NURS 6501 Week 8 Gastrointestinal Case Explanation Example

A Balance Tipped From Both Sides: Helicobacter pylori, a Nonsteroidal Anti-Inflammatory Drug, and a Bleeding Duodenal Ulcer in a 49-Year-Old Man

Student Name

College of Nursing, Walden University

NURS 6501: Advanced Pathophysiology

Instructor Name

Month Day, Year

A Balance Tipped From Both Sides: Helicobacter pylori, a Nonsteroidal Anti-Inflammatory Drug, and a Bleeding Duodenal Ulcer in a 49-Year-Old Man

Case Summary

The man described here is invented for this explanation. He is 49, works as a carpenter, and has taken naproxen twice daily for four months for a painful shoulder. For six weeks he has had a gnawing, burning pain in the upper abdomen that comes on two to three hours after meals and wakes him around 2 a.m.; eating or drinking milk eases it for a while. For the past ten days his stools have been black and sticky, and he has felt unusually tired and breathless climbing ladders. His hemoglobin is 10.1 g/dL with small, pale red cells, and a breath test is positive for Helicobacter pylori.

Defense Before Damage

The stomach and duodenum are exposed every day to hydrochloric acid and pepsin concentrated enough to digest tissue, yet the mucosa ordinarily does not digest itself. It is protected by layered defenses (Wallace, 2008). A layer of mucus secreted by surface cells traps bicarbonate, holding a near-neutral pH at the epithelial surface even when the lumen is strongly acidic. In the duodenum, bicarbonate secreted by the mucosa and delivered in pancreatic juice neutralizes acid arriving from the stomach. The epithelial cells are joined by tight junctions that limit back-diffusion of acid. A generous mucosal blood flow carries away any hydrogen ions that penetrate and delivers bicarbonate and oxygen. When small areas of injury occur, surviving cells migrate across the defect within minutes, a process called restitution, and the whole epithelial lining of the stomach is replaced every few days, so larger defects are also repaired quickly when the conditions for healing are present (McCance & Huether, 2019).

Prostaglandins, particularly prostaglandin E2 and prostacyclin produced through cyclooxygenase-1, sustain most of these defenses. They stimulate mucus and bicarbonate secretion, maintain mucosal blood flow, and support epithelial repair (Wallace, 2008). An ulcer, therefore, is not simply the result of acid; it is the result of aggressive factors exceeding a defense system that usually holds.

Two Exposures, Two Sides of the Balance

Helicobacter pylori works mainly on the aggressive side. The organism colonizes the gastric mucosa beneath the mucus layer, protected by its urease, which generates ammonia to buffer the acid around it. In most people with duodenal ulcers, infection is concentrated in the gastric antrum. Antral inflammation reduces the number of somatostatin-producing D cells, and because somatostatin normally restrains gastrin release, gastrin levels rise and drive parietal cells to secrete more acid (Lanas & Chan, 2017). The duodenum therefore receives a larger acid load than usual. Repeated acid exposure causes patches of gastric-type epithelium to develop in the duodenum, which the bacterium can then colonize, adding local inflammation to the excess acid.

Naproxen works mainly on the defensive side. Nonsteroidal anti-inflammatory drugs inhibit cyclooxygenase, and inhibition of cyclooxygenase-1 in the gastric and duodenal mucosa reduces the prostaglandins that maintain mucus, bicarbonate, blood flow, and repair (Wallace, 2008). The drug also has a direct topical effect on epithelial cells, but the systemic loss of prostaglandins is the more important mechanism, which is why ulcers occur even with enteric-coated or injected forms. Together, the two exposures compound rather than simply add: one increases the acid arriving at the duodenum while the other weakens the mucosa that must withstand it. Each is an independent risk factor for peptic ulcer, and the combination increases risk further (Lanas & Chan, 2017).

Why Food Changes the Pain

The pain pattern follows from the location of the defect and the timing of acid delivery. Shortly after a meal, food in the stomach buffers acid, and the pyloric sphincter releases gastric contents gradually, so the duodenum is exposed to relatively little free acid. Two to three hours later, the stomach empties while acid secretion stimulated by the meal continues, and unbuffered acid reaches the ulcer crater in the duodenal bulb, stimulating nerve endings exposed in its base. Eating again restores buffering and eases the pain for a time. Nighttime pain reflects the circadian peak in acid secretion around midnight to early morning, when the stomach is empty and nothing buffers it. A gastric ulcer, by contrast, often hurts soon after eating because food directly stimulates acid secretion onto a lesion in the stomach itself, which is why meal relief points toward the duodenum in this case. Smoking and severe physical stress would each have tipped the same balance further; neither appears in his history, so the two exposures above carry the explanation.

From a Bleeding Base to Tiredness

As the ulcer deepens, it erodes small vessels in the submucosa at its base. Naproxen worsens bleeding by inhibiting platelet thromboxane production, impairing the platelet plug that would otherwise seal a small vessel. The result is slow, continuing blood loss into the duodenum. As blood travels through the small intestine and colon, gastric acid and bacterial action convert hemoglobin to hematin and other iron-containing compounds, which turn the stool black and give it a tarry, sticky consistency. This is melena, and it indicates bleeding from a source high in the gastrointestinal tract, since blood from lower sources has less time to be altered.

The fatigue follows from what the bleeding removes. Each milliliter of blood carries iron, and slow, repeated loss depletes iron stores faster than dietary absorption can replace them. Once stores are exhausted, the bone marrow produces red cells with less hemoglobin, which are smaller and paler than normal. Reduced oxygen-carrying capacity limits delivery to muscle during exertion, which is why he tires and becomes breathless on ladders, and the small, pale cells on his blood count are the laboratory trace of that iron loss. A local lesion in the duodenum has become a whole-body symptom.

What the Case Does Not Show

The case does not show perforation, which would present with sudden severe pain and a rigid abdomen as acid and duodenal contents escaped into the peritoneum. Nor does it show obstruction of the gastric outlet, which scarring from recurrent ulcers can cause and which would produce vomiting of undigested food. His vital signs and the gradual course do not suggest brisk hemorrhage. The explanation above is limited to the findings he actually has, and nothing in the case establishes how deep the ulcer is or whether it has penetrated beyond the duodenal wall.

References

Lanas, A., & Chan, F. K. L. (2017). Peptic ulcer disease. The Lancet, 390(10094), 613-624. https://doi.org/10.1016/S0140-6736(16)32404-7

McCance, K. L., & Huether, S. E. (2019). Pathophysiology: The biologic basis for disease in adults and children (8th ed.). Elsevier.

Wallace, J. L. (2008). Prostaglandins, NSAIDs, and gastric mucosal protection: Why doesn't the stomach digest itself? Physiological Reviews, 88(4), 1547-1565. https://doi.org/10.1152/physrev.00004.2008