Carnett's sign

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Carnett's sign
Specialty Gastroenterology
Differential diagnosis Abdominal wall pain

In medicine, Carnett's sign is a finding on clinical examination in which (acute) abdominal pain remains unchanged or increases when the muscles of the abdominal wall are tensed. [1] [2] For this part of the abdominal examination, the patient can be asked to lift the head and shoulders from the examination table to tense the abdominal muscles. An alternative is to ask the patient to raise both legs with straight knees.

Contents

A positive test indicates the increased likelihood that the abdominal wall and not the abdominal cavity is the source of the pain (for example, due to rectus sheath hematoma instead of appendicitis). [3] [4] A negative Carnett's sign is said to occur when the abdominal pain decreases when the patient is asked to lift the head; this points to an intra-abdominal cause of the pain. [1]

History

This test was first described by John B. Carnett in 1926. [5] The first clear description of anterior abdominal wall pain arising from structures other than the underlying viscera was Edgar Ferdinand Cyriax in 1919. [6] Cyriax considered that pain could be mimicked by lesions that arose from the vertebra, ribs or other associated structure or that they were the result of direct irritation of intercostal nerves. By identifying conditions such as alterations in the normal vertebral curves, minor subluxation of vertebral bodies and pressure on the peripheral portions of the intercostal nerves, he was able to employ various mechanical treatments to correct the abnormalities and relieve his patients’ symptoms. Despite this paper little attention was paid to this problem until Carnett developed his simple clinical test. Carnett thought that lower abdominal pain was commonly caused by the lower six thoracic nerves and wanted to be able to distinguish this origin from that arising from the viscera.

Differential diagnosis

The differential diagnosis of a positive Carnett's test includes hernias, nerve entrapment syndrome, irritation of intercostal nerve roots, thoracic disk herniations, [7] anterior cutaneous nerve entrapment, slipping rib syndrome, myofascial pain, trigger points and rectus sheath hematomas.

All abdominal wall hernias may be associated with pain and Carnett's test may be useful in their evaluation. The hernias of the anterior abdominal wall include: epigastric hernias, umbilical hernias, spigelian hernias and incisional hernias. Those of the groin include: direct inguinal hernia, indirect inguinal hernia, femoral hernia and sports hernia. Those of the pelvic wall include: sciatic hernia, obturator hernia and perineal hernia. The support hernias include: vault prolapse, enterocele, cystocele, rectocele and uterine decensus. Although most hernias can be detected clinically with the presence of a lump with an expansile cough impulse some may be difficult to detect either because they are small or because the patient is obese. In cases where the diagnosis is suspected but clinically unconfirmed, additional investigation using radiography or ultrasonography may be helpful. Herniography, in which contrast medium is introduced into the peritoneal cavity, has been successfully used to reveal previously unsuspected inguinal hernias in patients with groin pain of uncertain origin and to detect impalpable interparietal lesions such as Spigelian hernias.

Slipping rib syndrome is characterized by pain along the costal margin and is caused by laxity of the eighth, ninth and tenth ribs at the interchondral junctions. These ribs do not articulate with the sternum but instead are bound to each other by a thin band of fibrous tissue. If this fibrous attachment becomes dislocated, the rib(s) may ride up and irritate the intercostal nerve(s), causing pain. Clinically the patient may be aware of a popping or clicking sensation as the ribs move relative to one another. The symptoms can be reproduced by the "hooking maneuver", in which the examiner will hook their fingers under the costal margin and pull upwards. [8] [9]

Spontaneous rectus sheath hematoma arises from rupture of the epigastric vessels. The patient usually presents with a sudden well-localized abdominal pain associated with a tender nonpulsatile abdominal mass, usually in the lower abdomen. There is frequently a plausible precipitating factor such as local trauma, a bout of coughing or anticoagulant therapy. The diagnosis can be confirmed on ultrasound examination and a conservative approach to treatment can be adopted provided that the hematoma does not enlarge. Carnett's test may be diagnostic in this setting.

