Abdominal Examination
Abdominal examination begins with inspection.
Abnormalities such as distention, scars, stretch marks, hematomas and engorged veins can provide
the first evidence for conditions involving the abdomen.
The abdomen can be separated into individual regions to more precisely depict anatomical
location. A classical distribution consists of four quadrants that are separated right
from left (by a single vertical plane), and superior from inferior (by a horizontal plane).
Another common scheme divides the anterior abdominal wall into nine anatomical regions.
As part of this distribution, the upper, middle, and lower abdomen are separated into thirds.
These regions enable more specific findings during examination.
In contrast to examining the chest, auscultation of the abdomen should occur before palpation.
Otherwise, stimulation of the bowels may trigger a false increase in peristalsis.
Bowel sounds are physiologically heard as clicks and gurgles in an irregular pattern.
Hypoactive or absent sounds can indicate a paralytic Ileus, resulting postoperatively
or from a condition like peritonitis. Hyperactive sounds may indicate gastrointestinal infection,
or trying to overcome obstruction, which could imply a mechanical ileus.
Besides bowel sounds, an aortic bruit due to an aneurysm or stenosis may be auscultated
at the upper umbilical area. Listen for possible renal artery bruits bilaterally from this
area.
Assessing percussion sounds is helpful in determining the size, position and density
of abdominal contents. Solid organs, fluids or tumors lead to dull sounds that may sound
similar to percussion sounds of the thigh.
In contrast, the percussion sound of hollow, air-filled intestines is more drum-like in
nature, and is therefore known as tympanic or tympanitic. Tympanitic sounds are even
more extreme in conditions involving the accumulation of excess gas within the bowels, as seen in
abdominal bloating.
A distended abdomen has various causes, including adiposity, bloating, a tumor, or ascites.
In addition to percussion, being able to form a belly fold may help in determining the cause.
Physiologically, the examiner should be able to form a small belly fold.
In contrast, in patients with with ascites, it would be difficult, or impossible, to do so.
The most reliable, clinical sign, to detect ascites is checking for shifting dullness.
If a patient with ascites is lying supine, fluid accumulates in the flank regions,
leading to dullness on percussion.
At the same time, the air-filled bowel loops are forced upwards by the free fluid due to buoyancy,
resulting in tympanitic percussion.
To locate specifically where dullness shifts to tympany, or the air fluid level, percussion should be performed
from the sides, towards the middle.
To confirm that the dullness is caused from ascites, ask the patient to switch to a lateral decubitus position.
If ascites is present, the air-filled bowel loops will shift accordingly, and remain at the surface of the fluid.
As a result, the air-fluid level will shift as well. This is known as 'shifting dullness'.
Palpation should be conducted last. It can be uncomfortable for some patients, causing
them to tense up. To help relax the abdominal muscles, you can try distracting patients
with a conversation or asking them to breathe deeply.
To prevent the patient from tightening the abdominal muscles, otherwise known as 'guarding',
it is important to begin palpating at a point far from any painful areas, and to avoid using cold hands.
Begin by shallowly palpating the surface.
Doing so may already illicit involuntary guarding that could indicate peritonitis.
Pay attention to the patient's expressions, such as flinching, as they may help in interpreting pain.
Now continue by systematically palpating deeper to assess the abdominal organs.
Take note of any pressure pain, rebound tenderness, or, abdominal masses.
Palpating a normal-sized liver is sometimes difficult. It usually extends beyond the rib
cage in the area of the right midclavicular line and traverses the epigastric region.
Even in this region, the liver can only be felt through deep palpation. Start the examination
by asking the patient to exhale. Afterwards, as the patient is inhaling, slowly slide your
fingers towards the right rib cage so they are near the liver’s edge.
When the lower liver edge is felt, its surface structure, consistency and size can be evaluated.
Since a severely enlarged liver can extend as far as the lower abdomen, palpation should
start further down in the right lower quadrant. If necessary, bimanual palpation can help
locate the liver in patients with a larger abdominal diameter.
Another possibility to determine the size of the liver is the scratch test, although
its reliability and precision remain controversial. One method is to place the stethoscope on
the chest just below the xiphoid process. Lightly scratch the abdominal skin in the
right lower quadrant with a fingernail, parallel to the expected liver border. The air-filled
bowel loops under the fingertip poorly transmit the sound waves to the stethoscope.
Proceed with the scratch test by gradually moving cranially towards the rib cage.
The transition from bowel to liver tissue, through which sound waves can travel more
intensely, is notable for a sudden increase in loudness of the scratching and marks the
lower liver border. Continue the scratch test further upwards,
until a sudden drop in loudness is observed, marking the transition from liver to lung.
This is where the upper liver border is located. In this patient, percussion, palpation and
scratch test reveal a physiological liver size: the craniocaudal length of the right
liver lobe in the midclavicular line is around 10 cm.
These examination techniques can help in examining a suspected hepatomegaly, but do not replace
the standard clinical practice of abdominal ultrasound, which helps assess the liver more
precisely. Assess the gallbladder next, which should
only be palpable in a pathological state, for example, if hydrops is present.
Palpation takes place somewhat medial to the midclavicular line below the right rib cage.
Evaluating for tenderness on palpation is important, since it may indicate cholecystitis.
Cholecystitis can also be evaluated by testing for a positive Murphy Sign.
To test this sign, first ask the patient to exhale, while palpating the gall bladder area, medial to the midclavicular line.
Now, instruct the patient to take a deep breath, so the gallbladder is pushed down
and against the examiner's fingertips, as the lungs expand.
If cholecystitis is present, the patient will experience a sharp and sudden pain, causing
an abrupt halt to inhalation. This reaction is known as a positive Murphy Sign.
The spleen is generally not palpable in healthy adults.
A pathologically enlarged spleen is palpated under the left costal margin during inspiration
as the inferior edge descends to the examiner's fingertips.
If an enlarged spleen is already suspected, palpation should begin further down.
The examination may be facilitated by gently lifting the left flank of the patient, ventrally.
Percussion of the kidneys, located in the retroperitoneum, can also be done on abdominal examination.
Keep in mind that the upper pole of the left kidney can be found at the level of the 12th thoracic vertebra.
Because of the liver, the right kidney lies around 3 cm, or about 1 inch, lower than the left.
Careful percussion of the flanks in the lower rib cage area should not elicit pain in a healthy patient.
Pain on percussion, however, should raise suspicion for a pathological process, such as pyelonephritis or urolithiasis.