ADYNAMIC OBSTRUCTION

Intestinal obstruction

Dynamic, in which peristalsis is working against a mechanical obstruction.

Adynamic, in which there is no mechanical obstruction;

peristalsis is absent or inadequate (e.g. paralytic ileus or pseudo-obstruction)

Paralytic ileus

• This may be defined as a state in which there is failure of transmission of peristaltic waves secondary to neuromuscular failure

• (i.e. in the myenteric (Auerbach’s) and submucous (Meissner’s plexuses).

• The resultant stasis leads to accumulation of fluid and gas within the bowel, with associated distension,

vomiting,absence of bowel sounds and absolute constipation.

Paralytic ileus

• Following most abdominal operations or injuries, the motility of the gastrointestinal tract is transiently impaired.

• Among the proposed mechanisms responsible for this dysmotility are surgical stress-induced sympathetic reflexes, inflammatory response-mediator release, and anesthetic/analgesic effects; each of which can inhibit intestinal motility.

Paralytic ileus Varieties

• Conventional recovery times have been reported at 4: small intestine: 0-24 hours stomach: 24-48 hours colon: 48-72 hours

• Postoperative. A degree of ileus usually occurs after any abdominal procedure and is self-limiting, with a variable duration of 24–72 hours. Postoperative ileus may be prolonged in the presence of hypoproteinaemia or metabolic abnormality.

•

Paralytic ileus Varieties

• Infection. Intra-abdominal sepsis may give rise to localised or generalised ileus.

Appendicitis Diverticulitis Nephrolithiasis Cholecystitis Pancreatitis Perforated Duodenal Ulcer

Paralytic ileus VarietiesInfectious, Inflammatory or irritation (bile, blood)

1. Intrathoracic Pneumonia Lower lobe rib fractures Myocardial Infarction

2. Intrapelvic e.g. Pelvic Inflammatory Disease

Intestinal IschemiaMesenteric embolism, ischemia or thrombosis

Paralytic ileus Varieties

• Metabolic. Uraemia and hypokalaemia are the most common contributory factors.

Serum electrolyte abnormality 1. Hypokalemia 2. Hyponatremia 3. Hypomagnesemia 4. Hypermagensemia

• Reflex ileus. This may occur following fractures of the spine or ribs, retroperitoneal haemorrhage or even the application of a plaster jacket.

Paralytic ileus Clinical features

• Paralytic ileus takes on a clinical significance if, 72 hours after laparotomy: • there has been no return of bowel sounds on auscultation; • there has been no passage of flatus. Abdominal distension becomes more marked and tympanitic. Colicky pain is not a feature. Distension increases pain from the abdominal wound. In the absence of gastric aspiration, effortless vomiting may occur. Radiologically, the abdomen shows gasfilled loops of intestine

with multiple fluid levels

Paralytic ileus Management

• Paralytic ileus is managed with the use of nasogastric suction and restriction of oral intake until bowel sounds and the passage of flatus return. Electrolyte balance must be maintained.

Paralytic ileus Management

• Specific treatment is directed towards the cause, but the following general principles apply:

• If a primary cause is identified, this must be treated. • Gastrointestinal distension must be relieved by decompression. • Close attention to fluid and electrolyte balance is essential. • There is no place for the routine use of peristaltic stimulants.

Rarely, in resistant cases, medical therapy with a gastroprokinetic agent, such as domperidone or erythromycin may be used, provided that an intraperitoneal cause has been excluded.

Paralytic ileus Management If paralytic ileus is prolonged, CT scanning is the

most effective investigation; it will demonstrate any intraabdominal sepsis or mechanical obstruction and therefore guide any requirement for laparotomy.

The need for a laparotomy becomes increasingly likely the longer the bowel inactivity persists, particularly if it lasts for more than 7 days or if bowel activity recommences following surgery and then stops again.

Pseudo-obstruction

This condition describes an obstruction, usually of the colon, that occurs in the

absence of a mechanical cause or acute intraabdominal disease.

It is associated with a variety of syndromes in which there is an underlying neuropathy and/or myopathy and a range of other factors

Factors associated with pseudo-obstruction

Metabolic :• Diabetes• Hypokalaemia• Uraemia• Myxodoema• Intermittent porphyria

Factors associated with pseudo-obstruction

Shock• Burns• Myocardial infarction• Stroke• Idiopathic• Septicaemia• Postoperative (for example, fractured neck of femur)

Factors associated with pseudo-obstruction

Retroperitoneal irritation• Blood• Urine• Enzymes (pancreatitis)• Tumour

Factors associated with pseudo-obstruction

Drugs• Tricyclic antidepressants• Phenothiazines• Laxatives

Factors associated with pseudo-obstruction

Drugs• Tricyclic antidepressants• Phenothiazines• LaxativesSecondary gastrointestinal involvement• Scleroderma• Chagas’ diseaseSevere trauma (especially to the lumbar spine and pelvis)

Colonic pseudo-obstruction

This may occur in an acute or a chronic form. The former, also known as Ogilvie’s syndrome, presents as acute large bowel obstruction.

