Gastrointestinal bleeding

George Gershman MD, PhD

Introduction

Bleeding from the gastrointestinal (GI) tract in infants and children is always stressful and frightening for patients and their parents and challenging for a physician, especially if bleeding is severe. The attending paediatrician should act promptly and adequately to the degree of haemodynamic instability and initiate a diagnostic work-up according to the mode of presentation and common age-specific causes of GI haemorrhage.

Epidemiology

The incidence of upper GI bleeding among infants and children is unknown. Epidemiological data from the UK and USA indicate that the incidence of upper GI bleeding in adults younger than 29 is approximately 18-23 per 100,000 adults per year, which is almost 4 to 5 times less than among older groups¹. It is reasonable to assume that the incidence of upper GI bleeding in infants and children is even lower. However, the risk of upper GI bleeding is higher (between 6.2 and 10.2%) in infants and children admitted to paediatric intensive care units²^, ³.

Although rectal bleeding is quite common in paediatric practice, the epidemiology of this problem is not well established. According to published data, rectal bleeding was a chief complaint of 0.3% of all visits to a tertiary emergency department during a 10-month period⁴.

Definitions

There are four presentations of blood loss from the GI tract: haematemesis, melena, occult bleeding, and haematochezia.

Haematemesis

Haematemesis is the vomiting of bright-red ‘fresh’ blood, or ‘coffee ground’ emesis of dark-brown ‘old’ blood with haemoglobin (Hb) converted to haematin in the stomach by hydrochloric acid. Usually, haematemesis reflects acute bleeding from the oesophagus, stomach, or proximal duodenum. Swallowing of maternal blood in neonates, and epistaxis in older children, should be ruled out.

Melena

Melena implies liquid, coal black, shiny, sticky, tarry, and foul-smelling stool. It suggests bleeding from the upper GI tract. Occasionally, the site of bleeding can be found in the ileum or right colon. However, in this case stool is black but not tarry. Melena suggests a minimum loss of 50-100 ml⁵ or 2% of blood volume⁶. Stool may remain black or tarry for a few days after massive haemorrhage, even though active bleeding has ceased.

Occult gastrointestinal bleeding

Occult GI bleeding is the presence of an invisible quantity of blood in stool detected by a special technique. It is a synonym of chronic, recurrent losses of small amounts of blood, which often lead to severe microcytic anaemia.

Haematochezia

Haematochezia is the passage of bright red or maroon blood from the rectum. This may be pure blood, bloody diarrhoea or blood mixed with stool. As a rule, it is a sign of lower GI bleeding from the colon or distal ileum.

Assessment

Initial assessment of the child with suspected GI bleeding should be focused on haemodynamic stability and clues for the
aetiology of bleeding. A prompt assessment of estimated blood loss and the degree of haemodynamic instability should be done using objective criteria, such as mental status, skin colour, capillary refill, pulse, blood pressure, and orthostatic manoeuvres (Table 6.1). Special attention should be focused on tachycardia and narrowed pulse pressure, which are the earliest signs of impending shock. Hypotension usually occurs in the late phase of shock in children, and is an ominous finding. The value of the initial haematocrit (Hct) may not accurately reflect the severity of blood loss. Firstly, the Hct does not fall immediately with haemorrhage due to proportionate reductions of plasma and red cell volumes. Secondly, it begins to fall due to compensatory restoration of the intravascular volume by the shift of extravascular fluids into the vascular bed. This process begins shortly after the onset of bleeding. However, it is not complete for 24-72 hours. At this point, plasma volume is larger than normal and the Hct reaches its true nadir assuming that bleeding has stopped.

Diagnosis

Red food and some medications can stain stool or emesis. Cranberries, cranberry juice, cherries, strawberries, beets, tomatoes, sweets, amoxicillin, phenytoin, and rifampin can colour stool and emesis to red or burgundy. Bismuth preparations, activated charcoal, iron, spinach, blueberries, liquorice can simulate bleeding by black staining of emesis and stool. An appropriate history, a normal physical examination, guaiac-negative stool, and/or gastroccult-negative vomitus are sufficient to rule out a true bleeding episode.

