6.3 Acute Abdomen, Peptic Ulcer Disease & Gastrointestinal Bleeding

6.3 Acute Abdomen, Peptic Ulcer Disease & Gastrointestinal Bleeding

Quick Answer: The acute abdomen denotes any non-traumatic abdominal condition of rapid onset requiring urgent medical evaluation and potential emergency surgical intervention. Systematic clinical examination mandates inspection, auscultation, percussion, and palpation in strict order so mechanical manipulation does not artificially distort bowel motility. Life-threatening abdominal pathologies include generalized peritonitis (involuntary guarding, board-like rigidity, and Blumberg's rebound tenderness), acute appendicitis (visceral periumbilical pain migrating to somatic McBurney's point tenderness), peptic ulcer disease (gastric versus duodenal patterns), and acute gastrointestinal hemorrhage. Nursing priorities focus on airway protection, establishing two large-bore IV lines, aggressive volume resuscitation, maintaining strict NPO status, and refraining from heat applications or laxatives.

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Systematic Physical Assessment of the Acute Abdomen

Physical assessment of abdominal emergencies must be performed methodically to localize pathology, assess peritoneal inflammation, and prevent clinical deterioration.

                 ABDOMINAL ASSESSMENT SEQUENCE
  1. INSPECTION   --> Symmetry, distention, visible peristalsis, scars
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  2. AUSCULTATION --> Done BEFORE touch (listen 5 mins for absent sounds)
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  3. PERCUSSION   --> Tympany (gas) vs. Dullness (fluid, masses, organomegaly)
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  4. PALPATION    --> Light first, then deep; tender quadrant examined LAST

1. Inspection

• Observe abdominal contour (scaphoid, flat, rounded, or grossly distended).
• Note presence of visible peristaltic waves (suggesting mechanical bowel obstruction), respiratory excursion (abdominal splinting during breathing indicates peritoneal irritation), and surgical scars.
• Inspect for characteristic ecchymoses: Cullen's sign (periumbilical ecchymosis) or Grey Turner's sign (flank ecchymosis), which denote retroperitoneal hemorrhage or acute hemorrhagic pancreatitis.

2. Auscultation (Mandatory Second Step)

• Why Auscultate Before Palpation: Palpation and percussion stimulate mechanoreceptors in intestinal smooth muscle, artificially generating or altering bowel sounds. Therefore, auscultation must always precede physical manipulation.
• Bowel Sound Categories:
  • Normal: 5 to 30 gurgling, clicking sounds per minute.
  • Hyperactive (Borborygmi): High-pitched, loud, rushing sounds indicating early mechanical bowel obstruction or acute gastroenteritis.
  • Hypoactive: Sluggish sounds ($< 5/\text{min}$) indicating paralytic ileus or electrolyte derangements (hypokalemia).
  • Absent: No sounds heard. The nurse must listen continuously for a minimum of 5 full minutes (listening across all four quadrants) before formally documenting bowel sounds as absent. Absent bowel sounds signify established paralytic ileus or generalized peritonitis.

3. Percussion

• Differentiates generalized gaseous distention (tympany) from fluid accumulation (ascites Dullness) or solid masses/organomegaly (dullness).

4. Palpation

• Ensure the patient is in a supine position with knees slightly flexed to relax abdominal wall musculature.
• Always ask the patient to point to the site of maximal pain and examine that area LAST to avoid precipitating voluntary muscular guarding that obscures the remainder of the exam.
• Perform light palpation ($1\text{--}2\text{ cm}$) to detect tenderness, superficial masses, and muscular resistance.
• Perform deep palpation ($4\text{--}5\text{ cm}$) to assess organomegaly and deeper pathological masses.

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Clinical Manifestations of Peritonitis

Peritonitis is an acute inflammation of the visceral and parietal peritoneum resulting from bacterial contamination or chemical leakage (e.g., perforated peptic ulcer, ruptured appendix, gangrenous bowel, anastomotic breakdown).

