4.2 Gastrointestinal & Hepatorenal Disorders

4.2 Gastrointestinal & Hepatorenal Disorders

Core Clinical Rule: In acute upper gastrointestinal bleeding, adopt a restrictive blood transfusion threshold: transfuse packed red blood cells only when hemoglobin is $< 7.0\text{ g/dL}$ to maintain a target of 7.0 to 8.0 g/dL (8.0 to 9.0 g/dL in severe cardiovascular disease). Overzealous, liberal transfusion increases portal venous pressure, dislodges fragile platelet-fibrin plugs, dramatically increases rebleeding rates, and escalates mortality. In decompensated cirrhotics presenting with upper GI bleeding, always administer prophylactic IV Ceftriaxone immediately to prevent Spontaneous Bacterial Peritonitis and death.

Gastrointestinal, hepatic, and renal disorders account for high rates of emergency department presentations and hospital morbidity across East Africa. Patients frequently present with hematemesis, jaundice, abdominal distension, or oliguria. Clinical officers must be adept at clinical risk stratification, procedural paracentesis, rational pharmacotherapy, and rapid intervention for life-threatening electrolyte disturbances.

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1. Peptic Ulcer Disease (PUD) & Helicobacter pylori Eradication

Peptic Ulcer Disease results from a pathological imbalance between mucosal protective mechanisms (mucus-bicarbonate barrier, mucosal blood flow, prostaglandins, cellular restitution) and aggressive luminal factors (gastric acid, pepsin, Helicobacter pylori infection, and Non-Steroidal Anti-Inflammatory Drugs [NSAIDs]).

Clinical Differentiation of Gastric vs Duodenal Ulcers

Helicobacter pylori Eradication Regimens (Kenya MOH / WHO Guidelines)

Helicobacter pylori is a microaerophilic, flagellated, gram-negative spiral bacterium that colonizes the gastric antrum and body. It produces copious urease, which hydrolyzes urea into carbon dioxide and ammonia, neutralizing gastric acid in its microenvironment and damaging mucosal epithelium.

+-----------------------------------------------------------------------------------+
|              FIRST-LINE TRIPLE THERAPY REGIMEN (14 DAYS DURATION)                 |
+-----------------------------------------------------------------------------------+
| 1. Proton Pump Inhibitor (PPI): Omeprazole 20 mg PO twice daily                   |
|    (or Esomeprazole 20-40 mg PO twice daily, or Pantoprazole 40 mg PO twice daily)|
| 2. Amoxicillin: 1000 mg (1 g) PO twice daily                                      |
| 3. Clarithromycin: 500 mg PO twice daily                                          |
+-----------------------------------------------------------------------------------+
| PENICILLIN ALLERGY ALTERNATIVE:                                                   |
| Replace Amoxicillin with Metronidazole 400 mg (or 500 mg) PO twice daily.         |
+-----------------------------------------------------------------------------------+
| BISMUTH QUADRUPLE THERAPY (Second-Line / High Resistance Settings):               |
| PPI standard dose BID + Bismuth Subsalicylate 524 mg QID + Metronidazole 400 mg   |
| TID or QID + Tetracycline 500 mg QID for 14 days.                                |
+-----------------------------------------------------------------------------------+

Testing for Eradication: To confirm bacterial clearance, perform a Stool Antigen Test or Urea Breath Test at least 4 weeks after completion of antibiotic therapy and at least 2 weeks after stopping PPI therapy. Serological antibody testing remains positive for months to years and must never be used to confirm cure.

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2. Acute Upper Gastrointestinal Bleeding (UGIB)

Upper GI bleeding is defined as hemorrhage originating proximal to the ligament of Treitz (duodenojejunal junction). Common etiologies include bleeding peptic ulcer disease (50%), ruptured esophageal or gastric varices (15–20%), Mallory-Weiss tears, erosive gastritis/duodenitis, and upper gastrointestinal malignancies.

Clinical Presentation & Triage

• Hematemesis: Vomiting of bright red blood or dark altered blood ('coffee-ground' emesis).
• Melena: Passage of black, tarry, foul-smelling stools resulting from bacterial degradation of hemoglobin in the small intestine (requires >= 50–100 mL of blood).
• Hematochezia: Passage of fresh maroon or red blood per rectum; typically indicates lower GI bleeding, but occurs in 10–15% of massive upper GI hemorrhages with hypermotile intestinal transit and hemodynamic collapse.

