood pressure, erythropoiesis and calcium metabolism Loop of Henle A loop in the nephron where urine concentration occurs Micturition Urination Nephron the functional unit of the kidney, which form urine Nephrotic syndrome A disorder with proteinuria, indicates a glomerular injury Oliguria Diminished urine excretion (< 400 mL/d or 30 mL/h) 8/19/2022 NURS 115 Pathophysiology 3  Structures of the Urinary System The renal system works with the lungs, skin and intestines for homeostasis to maintain the balance of essential chemicals and water in the body Adults excrete about 27 - Organs of the 68 fluid ounces [800 to Urinary system 2,000 milliliters] per day include 2 - Kidneys based on typical daily fluid 2 - Ureters intake of 68 fluid ounces 1 - Bladder [2,000 milliliters] 1 - Urethra 8/19/2022 NURS 115 Pathophysiology  Structure and function Kidneys The kidneys are a pair of Purplish-brown bean shaped organs that are found high in the back of the abdominal cavity, below the rib cage; one on either side of the spine The right kidney is slightly lower than the left kidney because of the position of the liver Adult kidneys measure 10 - 12cm in length and 5 - 7 cm in width and weigh approximately 150g Functions Remove excess water, urea, creatinine, wastes from the blood Water, Urea, Creatinine, Uric acid, other wastes form urine Keep substances stable in the blood [Homeostasis] Generate Erythropoietin [EPO] for Erythropoiesis Activate Vitamin D Regulate blood pressure 8/19/2022 NURS 115 Pathophysiology 5  Ureters Structure and function 2 Ureters Each kidney has one a narrow tube called a ureter, which carries urine from the kidney to the bladder Muscles in the ureter walls contract and relax forcing urine down each ureter, towards the bladder away from the kidneys If urine is static or backflows, a urinary tract infection [UTI] can occur ≈ Every 10 to 15 seconds, urine is emptied into the bladder from the ureters 8/19/2022 NURS 115 Pathophysiology 6  Bladder Structure and function 1 triangle-shaped, hollow organ located in the pelvic cavity A typical healthy adult bladder can store 400 - 500 mils of urine The bladder's walls relax / expand to store urine, and contract / flatten to empty urine through the urethra During urination, the bladder muscles squeeze, and two sphincters [valves] open to allow urine to flow out Urine exits the bladder into the urethra, which carries urine out of the body Because it passes through the penis, the urethra is longer in men [8 inches - 20cm] in women [1.5 inches - 4cm] 8/19/2022 NURS 115 Pathophysiology 7  Urethra Structure and function The Urethra is a tube that allows urine to be excreted outside of the body The bladder muscles to tighten, which squeezes urine out of the bladder and concurrently sphincter muscles relax to let urine exit the bladder through the urethra The female urethra has a nerve supply arises from the vesical plexus and the pudendal nerve have a Urethra which is short in length [≈ 4cm]and makes them more susceptible to a UTI The nerve supply to the male urethra is from the prostatic plexus, a sympathetic, and parasympathetic combination and is ≈ 15 - 20cm long 8/19/2022 NURS 115 Pathophysiology 8  Structures of the Kidney A pair of bean-shaped structures that are located just below and posterior to the liver in the peritoneal cavity The adrenal glands sit on top of each kidney and are also called the suprarenal glands Kidneys filter blood and purify it [“Clean”] All the blood in the human body is filtered 40 times a day by the kidneys require 25 % of cardiac output [1,250 mils/minute] and 25% of the total oxygen from the lungs to perform this function The filtrate coming out of the kidneys is called urine 8/19/2022 NURS 115 Pathophysiology 9  External Structures of the Kidney 3 layers Externally, the kidneys are surrounded by 3 layers The outermost layer is a tough connective tissue layer called the Renal fascia The second layer is the Perirenal fat capsule, which helps anchor the kidneys in place The third and innermost layer is the renal capsule 8/19/2022 NURS 115 Pathophysiology 10  Internal Structures of the Kidney 3 regions The Outer - Renal Cortex The functional unit of the kidney, the Nephron Filtration occurs here The Middle - Renal Medulla Renal pyramids, there are 8 in each kidney