Haematemesis and melaena
Haematemesis is the vomiting of blood, either bright or altered blood (so-called ‘coffee grounds’ vomitus), due to the action of acid on the blood. Melaena is the passage of black tarry stools. The tarriness is characteristic and distinguishes melaena from the passage of black stools due to dietary agents, including the ingestion of iron. Haematemesis occurs from a point that is usually not distal to the duodenum but melaena may occur not only from a proximal bleeding site, but rarely from a small intestinal cause.
Haematemesis and melaena is a common and important symptom complex presenting either as an acute catastrophic illness or more electively with prolonged minor bleeding. Patients with this condition make a major demand on hospital beds.
Patients with haematemesis and melaena require admission to hospital. The condition has a high mortality and demands a systematic approach to the initial resuscitation process, the diagnostic method and the therapeutic program. The overall management of this condition has been revolutionised by the introduction of new endoscopic techniques to control bleeding.
Causes of haematemesis
Swallowed blood from, for example, a bleeding site in the post-nasal space, must be excluded as a cause for haematemesis.
The list of causes of haematemesis and melaena is long (Table 62, “Common causes of haematemesis and melaena”). The common causes are:
- peptic ulcer (i.e. gastric or duodenal ulceration)
- oesophageal varices
- gastritis or duodenitis.
|Oesophageal||Reflux oesophagitis - other associated hiatus hernia|
|Oesophageal varices (portal hypertension)|
|Mallory-Weiss mucosal tear|
|Gastric||Gastric ulcer - usually benign|
The site of bleeding usually lies in the oesophagus, stomach or duodenum.
The most common cause of bleeding in the oesophagus is from oesophageal varices secondary to portal hypertension. Oesophageal varices are the cause of some 10–30% of major haematemesis episodes in most Western countries. Less commonly, oesophagitis secondary to gastro-oesophageal reflux is associated with haemorrhage. Oesophageal cancer rarely presents with bleeding.
Gastric ulcer is one of the most common causes of haematemesis and melaena. The ulcer may be in the body or the antrum of the stomach. The pre-pyloric position is the most common. Gastric ulcer may be the site of torrential haemorrhage because of the invasion of a major vessel (e.g. the splenic artery). Gastritis is also a common cause of gastric bleeding.
The common use of non-steroidal anti-flammatory drugs (NSAID) are associated with haematemesis and melaena due to gastric ulceration in many elderly patients. Despite the use of Cox2 inhibitor anti-arthiritic agents, ulceration can still occur, particularly when these drugs are prescribed in conjunction with aspirin. A Mallory-Weiss tear is a tear of the gastrooesophageal junction as a result of retching, with differential intra-abdominal and thoracic pressures leading to the tear. Characteristically the haematemesis appears after initial blood-free vomit.
Gastric varices may be associated with portal hypertension and coexist with oesophageal varices. Gastric cancer is not a common cause of haematemesis and melaena but a gastric ulcer may bleed and prove to be malignant on biopsy.
Duodenal ulcer is traditionally the most common cause of haematemesis and melaena. The ulcer is usually on the posterior wall of the duodenum and characteristically invades the gastroduodenal artery. Haemorrhage may be profuse but is usually self-limited.
In Western societies the number of patients presenting with duodenal ulcers is decreasing. However, there is an increasing number of patients presenting with gastric ulceration, particularly elderly patients on NSAID.
In most hospitals, patients with haematemesis and melaena are managed in a special unit and along a clinical pathway or algorithm to systemise management (Algorithm for management of haematemesis and melaena.).
The circulatory state of the patient is assessed. The extent of blood loss can be estimated on the basis of the patient's clinical status. Apprehension, air hunger, cerebral changes, marked pallor, thready pulse and hypotension indicate significant blood loss (up to 50% of blood volume). Maintenance of normal peripheral circulation without cerebral findings but with mild tachycardia and postural drop in blood pressure is consistent with 10–20% blood volume loss. This estimation of circulatory status gives an indication of the urgency of fluid replacement.
The cause of bleeding must then be diagnosed. This is often not obvious. However, the presence of a previous history of peptic ulceration or evidence of hepatic cirrhosis may indicate a likely site of blood loss.
Management of the patient
Optimal management of the patient with haematemesis and melaena involves vigorous resuscitation and early diagnosis.
Intravenous therapy is started with normal saline and/or colloid (Haemaccel or 5% albumin solution). Blood is then taken for cross-matching. Depending on the clinical state of the patient, urgent cross-match can be performed and blood given immediately. Rarely, O-negative blood is required for a patient in extremis.
Monitoring is essential to estimate the effectiveness of blood replacement. Successful resuscitation can be observed by noting improvement in the clinical state of the patient, return of blood pressure and pulse rate towards normal, and the presence of a satisfactory urine output.
Early endoscopy has been shown to be a safe and effective way of making a diagnosis. Once the patient's clinical condition is stabilised, this procedure is carried out either urgently if there is concern about continuing bleeding, or on the next elective endoscopy list if there is no indication for urgent intervention.
The patient is sedated with intravenous medication and the gastroscope is passed. The oesophagus, stomach and duodenum are carefully examined. There may be some difficulty in this examination process with the presence of either old blood, blood clot or fresh bleeding. Adequate suction and irrigation is required in order to define the bleeding point. Rarely the bleeding point is not identifiable. Throughout this procedure the patient requires adequate monitoring, the airway must be controlled and oxygen administered.
Usually a therapeutic procedure can be carried out at the time of endoscopy. Injection of alcohol or adrenaline close to the bleeding point will usually result in cessation of bleeding. If oesophageal varices are present, these may be injected or banded. If it is evident that a major problem exists, such as a large gastric ulcer or persistent bleeding from a large duodenal ulcer, or bleeding from oesophageal varices, then immediate consultation with the surgical team is mandatory and combined management is implemented.
Indications for surgical intervention
The indications for surgical intervention include massive haemorrhage not responding to conservative means, patients requiring more than six units of blood, and elderly patients, particularly if a large ulcer is present, because they tolerate blood loss poorly.
Where a second haemorrhage occurs in hospital or there is concern about persistent ongoing bleeding, surgery is necessary.
Results of treatment
Most bleeding sites causing haematemesis and melaena stop bleeding spontaneously or with interventional endoscopy. The modern medical management of peptic ulcers, including the eradication of Helicobacter pylori, is so effective that surgery is to be avoided unless absolutely indicated to save life.
The results of treatment of bleeding from varices due to portal hypertension will depend on the degree of liver disease and the extent of the varices. These patients usually require an intensive care unit program of therapy. In the short term, injection or banding of varices is usually effective in stopping the bleeding. If bleeding persists then the use of a Sengstaken-Blakemore tube or Linton balloon to apply direct pressure to the cardia will usually result in tamponade of the bleeding point and control the haemorrhage. Occasionally emergency surgery is required, with some form of direct ligation of varices or gastric disconnection in order to control bleeding. Direct ligation of varices involves opening the stomach or oesophagus and directly suturing the varices. A gastric disconnection procedure involves devascularising the stomach completely in order to interrupt the venous channels supplying the varices.