Stepwise Emergency Resuscitation Protocol

                 [Suspected Acute Upper GI Bleeding / Hematemesis]
                                         |
     +-----------------------------------+-----------------------------------+
     |                                                                       |
[AIRWAY & BREATHING]                                                [CIRCULATION / RESUSCITATION]
• High-flow oxygen if SpO2 < 94%                                    • TWO large-bore IVs (14G or 16G)
• Endotracheal intubation if:                                       • Send immediate cross-match, FBC,
  - Massive hematemesis                                               U&E, LFTs, Coagulation (PT/INR)
  - Altered consciousness (GCS < 8)                                 • Infuse isotonic crystalloids
  - Severe encephalopathy                                             (Hartmann's or Normal Saline)
     |                                                                       |
     +-----------------------------------+-----------------------------------+
                                         v
                        [TRANSFUSION TARGET STRATEGY]
                        • Restrictive Strategy: Target Hb 7.0 - 8.0 g/dL
                        • Target Hb 8.0 - 9.0 g/dL ONLY if active acute CAD
                                         |
     +-----------------------------------+-----------------------------------+
     |                                                                       |
[NON-VARICEAL BLEEDING (PUD)]                                       [VARICEAL BLEEDING (CIRRHOSIS)]
• IV High-Dose PPI:                                                 • Vasoactive Splanchnic Constrictor:
  Omeprazole 80 mg IV bolus,                                          Terlipressin 2 mg IV q4h OR
  then 8 mg/hr continuous infusion x 72h                              Octreotide 50 mcg bolus, then 50 mcg/hr
  (or 40 mg IV BID)                                                 • Prophylactic Antibiotic:
                                                                      Ceftriaxone 1 g IV daily x 5-7 days
     |                                                                       |
     +-----------------------------------+-----------------------------------+
                                         v
                        [URGENT DIAGNOSTIC & THERAPEUTIC ENDOSCOPY]
                        • Perform within 24 hours of presentation
                        • Variceal: Endoscopic Variceal Band Ligation (EVL)
                        • Non-Variceal: Dual therapy (Epinephrine + Clips/Cautery)

• Rationale for High-Dose PPI: Gastric acid prevents platelet aggregation and dissolves fibrin clots. At a gastric $pH > 6.0$, platelet aggregation is restored and clot stabilization occurs.
• Vasoactive Agents: Terlipressin (a synthetic vasopressin analogue with longer half-life) or Octreotide (a somatostatin analogue) cause selective splanchnic arterial vasoconstriction, significantly reducing portal venous blood flow, portal venous pressure, and variceal hemorrhage.
• Bacterial Prophylaxis in Cirrhotics: Cirrhotic patients with GI hemorrhage have up to a 50% incidence of severe bacterial infections (SBP, bacteremia, pneumonia) within 7 days. Administering IV Ceftriaxone 1 g daily for 5 to 7 days reduces recurrent bleeding, infections, and all-cause mortality.

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3. Chronic Liver Disease & Cirrhosis Decompensation

Cirrhosis is the histopathological end-stage of chronic progressive liver injury characterized by diffuse parenchymal destruction, regenerative nodule formation, and extensive fibrous bridging. Common causes in Kenya include chronic Hepatitis B virus (HBV), Hepatitis C virus (HCV), chronic alcohol use, Non-Alcoholic Fatty Liver Disease (MASLD), and Schistosoma mansoni (causing portal hypertension via periportal Symmers' pipestem fibrosis).

Child-Turcotte-Pugh (CTP) Prognostic Score

Evaluates 5 clinical and biochemical parameters (1 to 3 points each):

Class Interpretation: Class A (5–6 points: well-compensated, 1-year survival 100%); Class B (7–9 points: significant functional compromise, 1-year survival 80%); Class C (10–15 points: decompensated end-stage, 1-year survival 45%).

Ascites Evaluation & Serum-Ascites Albumin Gradient (SAAG)

Ascites is the pathological accumulation of free fluid within the peritoneal cavity. Diagnostic paracentesis is mandatory for all patients with new-onset ascites or hospital admission for worsening ascites.