Related Research Articles

Hernia Abnormal exit of tissues or organs from the cavity they usually reside in

A hernia is the abnormal exit of tissue or an organ, such as the bowel, through the wall of the cavity in which it normally resides. Hernias come in a number of types. Most commonly they involve the abdomen, specifically the groin. Groin hernias are most commonly of the inguinal type but may also be femoral. Other hernias include hiatus, incisional, and umbilical hernias. Symptoms are present in about 66% of people with groin hernias. This may include pain or discomfort, especially with coughing, exercise or going to the bathroom. Often, it gets worse throughout the day and improves when lying down. A bulging area may appear that becomes larger when bearing down. Groin hernias occur more often on the right than left side. The main concern is strangulation, where the blood supply to part of the bowel is blocked. This usually produces severe pain and tenderness in the area. Hiatus, or hiatal, hernias often result in heartburn but may also cause chest pain or pain with eating.

Abdominal pain Stomach aches

Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues.

Inguinal hernia Medical condition

An inguinal hernia is a protrusion of abdominal-cavity contents through the inguinal canal. Symptoms are present in about 66% of affected people. This may include pain or discomfort especially with coughing, exercise, or bowel movements. Often it gets worse throughout the day and improves when lying down. A bulging area may occur that becomes larger when bearing down. Inguinal hernias occur more often on the right than left side. The main concern is strangulation, where the blood supply to part of the intestine is blocked. This usually produces severe pain and tenderness of the area.

Pancoast tumor Medical condition

A Pancoast tumor is a tumor of the apex of the lung. It is a type of lung cancer defined primarily by its location situated at the top end of either the right or left lung. It typically spreads to nearby tissues such as the ribs and vertebrae. Most Pancoast tumors are non-small-cell lung cancers.

Rectus abdominis muscle

The rectus abdominis muscle, also known as the "abdominal muscle", is a paired muscle running vertically on each side of the anterior wall of the human abdomen, as well as that of some other mammals. There are two parallel muscles, separated by a midline band of connective tissue called the linea alba. It extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of ribs V to VII superiorly. The proximal attachments are the pubic crest and the pubic symphysis. It attaches distally at the costal cartilages of ribs 5-7 and the xiphoid process of the sternum.

Transverse abdominal muscle

The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral abdominal wall which is deep to the internal oblique muscle. It is thought by most fitness instructors to be a significant component of the core.

Abdominal internal oblique muscle

The abdominal internal oblique muscle, also internal oblique muscle or interior oblique, is an abdominal muscle in the abdominal wall that lies below the external oblique muscle and just above the transverse abdominal muscle.

Meralgia paresthetica or meralgia paraesthetica is numbness or pain in the outer thigh not caused by injury to the thigh, but by injury to a nerve that extends from the spinal column to the thigh.

Athletic pubalgia, also called sports hernia, core injury, hockey hernia, hockey groin, Gilmore's groin, or groin disruption is a medical condition of the pubic joint affecting athletes.

Abdomen Part of the body between the chest and pelvis

The abdomen 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 trunk. The area occupied by the abdomen is called the abdominal cavity. In arthropods it is the posterior tagma of the body; it follows the thorax or cephalothorax.

Inguinal triangle

In human anatomy, the inguinal triangle is a region of the abdominal wall. It is also known by the eponym Hesselbach's triangle, after Franz Kaspar Hesselbach.

Inferior epigastric artery Blood vessel

In human anatomy, inferior epigastric artery refers to the artery that arises from the external iliac artery. It anastomoses with the superior epigastric artery. Along its course, it is accompanied by a similarly named vein, the inferior epigastric vein. These epigastric vessels form the lateral border of Hesselbach's triangle, which outlines the area through which direct inguinal hernias protrude.

Conjoint tendon Medial part of the posterior wall of the inguinal canal

The conjoint tendon is a sheath of connective tissue formed from the lower part of the common aponeurosis of the abdominal internal oblique muscle and the transversus abdominis muscle, joining the muscle to the pelvis. It forms the medial part of the posterior wall of the inguinal canal.

Epigastric hernia Medical condition

An epigastric hernia is a type of hernia that causes fat to push through a weakened area in the walls of the abdomen. It may develop in the epigastrium. Epigastric hernias are more common in adults and usually appear above the umbilical region of the abdomen. It is a common condition that is usually asymptomatic although sometimes their unusual clinical presentation can present a diagnostic dilemma for the clinician. Unlike the benign diastasis recti, epigastric hernia may trap fat and other tissues inside the opening of the hernia, causing pain and tissue damage. It is usually present at birth and may appear and disappear only when the patient is doing an activity that creates abdominal pressure, pushing to have bowel movements, or crying.