Each pyramid has a column through which blood vessels pass The tips of the pyramids are called renal papillae and point toward the renal pelvis The Inner - Renal Pelvis Has the hilum of the kidney The hilum where blood vessels, nerves enter and exit The hilum is where the ureters exit/empty into the bladder Internally, the renal pelvis branches into the major calyces, which further branch into the minor calyces 8/19/2022 NURS 115 Pathophysiology 11  Nephron Functional unit - Renal Cortex 1,000,000 nephrons Renal cortex ONE KIDNEY Nephrons are the “Functional units” of the kidney; they cleanse the blood and maintain homeostasis in the circulation , with 3 main functions, Filtration, Reabsorption, Secretion Each kidney has > one million nephrons in the renal cortex Secondary functions are blood pressure control, synthesizing Renin, Erythropoiesis synthesizing Erythropoietin, Calcium absorption, generating Vitamin D 8/19/2022 NURS 115 Pathophysiology 12  Nephron Structure Each nephron comprises of a renal corpuscle, with a Glomerulus within the Bowman's capsule The first part is the proximal convoluted tubule due to its proximity to the glomerulus; in the renal cortex The second part is the Loop of Henle because it forms a loop with descending and ascending parts that goes through the renal medulla The third and last part is the Distal convoluted tubule in the renal cortex, which connects and empties its contents into collecting ducts in the medullary pyramids The Collecting ducts collect contents from many nephrons and combine as they enter the papillae of the renal medulla 8/19/2022 NURS 115 Pathophysiology 13  Bowman’s capsule Glomerular capsule The high blood pressure in the glomerulus is due to efferent arteriole is narrower than the afferent arteriole creating a high filtration pressure Filtration pressure is generated by the pumping action of the heart Bowman’s capsule is only 1 cell thick The filtration at the glomerular capillaries is known as ultrafiltration 180 liters of glomerular filtrate are formed every 24 hours 8/19/2022 NURS 115 Pathophysiology 14  Proximal Convoluted Tubule [PCT] PCT function Reabsorption Total reabsorption of glucose and amino acids Four fifths of the ion salts and water are reabsorbed Glucose, amino acids and salts are reabsorbed by active transport Water is reabsorbed by osmosis The cells lining the PCT are rich in mitochondria, which supply the ATP for active transport These cells are sited in the Renal medulla. 8/19/2022 NURS 115 Pathophysiology 15  Loop of Henle Henle’s Loop, is present in the renal medulla and is U shaped The descending limb is highly permeable to water but impermeable to ions, causing a large amount of water to be reabsorbed, which increases osmolarity to 1200 mOSm/L In contrast, the ascending limb of Henle’s loop is impermeable to water but highly permeable to ions, which causes a large drop in the osmolarity of fluid passing through the loop, to 100 mOSm/L This creates a countercurrent mechanism, because the descending and ascending loops fluid flows in opposite directions 8/19/2022 NURS 115 Pathophysiology 16  Distal Convoluted loop The distal convoluted tubule and collecting duct is the final site of reabsorption in the nephron. Unlike the other components of the nephron, its permeability to water is variable depending on a hormone stimulus [ADH] to enable the complex regulation of blood osmolarity, volume, pressure, potassium, sodium, calcium, and pH 8/19/2022 NURS 115 Pathophysiology 17  Collecting Ducts The collecting ducts are continuous with the nephron but not technically part of it, each duct collects filtrate from several nephrons Collecting ducts are lined with simple squamous epithelium with receptors for ADH, allow water to pass from the duct lumen through the cells and into the interstitial spaces to be recovered by the vasa recta This process allows for the recovery of large amounts of water from the filtrate back into the blood 8/19/2022 NURS 115 Pathophysiology 18  Nephron Summary Absorption / Secretion sites Diffusion Active Transport Ions Active transport DCT Bowman’s capsule PCT Glomerulus Functions Excretion Descending Nitrogenous wastes HL urea, uric acid, excess salts, excess water Osmoregulation Ascending HL Maintaining the blood at Water a suitable constant