Note the size, shape and symmetry of the abdominal wall. These factors may be influenced by fat, a large bladder or uterus (such as in pregnancy or fibroids). Distension may be due to gas, fluid (ascites) or solid masses and viscera (table 6). The wall may be sunken (scaphoid) in very thin patients, this is particularly so with starvation and the weight loss of malignancy. The position of the umbilicus provides information on symmetry and it may be flattened or everted and contain various amounts of debris related to the age and hygiene of the patient. It may also be the site of a hernia or a congenital discharging sinus (patent urachus). It is occasionally the site of inflammation or a metastatic nodule (Sister Joseph’s nodule).

Table 6 Abdominal distention

GasFluid - AscitiesAbdominal masses
• Gastric dilatation • Intestinal obstruction • Megacolon (Chagas, Hirshsprung) • Toxic dilatationExudative: • Peritonitis acute, chronic (TB, filariasis, schistosomasis, granulomas)• Pancreatitis acute and chronic • Trauma to thoracic duct and other abdominal lymphatics • Benign and malignant (primary and secondary) neoplasm (including Meig’s syndrome). Transudative: • Liver failure • Portal venous hypertension • Hypoalbuminemia — liver and renal failure, malnutrition • Hepatic lymphatic obstruction • Abdominal wall tumors: desmoid, endometriosis; mesenteric cysts, neoplasm • Hepatosplenomegaly • Aneurysms Colonic: inflammatory bowel disease, actinomycosis, TB, amebiasis, helminths (ascariasis, schistosoma), benign and malignant neoplasm • Renal: cysts, hydronephrosis, pyonephrosis, perinephric abscess, benign and maligant neoplasm; full bladder • Retroperitoneal: sarcoma, hematoma (trauma, anticoagulants, ruptured aneurysm), abscess, pyomyositis • Uterine pregnancy, neoplasms; ovarian neoplasms

The laxity of abdominal skin is related to age and weight gain or loss. Stretch marks of pregnancy are usually laterally placed and are vertical pale scars. They may be slightly bluish, whereas those of Cushing’s syndrome have a distinct purplish hue. Excessive hair in the female or absence in the male may be an indication of hormonal abnormalities, requiring examination of other secondary sexual characteristics.

The veins on the abdominal wall have no valves and may enlarge to provide collateral channels in inferior or superior vena caval obstruction and portal hypertension. They radiate from the umbilicus and, when prominent, produce the pattern termed a caput medusa (figure 18). The application of a hot water bottle to the skin produces a characteristic mottled, faint pigmentation (erythema ab igne). These markings on the abdomen usually indicate a painful site, indicating that the patient has tried to soothe the pain by the application of heat.

Note recent wounds, dressings, fistulae, sinuses and stomas, and the position of old scars (figure 19). Ask the patient to explain each one. The abdominal wall should move freely and symmetrically in quiet (diaphragmatic) respiration. This is not so with diaphragmatic or abdominal wall paralysis. Pain also interferes with these movements. The restriction may be limited to one quadrant but is more widespread in generalised peritonitis, the maximum is found in perforated peptic ulcer and acute pancreatitis.

 

Figure 19 Abdominal incisions.

 

1. Rooftop
2. Laparoscopy ports for insertion
6. of telescope and operative
8. instruments
3. Right subcostal
4. Upper midline
5. Transverse abdominal
7. Nephrectomy
9. Left lower paramedian
10. Appendix
11. Lower midline
12. Left iliac muscle cutting
13. Suprapubic

Movements and bulges can be more easily seen if you rest on one knee and bring your eyes down to the level of the anterior abdominal wall (figure 20).

Ask the patient to draw their abdomen in, and then blow it out as far as it will go (figure 21a,b). These manoeuvres demonstrate limitation of movement due to tenderness, providing a good deal of information without any manual contact.

Coughing accentuates these differences and also produces pain over tender areas On coughing, observe the abdominal wall for the presence of hernias, particularly over the superficial inguinal rings, old scars for incisional hernias, and the midline for umbilical and paraumbilical hernias, and divarication of the rectus muscles. Incisional and midline hernias are often accentuated by asking the patient to raise their head and shoulder off the bed (figure 22).

Movement deep to the abdominal wall may be produced by gut peristalsis or pulsation. Pulsation is transmitted from the heart or the aorta, in a thin person, and with abnormalities such as abdominal aortic aneurysms, a mass in front of the aorta or the pulsatile liver of tricuspid incompetence. Normal gut peristalsis is occasionally seen in a very thin individual or in an incisional hernia, when the gut is covered only by skin and fascia. However, visible peristalsis usually represents pathological obstruction, such as pyloric stenosis, and upper and lower intestinal obstruction, where coils of small gut produce a ladder-like writhing pattern.

The abdominal wall may bulge over normal or abnormal organs and masses, such as a pregnant uterus, an enlarged liver, spleen, bladder, ovary or gall bladder, segments of gut and mesenteric cysts. Before proceeding to percussion and palpation, ask the patient to point out and personally palpate tender spots. This indicates the extent to which they are willing to have their abdomen indented (figure 23a–c). This is a useful technique in children.