• SAAG Calculation:
  $\text{SAAG} = \text{Serum Albumin (g/L)} - \text{Ascitic Fluid Albumin (g/L)}$
• High SAAG ($\ge 11\text{ g/L}$ or $\ge 1.1\text{ g/dL}$): Indicates Portal Hypertension (sinusoidal hypertension creates hydrostatic transudation). Causes: Cirrhosis, alcoholic hepatitis, congestive heart failure, Budd-Chiari syndrome, constrictive pericarditis.
• Low SAAG ($< 11\text{ g/L}$ or $< 1.1\text{ g/dL}$): Indicates Non-Portal Etiology (increased peritoneal capillary permeability or lymphatic blockage). Causes: Peritoneal carcinomatosis, peritoneal tuberculosis, nephrotic syndrome, acute pancreatitis, bowel obstruction.
• Pharmacological Management:
  • Dietary sodium restriction to $< 2.0\text{ g/day}$ (88 mmol/day).
  • Dual Diuretic Therapy: Combine Spironolactone (aldosterone antagonist) and Furosemide (loop diuretic) in a fixed 100 mg : 40 mg ratio (e.g., Spironolactone 100 mg + Furosemide 40 mg PO daily; titrated every 3–5 days up to a maximum of 400 mg : 160 mg). This ratio maintains normokalemia and targets weight loss of 0.5 kg/day (or 1.0 kg/day if concurrent peripheral edema).
  • Refractory Ascites: Perform Large-Volume Paracentesis (LVP). When removing $> 5\text{ Liters}$ of ascitic fluid, infuse intravenous Albumin (20% or 25% solution) at a dose of 6 to 8 grams per liter of ascitic fluid removed to prevent Paracentesis-Induced Circulatory Dysfunction (PICD), rapid renal failure, and death.

Spontaneous Bacterial Peritonitis (SBP)

SBP is an acute bacterial infection of ascitic fluid occurring in the absence of an identifiable surgically remediable intra-abdominal source. Driven by bacterial translocation across permeable gut walls into mesenteric lymph nodes and ascitic fluid.

• Diagnostic Criterion: Diagnostic paracentesis revealing an ascitic fluid absolute neutrophil count (ANC) $\ge 250\text{ cells/mm}^3$ (calculated as $\text{Total Ascitic WBC} \times %\text{ Polymorphonuclear cells}$). Common pathogens: Escherichia coli, Klebsiella pneumoniae, and Streptococcus pneumoniae.
• Therapeutic Regimen:
  • Empirical Antibiotics: IV Ceftriaxone 2 g once daily OR IV Cefotaxime 2 g 8-hourly for 5 to 7 days.
  • Intravenous Albumin (Mandatory Survival Intervention): Administer Albumin 1.5 g/kg IV within 6 hours of diagnosis, followed by 1.0 g/kg IV on Day 3. This reduces the incidence of hepatorenal syndrome from 30% to 10% and cuts hospital mortality from 29% to 10%.
  • Secondary Prophylaxis: After completing therapy, initiate lifelong oral Ciprofloxacin 500 mg daily or Norfloxacin 400 mg daily to prevent recurrent SBP.

Hepatic Encephalopathy (HE)

A spectrum of reversible neuropsychiatric abnormalities resulting from portal-systemic shunting and hepatocellular failure, allowing neurotoxic gut products (primarily ammonia, $NH_3$) to bypass hepatic clearance and enter the systemic and cerebral circulations.

• West Haven Staging Criteria:
  • Grade 1: Trivial lack of awareness, shortened attention span, euphoria or anxiety, reversed sleep-wake cycle.
  • Grade 2: Lethargy, apathy, disinhibited behavior, slurred speech, overt asterixis ('flapping tremor').
  • Grade 3: Somnolence to semi-stupor, responsive to verbal stimuli, marked confusion, gross disorientation.
  • Grade 4: Coma (unresponsive to verbal or painful stimuli).
• Identify & Treat Precipitating Causes: Gastrointestinal bleeding (nitrogen load), infection (SBP, UTI, pneumonia), constipation, hypokalemic metabolic alkalosis (promotes conversion of unabsorbable ammonium $NH_4^+$ to diffusible $NH_3$), overdiuresis, dehydration, or sedatives.
• Medical Therapy:
  • Lactulose (First-Line): 20 to 30 mL (15–30 g) orally or via nasogastric tube 2 to 4 times daily, titrated to achieve 2 to 3 soft, semiformed bowel movements per day. Lactulose is degraded by colonic flora into lactic and acetic acids, acidifying the colon lumen ($pH < 5.0$), converting ammonia ($NH_3$) to unabsorbable ammonium ($NH_4^+$), trapping it for excretion, and exerting an osmotic laxative effect.
  • Rifaximin: 550 mg PO twice daily added to lactulose for secondary prevention of recurrent encephalopathy; reduces ammonia-producing colonic bacteria without systemic absorption.

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4. Acute Kidney Injury (AKI) & Life-Threatening Hyperkalemia

Acute Kidney Injury is defined as an abrupt reduction in kidney function resulting in retention of nitrogenous waste products (urea, creatinine) and dysregulation of extracellular fluid volume and electrolytes.

