5.2 Gastrointestinal & Hepatic Disorders

5.2 Gastrointestinal & Hepatic Disorders

Gastrointestinal (GI) and hepatobiliary disorders represent high-acuity clinical challenges encountered across medical-surgical wards, intensive care units, and endoscopy suites. For the DOH Abu Dhabi nursing examination, candidates must demonstrate advanced clinical judgment in rapid hemodynamic stabilization during acute hemorrhage, decompression of mechanical bowel obstructions, recognition of necrotizing pancreatitis, and management of advanced liver cirrhosis complications, including portal hypertension and encephalopathy.

---

Gastrointestinal Bleeding: Upper vs. Lower GI Hemorrhage

Gastrointestinal hemorrhage is classified by its anatomical location relative to the ligament of Treitz (suspensory muscle of the duodenum), which dictates clinical presentation, diagnostic approach, and emergency nursing priorities.

Upper vs. Lower GI Bleeding Comparison

Hemodynamic Stabilization Priorities & Resuscitation Protocol

Assess airway, breathing and circulation immediately while obtaining help and starting hemodynamic resuscitation. Active hematemesis or impaired consciousness may require urgent airway protection; do not postpone it to complete vascular interventions:

1. Vascular Access & Fluid Resuscitation:
   • Immediately establish two large-bore peripheral IV lines (16-gauge or 18-gauge) or assist with central venous catheterization.
   • Infuse isotonic crystalloids (0.9% Normal Saline or Lactated Ringer's) rapidly to restore circulating plasma volume. Titrate infusion to maintain Mean Arterial Pressure (MAP) >=65 mmHg, systolic blood pressure >90 mmHg, and urine output >=0.5 mL/kg/hr.
2. Blood Component Transfusion:
   • Send blood stat for Type and Crossmatch (4 to 6 units of PRBCs), complete blood count (CBC), prothrombin time/INR, and fibrinogen.
   • Transfuse Packed Red Blood Cells (PRBCs) using a restrictive transfusion strategy (target hemoglobin 7 to 8 g/dL in stable patients; maintain >9 g/dL in patients with active acute coronary syndromes or profound hemodynamic instability).
   • Guide hemostatic products by the bleeding cause and clinical protocol. Do not routinely give FFP to correct INR in acute variceal bleeding; it can worsen volume overload and portal pressure. Refractory bleeding requires individualized specialist decisions.
3. Pharmacotherapy:
   • Proton Pump Inhibitors (PPIs): Use prescribed high-dose PPI for ulcer bleeding. If started before the source is known, discontinue it after confirmation of a variceal source unless another indication remains.
   • Vasoactive Splanchnic Constrictors: In suspected variceal hemorrhage, immediately initiate Octreotide (Sandostatin) (50 mcg IV bolus followed by 50 mcg/hr continuous IV infusion). Octreotide selectively constricts splanchnic arterial vascular beds, reducing mesenteric blood flow, portal venous inflow, and intravariceal pressures.
4. Endoscopic Intervention:
   • After resuscitation, prepare for EGD within 12 hours of presentation for suspected variceal bleeding, or within 24 hours for other upperGI bleeding. Persistent instability requires endoscopy as soon as it can be performed safely.

---

Liver Cirrhosis, Portal Hypertension & Hepatic Failure

Liver cirrhosis is the irreversible, end-stage disruption of hepatic architecture characterized by diffuse hepatocellular necrosis, extensive fibrous bridging, and nodular regeneration. These structural changes compress intrahepatic sinusoids, elevating portal venous resistance and creating portal hypertension (hepatic venous pressure gradient>5 mmHg; clinically significant portal hypertension in cirrhosis is>=10 mmHg).

Major Complications of Cirrhosis and Nursing Management

1. Ascites and Fluid Overload

Portal hypertension combined with severe hypoalbuminemia (diminished hepatic synthesis) reduces intravascular oncotic pressure, driving fluid transudation into the peritoneal cavity. Concurrent splanchnic arterial vasodilation triggers renal sodium and water retention via the renin-angiotensin-aldosterone system.

• Medical & Nursing Care: Strict dietary sodium restriction (<2000 mg/day / 88 mmol/day). Diuretic therapy utilizing a combination of Spironolactone (aldosterone antagonist, potassium-sparing) and Furosemide (loop diuretic) titrated at a 100 mg : 40 mg ratio to preserve serum potassium balance. Measure daily morning weights and abdominal girth at the level of the umbilicus.
• Therapeutic Paracentesis Protocol: When performing large-volume paracentesis (>5 liters removed) for tense, refractory ascites, the nurse must ensure administration of Intravenous Concentrated Albumin (20% or 25%) at a dose of 6 to 8 grams per liter of ascites removed. Administering albumin preserves intravascular oncotic volume and prevents Paracentesis-Induced Circulatory Dysfunction (PICD), severe hypotension, and acute hepatorenal syndrome.

