Obstruction of the colon

Strangulation is rare, except in case of volvulus. The sequestration of liquids and electrolytes evolve more slowly. Progressive distension against a sufficient ileocecal valve is, in essence, a closed loop obstruction, and will culminate in perforation of the cecum, according to Laplace's law (tension = pressure x diameter x).

Clinical manifestations

The initial symptoms are abdominal pain, vomiting and bowel closure, followed by abdominal distension, severe cramping pain with hyperperistalsis, periods of acquiescence and then diffuse pain; In the end, there is constant generalized discomfort. Vomiting occurs immediately (reflex) and at a variable time later, depending on the level of the obstruction. Fecaloid material indicates that the obstruction is low.

Physical examination

Initially there are few signs, except the colic that signals the patient. Auscultation indicates high-pitched and intense metallic noises, with "borgorigmos" and periods of complete silence. Over time, dehydration, bloating, and acute abdominal signs (strangulation) will arise.

Laboratory data

They include dehydration, with increased hematocrit and blood urea nitrogen, and oliguria, metabolic acidosis and CO2 retention due to abdominal distension. Large leukocytosis suggests strangulation or ischemia. There is also hypermilasemia. Radiographic signs. The most important diagnostic studies are plain radiographs in dorsal decubitus and with the subject erect. Barium enema is useful if colon obstruction is suspected. The small intestine series allows to differentiate between mechanical obstruction and adynamic ileus.

Treatment

Administration of fluids and electrolytes corrects losses, followed by surgical operation. It is important to replenish potassium. Diuresis, central venous pressure measurement and initial hematocrit elevation should be used to assess the intensity of dehydration. Losses must be compensated with isoosmotic liquids. Surgery may not be necessary in immediate postoperative obstruction (less than 30 days after surgery). Strangulated obstructions are surgical emergencies. Only 12 to 20% of partial obstructions of the small intestine require surgery.

Gastrointestinal intubation

In the preparation of the patient, a double-lumen nasogastric tube should always be used. Long bowel tubes have questionable utility and may cause treatment of a strangulated obstruction to be deferred. Durable aspiration should be reserved for patients in the immediate postoperative period with partial obstruction or cautiously in the case of obstruction secondary to treatable inflammation (such as Crohn's disease).

Operation

Closed loop obstructions, due to early colic or complete strangulation, should be treated as surgical emergencies. The five types of surgical techniques are: a) lysis, manipulation-reduction technique, b) enterotomy, to remove the filling, c) ablation of obstructive lesions or strangulated segments with primary reanastomosis, d) bypass techniques, and e) creation of artificial holes in proximal area (ostomies). Features of peritoneal fluid include its straw color, but the presence of blood denotes strangulation. The surgeon can break the adhesions by lysis and reduce the handles, before removing handles of doubtful viability. Transoperative decompression facilitates closure and improves blood flow and can be accomplished with a long tube through the mouth, nasal passage, or gastrostomy.

Postoperative care

It includes preservation of fluid and electrolyte balance, antibiotics and decompression. In the immediate postoperative period, there is a continuous loss of isotonic fluid towards the third space, followed at the end by self-incorporation of sequestered fluid, when the viability of the intestine is restored. Decompression is sometimes needed for five days.