The abdomen must not be palpated before thorough inspection or before painful sites have been identified from the history, by the patient pointing them out and by percussion. Throughout percussion and palpation watch the patient’s face for indications of tenderness and how the examination should proceed. Start with gentle light superficial palpation, proceed to deeper palpation of all regions and then examine specific organs, using bimanual techniques as appropriate.
Stand on the right side of the patient and use the flat of your right hand, with fingers together, firm but capable of molding to the contours of the abdominal wall. Feel each quadrant in turn (figure 28a–d). If there is a painful area, leave this till last. Some normal subjects find it difficult to relax the abdominal wall, particularly if the environment or the examiner’s hands are cold, or if there is a lack of privacy or any other source of embarrassment. Reassure the patient. Ask them to breathe deeply through an open mouth, and, if necessary, to bend their knees to more than a right angle, and place their feet flat on the couch. Feel specifically for tenderness, guarding, rigidity and obvious masses.
On palpation, tenderness produces local voluntary tensing (guarding) of the abdominal wall. There may also be involuntary reflex contraction (rigidity), unrelated to the external pressure or to tenderness, this indicates peritoneal inflammation (peritonism). The most extreme form is seen in the board-like rigidity often associated with a perforated peptic ulcer. In the latter, it is not possible to depress any part of the abdominal wall and thumping on this board-like abdomen on any quadrant does not necessarily produce any focal tenderness. Guarding and rigidity, however, may be localized, as over an acutely inflamed appendix in the right iliac fossa or diverticulitis in the left iliac fossa.
Each region of the abdomen must be systematically examined to identify normal and abnormal viscera and masses. A rigid, flat yet malleable right hand is again used, but placed more steeply than in gentle superficial palpation. Your fingers identify the shape and size of each structure by compressing them through the lax anterior abdominal wall onto the firm posterior abdominal wall, made up of vertebral bodies and muscles. Pressure can be increased by pressing the fingers of the left hand onto the back of the right (figure 29a–d). When examining a mass or a specific organ, note the size, shape, consistency and any associated tenderness.
Both hands may be used, to measure the approximate sizes of normal and abnormal viscera, to hold mobile structures and to assess expansile pulsation, by pressing on either side of the structure. As with all other aspects of abdominal palpation, watch the patient’s face throughout the examination to recognize and minimize discomfort, and ensure that the subject is relaxed and breathing through an open mouth.
Emphasis has already been given to the use of percussion rebound to localize tenderness. The classical method for detecting rebound tenderness is to press firmly and deeply with the hand, possibly the left hand pressing down on the back of the right, and suddenly releasing the pressure. The swing of the abdominal wall produces tension on local structures and elicits pain from any sensitive peritoneum. The method is useful in detecting mild and unsuspected tenderness. However, it must never be used when obvious tenderness exists, as it can produce severe discomfort.
The order of palpation is directed by previous information, based on the site of pain and tenderness, and abnormalities picked up on observation, percussion and gentle superficial palpation; particularly the presence of masses and hernias. It is common, after superficial palpation, to start by examining for the liver and spleen in the right and left hypochondria, then the kidneys in each flank, as described for the specific organs below. One danger is to concentrate on the four quadrants and miss midline structures such as an abdominal aortic aneurysm.
A possible order for routine examination is from the right to the left hypochondrium, across the epigastrium, assessing the liver, the pancreas and celiac regions, the spleen and renal masses. Pass downwards to the umbilicus to detect the presence of an aortic aneurysm or periaortic masses, and lesions of the transverse colon and stomach. Pass downwards into the suprapubic region, considering bladder, ovarian, uterine and small bowel masses, and then into each iliac fossa, with the cecum and appendix to the right and the sigmoid colon on the left (figure 30a–c).
Leave the lumbar regions until last. They are examined bimanually, your left hand is slid behind the region and the hands pressed together to assess structures between, such as kidneys and the ascending and descending colon (see below).
The site gives a strong indication of the underlying anatomy. Define the borders of a structure and whether its surface is smooth, whether it is possible to feel above, below and all around it, and whether it can be moved or moves with respiration. It may be possible to move separate masses, such as omental metastases, or decide whether a mass is within the omentum, such as a large omental cyst, or a retroperitoneal structure fixed to the posterior abdominal wall, such as a pancreatic cyst.
Abdominal masses may become more or less prominent when tensing the abdominal wall. Prominence is accentuated when a mass is superficial to the abdominal muscles, either as part of the wall or a protrusion through it, such as a hernia. The abdominal wall is tensed by coughing, or asking the subject to raise their head and shoulders off the bed without using an elbow.
When a lot of ascites is present, structures float and it is possible to bounce large structures, such as a liver or spleen, feeling them hit the posterior abdominal wall or the anterior abdominal wall on rebound: this maneuver is known as balloting.
Vibration of fluid (fluid thrill) may also be produced by tapping one side of the abdomen and feeling the other. The patient or an observer places the side of a hand along the midline to prevent vibration of the anterior abdominal wall and consequent misinterpretation (figure 31).