Arcuate line of rectus sheath

The arcuate line of rectus sheath, the linea semicircularis, the arcuate line, or the semicircular line of Douglas, is a horizontal line that demarcates the lower limit of the posterior layer of the rectus sheath. It is commonly known simply as the arcuate line. It is also where the inferior epigastric vessels perforate the rectus abdominis.

Rectus sheath hematoma Medical condition

A rectus sheath hematoma is an accumulation of blood in the sheath of the rectus abdominis muscle. It causes abdominal pain with or without a mass.

Outline of human anatomy Overview of and topical guide to human anatomy

The following outline is provided as an overview of and topical guide to human anatomy:

Quadrants and regions of abdomen

The human abdomen is divided into quadrants and regions by anatomists and physicians for the purposes of study, diagnosis, and treatment. The division into four quadrants allows the localisation of pain and tenderness, scars, lumps, and other items of interest, narrowing in on which organs and tissues may be involved. The quadrants are referred to as the left lower quadrant, left upper quadrant, right upper quadrant and right lower quadrant. These terms are not used in comparative anatomy, since most other animals do not stand erect.

Anterior cutaneous nerve entrapment syndrome (ACNES) is a nerve entrapment condition that causes chronic pain of the abdominal wall. It occurs when nerve endings of the lower thoracic intercostal nerves (7–12) are 'entrapped' in abdominal muscles, causing a severe localized nerve (neuropathic) pain that is usually experienced at the front of the abdomen.

Slipping rib syndrome Medical condition

Slipping rib syndrome (SRS) is a condition in which the interchondral ligaments have increased laxity, causing the costal cartilage tips to subluxate. This results in pain or discomfort due to pinched or irritated intercostal nerves, straining of the intercostal muscles, and inflammation. The condition affects the 8th, 9th, and 10th ribs, referred to as the false ribs, with the 10th rib most commonly affected.

References

  1. 1 2 Suleiman S, Johnston DE (August 2001). "The abdominal wall: an overlooked source of pain". Am Fam Physician. 64 (3): 431–8. PMID   11515832.
  2. Cartwright SL, Knudson MP (April 2008). "Evaluation of acute abdominal pain in adults". Am Fam Physician. 77 (7): 971–8. PMID   18441863.
  3. Gray DW, Dixon JM, Seabrook G, Collin J (July 1988). "Is abdominal wall tenderness a useful sign in the diagnosis of non-specific abdominal pain?". Ann R Coll Surg Engl. 70 (4): 233–4. PMC   2498809 . PMID   2970820.
  4. Thomson H, Francis DM (November 1977). "Abdominal-wall tenderness: A useful sign in the acute abdomen". Lancet. 2 (8047): 1053–4. doi:10.1016/S0140-6736(77)91885-2. PMID   72957. S2CID   1292751.
  5. Carnett JB (1926) Intercostal neuralgia as a cause of abdominal pain and tenderness. J. Surg. Gynecol. Obstet. 42:625-632
  6. Cyriax EF (1919) On various conditions that may stimulate the referred pains of visceral disease, and a consideration of these from the point of view of cause and effect. Practitioner 102:314-322
  7. Chronic Abdominal Syndrome Due to Nervous Compression. Study of 100 Cases and Proposed Diagnostic-Therapeutic Algorithm Francisco Javier Pérez Lara,nJ. Quintero Quesada, J. A. Moreno Ramiro, R. Bustamante Toledo, A. Del Rey Moreno, and H. Oliva Muñoz J Gastrointest Surg. 2015; 19(6): 1059–1071. PMID   25801595
  8. Beltsios, ET; Adamou, A; Kontou, M; Panagiotopoulos, N (April 2021). "Surgical Management of the Slipping Rib Syndrome". SN Comprehensive Clinical Medicine. 3 (6): 1404–1411. doi:10.1007/s42399-021-00886-4. ISSN   2523-8973.
  9. Obourn, PJ; Benoit, J; Brady, G; Campbell, E; Rizzone, K (March 2021). "Sports Medicine-Related Breast and Chest Conditions—Update of Current Literature". Current Sports Medicine Reports. 20 (3): 140–149. doi:10.1249/JSR.0000000000000824. ISSN   1537-8918.