Table 6.1 Manifestations of different degrees of GI blood loss

Symptoms and signs	Blood loss <15%	Blood loss <30%	Blood loss >30%
Normal appearance	+	−	−
Some anxiety	±	+	+
Disorientation	−	−	+
Lethargy	−	±	+
Tachycardia	±^*	++	+
Pallor	−	+	++
Livedo reticularis	−	+	++
Cold extremities	−	+	+
Capillary refill	<2 sec	−	+
Hypotension	−	±	++
Narrowed pulse pressure	−	+	+
Elevated diastolic pressure	−	+	−
Low diastolic pressure	−	−	+
^*Tachycardia could be due to agitation or anxiety in children with mild blood loss

It is important to remember that haematemesis and/or melena can be secondary to epistaxis. History of recent tonsillectomy and adenoidectomy or picking nose habits increases the probability of epistaxis. Thorough examination of the nose and oropharynx can help to establish the right diagnosis.

Detailed history and physical examination can help to narrow the diagnostic work-up. For example, treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) is a risk factor for acute gastric ulcers and bleeding from the stomach. Jaundice, hepatomegaly, spider haemangiomata, prominent vessels of the abdominal wall, or ascites are signs of chronic liver disease and suggestive of portal hypertension. Alternatively, GI bleeding in an acutely ill, febrile child with jaundice could be secondary to coagulopathy or the acute ulceration of the stomach or the duodenum due to sepsis. Careful assessment of the
perineum can reveal fissures, fistulas, or perianal induration.

If the source of bleeding is not obvious, the placement of a nasogastric tube is very useful. The largest bore tolerable tube should be placed for adequate gastric lavage: a 10 to 12 Fr sump tube is a reasonable choice for small children and 14 to 16 Fr for older patients. Room temperature saline is the optimal fluid for this procedure. Iced saline lavage is no longer recommended because it compromises platelet function at the bleeding site and may induce hypothermia (especially in infants) and subsequent clinically significant arrhythmia. A bloody or coffee ground aspirate indicates upper GI bleeding, if epistaxis was ruled out. The absence of blood in the stomach does not exclude upper GI bleeding, since the source of haemorrhage can be in the duodenum. The presence of coffee ground fluid in gastric aspirate, which promptly clears by gastric lavage, suggests that bleeding has stopped. Ineffective gastric lavage indicates ongoing bleeding.

Table 6.2 Common causes of GI bleeding in children

Age	Upper GI Bleeding	Low GI bleeding
Neonates (0-30 days)	Swallowed maternal blood Stress ulcers/sepsis Haemorrhagic gastritis Haemorrhagic disease of the newborn	Necrotizing enterocolitis Midgut volvulus Hirschsprung’s disease Vascular malformation
Infants (30 days to 6 months)	Cow’s milk or soy protein allergy Oesophagitis ‘Prolapse gastropathy’	Anal fissure Allergic proctitis or enterocolitis Nodular lymphoid hyperplasia Intussusception
Infants and children (6 months to 6 years)	Epistaxis Oesophagitis ‘Prolapse gastropathy’ Portal hypertension Drug-induced ulcers Gastritis Mallory-Weiss tear	Anal fissures Intussusception Meckel’s diverticulum Nodular lymphoid hyperplasia Polyps Infectious colitis Haemolytic uremic syndrome Henoch-Schönlein purpura
Children and teenagers (7 years to 18 years)	Epistaxis Drug-induced gastropathy and acute ulcers Peptic ulcer Oesophagitis Gastritis Portal hypertension	Infectious colitis Ulcerative colitis Crohn’s disease Anal fissure Polyps

The results of blood test can give some clues to the nature of bleeding. Low Hb and Hct with normal mean cell volume (MCV) are typical for recent blood loss. An elevated blood urea nitrogen (BUN) suggests volume depletion and absorption of the blood proteins in the small intestine, which support the diagnosis of upper GI bleeding. Very low Hb, Hct, and MCV in haemodynamically stable patients, is consistent with chronic GI blood loss. Knowledge of common causes of GI bleeding in age-specific groups of children helps with the diagnostic strategy (Table 6.2).

Only gold members can continue reading. Log In or Register to continue