Examination of the abdomen

Examination of the abdomenAn abdominal examination consists of several parts: examination of the abdomen, of the inguinal region, examination of the scrotum, testes, and rectal examination.

Abdominal examination

Good examination of the abdomen entails certain requirements, such as a well-lit room to detect skin colour changes and a warm environment to prevent shivering, which results in contractions of the abdominal wall, thereby interferes with palpation of the abdomen. If the sick man is in a multibed unit, curtains are drawn around the bed for privacy during the examination.

The sick man is examined supine with one pillow beneath the head and a sheet or blanket covering the pubic region and the lower limbs. Patients with an acute abdomen are often more comfortable with the legs drawn up as this relieves tension on the anterior abdominal musculature. No attempt must be made to straighten their lower limbs as this will exacerbate the pain and limit the scope of the examination. Right-handed individuals should examine patients from the right side of the bed, left-handed individuals from the other side. Ideally, the patient’s abdomen should be at the level of the examiner’s elbow. This is achieved either by elevating the bed to the right level or by the examiner bending.

Surface anatomy

The various quadrants described in anatomical textbooks are not practical because of considerable overlap. A better subdivision for clinical purposes, which has the following components: four quadrants, epigastric, periumbilical (or central), suprapubic and two flank (or loin) regions.

The important cutaneous landmarks on the anterior aspect are the costal margins, xiphoid process, umbilicus, anterior iliac spine, pubic tubercle, symphysis pubis and the inguinal ligament. The useful cutaneous landmarks on the posterior aspect are the tip of the 11th rib (the 12th rib is not usually palpable), the ridge of the paraspinal muscles (erector spinae), the vertebral spinous processes and the iliac crest.

Inspection of the abdomen

MOVEMENT AND CONTOUR

In normal individuals, the anterior abdominal wall moves passively with respiration (expands with inspiration and recedes with expiration). This movement is abolished or considerably reduced in patients with an acute abdomen, where the abdominal muscular walls are in spasm.

The contour of the anterolateral abdominal wall and the flank provides useful information in both the elective and emergency situations. In normal individuals in the supine position, the abdomen is flat, although it may be scaphoid in thin people; the contour of the flank is flat in males and concave in females. Bulging of the flanks and abdominal distension are encountered in obesity, ascites, pregnancy and intestinal obstruction.

SURFACE MARKINGS AND ABNORMALITIES

These include the following:

  • previous operation scars (normal, keloid, pitted due to previous infection);
  • skin lesions;
  • scratch marks (in jaundice);
  • striae (previous pregnancy or obesity);
  • bruising or staining of the skin of the abdomen, e.g. flank in acute pancreatitis (Turner’s sign), periumbilical staining due to haemoperitoneum (Cullen’s sign);
  • obvious swellings;
  • dilated abdominal wall veins (obstruction or compres­sion of the inferior vena cava);
  • previously constructed ostomies (colostomy, ileostomy);
  • abnormal pulsations (abdominal aortic aneurysm).

HERNIAL DEFECTS

Herniation may occur through natural orifices such as the inguinal or femoral canal or through weaknesses in the anterior abdominal wall such as beside the umbilical cicatrix (paraumbilical hernia) or through a poorly healed surgical wound (incisional hernia). During inspection with the sick man in the supine position, an unobstructed hernia appears as a momentary bulge when the intra-abdominal pressure is raised by asking the sick man to cough or tense the abdominal muscles. In some patients atrophy of the recti abdominis muscles together with their separation from each other results in a central abdominal bulging defect. This is most commonly seen in multiparous females but is also encountered in males and is referred to as divarication of the recti or ventral hernia. An irreducible hernia (one that is stuck in the parietes) or an obstructed hernia appears as a constant bulge that cannot be reduced by either the patient or the doctor.

The demonstration of an incisional or ventral hernia is best achieved simply by asking the patient to lift his or her head (without support from the upper arms) from the pillow. This raises the abdominal pressure and produces a distinctive bulge. The same effect can be achieved by asking the sick man to lift the lower limbs off the bed.

Palpation

Palpation is the important aspect of the examination of the abdomen. Various techniques are used: light palpation, deep palpation, palpation of specific organs (liver and spleen), bimanual palpation (kidneys and retroperitoneum) and palpation of a fluid thrill.