KDIGO Staging Criteria for AKI

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|                         KDIGO CLINICAL STAGING FOR AKI                            |
+-----------------------------------------------------------------------------------+
| Stage | Serum Creatinine Criteria                   | Urine Output Criteria       |
+-------+---------------------------------------------+-----------------------------+
| 1     | Rise >= 26.5 micromol/L (>= 0.3 mg/dL) in 48h| < 0.5 mL/kg/hr for 6-12     |
|       | OR 1.5 to 1.9 times baseline within 7 days  | consecutive hours           |
+-------+---------------------------------------------+-----------------------------+
| 2     | 2.0 to 2.9 times baseline                   | < 0.5 mL/kg/hr for >= 12    |
|       |                                             | consecutive hours           |
+-------+---------------------------------------------+-----------------------------+
| 3     | >= 3.0 times baseline                       | < 0.3 mL/kg/hr for >= 24h   |
|       | OR Serum Creatinine >= 353.6 micromol/L     | OR Anuria for >= 12 hours   |
|       | OR Initiation of Renal Replacement Therapy  |                             |
+-----------------------------------------------------------------------------------+

Etiological Classification: Prerenal vs Intrinsic vs Postrenal

Emergency Management of Life-Threatening Hyperkalemia

Severe hyperkalemia is defined as a serum potassium $> 6.5\text{ mmol/L}$ or any potassium elevation accompanied by electrocardiographic changes: tall tented peaked T waves $\rightarrow$ prolonged PR interval $\rightarrow$ flattening/loss of P wave $\rightarrow$ widening of QRS complex $\rightarrow$ 'sine wave' pattern $\rightarrow$ ventricular fibrillation or asystole.

+-----------------------------------------------------------------------------------+
|              STEPWISE EMERGENCY HYPERKALEMIA MANAGEMENT PROTOCOL                  |
+-----------------------------------------------------------------------------------+
| 1. CARDIOPROTECTION (IMMEDIATE)                                                   |
|    • 10% Calcium Gluconate: 10 mL IV slow push over 5 to 10 minutes.              |
|    • Mechanism: Antagonizes potassium-induced membrane excitability; restores     |
|      myocardial resting membrane potential. Does NOT lower serum K+ levels!       |
|    • Onset: 1-3 minutes; duration 30-60 minutes. Repeat in 5-10 min if ECG persists|
+-----------------------------------------------------------------------------------+
| 2. INTRACELLULAR POTASSIUM SHIFTING (FAST REDISTRIBUTION)                         |
|    • Regular Insulin + Dextrose: 10 units Regular Insulin in 50 mL 50% Dextrose   |
|      (or 100 mL 20% Dextrose) infused IV over 20 to 30 minutes.                   |
|      (Stimulates Na+/K+-ATPase; lowers K+ by 0.5-1.0 mmol/L within 30-60 min).    |
|    • Nebulized Salbutamol: 10 to 20 mg nebulized in 4 mL normal saline over 15 min|
|      (Synergistic beta-2 receptor mediated intracellular potassium uptake).       |
|    • Sodium Bicarbonate: 50-100 mEq IV infusion ONLY if severe concurrent acidosis|
+-----------------------------------------------------------------------------------+
| 3. POTASSIUM ELIMINATION FROM THE BODY (DEFINITIVE CLEARANCE)                     |
|    • Loop Diuretic: IV Furosemide 40-80 mg (if residual renal perfusion exists).  |
|    • Gastrointestinal K+ Binders: Calcium Polystyrene Sulfonate (Calcium Resonium)|
|      15 g PO 8-hourly, or Sodium Zirconium Cyclosilicate (Lokelma).               |
+-----------------------------------------------------------------------------------+
| 4. EMERGENCY HEMODIALYSIS (REFRACTORY CASES)                                      |
|    • Definitive clearance modality for severe refractory hyperkalemia.             |
+-----------------------------------------------------------------------------------+

Indications for Emergency Hemodialysis: The 'AEIOU' Mnemonic

1. A - Acidosis: Severe, uncorrectable metabolic acidosis ($pH < 7.15$ or refractory to medical therapy).
2. E - Electrolytes: Severe, refractory hyperkalemia ($K^+ > 6.5\text{ mmol/L}$) or rapid worsening despite medical shifting.
3. I - Ingestions / Toxins: Dialyzable toxic ingestions: SLIME (Salicylates, Lithium, Isopropanol, Methanol, Ethylene glycol).
4. O - Overload: Intractable hypervolemic pulmonary edema refractory to high-dose loop diuretics.
5. U - Uremia: Symptomatic uremic end-organ complications: uremic pericarditis (pericardial friction rub), uremic encephalopathy (confusion, asterixis, seizures, coma), or uremic coagulopathy (abnormal platelet function and bleeding).