Water Osmosis Osmosis concentration Homeostasis Collecting Duct Maintaining a suitable constant internal Urea environment to sustain Uric Acid efficient metabolism Creatinine 8/19/2022 NURS 115 Pathophysiology Excess water 19  Nephron Secretion / Filtration / Reabsorption Nephrons filter blood and excrete wastes as urine Principle functions Filtration Reabsorption Secretion Urine is the waste byproduct formed from excess water and metabolic waste molecules during the process of renal system filtration Steps involved in urine formation Glomerular filtration Tubular reabsorption Tubular secretion Filtrate 8/19/2022 NURS 115 Pathophysiology 20  Urine / Filtrate Characteristics Characteristic Normal values Color Pale yellow to deep amber Odor Odorless Volume 750–2000 mL/24 hour pH 4.5 – 8.0 Specific gravity 1.003 –1.032 Osmolarity 40 –1350 mOsmol/kg Urobilinogen 0.2 –1.0 mg/100 mL White blood cells None Leukocyte esterase None Protein None or trace Bilirubin 2.5 excess caffeine or alcohol; kidney Polyuria L/day disease; diuretics; sickle cell anemia excessive water intake Dehydration; blood loss; diarrhea 300–500 Oliguria cardiogenic shock; kidney disease mL/day enlarged prostate < 50 Kidney failure; obstruction, kidney Anuria mL/day stone or tumor; enlarged prostate 8/19/2022 NURS 115 Pathophysiology 22 8/19/2022 NURS 115 Pathophysiology 23  Action of Diuretics 8/19/2022 NURS 115 Pathophysiology 24  Nephron Renal Blood flow Each renal artery enters at the renal hilum, the entry and exit point for renal vessels and nerves The renal artery branches into smaller arterioles, until reaching the afferent arteriole, to each nephron to each glomerulus, more than 1.3 million in each kidney Filtered blood exits the glomerulus via the efferent arteriole, moves through the peritubular capillaries, and vasa recta Filtered blood leaves the kidneys through the interlobar renal vein, then renal vein to return to the systemic circulation 8/19/2022 NURS 115 Pathophysiology 25  Nephron Blood supply Each nephron has its own independent blood supply The renal artery first divides into smaller arteries, pass through the renal columns to reach the cortex. In the cortex they divide further and form the afferent arterioles The afferent arterioles service about 1.3 million nephrons in each kidney The branch that enters the glomerulus is called the afferent arteriole, which has a group of specialized cells known as the Juxtaglomerular apparatus (JGA) The JGA secretes an enzyme called RENIN, which is involved in blood volume homeostasis Glomerular capillaries are fenestrated capillaries and allow substances less than 8 nm in size to cross Water, molecules like glucose, urea, ions like sodium cross easily. Erythrocytes and proteins, such as albumins, are too big to pass through the fenestrations 8/19/2022 NURS 115 Pathophysiology 26  Generic Renal Assessment / Diagnostics Urine output measurements Urine collection [24 hour] Urine tests Urinalysis may reveal abnormalities that suggest kidney failure Renal stone analysis Blood tests Serum urea and creatinine determine kidney function Imaging tests Renal scan Cystoscopy Ultrasound Computerized tomography MRI MAG3 Scan Retrograde pyelogram Biopsy Percutaneous kidney biopsy to remove a small sample of kidney tissue for lab testing 8/19/2022 NURS 115 Pathophysiology 27  Normal Renal Function Tests 8/19/2022 NURS 115 Pathophysiology 28  Generic Renal Medication regimes Treatment options depend on kidney disorder etiology Pre-renal - Before the kidney - Hypotension Intra-renal - In the kidney - Glomerulonephritis Post renal - After the kidney – Urethral obstruction Treat complications / disorder / disease Analgesia / kidney stones Antibiotics / Hydronephrosis [Mild] Anticoagulants / Thrombosis risk Antihypertensives / secondary hypertension ACE inhibitors or ARB blockers Calcium, Glucose or Insulin for hyperkalemia Calcium and Vitamin D supplements if hypocalcemia Corticosteroids / Nephrotic syndrome Diuretics if overloaded Erythropoietin / iron if anemia Statins to lower LDL- cholesterol levels 8/19/2022 NURS 115 Pathophysiology 29  Alterations Renal and Urinary Tract Function 8/19/2022 NURS 115 Pathophysiology 30  Acute kidney failure Acute Kidney Injury Acute kidney injury [AKI] is defined as an abrupt, within 48 hours reduction