GENERAL PRINCIPLES

Aside from ensuring that the sick man is in a comfortable supine position, palpation must be carried out gently with warm hands and in a systematic fashion from quadrant to quadrant. Long fingernails, by digging into the patient’s skin, impair the ability to conduct the examination. A common mistake made by the inexperienced is to hurry the palpation (flitting palpation). The hand should not be transferred to another region until the doctor has regis­tered whether the area concerned feels normal or not. Light palpation is conducted before deep pal­pation. In general, the more one presses the abdominal wall, the less one feels for two reasons. First, the tactile sen­sation is diminished with constant sustained pressure. Second, clumsy deep palpation hurts the patient and induces spasm of the abdominal muscular walls. The tech­nique used varies with the state of the abdomen: acute or non-acute.

ACUTE ABDOMEN

These patients are acutely ill, usually in considerable pain and some may be in shock from dehydration/ hypovolaemia. The primary concern is therefore resuscitation and relief of pain by intravenous opiates. Both these measures must precede palpation of the abdomen. Opiates should be administered via the intravenous route, especially in shocked patients, since the peripheral shutdown greatly reduces uptake of the drug by the circulation when administered via the intramuscular route. Relief of pain is not only kind and humane but also facilitates the conduct of the examination by increasing patient comfort and allaying anxiety. The belief that anal­gesia may mask physical signs is completely unfounded.

The abdominal palpation of patients with an acute abdomen must be conducted with the utmost gentleness and is primarily designed to establish the presence of reflex spasm of the abdominal muscles (guarding and rigidity) and the presence, extent and location of abdom­inal tenderness. In the presence of peritoneal irritation due to infection or escape of gastrointestinal contents (e.g. perforated peptic ulcer), both the visceral and the parietal peritoneum become inflamed (peritonitis). The localized pain and tenderness and the resulting spasm of the overlying abdominal muscles are due to stimulation of the somatic nerves supplying the abdominal parietes. When the abdominal wall is depressed by palpation, the pain is enhanced over the inflamed area. Moreover, the pain is intensified further as the pressure from the fingers is released. This is known as rebound tenderness. The test, although valuable, must be elicited with the minimum of suffering possible. In the vast majority of patients, simple coughing will induce pain in the affected region and this is equivalent to eliciting rebound tenderness by light palpa­tion. In others, gentle percussion by the right hand on the examiner’s left fingers can elicit the sign. In any event, deep palpation must never be practised in these patients.

The extent of spasm of the abdominal musculature varies from increased tension of the abdominal wall (guarding) to board-like rigidity. To some extent, the degree of rigidity depends on the state of the individual patient’s musculature. Thus, elderly patients with atro­phic muscles may not exhibit significant rigidity despite an established generalized peritonitis, although they will always experience tenderness with rebound during the examination. The abdomen of a previously fit athletic male patient with a perforated ulcer will be board-like in most instances. Physical signs, including guarding and rebound tenderness, may be abrogated by drugs (especially steroids), old age and immunosuppres­sion from any cause. Thus, a high index of suspicion must be kept in these groups of patients.

NON-ACUTE ABDOMEN

Light palpation is used in the first instance and suffices for most patients. The technique entails using a slightly cupped hand that is warm and relaxed (almost dead weight), with the terminal phalanges gently depressing the anterior abdominal. The sensitivity and ability to feel lumps and normal organs increase with practice and expe­rience, for which there is no substitute. Deep palpation is necessary in obese individuals and patients with well-developed abdominal musculature. The best technique entails the use of both hands: the left on the abdominal wall (the sensing hand) is overlapped and depressed by the right hand. Again, as little force as is necessary is applied. Some clinicians perform deep palpation using one hand. Palpation of the abdomen in the non-acute situation is designed to detect the presence of tenderness, the enlargement of organs, the presence of any intra-abdominal masses.

SPECIFIC ORGANS

Liver and gallbladder examination. The lower edge of the liver is just palpable in most normal individuals with the tips of the fingers pointing upwards, starting in the right lower quad­rant, moving up towards the right costal margin. Normally, a distinct smooth edge is felt that moves and becomes more prominent with inspiration. The substance of the liver lies underneath the thoracic cage and its upper margin is therefore impalpable; however, its position can be identified by percussion (see later). When the liver enlarges as a result of disease, the anterior superior surface becomes palpable as a firm mass extending from the right hypochondrium to the epigastric region. Normally, the gallbladder is not palpable. When enlarged, as in patients with cancer ofthehead of the pancreas, it is felt as a round smooth swelling that moves with respiration in the right hypochondrium along the midclavicular line.

Spleen examination. This has to be enlarged to one-and-a-half to twice its normal size before it can be felt. As the spleen enlarges medially and inferiorly, it projects for a varying distance below the left costal margin towards the right lower quadrant. Palpation of the spleen requires ele­vation of the left lower ribcage and flank as the abdomen is palpated with the right hand starting in the right iliac fossa. When uncertainty remains as to whether a spleen is palpable or not, the patient should be positioned in the right semiprone position as this results in anterior displacement of the organ.

