Gastrointestinal, Renal & Endocrine Disorders

Medical-surgical nursing of gastrointestinal, renal, and endocrine systems encompasses fluid homeostasis, acid-base regulation, metabolic balance, and acute life-threatening decompensations.

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1. Peptic Ulcer Disease (PUD) & Post-Gastrectomy Care

Peptic Ulcer Disease (PUD) involves mucosal ulcerations in the stomach or proximal duodenum extending through the muscularis mucosae. The primary etiologic agents are Helicobacter pylori infection (a gram-negative spiral bacillus that produces urease) and chronic use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), which inhibit cyclooxygenase-1 (COX-1) and deplete mucosal prostaglandins.

Comparison: Gastric vs. Duodenal Ulcers

Life-Threatening Complications of PUD

1. Perforation: The most lethal acute complication. Gastric or duodenal contents leak into the peritoneal cavity, precipitating chemical peritonitis followed by bacterial sepsis.
   • Clinical Triad: Sudden, excruciating, sharp severe abdominal pain radiating to the shoulders, followed by a board-like, rigid abdomen, absent bowel sounds, extreme rebound tenderness, and shallow rapid breathing.
   • Diagnostic Finding: Free air under the diaphragm on an upright abdominal or chest radiograph.
   • Immediate Nursing Action: Place patient in low Fowler's position, make strictly NPO, insert a nasogastric tube for continuous low suction, start IV fluids, and prepare for emergency laparotomy.
2. Hemorrhage: Hematemesis ("coffee-ground" or frank bright red blood) or melena. Monitor for hypovolemic shock (hypotension, tachycardia, cold clammy skin). Maintain two large-bore IV lines (16- or 18-gauge), administer IV proton pump inhibitors (pantoprazole drip), and prepare for emergency endoscopy.
3. Gastric Outlet Obstruction: Caused by scarring or acute inflammatory edema. Manifests as persistent vomiting of undigested food ingested hours earlier, epigastric fullness, and visible peristaltic waves.

Post-Gastrectomy Dumping Syndrome

Rapid gastric emptying occurs when the pyloric sphincter is bypassed or removed (e.g., Billroth I, Billroth II, or total gastrectomy), allowing a hyperosmolar bolus of food to enter the jejunum rapidly.

• Early Dumping Syndrome (15–30 minutes postprandial): Hyperosmolar chyme pulls intravascular fluid into the jejunal lumen by osmosis. Symptoms include abdominal distension, cramping, hyperactive bowel sounds, diarrhea, alongside vasomotor symptoms: tachycardia, diaphoresis, pallor, dizziness, and palpitations.
• Late Dumping Syndrome (2–3 hours postprandial): Rapid glucose absorption causes an excessive spike in blood sugar, triggering a massive insulin surge. This leads to profound reactive hypoglycemia, manifesting as shakiness, diaphoresis, confusion, tremors, and hunger.
• Dietary & Nursing Interventions:
  • Provide small, frequent meals (6 meals per day) rich in protein and complex fats, with low to moderate complex carbohydrates and elimination of simple concentrated sugars.
  • Withhold fluids with meals; drink fluids 30 to 60 minutes before or after eating to prevent rapid transit.
  • Instruct the patient to assume a recumbent or supine position for 20 to 30 minutes after meals to delay gastric emptying.

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2. Intestinal Obstruction

• Mechanical Obstruction: Physical blockage of the lumen caused by postoperative adhesions (most common in small bowel), incarcerated hernias, neoplasms (most common in large bowel), volvulus, or intussusception. Presents with intermittent, crampy, severe colicky abdominal pain, early high-pitched hyperactive tinkling bowel sounds, and profuse vomiting (bilious to feculent).
• Paralytic (Neurogenic) Ileus: Failure of intestinal peristalsis without physical obstruction, caused by abdominal surgery, peritonitis, hypokalemia, or narcotics. Presents with diffuse, constant dull discomfort, marked abdominal distension, and completely absent (silent) bowel sounds.
• Nursing Interventions: Strict NPO, decompression with a Salem sump nasogastric tube connected to low intermittent suction, IV fluid replacement with electrolyte correction, and monitoring for signs of bowel strangulation (fever, localized tenderness, leukocytosis).

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3. Liver Cirrhosis & Hepatic Decompensation

Cirrhosis is chronic, irreversible destruction of hepatic parenchyma with diffuse fibrous septa and regenerative nodule formation, impairing synthetic, metabolic, and detoxifying functions.