in kidney function based on an elevation in serum creatinine level, a reduction in urine output, the need for renal replacement therapy, dialysis, or a combination of these factors It is classified in 3 stages, Pre-Intra-Post renal failure The term AKI should replace terms such as acute renal failure and acute renal insufficiency, which previously have been used to describe the same clinical condition Mayo Clinic (2020) 8/19/2022 NURS 115 Pathophysiology 31  Acute renal failure Classifications 8/19/2022 NURS 115 Pathophysiology 32  Pre-renal Impaired blood flow to the kidneys Etiology Hypovolemic shock Hemorrhagic shock Cardiogenic shock Septic shock Anaphylactic shock Cardiovascular medications Acute coronary syndromes Heart disease/Failure Severe infections Liver failure NSAIDs Severe burns Severe dehydration 8/19/2022 NURS 115 Pathophysiology 33  Intrinsic-renal Thrombosis Damage to the kidneys Atherosclerosis Etiology Glomerulonephritis Hemolytic uremic syndrome Severe infection Lupus, causing glomerulonephritis Medications Chemotherapy drugs Antibiotics Dyes used during imaging tests Scleroderma, Thrombotic thrombocytopenic purpura, Toxins Alcohol Heavy metals Cocaine Rhabdomyolysis Tumor lysis syndrome 8/19/2022 NURS 115 Pathophysiology 34  Post-renal Obstruction to urine flow from the kidneys Etiology Kidney stones Urinary tract thrombosis Bladder nerve damage Enlarged prostate [BPH] Bladder cancer Prostate cancer Cervical cancer Colon cancer 8/19/2022 NURS 115 Pathophysiology 35  Acute kidney failure Manifestations Anxious Confusion Fatigue Nausea Weakness Peripheral edema Shortness of breath Pulmonary edema Cardiac dysrhythmias Chest pain / angina Oliguria Seizures Coma in severe cases 8/19/2022 NURS 115 Pathophysiology 36  Common Signs and Symptoms Kidney Failure 8/19/2022 NURS 115 Pathophysiology 37  Acute kidney failure Complications Acute pulmonary edema / effusion Pericarditis Muscle fatigue Uremia syndrome Heart failure Myocardial infarction Seizures LOC Uremic encephalopathy eGFR falls and remains below 15 mL/min Permanent kidney damage End-stage renal disease Death 8/19/2022 NURS 115 Pathophysiology 38  Acute kidney failure Assessment / Diagnostics Serum Creatinine Acute versus Chronic can be identified Complete Blood count AKI Hemolytic uremic syndrome or thrombotic thrombocytopenic purpura. Urine analysis An important baseline Urine electrolyte Can determine pre-renal from intrinsic causes Imaging studies Renal ultrasonography can identify post renal, tumors, hydronephrosis, BPH CT and MRI Renal biopsy Prerenal and postrenal causes of acute kidney injury have been excluded and the cause of intrinsic renal injury is unclear 8/19/2022 NURS 115 Pathophysiology 39  Acute kidney failure Management Patients with AKI should be hospitalized assuring adequate renal perfusion, maintaining hemodynamic stability and avoiding hypovolemia Maintain a mean arterial pressure > 65 mm Hg, cardiac function can be optimized with positive inotropes, or afterload and preload reduction Attention to electrolyte imbalances, hyperkalemia, hyperphosphatemia, hypermagnesemia, hyponatremia, hypernatremia, metabolic acidosis is important Note: Diuretics do not improve morbidity, mortality, or renal outcomes, and should not be used to prevent or treat AKI unless volume overload Initiation of renal replacement therapy [Dialysis] include refractory hyperkalemia, volume overload refractory to medical management, uremic pericarditis, uremic encephalopathy, intractable acidosis 8/19/2022 NURS 115 Pathophysiology 40  Acute kidney failure Prognosis Patients with acute kidney injury are more likely to develop chronic kidney disease in the future They are also at higher risk of end-stage renal disease and premature death Patients who have an episode of acute kidney injury should be monitored for the development or worsening of chronic kidney disease 8/19/2022 NURS 115 Pathophysiology 41  Chronic kidney failure Chronic Kidney Disease Chronic kidney disease [CKD], AKA chronic kidney failure, involves a gradual loss of kidney function In the early stages [1 – 3] of CKD , there are few clinical manifestations and might not realize that you have CKD until the condition is advanced Treatment for CKD focuses on slowing the progression of kidney damage, by controlling the cause [ Diabetes Mellitus, Hypertension] Controlling the cause does not prevent the kidney damage from progressing CKD will progress to end-stage kidney failure, which is fatal and without Dialysis or a kidney transplant, a death sentence Mayo Clinic (2020) 8/19/2022 NURS 115 Pathophysiology 42  Chronic Kidney Disease 5 Stages Normal GFR range 90 to 120 mL/min/1.73 m2 National Kidney Foundation. 