Approach to melena and hematemesis (pediatrics): Clinical sciences

Melena refers to a dark, black, and tarry stool that contains partially digested blood, while hematemesis refers to the vomiting of blood. Patients with hematemesis might vomit bright red blood, but exposure to gastric acid can oxidize hemoglobin, causing the emesis to resemble coffee grounds.

The presence of melena or hematemesis suggests a source of bleeding proximal to the ligament of Treitz, in the esophagus, stomach, or duodenum.

If a pediatric patient presents with melena or hematemesis, first perform an ABCDE assessment to determine if they are stable or unstable. If unstable, stabilize the airway, breathing, and circulation. Next, obtain IV or IO access and consider administering IV fluids, as well as a transfusion of packed red blood cells.

Patients with brisk gastrointestinal bleeding can decompensate quickly, so remember to monitor them closely for signs of hemorrhagic shock, such as tachypnea, tachycardia, and hypotension. Place your patient on continuous vital sign monitoring, and provide supplemental oxygen if needed.

Consider placing a nasogastric tube, with or without nasogastric lavage. Finally, consider an emergent endoscopy as a diagnostic or therapeutic intervention, as well as an infusion of a proton pump inhibitor or vasopressin.

Alright, let’s go back to the ABCDE assessment and look at stable patients. First, perform a focused history and physical examination and obtain a fecal occult blood test.

Patients or their caregivers usually report vomiting, with emesis containing bright red blood or debris that resembles coffee grounds. Some may describe black or tarry stools.

Physical exam reveals no active bleeding from the oropharynx or nasal passages, but you might detect epigastric or abdominal tenderness, as well as abdominal distension. Finally, the fecal occult blood test is usually positive.

With these findings, consider an upper gastrointestinal bleed, and perform an endoscopy within 24 to 48 hours.

Here are a couple of clinical pearls to keep in mind! During your initial evaluation of melena or hematemesis, consider ordering labs like a CBC, CMP, PT, and PTT, since abnormal results can identify other underlying conditions. As an example, the CBC might reveal anemia or thrombocytopenia, while elevated creatinine suggests acute kidney injury. Finally, if PT or PTT are prolonged, consider the possibility of an inherited or acquired bleeding disorder.

Now, melena and hematemesis don’t always indicate an upper gastrointestinal source of bleeding. In some cases, they’re caused by upper airway bleeding, like epistaxis, or procedures like dental surgery or tonsillectomy.

In newborns, minor hematemesis or melena may represent maternal blood that was swallowed during delivery or nursing.

However, severe gastrointestinal bleeding may indicate hemorrhagic disease of the newborn, especially if your patient did not receive vitamin K supplementation.

Finally, pigments from ingested substances like red crayons or medications occasionally cause dark stools or red emesis that mimic melena or hematemesis. One classic example is iron supplementation, which can cause stool to appear black.

Alright, your next step is to assess for the presence of liver disease, which can help you narrow down potential causes of melena or hematemesis.

Lets first look at patients with a known history of liver disease.

In addition to a positive history, your patient may also present with exam findings suggesting liver disease, like jaundice, hepatosplenomegaly, caput medusae, ascites, or spider angioma.

If your patient has any of these findings, you should immediately consider esophageal varices. These patients typically describe heavy, brisk bleeding, and patients often report chronic liver disease or poor weight gain.

On endoscopy, you’ll find dilated esophageal vessels, red streaks, and red spots. With these findings, diagnose esophageal varices.

Here’s a clinical pearl! Since variceal bleeding can be profuse, an endoscopy should be performed as soon as you suspect varices, without delay.

Let’s switch gears and look at patients who have no evidence of liver disease.

In this case, you should assess for the presence of epigastric pain. If your patient reports no epigastric pain, consider the possibility of a vascular malformation.

Affected patients may report skin lesions or occasionally, a family history of vascular malformations. Physical exam may reveal cutaneous lesions, such as port wine stains, hemangiomas, or telangiectasias.

If the endoscopy demonstrates a bluish-purple submucosal mass with telangiectasias or small ectatic vessels, and oozing or spurting blood, diagnose a vascular malformation.