Portal Hypertension & Complications

Fibrotic compression of hepatic sinusoids increases vascular resistance, elevating portal venous pressure (> 10–12 mmHg). Blood is shunted through collateral vessels at portosystemic anastomoses:

1. Ascites: Accumulation of serous fluid in the peritoneal cavity due to portal hypertension, hypoalbuminemia (decreased hepatic synthesis), and secondary hyperaldosteronism.
   • Nursing Management: Daily weights, abdominal girth measurement at the umbilicus, sodium restriction (< 2 g/day), and potassium-sparing diuretics (spironolactone).
   • Abdominal Paracentesis Protocol: Have the patient void immediately prior to the procedure to prevent accidental urinary bladder puncture. Position patient upright in high Fowler's or sitting position on the edge of the bed. Monitor blood pressure and pulse during and after fluid removal to detect hypovolemic shock resulting from rapid vascular fluid shifts. Administer IV albumin as ordered following large-volume paracentesis (> 5 L) to prevent circulatory dysfunction.
2. Bleeding Esophageal Varices: Fragile, tortuous, dilated submucosal veins in the lower esophagus prone to catastrophic rupture.
   • Pharmacological Therapy: Intravenous octreotide or somatostatin to produce selective splanchnic vasoconstriction, reducing portal venous inflow.
   • Endoscopic Therapy: Endoscopic variceal ligation (EVL / banding) or sclerotherapy.
   • Balloon Tamponade (Sengstaken-Blakemore / Minnesota Tube): Multi-lumen tube with gastric and esophageal balloons providing mechanical compression.
   • CRITICAL NURSING SAFETY RULE: Keep a pair of surgical scissors taped to the head of the bed at all times. If the gastric balloon accidentally ruptures or deflates, upward traction causes the esophageal balloon to migrate into the oropharynx, acutely obstructing the airway. The nurse must immediately cut all lumens across the tube, deflating the balloons instantly, and withdraw the tube.
3. Hepatic Encephalopathy: Neuropsychiatric syndrome caused by accumulation of neurotoxins, primarily ammonia (NH3), which crosses the blood-brain barrier.
   • Hallmark Clinical Signs: Asterixis ("flapping tremor" elicited by extending arms and dorsiflexing wrists), fetor hepaticus (musty, sweet breath odor), altered sleep-wake cycle, confusion, lethargy, progressing to hepatic coma.
   • Pharmacotherapy: Lactulose (Cephulac): Acidifies colonic contents (converting NH3 to non-absorbable ammonium NH4+, which is trapped and excreted). Titrate dosage to achieve 2 to 3 soft, formed bowel movements per day. Monitor for diarrhea, dehydration, and hypokalemia. Co-administer oral non-absorbable antibiotics (Rifaximin or Neomycin) to eliminate ammonia-producing intestinal bacteria.

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4. Renal Disorders: AKI, CKD & Dialysis

Acute Kidney Injury (AKI)

AKI is an abrupt decline in renal function occurring over hours to days, resulting in retention of nitrogenous wastes (urea, creatinine) and dysregulation of extracellular volume and electrolytes.

• Prerenal AKI: Caused by renal hypoperfusion without structural parenchymal damage (e.g., severe hypovolemia, hemorrhage, septic shock, congestive heart failure). Characterized by BUN:creatinine ratio > 20:1, fractional excretion of sodium (FENa) < 1%, and high urine specific gravity (> 1.020).
• Intrarenal (Intrinsic) AKI: Direct structural damage to glomeruli or renal tubules (Acute Tubular Necrosis / ATN), caused by prolonged ischemia, nephrotoxic agents (aminoglycosides, radiocontrast dye, NSAIDs), or myoglobinuria from rhabdomyolysis. Characterized by FENa > 2% and dirty brown granular casts in urine sediment.
• Postrenal AKI: Mechanical obstruction of urinary outflow from the renal pelvis to the urethral meatus (bilateral ureteral calculi, benign prostatic hyperplasia, bladder outlet obstruction). Reversible upon relieving the obstruction.

Clinical Phases of AKI

1. Oliguric Phase: Urine output < 400 mL/day. Manifests as fluid overload, pulmonary edema, metabolic acidosis (inability to excrete H+ and regenerate HCO3-), hyperkalemia, hyponatremia, and elevated BUN and serum creatinine. Lasts 1 to 2 weeks.
2. Diuretic Phase: Daily urine output gradually increases to 1 to 5 L/day. Nephrons filter fluid but lack concentration ability. Patients are at high risk for profound dehydration, hypovolemia, hypokalemia, and hyponatremia.
3. Recovery Phase: Glomerular filtration rate (GFR) normalizes; BUN and creatinine stabilize. May take up to 12 months for full renal functional recovery.