2. Esophageal Varices & Balloon Tamponade

Collateral circulation develops between portal and systemic venous beds (gastroesophageal junction, retroperitoneum, abdominal wall, and hemorrhoidal veins). Esophageal varices are fragile, dilated submucosal veins under high pressure prone to rupture.

• Primary Bleeding Prophylaxis: Administer non-selective beta-blockers (propranolol or nadolol) titrated to achieve a resting heart rate of 55 to 60 bpm. Beta-blockers reduce portal inflow via beta-1 cardiac output reduction and beta-2 unopposed splanchnic vasoconstriction.
• Acute Variceal Hemorrhage: Emergency IV octreotide infusion, antibiotic prophylaxis (IV ceftriaxone to prevent spontaneous bacterial peritonitis), and urgent Endoscopic Variceal Ligation (EVL / banding).
• Sengstaken-Blakemore / Minnesota Tube (Balloon Tamponade): Multi-lumen esophageal tube utilized as a temporary, emergency mechanical tamponade bridge when massive variceal hemorrhage fails to stop with endoscopic therapy.
  • The gastric balloon is inflated with 200 to 250 mL of air and pulled firmly against the gastroesophageal junction under gentle traction (approx. 1 kg using a helmet or traction device).
  • The esophageal balloon is inflated only if bleeding continues, maintaining pressure between 20 and 45 mmHg (monitored continuously with a manometer).
  • CRITICAL LIFE SAFETY RULE: A pair of scissors must be kept taped to the head of the bed or immediately at the patient's bedside at all times. If the gastric balloon deflates or bursts, the esophageal balloon will migrate upward into the posterior pharynx, completely occluding the larynx and trachea. If the patient develops sudden respiratory distress, cyanosis, or stridor, the nurse MUST immediately cut all tube lumens to deflate the balloons and extract the tube instantly from the airway.

3. Hepatic Encephalopathy (HE)

Hepatic encephalopathy is a spectrum of reversible neuropsychiatric abnormalities resulting from hepatic failure and portosystemic shunting. The failing liver cannot convert neurotoxic intestinal ammonia (NH3) into urea. Unmetabolized ammonia crosses the blood-brain barrier, triggering astrocyte swelling, brain edema, and impaired neurotransmission.

• Clinical Manifestations: Staged using the West Haven Criteria from Stage 1 (mild confusion, sleep inversion) to Stage 4 (deep coma). The classic physical sign is Asterixis ("flapping tremor"), elicited by asking the patient to extend their arms, hyperextend the wrists, and spread their fingers; intermittent sudden brief losses of wrist extension produce an involuntary flapping motion. Other signs include fetor hepaticus (a sweet, musty, fecal odor on the breath caused by dimethyl sulfide).
• Precipitating Factors: Constipation (increased intestinal ammonia contact time), gastrointestinal bleeding (digestion of blood protein yields large ammonia loads), infection (spontaneous bacterial peritonitis, sepsis), hypokalemia and metabolic alkalosis (alkalosis converts NH4+ into diffusible NH3), dehydration, and sedatives.
• Pharmacological Interventions:
  1. Lactulose (Cephulac): A non-absorbable synthetic disaccharide that passes intact to the colon, where bacteria ferment it into lactic and acetic acids. Colonic acidification converts diffusible ammonia (NH3) into charged ammonium ions (NH4+), which cannot cross mucosal membranes and are trapped and excreted in the feces ("ammonia trapping"). Lactulose also exerts an osmotic laxative effect.
     • Dosing Goal: Titrate lactulose dose (typically 20–30 g / 30–45 mL two to four times daily) to produce 2 to 3 soft, semi-formed bowel movements per day.
     • Nursing Alert: Over-administration produces profuse watery diarrhea, resulting in dehydration, hypernatremia, and hypokalemia (which paradoxically worsens encephalopathy).
  2. Rifaximin (Xifaxan): A non-absorbable oral antibiotic that eradicates urease-producing gut flora (such as Escherichia coli and Proteus), reducing ammonia generation without causing systemic adverse effects.
• Dietary Protein Management: Historical practice of imposing severe, long-term dietary protein restriction is outdated and harmful. Severe restriction induces muscle wasting and catabolism (skeletal muscle is an important secondary site for ammonia clearance). Current clinical guidelines mandate maintaining adequate protein intake (1.2 to 1.5 g/kg/day), emphasizing vegetable and dairy proteins rich in branched-chain amino acids.

---

Acute Pancreatitis: Pathophysiology, Assessment & Resuscitation

Acute pancreatitis is an acute inflammatory process of the pancreas characterized by premature intracellular activation of digestive zymogens (trypsinogen to trypsin), leading to pancreatic autodigestion, localized tissue necrosis, capillary leak, and severe Systemic Inflammatory Response Syndrome (SIRS).

