||The Abdominal Exam|
A well-performed abdominal exam is one of the foundations of the complete physical. It is also one of the most difficult skills to master.
- ascites - interstitial fluid in the abdomen, often seen in patients with liver disease. Current recommendations are to test it using a "serum-ascites albumin gradient," which requires lab values of both the serum albumin content and the fluid albumin concentration. If the difference between the two values is >1.1, this strongly suggests portal hypertension. You may hear the terms "exudate" and "transudate" discussed - the ascitic fluid can be tested to determine if it is a transudate (pulled from the cells through their membranes, therefore having little protein - suggests osmotic/oncotic pressures) or an exudate (released from pores or tears in cells, and having a similar high-protein composition - suggests cell damage).
- colicky pain - any pain that comes in waves, which suggests a blockage in a tube, such as the stomach, intestines, bile/pancreatic duct, ureter, etc.
- guarding - muscle tension, can be voluntary or involuntary, that the patient creates to protect a tender area. You can simulate guarding by tensing up as if you are about to be punched in the stomach. Involuntary guarding, or a rigid abdomen, is probably the most reliable indicator of an acute surgical abdomen. Itís much more specific than rebound tenderness, which is often seen in the absence of a surgical abdomen.
- hernia - a hernia is present whenever abdominal contents protrude through something that's supposed to be containing them. They can poke through the inguinal canal (inguinal hernia), along the abdominal midline between the rectus abdominus muscles (ventral hernia), out through the umbilicus (umbilical hernia), along any incision (incisional hernia), through the diaphragm and into the thorax (hiatal hernia - this specifically refers to the stomach rising through the diaphragm), etc. Hernias may or may not be symptomatic or clinically relevant.
- intussusception - the "telescoping" of one portion of intestine into another portion of intestine, similar to the way a car antenna retracts. It may cause obstruction, bloating, intense pain. Usually diagnosed (and sometimes simultaneously corrected) by barium enema, although surgery is frequently required.
- McBurney's point - 1/3 of the way from the ASIS (anterior superior iliac spine/crest - the hip bone) to the umbilicus. This is where the appendix is located, and where patients typically have focal tenderness as appendicitis progresses.
- Murphy's sign - inspiratory arrest on subcostal RUQ palpation, suggestive of gall bladder disease. In other words, if you push on the gall bladder and the person stops inhaling (a guarding mechanism), you should consider evaluation of the gall bladder.
- obturator sign - considered positive if the patient experiences RLQ pain while you flex the hip and knee and internally rotate the leg - suggests appendicitis.
- psoas sign - considered positive if the patient experiences RLQ pain while you provide resistance against the patient lifting the right thigh (flexing the right hip)- suggests appendicitis.
- rebound - pain on rapid withdrawal of pressure - considered a "peritoneal sign," meaning that it suggests the likelihood of peritoneal inflammation.
- Rosving's sign - considered positive if the patient experiences RLQ pain as you apply LLQ pressure - suggests appendicitis.
- striae - "stretch marks." These can occur naturally as a result of weight gain such as in pregnancy and obesity, or as the skin is stretched in bodybuilding. It can also be a sign of Cushing's disease, in which there is excessive cortisol production by the adrenals.
- surgical abdomen - aka "acute abdomen." This means different things to different people, but in its most basic sense it refers to any abdomen that should be looked at &/or operated on by a surgeon. Typical things that would make you classify an abdomen as "acute" would include peritoneal signs, bleeding, focal tenderness at McBurney's point, exquisite focal tenderness in any quadrant, or severe colicky pain.
- torsion - the twisting of a section of intestine, similar to wringing a towel. It can cause obstruction of the lumen, and can result in ischemia, bloating, and intense pain.
- volvulus - the twisting of a portion of the GI tract around the mesentery, which can result in ischemia, bloating, and intense pain.
Review of General Anatomic Landmarks (surface anatomy)
- The renal arteries lie approximately 2 inches above the umbilicus, and bruits can best be heard about two inches either side of midline.
- The aorta runs midline (or very slightly left of midline) from the sternum down to the umbilicus, where it splits into the iliac arteries.
- The iliac arteries begin at the umbilicus, then travel towards the medial half of the inguinal ligament, where they become the femoral arteries.
- The femoral arteries begin at the inguinal ligament. They can be found in the medial half of that ligament (towards the groin) and are easiest to palpate along that ligament. This is also a good place to listen for bruits.
- The stomach lies directly below the xiphoid process (lowest part of the sternum) and extends about 3 inches to the left of midline, and 2 to the right, along the costal margin.
- The small intestine is distributed throughout the abdomen.
- The gall bladder lies along the inferior aspect of the liver, typically near the midclavicular line. It is usually not palpable.
- The appendix is found at McBurney's point in the RLQ.
- The ascending colon runs along the lateral aspect of the RLQ to the RUQ.
- The transverse colon generally runs about 1-2 inches inferior to the costal margin, horizontally along the upper quadrants. There is great variability among patients in the specific path the transverse colon follows.