Chronic Kidney Disease (CKD) & Uremic Syndrome

CKD is defined as kidney damage or GFR < 60 mL/min/1.73 m² for ≥ 3 months. Staged by GFR: Stage 1 (≥ 90), Stage 2 (60–89), Stage 3a (45–59), Stage 3b (30–44), Stage 4 (15–29, preparation for replacement), and Stage 5 (GFR < 15 mL/min, End-Stage Renal Disease requiring renal replacement therapy).

• Clinical Manifestations of Uremia: Uremic frost (urea crystals on skin), severe pruritus, uremic fetor (ammonia breath), pericarditis, normocytic normochromic anemia (deficient renal erythropoietin production—managed with recombinant human erythropoietin and iron supplements), and renal osteodystrophy (hyperphosphatemia and hypocalcemia due to deficient 1,25-dihydroxyvitamin D3 synthesis; managed with phosphate binders taken with meals).
• Dietary Restrictions: Low protein (0.6–0.8 g/kg/day unless on dialysis), low sodium (2 g/day), low potassium (avoid bananas, oranges, potatoes, tomatoes), low phosphorus (limit dairy, nuts, cola), and fluid restriction (previous day's total urine output + 500 to 600 mL for insensible losses).

Dialysis Modalities

• Hemodialysis & Arteriovenous (AV) Fistula: Surgical creation of an anastomosis between an artery and a vein (typically radial artery to cephalic vein). Requires 2 to 3 months to mature and arterialise.
  • Nursing Assessment: Palpate for a thrill (vibratory sensation) and auscultate for a bruit (swishing vascular sound) every shift to confirm patency.
  • Safety Precautions: Never take blood pressure, perform venipuncture, or administer IV fluids/medications on the extremity with an AV fistula or graft. Post prominent signs over the bed.
  • Complication: Dialysis Disequilibrium Syndrome: Rapid reduction in blood urea creates a transient osmotic gradient, pulling fluid into brain tissue and causing cerebral edema. Signs include headache, nausea, restlessness, confusion, twitching, and seizures. Managed by slowing the dialysis blood flow rate.
• Peritoneal Dialysis (PD): The peritoneal membrane serves as the semipermeable dialyzing filter.
  • Peritonitis: The most common and serious complication. Earliest clinical sign is cloudy or turbid dialysate effluent (containing WBCs > 100/μL), followed by diffuse abdominal pain, rebound tenderness, and fever. Inspect effluent at every exchange and send cloudy fluid for Gram stain and culture.

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5. Endocrine Disorders: Diabetes Mellitus

Diabetes mellitus represents a group of metabolic diseases characterized by chronic hyperglycemia resulting from defects in insulin secretion, insulin action, or both.

• Type 1 Diabetes Mellitus: Autoimmune destruction of pancreatic beta cells in the islets of Langerhans, leading to absolute insulin deficiency. Early onset; prone to ketoacidosis; requires lifelong exogenous insulin.
• Type 2 Diabetes Mellitus: Progressive insulin resistance in peripheral tissues coupled with a relative secretory defect of beta cells. Associated with metabolic syndrome and central obesity; managed with lifestyle, oral hypoglycemics, and insulin.

Diagnostic Criteria (ADA Guidelines)

1. Fasting Plasma Glucose (FPG) ≥ 126 mg/dL (7.0 mmol/L) after an 8-hour fast.
2. Two-hour plasma glucose ≥ 200 mg/dL (11.1 mmol/L) during a 75 g oral glucose tolerance test (OGTT).
3. Glycated Hemoglobin (HbA1c) ≥ 6.5% (48 mmol/mol).
4. Classic symptoms of hyperglycemia (polyuria, polydipsia, unexplained weight loss) plus a random plasma glucose ≥ 200 mg/dL.

Comparison: DKA vs. Hyperglycemic Hyperosmolar State (HHS)

Emergency Management of DKA

1. Fluid Resuscitation: Initial fluid of choice is 0.9% Normal Saline (0.9% NaCl) at 1 L/hour for the first 1–2 hours to restore intravascular volume. Switch to 0.45% NaCl if serum sodium is normal or elevated. When blood glucose drops to 200–250 mg/dL, add 5% Dextrose to the IV fluids (e.g., D5 0.45% NaCl) to prevent rapid hypoglycemia and cerebral edema while continuing insulin to clear ketonemia.
2. Insulin Therapy: Continuous IV Regular Insulin infusion (0.1 units/kg/hour). Never bolus or infuse insulin if serum potassium is < 3.3 mEq/L. Target glucose reduction rate: 50–75 mg/dL per hour.
3. Potassium Management: Insulin drives potassium into cells. Even if initial serum potassium is normal, total-body potassium is depleted. Add potassium chloride (20–30 mEq/L) to IV fluids once urine output is established (> 30 mL/hr) and serum potassium is < 5.0 mEq/L to prevent fatal arrhythmias.