Etiologies

• Gallstones (Biliary Calculus): Account for approximately 40% of cases due to mechanical impaction at the ampulla of Vater.
• Alcohol Abuse: Accounts for approximately 35% of cases via direct acinar toxicity and protein plugging of pancreatic ductules.
• Other Causes: Hypertriglyceridemia (>1000 mg/dL / 11.3 mmol/L), post-Endoscopic Retrograde Cholangiopancreatography (post-ERCP), hypercalcemia, abdominal trauma, and medications (e.g., azathioprine, sulfonamides, thiazides).

Assessment Findings & Diagnostic Hallmarks

• Abdominal Pain: Severe, unrelenting, knife-like epigastric pain that characteristically radiates directly through to the back. Pain is exacerbated in the supine position and after meals, and partially relieved by sitting upright and leaning forward or adopting a fetal posture.
• Laboratory Hallmarks: Serum Lipase elevated >=3 times the upper limit of normal (lipase is highly specific for pancreatic inflammation and remains elevated for 8 to 14 days). Serum Amylase rises rapidly within 12 hours but normalizes within 48 to 72 hours (less specific).
• Physical Signs of Retroperitoneal Hemorrhage (Severe Necrotizing Pancreatitis):
  • Cullen's Sign: Bluish-purple periumbilical ecchymosis resulting from retroperitoneal blood tracking along the falciform ligament to the umbilicus.
  • Grey Turner's Sign: Bluish-purple discoloration along the flanks resulting from blood tracking through the posterior pararenal space.
  • Both signs signify extensive pancreatic necrosis and retroperitoneal hemorrhage, carrying a high mortality rate (>30%).

Evidence-Based Clinical Management

1. Early Nutrition as Tolerated:
   • In mild pancreatitis, offer a low-fat solid diet within 24–48 hours as tolerated rather than routinely fasting the patient to suppress pancreatic secretion.
   • If oral intake is not tolerated, use enteral nutrition; nasogastric feeding is generally preferred, with jejunal feeding used when indicated. Avoid parenteral nutrition when the enteral route is usable.
2. Reassessed Crystalloid Hydration:
   • Prefer Lactated Ringer's and give moderately aggressive, goal-directed hydration, with additional boluses when hypovolemia is present.
   • Reassess vitals, urine output, BUN/hematocrit and signs of overload within the first 6 hours and repeatedly thereafter. Adjust treatment to the response; a fixed aggressive 250–500 mL/hour regimen is not appropriate for every patient.
3. Analgesic Management & Meperidine Avoidance:
   • Effective pain management is vital to blunt sympathetic overdrive. Administer IV opioids such as hydromorphone (Dilaudid) or fentanyl.
   • MEPERIDINE (DEMEROL) AVOIDANCE: Meperidine is strictly avoided in modern practice. Repeated administration leads to the accumulation of its toxic active metabolite, normeperidine, which has a 15- to 30-hour half-life. Normeperidine accumulation causes central nervous system excitation, manifesting as tremors, hyperreflexia, multifocal myoclonus, and grand mal seizures, particularly in patients with impaired renal clearance.
4. Systemic Complication Surveillance:
   • Hypocalcemia: Free fatty acids released during pancreatic fat necrosis bind ionized calcium, producing insoluble calcium soaps (fat saponification). Assess for tetany, Chvostek's sign, and Trousseau's sign; keep IV calcium gluconate accessible.
   • Acute Respiratory Distress Syndrome (ARDS): Pancreatic phospholipase A2 destroys pulmonary surfactant, and activated enzymes damage alveolar capillary membranes. Monitor continuous pulse oximetry, arterial blood gases, and assess for tachypnea and crackles.

---

Bowel Obstruction & Ostomy Care

Small Bowel Obstruction (SBO) vs. Large Bowel Obstruction (LBO)

Nursing Management of Bowel Obstruction

• Maintain strict NPO status.
• Insert a Nasogastric (NG) tube and connect to low intermittent wall suction (30 to 40 mmHg) to decompress the stomach, remove swallowed air and retained secretions, and prevent pulmonary aspiration.
• Monitor NG drainage: measure volume, record color (bilious vs. feculent), and assess tube patency (flush with 30 mL normal saline if obstructed).
• Maintain fluid and electrolyte replacement with IV isotonic fluids.
• Monitor closely for signs of bowel strangulation and perforation: fever, leukocytosis, localized rebound tenderness, tachycardia, and a rigid, board-like abdomen, requiring immediate emergency exploratory laparotomy.