Kidneys examination. The kidneys are examined by the technique of bimanual palpation. For the right kid­ney, the left hand is placed beneath the right flank, the right hand is placed anteriorly. The left hand is used to lift the retroperitoneal contents and thereby trap the mass or kidney between the two hands. The kidneys are not palpa­ble in health, although in thin patients the lower poles may be felt occasionally. On the right side, an enlarged kidney has to be differentiated from a mass in the hepatic flexure or enlarged liver. On the left, the differentiation is between an enlarged spleen, mass in the descending colon.

INTRA-ABDOMINAL MASSES

Distinction between intra-abdominal masses, swel­lings within the abdominal wall is achieved by asking the patient to contract the abdominal muscles. This accen­tuates intramural masses and renders intra-abdominal swellings less distinct or impalpable. The most important clue to the nature of a swelling within the abdomen is the site. Other important features include pres­ence of tenderness over the mass (denotes an inflammat­ory component), mobility with palpation, movement with respiration and consistency.

Percussion

Percussion is best regarded as an adjunct to palpation. It is used to determine the presence of tenderness, to estimate the size of an enlarged organ or mass, and to distinguish gaseous distension of hollow organs from an excessive amount of fluid in the peritoneal cavity (ascites), both of which cause generalized abdominal distension. The technique consists of gentle tapping with the right fingers (and a relaxed right wrist) on the index, middle finger of the left hand placed on the area to be percussed. A resonant note is obtained over a hollow organ distended with air (dilated stomach, colon, etc.) whereas a dull note is elicited over a solid organ (e.g. liver) or mass and fluid- filled cavities (e.g. distended urinary bladder, intra­abdominal cyst, ascites).

Liver examination. The objective is to determine the size of the liver. The upper margin is defined first. This is normally situ­ated at the level of the sixth rib in the midclavicular line but maybe displaced downwards in patients with obstruc­tive airways disease (emphysema) and in asthenic patients whose liver is loosely attached and ptotic. To determine the upper margin of the liver, percussion is started on the right anterior chest wall at the fourth intercostal space. A resonant note (due to aerated lung parenchyma) is obtained initially. This changes to relative dullness as the upper margin of the liver (still overlapped by lung) is reached. A few centimetres further down the percussion note becomes dull and remains so until the lower margin of the liver is reached. The normal anterior span of the liver varies with body size and ranges from 11 to 15 cm in males and 9 to 13 cm in females.

Auscultation

Auscultation of the abdomen is performed with the diaphragm end-piece of the stethoscope. It is used to listen for bowel sounds, bruits and venous hums and succussio’n splashes. An adequate technique is required to avoid spu­rious sounds caused by movement of the stethoscope over the abdominal wall, particularly in hairy individuals. During auscultation the diaphragm must be held abso­lutely still.

BOWEL SOUNDS

The normal bowel sounds are difficult to describe, indeed exhibit a wide range of frequency, intensity and pitch. They are caused by peristaltic activity. In mechan­ical intestinal obstruction, they become hyperactive due to the enhanced peristaltic activity prox­imal to the obstruction and can be heard as loud rushes coincident with episodes of colicky abdominal pain. Absent bowel sounds (during a 2-min period of ausculta­tion) indicate loss of peristaltic activity and are encoun­tered in adynamic ileus from any cause. In some of these patients, particularly those with hugely distended small intestine, tinkling sounds are heard. These result from the passive movement of fluid contents inside the cavernous intestinal loops.

BRUITS

Most bruits are heard in the midline between the xiphoid process and the umbilicus. They are caused by aneurysms (aorta, splenic artery) or stenosis (renal artery). A soft hum may be heard over the liver in portal hypertension and large vascular hepatic tumours, including hepatomas. A friction rub may be audible over the splenic region along the lower part of the left costal margin in patients with splenic infarct or perisplenitis.

SUCCUSSION SPLASH

The stomach becomes distended with fluid (ingested liquid, saliva and gastric juice) when the pylorus is obstructed by tumour or cicatricial stenosis.

Examination of the abdomen for ascites

Ascites causes abdominal distension that is dull to percussion. Similar findings on physical examination may be caused by large cysts that usually arise from the pelvis and are ovarian in origin, although some large cysts arise in the small-bowel mesen­tery. As distinct from large cysts, ascites is always accom­panied by bulging of the flanks and the patient often has an everted umbilicus due to the formation of an umbilical hernia. Both specific palpation and percussion techniques are used to identify large cysts and differentiate one from the other.

The presence of ascites can only be established clinically by the detection of shifting dullness.

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