Abdominal radiographs show evidence of colonic obstruction, with marked caecal distension being a common feature.

Indeed, caecal perforation is a well-recognised complication.

Colonic pseudo-obstruction• The absence of a mechanical cause requires urgent confirmation by

colonoscopy or a single-contrast water-soluble barium enema or CT. • Once confirmed, pseudo-obstruction requires treatment of any

identifiable cause. • If this is ineffective, intravenous neostigmine should be given (1 mg

intravenously), with a further 1 mg given intravenously within a few minutes

• if the first dose is ineffective. During this procedure, it is best to sit the patient on a commode. ECG monitoring is required and atropine should be available.

• If neostigmine is not effective, colonoscopic decompression should be performed.

Colonic pseudo-obstruction

• Caecal perforation can occur in pseudo-obstruction. • Abdominal examination should pay attention to

tenderness and peritonism over the caecum and as with mechanical obstruction, caecal perforation is more likely if the caecal diameter is 14 cm or greater.

• Surgery is associated with high morbidity and mortality and should be reserved for those with impending perforation when other treatments

have failed or perforation has occurred.

Small intestinal pseudo-obstruction

• This condition may be primary (i.e. idiopathic or associated with familial visceral myopathy) or secondary.

• The clinical picture consists of recurrent subacute obstruction.

• The diagnosis is made by the exclusion of a mechanical cause.

• Treatment consists of initial correction of any underlying disorder.

• Metoclopramide and erythromycin may be of use.

Q.Post-operative ileus is most pronounced in:

a. Colon b. Stomach • c. Ileum d. Duodenum

Q.First to recover from post-operative ileus: (DNB 2008)

a. Small intestine b. Stomach c. Colon d. None

Q. Paralytic ileus is characterized by all except: (SGPGI 2005) a. No bowel sound on ausculatation b. No passage of flatus c. Gas filled loops of intestine with multiple fluid levels d. Loops of intestine are not seen due to loss of peristalsis

Q. Most common electrolyte imbalance that causes Paralytic ileus is: (DNB 2014)

a. Hyponatremia b. Hypernatremia c. Hypokalemia d. Hyperkalemia

Q. Commonest cause of acute intestinal obstruction is: (NEET Pattern, PGI 88)

a. Adhesions b. Volvulus c. Inguinal hernias d. Internal hernias

Q.A women of 35-years, comes to emergency department with symptoms of pain in abdomen and bilious vomiting but no distension of bowel. Abdominal X-ray showed no air fluid level. Diagnosis is: (AIIMS June 99)

a. CA rectum b. Duodenal obstructionc. Adynamic ileus d. Pseudo-obstruction

Q.Distended abdomen in intestinal obstruction is mainly due to: (All India 95, PGI Dec 98)

a. Diffusion of gas from blood b. Fermentation of residual food c. Bacterial actiond. Swallowed air

Q.A neonate presents with colicky pain and vomiting with sausage-shaped lump in the abdomen, diagnosis is: (UPPG 2009)

a. Enterocolitis b. Perforation of the abdomen c. Intussusception d. Acute appendicitis

Q.The most common type of intussusception: (DNB 2009, 2005, 2001, 2000, All India 99, PGI Dec 95, MHPGMCET 2009)

a. Ileocolic b. Colocolic c. Ileoileal Sd. Retrograde

Q. A 6 months old child woke up in night, crying with abdominal pain, which got relieved on passing red stool. What is the most likely diagnosis? (AIIMS November 2014)

a. Meckel’s diverticulum b. Intussusception c. Malrotation d. Intestinal obstruction

Q.Most common cause of colonic obstruction is: (AMI 86, PGI 86, UPSC 88) a. Volvulus b. Hernia c. Adhesions d. Neoplasm

Q. Acute pseudo-obstruction of the colon known as: (DNB 2012, UPPG 2007)

a. Sjogren’s syndrome b. Gardener’s syndrome c. Ogilvie’s syndrome d. Peutz-Jegher’s syndrome

Q.Most common site of volvulus: (DNB 2012, GB PANT 2011)

a. Sigmoid colon b. Caecum c. Transverse colon d. Stomach

Q.Bowel can get strangulated in all of the following space except: (AIIMS Nov 2000)

a. Recto uterine pouch b. Ileocolic recess c. Paraduodenal recess d. Omental recess

Q.A young healthy male patient presented with abdominal pain and history of altered bowel habits from the last 6 months. On CT examination, there was dilated distal part of ileum, thickened ileocecal junction with thickened cecum with presence of sacculations on the antimesenteric border. The vascularity of adjoining mesentery is also increased and there is surrounding mesentery fat. Which of the following is not a differential diagnosis? (AIIMS Nov 2013)

• a. Ulcerative colitis b. Crohn’s disease • c. Tuberculosis d. Ischemic bowel disease

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