Stoma Assessment & Evidence-Based Ostomy Care

1. Stoma Viability Assessment:
   • Healthy Stoma: Should appear bright red or deep pink ("beefy red"), moist, warm, and slightly elevated above skin level. Mild post-operative edema is normal for the first 4 to 6 weeks.
   • Compromised Stoma (Ischemia/Necrosis): Pale pink may indicate anemia or impaired perfusion; dusky, dark red, purple, brown, or black mucosa indicates mesenteric vascular insufficiency, venous congestion, or acute tissue infarction.
   • PRIORITY ACTION: If a stoma appears dusky or black, notify the surgical team immediately and keep the patient NPO pending assessment. Necrosis extending below the fascia requires emergency revision; superficial changes may be managed conservatively.
2. Appliance Sizing and Skin Protection:
   • Measure stoma diameter using a circular stoma measuring guide.
   • Cut the opening of the skin barrier/wafer no more than 1/8 inch (2 to 3 mm) larger than the stoma base.
   • Rationale: Cutting the barrier too large exposes peristomal skin to corrosive digestive enzymes (especially alkaline ileostomy effluent), causing chemical dermatitis and ulceration; cutting too small constricts the stoma, causing ischemia or laceration.
3. Pouch Emptying Protocol:
   • Empty the ostomy pouch when it is 1/3 to 1/2 full of effluent or gas.
   • Rationale: Allowing the pouch to overfill creates excessive gravitational drag that breaks the adhesive peristomal seal, predisposing to leakage, skin excoriation, and offensive odor.

---

Enteral & Parenteral Nutrition

Enteral Tube Feeding Safety Bundles

• Verification of Initial Placement: The mandatory gold standard for verifying initial feeding tube placement (nasogastric or nasojejunal) is an abdominal/chest X-ray. Feeding or medication administration must never begin without radiographic confirmation.
• Secondary Bedside Verification: Prior to each intermittent feed or every 4 to 8 hours during continuous feeding, test the pH of aspirated fluid. Gastric aspirate characteristically exhibits a pH <=5.5 (acidic). Fluid aspirate with pH >=6.0 suggests intestinal placement or respiratory tract entry.
• Discredited Method: Injecting air into the tube while auscultating over the epigastrium ("air whoosh test") is unreliable, unsafe, and condemned by international guidelines, as air sounds transmit clearly even when the tube is lodged in the pulmonary bronchial tree.
• Aspiration Prevention Bundle:
  • Maintain the head of the bed (HOB) continuously elevated at 30 to 45 degrees during active feeding and for at least 30 to 60 minutes following bolus feeding.
  • Check Gastric Residual Volume (GRV) per institutional protocol (typically every 4 hours for continuous feeds). Although modern guidelines discourage holding feeds for isolated GRV <500 mL in the absence of signs of intolerance, persistent high GRV combined with abdominal distension, nausea, or vomiting warrants pausing feeds, checking prokinetics, and evaluating for obstruction. Always re-instill aspirated residual into the stomach to prevent electrolyte and fluid depletion unless volume exceeds 500 mL or protocol dictates.
  • Flush feeding tubes with 30 mL of water every 4 hours during continuous feeding, before and after bolus feeds, and before and after medication administration.

Total Parenteral Nutrition (TPN) Protocols

TPN is a complex, hypertonic intravenous admixture containing dextrose (20%–50%), crystalline amino acids, electrolytes, trace minerals, and vitamins, administered to patients unable to absorb nutrients via the gastrointestinal tract for prolonged periods.

• Route of Administration: Because TPN has a high osmolarity (>1000 mOsm/L), it MUST be infused exclusively through a Central Venous Access Device (CVAD) (e.g., PICC, internal jugular, or subclavian line) terminating in the superior vena cava. Administering hypertonic TPN through a peripheral vein causes rapid chemical thrombophlebitis, vessel sclerosis, and tissue necrosis.
• Dedicated Line: Dedicate one central line lumen exclusively for TPN. Never infuse blood products, bolus medications, piggyback drugs, or draw blood specimens through the TPN lumen.
• Infection Control & Tubing Changes: High dextrose and lipid concentrations provide an ideal culture medium for bacterial and fungal growth (such as Candida albicans). The nurse must change the TPN infusion bag and IV administration tubing every 24 hours using strict aseptic technique. Utilize an in-line intravenous filter (0.22-micron filter for standard amino acid/dextrose solutions, 1.2-micron filter for total nutrient admixtures containing lipid emulsions).
• Glycemic Surveillance: Check point-of-care capillary blood glucose every 4 to 6 hours. Hyperglycemia is common due to high dextrose loads; administer regular insulin sliding scale coverage as prescribed.
• Preventing Rebound Hypoglycemia: Unexpected interruption of continuous TPN may cause hypoglycemia, particularly when insulin remains active. If the bag empties before a replacement arrives, check glucose, contact the pharmacy/prescriber, and infuse 10% Dextrose in Water (D10W) at the same hourly rate as prescribed by the interruption protocol, with continued glucose monitoring.

---

Summary of Gastrointestinal Emergencies and Nursing Priorities