Hypoglycemia Management & "Rule of 15"

Hypoglycemia is defined as blood glucose < 70 mg/dL (< 3.9 mmol/L).

• Adrenergic Symptoms (Epinephrine release): Shakiness, tremors, diaphoresis, tachycardia, palpitations, anxiety, and pallor.
• Neuroglycopenic Symptoms (Brain glucose deprivation): Headache, confusion, slurred speech, blurred vision, irrational behavior, seizures, and loss of consciousness.
• The Rule of 15 (Conscious Patient):
  1. Administer 15 grams of fast-acting simple carbohydrate (4 oz / 120 mL fruit juice or regular soda, 3–4 glucose tablets, or 1 tablespoon of sugar/honey).
  2. Wait 15 minutes and recheck blood glucose.
  3. If blood glucose remains < 70 mg/dL, administer another 15 g of carbohydrate.
  4. Once blood glucose normalizes, provide a snack with complex carbohydrates and protein (e.g., crackers with cheese or peanut butter).
• Unconscious Patient / NPO: Administer 25 to 50 mL of 50% Dextrose in Water (D50W) IV push, or administer 1 mg Glucagon subcutaneously or intramuscularly if IV access is unavailable.

Insulin Pharmacokinetics

Special Phenomena:

• Somogyi Effect: Nocturnal hypoglycemia (around 2:00–3:00 AM) triggers counter-regulatory hormone release (cortisol, glucagon, epinephrine), causing rebound morning hyperglycemia. Management: Decrease bedtime insulin dose or provide a bedtime protein snack.
• Dawn Phenomenon: Morning hyperglycemia caused by normal early morning surges of growth hormone and cortisol without preceding nocturnal hypoglycemia. Management: Increase evening/bedtime insulin dose.

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6. Thyroid & Adrenal Disorders

Hyperthyroidism vs. Hypothyroidism

• Hyperthyroidism (Graves' Disease): Autoimmune stimulation of TSH receptors by thyroid-stimulating immunoglobulins. Characterized by elevated free T3/T4 and suppressed TSH. Clinical features include heat intolerance, weight loss despite increased appetite, exophthalmos (proptosis), fine tremors, diarrhea, and palpitations.
  • Thyroid Storm (Thyrotoxic Crisis): Life-threatening hypermetabolic state triggered by infection, surgery, or abrupt cessation of antithyroid medications. Marked by extreme hyperpyrexia (> 104°F / 40°C), tachycardia (> 140 bpm), atrial fibrillation, delirium, and shock. Treated with propylthiouracil (PTU) or methimazole, beta-blockers (propranolol), Lugol's iodine solution (administered 1 hour after thionamides to prevent hormone release), and cooling blankets. Avoid aspirin (displaces thyroid hormone from binding proteins).
• Hypothyroidism (Hashimoto's Thyroiditis): Autoimmune destruction of the thyroid gland. Characterized by low free T4 and elevated TSH. Clinical features include cold intolerance, weight gain, constipation, dry skin, coarse brittle hair, periorbital edema, bradycardia, and lethargy.
  • Myxedema Coma: Medical emergency characterized by hypothermia, severe hypotension, hypoventilation, bradycardia, and coma. Treated with IV levothyroxine, IV hydrocortisone, and passive external rewarming.
  • Levothyroxine (Synthroid) Patient Education: Must be taken in the morning on an empty stomach with a full glass of water, 30 to 60 minutes before breakfast. Lifetime therapy; monitor for signs of hyperthyroidism (chest pain, palpitations, insomnia).

Cushing's Syndrome vs. Addison's Disease

• Cushing's Syndrome: Adrenocortical hyperfunction with excess cortisol. Presents with "moon face," "buffalo hump," truncal obesity with thin extremities, purple abdominal striae, hirsutism, hyperglycemia, hypertension, hypokalemia, osteoporosis, and impaired wound healing.
• Addison's Disease: Primary adrenocortical insufficiency (deficient cortisol and aldosterone). Presents with bronze hyperpigmentation of skin and mucous membranes (elevated ACTH), fatigue, weight loss, hypotension, hyponatremia, hyperkalemia, and hypoglycemia.
  • Addisonian Crisis: Acute vascular collapse triggered by stress, trauma, or abrupt cessation of steroid therapy. Presents with profound hypotension refractory to fluids, severe hypoglycemia, and hyperkalemia. Treated immediately with IV hydrocortisone 100 mg bolus, IV normal saline with 5% dextrose, and vasopressors.