The symptoms
Free air in the abdominal cavity increases the pressure and thus leads to complaints. The symptoms depend mainly on the amount of free air and the cause. Free air that remains in the abdominal cavity after an operation usually causes only minor complaints.Patients feel bloated and feel an unpleasant pressure in the abdomen.
The perforation (piercing) of an abdominal organ, however, suddenly causes severe abdominal pain. In addition, the abdominal wall is clearly hardened. In addition, patients are in a generally poor condition, which can develop into a circulatory shock.
The pain can sometimes be so severe that the affected person suffers from nausea and has to vomit. Doctors refer to this complex of symptoms as acute abdomen (lat. belly).
An acute abdomen is an absolute emergency situation and requires immediate medical attention. If the small or large intestine is perforated, intestinal contents enter the abdominal cavity, causing peritonitis. Patients develop high fever, suffer from nausea, vomiting and constipation or diarrhoea.
You can read more about the acute abdomen here. Small amounts of free air, such as those remaining in the abdomen after an operation, cause no or only slight pain. If, however, free air enters the abdominal cavity through the perforation of a hollow organ, the affected person feels very severe abdominal pain, which occurs suddenly.
The pain is described as burning and dull and is very difficult to localize. The patient assumes a relieving posture and tries to relieve the pain by bending the abdomen. During the examination by a doctor, the hard abdominal wall is particularly noticeable, which, along with the severe pain, is one of the main symptoms of an acute abdomen.
The diagnosis
The physician can diagnose a pneumoperitoneum using imaging techniques. The air in the abdominal cavity can be easily visualized in an x-ray or computed tomography (CT) of the abdominal cavity and even very small amounts can be easily detected. In an X-ray image taken in a standing position, the free air can be seen as a narrow sickle under the diaphragm. In a CT scan, the free air can be detected as an air bubble under the diaphragm (standing image) or as a lateral brightening above the liver (left-sided image), depending on the patient’s position.
