Pneumoperitoneum is
pneumatosis
Pneumatosis is the abnormal presence of air or other gas within tissues.
In the lungs, emphysema involves enlargement of the distal airspaces, (abnormal presence of air or other gas) in the
peritoneal cavity
The peritoneal cavity is a potential space between the parietal peritoneum (the peritoneum that surrounds the abdominal wall) and visceral peritoneum (the peritoneum that surrounds the internal organs). The parietal and visceral peritonea are la ...
, a
potential space
In anatomy, a potential space is a space between two adjacent structures that are normally pressed together (directly apposed). Many anatomic spaces are potential spaces, which means that they are potential rather than realized (with their realiz ...
within the
abdominal cavity. The most common cause is a perforated
abdominal organ
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
, generally from a perforated
peptic ulcer
Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines ...
, although any part of the
bowel
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...
may perforate from a benign ulcer,
tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
or
abdominal trauma. A perforated
appendix seldom causes a pneumoperitoneum.
Spontaneous pneumoperitoneum is a rare case that is not caused by an abdominal organ rupture. This is also called an idiopathic spontaneous pneumoperitoneum when the cause is not known.
In the mid-twentieth century, an "artificial" pneumoperitoneum was sometimes intentionally administered as a treatment for a
hiatal hernia
A hiatal hernia or hiatus hernia is a type of hernia in which abdominal organs (typically the stomach) slip through the diaphragm into the middle compartment of the chest. This may result in gastroesophageal reflux disease (GERD) or laryngop ...
. This was achieved by insufflating the abdomen with
carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...
. The practice is currently used by surgical teams in order to aid in performing
laparoscopic surgery
Laparoscopy () is an operation performed in the abdomen or pelvis using small incisions (usually 0.5–1.5 cm) with the aid of a camera. The laparoscope aids diagnosis or therapeutic interventions with a few small cuts in the abdomen.Medli ...
.
Causes
* Perforated
duodenal ulcer – The most common cause of rupture in the abdomen. Especially of the anterior aspect of the first part of the duodenum.
* Perforated
peptic ulcer
Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines ...
*
Bowel obstruction
* Ruptured
diverticulum
*
Penetrating trauma
* Ruptured
inflammatory bowel disease (e.g.,
megacolon
Megacolon is an abnormal dilation of the colon (also called the large intestine). This leads to hypertrophy of the colon. The dilation is often accompanied by a paralysis of the peristaltic movements of the bowel. In more extreme cases, the feces ...
)
*
Necrotising enterocolitis
Necrotizing enterocolitis (NEC) is a devastating intestinal disease that affects premature or very low birth weight infants.Gephart S.M., Quinn M. A call to action to fight for equity and end necrotizing enterocolitis disparities. ''Adv. Neonata ...
/pneumatosis coli
*
Bowel cancer
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel m ...
*
Ischemic bowel
*
Steroids
* After
laparotomy
A laparotomy is a surgical procedure involving a surgical incision through the abdominal wall to gain access into the abdominal cavity. It is also known as a celiotomy.
Origins and history
The first successful laparotomy was performed without ane ...
* After
laparoscopy
Laparoscopy () is an operation performed in the abdomen or pelvis using small incisions (usually 0.5–1.5 cm) with the aid of a camera. The laparoscope aids diagnosis or therapeutic interventions with a few small cuts in the abdomen.Medlin ...
* Breakdown of a
surgical anastomosis
* Bowel injury after
endoscopy
An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are inse ...
*
Peritoneal dialysis
Peritoneal dialysis (PD) is a type of dialysis which uses the peritoneum in a person's abdomen as the membrane through which fluid and dissolved substances are exchanged with the blood. It is used to remove excess fluid, correct electrolyte pro ...
(PD), although the prevalence of pneumoperitoneum is estimated to be less than 4% among people with PD in a more recent study in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
.
* Vaginal insufflation (air enters via the
fallopian tubes
The fallopian tubes, also known as uterine tubes, oviducts or salpinges (singular salpinx), are paired tubes in the human female that stretch from the uterus to the ovaries. The fallopian tubes are part of the female reproductive system. In ot ...
; e.g., water-skiing, oral sex)
* Colonic or peritoneal
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...
* From chest (e.g., bronchopleural
fistula
A fistula (plural: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow or ...
)
* Non-invasive PAP (positive airway pressure) can force air down duodenum as well as down trachea.
Spontaneous pneumoperitoneum
A spontaneous pneumoperitoneum is a rare case that is not caused by an abdominal organ rupture. This is also called an idiopathic spontaneous pneumoperitoneum when the cause is not known. Causes of a spontaneous pneumoperitoneum, with no
peritonitis
Peritonitis is inflammation of the localized or generalized peritoneum, the lining of the inner wall of the abdomen and cover of the abdominal organs. Symptoms may include severe pain, swelling of the abdomen, fever, or weight loss. One part o ...
include a
barotrauma
Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in tens ...
due to
mechanical ventilation
Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV), is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move a ...