• Involuntary Muscular Guarding: Constant spasm and contraction of the abdominal wall musculature that persists regardless of patient relaxation or distraction.
• Board-Like Abdominal Rigidity: The entire anterior abdominal wall feels extraordinarily hard, unyielding, and rigid on palpation.
• Rebound Tenderness (Blumberg's Sign): The nurse deeply depresses the abdominal wall slowly and then releases pressure abruptly. The sudden release produces sharp, lancinating pain due to parietal peritoneal recoil.
• Absent Bowel Sounds: Intestinal paralysis resulting from widespread peritoneal inflammation.
• Systemic Signs: High fever ($> 38.5^\circ\text{C}$), tachycardia ($> 110\text{ bpm}$), shallow rapid respirations (thoracic breathing to minimize diaphragm movement against inflamed peritoneum), and progressive septic shock.

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Acute Appendicitis: Pain Progression & Diagnostic Signs

Acute appendicitis is the most common cause of the acute abdomen requiring emergency laparotomy. Obstruction of the appendiceal lumen by a fecalith (hardened stool), lymphoid hyperplasia, or parasites initiates luminal distention, bacterial overgrowth, ischemic necrosis, and perforation within 24 to 36 hours.

Progression from Visceral to Somatic Pain

1. Early Phase (Visceral Pain): Obstruction distends the appendix, stimulating visceral afferent autonomic pain fibers entering the spinal cord at T10. The patient describes dull, vague, poorly localized, crampy discomfort centered around the periumbilical area.
2. Late Phase (Somatic Pain): Within 12 to 24 hours, the inflammatory process breaches the appendiceal wall and inflames the overlying parietal peritoneum. The pain shifts and sharpens, localizing intensely in the Right Lower Quadrant (RLQ).

Pathognomonic Diagnostic Signs

• McBurney's Point Tenderness: Severe localized tenderness elicited by pressure applied at McBurney's point, located precisely one-third of the distance along a line drawn from the right anterior superior iliac spine (ASIS) to the umbilicus.
• Rovsing's Sign: Palpation and continuous deep pressure applied in the Left Lower Quadrant (LLQ) elicits referred sharp pain in the Right Lower Quadrant (RLQ) as gas is displaced retrogradely into the cecum, stretching the inflamed appendix.
• Psoas Sign: The patient lies on their left side while the examiner passively hyperextends the right hip (or has the patient flex the right thigh against resistance). RLQ pain indicates an inflamed retrocecal appendix contacting the right iliopsoas muscle.
• Obturator Sign: With the patient supine and right hip and knee flexed to $90^\circ$, the examiner passively rotates the hip internally. RLQ pain indicates an inflamed pelvic appendix contacting the obturator internus muscle.

                  ACUTE APPENDICITIS: STRICT CONTRAINDICATIONS
  +-----------------------------------------------------------------------------+
  |  1. NO HEAT APPLICATION: Applying a hot water bottle or heating pad to      |
  |     the abdomen induces vasodilation, accelerates inflammation, and causes   |
  |     RAPID RUPTURE AND PERFORATION of the inflamed appendix.                 |
  |  2. NO ENEMAS OR LAXATIVES: Strong cathartics dramatically increase         |
  |     intraluminal peristalsis and pressure, precipitating PERFORATION.       |
  +-----------------------------------------------------------------------------+

Immediate Pre-operative Nursing Management

• Place the patient on strict NPO (nothing by mouth) status immediately.
• Establish intravenous access and initiate isotonic crystalloid fluid resuscitation ($0.9%$ Normal Saline or Ringer's Lactate).
• Position the patient in a semi-Fowler's position to encourage any localized exudate to gravitate downward into the pelvis rather than spreading toward the diaphragm.
• Administer prescribed intravenous broad-spectrum antibiotics (e.g., ceftriaxone plus metronidazole).

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Peptic Ulcer Disease (PUD): Gastric vs. Duodenal Ulcers

Peptic Ulcer Disease involves mucosal erosions penetrating the muscularis mucosae of the gastrointestinal tract, driven primarily by Helicobacter pylori infection and the chronic use of Nonsteroidal Anti-inflammatory Drugs (NSAIDs).

Triple Eradication Therapy for H. pylori

Standard first-line eradication therapy involves a 14-day triple regimen combining acid suppression with two synergistic antimicrobials:

1. Proton Pump Inhibitor (PPI): Omeprazole $20\text{ mg}$ twice daily (or Esomeprazole $40\text{ mg}$ twice daily) administered 30 minutes before meals.
2. Amoxicillin: $1000\text{ mg}$ ($1\text{ g}$) twice daily (substitute Metronidazole $500\text{ mg}$ twice daily if penicillin-allergic).
3. Clarithromycin: $500\text{ mg}$ twice daily.