8/19/2022 NURS 115 Pathophysiology 43  Chronic Kidney Disease Etiology Diabetes Mellitus Hypertension Glomerulonephritis Interstitial nephritis Polycystic kidney disease Inherited kidney diseases Enlarged prostate Kidney stones Cancer Vesicoureteral reflux Pyelonephritis 8/19/2022 NURS 115 Pathophysiology 44  Chronic Kidney Disease Clinical manifestations Nausea and Vomiting Anorexia Fatigue and weakness Sleep problems Polyuria, Oliguria, Anuria Decreased mentation Muscle cramps Peripheral edema Pruritis Uncontrolled hypertension Pulmonary edema Pericarditis 8/19/2022 NURS 115 Pathophysiology 45  Chronic Kidney Disease Complications Right and left Heart failure Cor pulmonale / Pulmonary edema Hyperkalemia > 7 mmol/L Anemia Osteoporosis Decreased libido Erectile dysfunction Reduced fertility Mentation disruptions Seizures Decreased immune response Pericarditis Pregnancy complications End-stage kidney disease 8/19/2022 NURS 115 Pathophysiology 46  Chronic Kidney Disease Assessment / Diagnostics Serum Creatinine Acute versus Chronic can be identified Complete Blood count AKI Hemolytic uremic syndrome or thrombotic thrombocytopenic purpura. Urine analysis An important baseline Urine electrolyte Can determine pre-renal from intrinsic causes Imaging studies Renal ultrasonography can identify post renal, tumors, hydronephrosis, BPH CT and MRI Renal biopsy Prerenal and postrenal causes of acute kidney injury have been excluded and the cause of intrinsic renal injury is unclear 8/19/2022 NURS 115 Pathophysiology 47 Chronic Kidney Disease Management Treating complications Antihypertensive medications Diuretics Iron supplements. Anti-cholesterol medications Calcium supplements A low protein diet reduces nitrogen load End - Stage Kidney Disease Management Renal replacement therapies Hemodialysis Peritoneal dialysis Kidney transplant 8/19/2022 NURS 115 Pathophysiology 48  Nephrotic syndrome Chronic Kidney Disease Nephrotic syndrome is a kidney disorder with the following group of symptoms Peripheral edema Heavy proteinuria Hypoalbuminemia Hyperlipidemia Nephrotic syndrome is usually caused by damage to the the functional unit of the kidney; the glomerulus 8/19/2022 NURS 115 Pathophysiology 49  Nephrotic syndrome Etiology Primary cause A disease called focal segmental glomerulosclerosis [FSGS], characterized by scarring of glomeruli, occurs from a secondary diseases, a genetic defect, medications or is idiopathic * Has a poor prognosis even wit management Secondary causes Diabetic nephropathy that affects the glomeruli * Minimal change disease is idiopathic and the most common cause of nephrotic syndrome in children, which results in abnormal kidney function, but when tissue is examined, it appears normal or nearly normal Membranous nephropathy results in thickening membranes within the glomeruli, autoimmune system disorder or with systemic lupus erythematosus, Hepatitis B, malaria, cancer, or is idiopathic Amyloidosis, amyloid proteins accumulate in the glomeruli and prevent filtering 8/19/2022 NURS 115 Pathophysiology 50  Nephrotic syndrome Edema Manifestations Eyes Chest – Pulmonary edema Abdomen - Ascites Ankles Feet Foamy urine Proteinuria Weight gain Fluid retention Dyspnea Fatigue Pallor Anorexia Abdominal pain Nausea and vomiting 8/19/2022 NURS 115 Pathophysiology 51  Nephrotic syndrome Complications Thrombosis Loss proteins C and S due to glomeruli dysfunction Hypercholesterolemia and hypertriglyceridemia Compensatory hepatic synthesis of albumin, cholesterol and triglycerides Poor nutrition Hypoalbuminemia, Anemia, Vitamin D deficiency Heart Failure / Hypertension Excess fluid in the circulation Acute kidney injury Uremia End Stage Kidney disease Dialysis or a kidney transplant Infections Lower immune response, increased risk 8/19/2022 NURS 115 Pathophysiology 52  Nephrotic syndrome Management There is NO CURE for Nephrotic Proteinuria reduced to