, and a tracheal rupture following an emergency
intubation
Intubation (sometimes entubation) is a medical procedure involving the insertion of a tube into the body. Patients are generally anesthetized beforehand. Examples include tracheal intubation, and the balloon tamponade with a Sengstaken-Blake ...
. In the ventilation case, air had passed from the chest into the abdominal cavity through the
diaphragm. In the tracheal rupture air had passed along the
great vessels
Great vessels are the large vessels that bring blood to and from the heart. These are:
*Superior vena cava
*Inferior vena cava
*Pulmonary arteries
* Pulmonary veins
*Aorta
Transposition of the great vessels is a group of congenital heart defec ...
.
Diagnosis
When present, pneumoperitoneum can often be seen on
projectional radiography
Projectional radiography, also known as conventional radiography, is a form of radiography and medical imaging that produces two-dimensional images by x-ray radiation. The image acquisition is generally performed by radiographers, and the images a ...
, but small amounts are often missed, and
CT scan is nowadays regarded as a criterion standard in the assessment of a pneumoperitoneum. CT can visualize quantities as small as 5 cm³ of air or gas.
Signs that can be seen on projectional radiography are shown below:
The ''double wall sign'' marks the presence of air on both sides of the
intestine. However, a false double wall sign can result from two loops of bowel being in contact with one another. The sign is named after
Leo George Rigler Leo George Rigler (16 October 1896, Minneapolis – 25 October 1979) was an American radiologist remembered for describing Rigler's sign.
Biography
Leo Rigler attended the University of Minnesota, receiving a B.S. in 1917, B.M. in 1919 and ...
. It is not the same as
Rigler's triad
Rigler's triad is a combination of findings on an abdominal radiograph of people with gallstone ileus, a condition where a large gallstone causes bowel obstruction. Rigler's triad consists of: (1) small bowel obstruction, (2) a gallstone outside ...
.
The ''football sign'' is when the abdomen appears as a large oval
radiolucency
Radiodensity (or radiopacity) is opacity (optics), opacity to the radio wave and X-ray portion of the electromagnetic spectrum: that is, the relative inability of those kinds of electromagnetic radiation to pass through a particular material. Radi ...
reminiscent of an
American football
American football (referred to simply as football in the United States and Canada), also known as gridiron, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, the team wi ...
on a supine projectional radiograph.
The football sign is most frequently seen in
infants with spontaneous or
iatrogenic
Iatrogenesis is the causation of a disease, a harmful complication, or other ill effect by any medical activity, including diagnosis, intervention, error, or negligence. "Iatrogenic", ''Merriam-Webster.com'', Merriam-Webster, Inc., accessed 27 ...
gastric perforation causing pneumoperitoneum. It is also seen in bowel obstruction with secondary perforation, as in
Hirschprung disease, midgut volvulus,
meconium ileus
Meconium is the earliest stool of a mammalian infant resulting from defecation. Unlike later feces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, amniotic ...
and
intestinal atresia. Iatrogenic causes like endoscopic perforation may also give football sign.
The ''Cupola sign'' is seen when air is accumulated under the central tendon of the diaphragm.
Image:Pneumoperitoneum chest X-ray.jpg, Another pneumoperitoneum on chest X-ray.
Image:Pneumoperitoneum lateral decubitus.jpg, Pneumoperitoneum seen on X-ray with the patient lying on his left side.
File:Double wall sign annotated.jpg, Double wall sign. This is a secondary sign of pneumoperitoneum. Patient is supine, and air within the abdomen and lumen of the bowel accentuate both sides of the bowel wall.
File:UOTW 68 - Ultrasound of the Week 2.webm, Ultrasound finding of pneumoperitoneum known as "peritoneal stripe sign"
Differential diagnosis
As differential diagnoses, a
subphrenic abscess, bowel interposed between diaphragm and liver (
Chilaiditi syndrome), and linear
atelectasis
Atelectasis is the collapse or closure of a lung resulting in reduced or absent gas exchange. It is usually unilateral, affecting part or all of one lung. It is a condition where the alveoli are deflated down to little or no volume, as distinct ...
at the base of the lungs can simulate free air under the diaphragm on a chest X-ray.
Treatment
Treatment depends on the cause of the condition.
Terminology
Pneumoperitoneum can be described as peritoneal emphysema,
just as
pneumomediastinum
Pneumomediastinum (from Greek ''pneuma'' – "air", also known as mediastinal emphysema) is pneumatosis (abnormal presence of air or other gas) in the mediastinum, the central part of the chest cavity. First described in 1819 by René Laennec, ...
can be called mediastinal emphysema, but ''pneumoperitoneum'' is the usual name.
See also
*
Cupola sign
*
Football sign
*
Pneumoretroperitoneum
*
Rigler's sign
Pneumoperitoneum is pneumatosis (abnormal presence of air or other gas) in the peritoneal cavity, a potential space within the abdominal cavity. The most common cause is a perforated abdominal organ, generally from a perforated peptic ulcer, altho ...
References
External links
{{Digestive system diseases
Disorders of fascia
Peritoneum disorders