Nursing Instruction: Emphasize strict compliance for the entire 14 days to prevent bacterial resistance and treatment failure.

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Gastrointestinal Bleeding: Upper vs. Lower Presentations

Distinguishing the anatomical origin of gastrointestinal hemorrhage guides diagnostic and therapeutic pathways:

• Upper GI Bleeding (Proximal to the Ligament of Treitz):
  • Hematemesis: Vomiting of bright red blood (indicates rapid, massive active bleeding, such as ruptured esophageal varices) or "coffee-ground" emesis (dark, clotted blood converted to acid hematin by gastric hydrochloric acid, indicating slower or settled bleeding).
  • Melena: Passage of black, tarry, highly offensive stools. Results from the digestive oxidation and enzymatic breakdown of blood proteins over several hours within the intestinal tract (requires at least $50\text{--}100\text{ mL}$ of blood loss in the upper GI tract).
  • Blood Urea Nitrogen (BUN): Elevated out of proportion to serum creatinine due to systemic absorption of digested blood protein breakdown products across the small bowel.
• Lower GI Bleeding (Distal to the Ligament of Treitz):
  • Hematochezia: Passage of fresh, bright red or maroon blood and clots per rectum, typically originating from the colon, rectum, or anus (diverticulosis, arteriovenous malformations, hemorrhoids, or colorectal malignancy). Exception: Massive upper GI hemorrhage ($> 1000\text{ mL}$) with hypermotility can present with hematochezia.

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Emergency Resuscitation for Massive Upper GI Bleeding

                      MASSIVE GI HEMORRHAGE RESUSCITATION
  1. AIRWAY & BREATHING  --> Left lateral decubitus, high-flow O2, suction ready
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  2. TWO LARGE-BORE IVs  --> 16-gauge or 18-gauge cannulae in antecubital fossae
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  3. RAPID ISOTONIC IVF  --> 0.9% Normal Saline or Ringer's Lactate wide open
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  4. TYPE & CROSS-MATCH  --> 2-4 units Packed Red Blood Cells (PRBCs) stat
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  5. HIGH-DOSE IV PPI    --> Pantoprazole 80 mg IV bolus -> 8 mg/hr infusion
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  6. NASOGASTRIC TUBE    --> Decompress stomach, verify bleeding, room-temp lavage

1. Airway Protection & Breathing: Position the patient in a semi-recumbent or left lateral decubitus position to avoid pulmonary aspiration during vomiting. Provide high-flow oxygen via mask and keep a working suction unit at the bedside.
2. Circulatory Access: Immediately insert two large-bore peripheral intravenous cannulae (16-gauge or 18-gauge) in the antecubital fossae. Do not use small-gauge (20G or 22G) needles for active hemorrhagic shock resuscitation.
3. Fluid Resuscitation: Infuse isotonic crystalloids ($0.9%$ Normal Saline or Ringer's Lactate) rapidly through both lines to restore mean arterial pressure and cardiac output.
4. Laboratory Sampling & Blood Transfusion: Immediately draw blood for emergent type and cross-match (at least 2 to 4 units of packed red blood cells), complete blood count (note: initial hemoglobin/hematocrit may appear deceptively normal until vascular fluid shifts equilibrate), coagulation screen (PT/INR, aPTT), and serum biochemistry.
5. Intravenous Pharmacotherapy: Administer high-dose intravenous Proton Pump Inhibitors (e.g., Pantoprazole $80\text{ mg}$ IV bolus, followed by a continuous infusion of $8\text{ mg/hr}$). Neutralizing gastric $\text{pH} > 6.0$ stabilizes blood clots and prevents fibrinolysis. If esophageal variceal hemorrhage is suspected, administer an Octreotide bolus ($50\text{ mcg}$ IV) and infusion ($50\text{ mcg/hr}$) to induce splanchnic vasoconstriction.
6. Nasogastric Tube (NGT) & Lavage: Insert a large-bore NGT to evacuate blood clots, decompress the stomach, and perform room-temperature saline lavage prior to emergent therapeutic endoscopy.
7. Monitoring: Insert an indwelling catheter to monitor urine output every hour ($> 30\text{ mL/hr}$). Maintain continuous automated blood pressure, pulse oximetry, and cardiac monitoring.