- The descending colon runs along the lateral aspect of the LUQ to the LLQ.
- The sigmoid colon and rectum are considered to be pelvic structures, and are typically not palpable on abdominal exam.
- The liver is located beneath the right-sided ribs. The liver edge may drop to ~4 cm below the costal margin on deep inspiration in a normally sized and positioned liver. In hepatomegaly or COPD, the liver edge may be palpable beneath the costal margin without deep inspiration. Normal liver span is ~6-12 cm when measured along the midclavicular line, typically by percussion or by the scratch test.
- The spleen is located in the lateral LUQ, along the anterior axillary line. It is usually not palpable in a healthy patient, even with deep inspiration. Its lowest point is generally at about the 10th rib. You increase your chances of feeling the spleen by pressing anteriorly from the left flank while you compress beneath the left subcostal margin, and asking the patient to take a deep breath.
- The kidneys lie at the costovertebral angles (CVA), which are the angles made by the junction of the spine with the bottom of the rib cage. If thumping there elicits pain, this is suggestive of pyelonephritis. The kidneys can occasionally be directly palpated by compressing the abdomen at the midclavicular line on either side, in the upper quadrants. The kidney can be felt between the hands (left is easier to feel than right, due to the presence of the liver on the right).
- The urinary bladder lies midline, and is palpable (particularly if filled with urine) directly superiorly to the symphysis pubis.
- normoactive - Normal bowel sounds typically occur 5-35 times per minute, and are of medium to low frequency.
- borborygmi - Stomach gurgles of peristalsis. People rarely use this term in real life - we just say "bowel sounds." You can use it to refer to very active bowel sounds if you want to sound like a geek.
- hyperactive - Technically, >40 sounds per minute, or continuous bowel sounds - but in reality, it's a subjective term. Associated with diarrhea, or the early phases of bowel obstruction.
- absent - No bowel sounds heard over a 2+ minute period of continuous listening. Commonly associated with ileus, a physiologic response in which the intestines stop all activity in response to injury, as seen in volvulus, torsion, intussusception, visceral perforation (such as perforated peptic ulcer, ruptured gall bladder, ruptured appendix, ruptured/perforated intestine) or after almost any abdominal surgery.
- hypoactive - Technically, <5 sounds per minute over at least 3 minutes. This is also a subjective term in common usage.
- rushes - High-pitched, often hyperactive bowel sounds, often accompanied by cramping feeling. Suggestive of material being forced past or against an obstruction.
- tinkles - Brief, high-pitched (tinkling) bowel sounds, which represent air & fluid under pressure. Suggestive of intestinal dysmotility, also suggesting a partial or complete bowel obstruction.
- Observe for contour, masses, symmetry.
- Listen for bowel sounds, then renal arteries, then iliacs, then femoral arteries. Be sure to listen before you touch the abdomen - by manipulating the abdomen, you can cause bowel sounds to appear, causing a false positive. This obviously defeats the purpose of listening for bowel sounds in the first place.
- Percuss for areas of dullness throughout entire abdomen, with specific attention to the left quadrants to confirm tympany - if you don't check for dullness, you may miss an enlarged spleen.
Identify the stomach gas bubble, percuss liver span.
- Palpate, beginning with soft palpation, feeling for superficial masses or tenderness.
Progress to deep palpation, feeling for masses throughout abdomen, looking for areas of tenderness.
Palpate liver and spleen (you may be able to feel the liver, but should not be able to feel the spleen in a healthy patient).
Palpate the aorta with both hands, applying firm pressure on either side, and checking for symmetric pressure on both hands.
Thump on the back - place your flattened hand on the patient's back at the CVA, and strike your hand firmly with the side of your fist.
To aid in relaxation in patients who may have tense abdominal muscles or who are guarding, you can ask patients to flex their hips and rest the bottoms of their feet on the exam table (with knees bent). You can ask your patient to inhale deeply, and perform deep palpation during expiration. Finally, with patients who are having great difficulty relaxing, it may help to perform the initial part of the exam with your hand guiding the patient's hand (as if you were teaching the patient to perform the exam themselves), until the abdomen relaxes.
Be sure to start low - typically at the level of the umbilicus - when both percussing and palpating for the liver and spleen. What you're really feeling for is a change in the firmness of the abdomen as your signal that you're palpating these organs. If they are enlarged and you begin to palpate too high, you won't feel a change in texture as you continue superiorly, since you will already be palpating the organ. So start low to make sure you don't miss the inferior margin (bottom edge).
If you suspect peritoneal signs will be present, as in appendicitis, there are numerous ways to elicit peritoneal signs without performing the classic rebound maneuver (pushing deeply then rapidly removing your hand). It is probably more humane to begin by trying to elicit the psoas sign, the obturator sign, or Rosving's sign. Alternatively, in patients with advanced disease, simply jiggling the bed with your hip will cause them discomfort.