Intestinal obstruction

TUOTORIAL:Dr. Mohammad Al-Akeely

Assoc.prof.&consultant surgeonKKUH & KSMC

Definition

• Any condition that interferes with normal propulsion and passage of intestinal contents.

• Can involve the small bowel, colon or both small and colon as in generalized ileus.

Classification

• According to the cause of obstruction : mechanical(dynamic) or functional (paralytic ileus, adynamic) .• According to duration of the obstruction: acute or chronic.• According to the extent of obstruction : partial or complete• According to the nature of obstruction : simple or complex (closed loop or strangulation) .

Mechanical obstruction• There is physical blockage to intestinal content which may be due to:

1. Intramural : congenital-tumor-hematoma-inflammatory2. Extramural : adhesion-volvulus-hernia –abscess-hematoma3. Lumen obstruction: stone-meconium-foreign body- impaction (stool-

worm-barium)

• This mechanical obstruction can be partial ( lumen narrowed but allow transit some content) or complete ( lumen totally obstructed). Therefore complete obstruction is either:

A. simple obstruction (no vascular impairment)B. closed loop ( both ends are obstructed) .C. strangulation obstruction

5

6

Functional (paralytic) obstructionThis obstruction is commonly secondary to factors causing

either paralysis or dysmotility of intestinal peristalsis.Postoperative ileus is the most common form of functional

bowel obstruction following intra-abdominal operations which correlates with degree of surgical trauma and type of operation ,so patients operated on for chronic obstruction or sever peritonitis has more prolonged post op ileus.

Different anatomic segments of GIT also recover at different rates after manipulation and trauma :

1. Small bowel within hours after operation.2. Stomach may take 24-48 hr .3. Colon 3-5 days post op.

NOTE :

Patients who has prolonged post op ileus ( <72 hrs)or had the ileus after a period of normal bowel sounds and motion, you

should suspect complication of surgery eg: fibrinous adhesions ( cause > 90%).

other causes are:Internal herniation

intra-abdominal abscessintramural hematomaanastomotic edema and leak

Difficult to differentiate by clinical presentation and X-ray. but CT scan is helpful .

9

Pathophysiology

Proximal bowel: increased peristalsis, dilates(fluid&gas)

Distal bowel: normal peristalsis, collapse

Gas(swallowed air&fermentation by bacterial),90%.N2.Fluid (oral intake, gut secretions and gut wall leakage) .

10

Pathophysiology

Dehydration and electrolyte imbalance is due to:* Reduced intake

* Defective absorption* Vomiting

* Sequestration in gut

Common causes of mechanical bowel obstruction:

A. Small bowel obstruction:1. Adhesion 60%2. Hernia 20%3. Neoplasm 5%4. Volvulus 5%.5. Others: IBD-GALL STONE-FOREIGN BODY-

INTUSSUSCEPTION.

B. Large bowel obstruction :1. Cancer 60%.2. Diverticular disease 15%.3. Volvulus 15%.4. Fecal impaction.

14

15

19

20

Common causes of functional bowel obstruction:

Vascular occlusion ileus.

Adynamic or paralytic ileus :– Post operation: mostly after abdominal surgery– Metabolic causes: DKA- hyponatremia-hypokalemia –

hypomagnesemia.– Drugs: morphine –TCA-antacid-anticonvulsant.

Intra-abdominal inflammation—sepsis—occult wound infection.

Pneumonia—renal stone—retroperitoneal hematoma---fracture spine and ribs

Sentinel loop: localised distended

Small bowel segment eg: pancreatitis

bowel ischemia

Pseudo colonic obstruction (Ogilvie syndrome)

DiagnosisHistory and physical examination:

Four cardinal symptoms:( pain-vomiting-distension and obstipation.)

Proximal obstruction earlier symptoms with prominent projectile vomiting and less distension. While vomiting is a late feature in

colon obstruction and is usually fecolent. Location and characteristic of pain differentiate between mechanical obstruction and ileus which severe –cramp localized in mid of abdomen in mechanical while diffuse and mild in ileus.Examination:

o Vital signs.( PR , Temp , BP)o Hydration status.o Abdominal exam for distention, scars, v. peristalses. Tenderness, reb.

tenderness, masses, hernias, and rectal / vaginal examination.

25

Diagnosis

Laboratory: CBC: increased hct (dehydration ) and increase in WBC.

KFT: increase in BUN and creatinine. Lactate concentration (LDH) useful but not sensitive indicator for bowel ischemia

ABG: metabolic acidosis may indicate bowel ischaemia and sepses.

Electrolytes: for hyponatremia & hypokalemia

DiagnosisRadiological:

erect CXR, supine and upright abdominal x ray.CXR :

Detect extra-abdominal condition tht may present in bowel obstruction e.g. aspiration pneumonia.Presence of pneumoperitonium indicates perforated viscus.

Abdominal X-RAYSmall bowel considered dilated when diameter more than 3 cm while proximal colon 9 cm and the sigmoid 5 cm.

Dilated small bowel tend to be in the central portion of abdomen recognized by presence plicae circularis.

Dilated colon tend to be in the periphery of abdomen and recognized by haustral marking.

Can be diagnostic in 50-80% of patientsThe cause of bowel obstruction can often determined Presence of pneumobilia suggest G.S ileus.Sigmoid and cecal volvulus produce pathognomnic images.

28

29

Supine

30

•Colonic haustrations

DiagnosisContrast studies:

Gastrograffin follow through. Identify site and often the cause of obstruction.

Differentiate between colonic and distal small bowel obstruction

Differentiate between ileus-partial and complete obstruction.

Computed tomography: Recently become valuable in diagnosis of intestinal obstruction

and ischemia. It has a high sensitivity and specificity .

Treatment

A. Resuscitation.B. Conservative treatment

1. Previous surgery.2. Incomplete obstruction.3. Advanced malignancy.4. Uncertain diagnosis.

C. Indications for surgery 1. Generalized or localized peritonitis.2. Perforation.3. Irreducible hernia.4. Palpable mass.5. Virgin abdomen.6. Closed loop

7. Failure to improve.

35

Volvulus

Is an axial rotation of bowel at its mesentery which could be congenital or secondary.

Small intestine, caecum, sigmoid are commonly affected.

Caecal volvulus twists clockwise .(resection is required if gangrene develops)

36

Sigmoid volvulus

The commonest type of volvulus.

Anticlockwise twist.

Causes: Bands, overloaded colon, large mesocolon,

narrow pelvic meso-colon attachment.

Treatment of volvuls: simple: colonoscopic deflation for few days

followed by colon preparation and then resection and primary anastomosis.

Strangulation or perforation: urgent resection and stoma followed by reversal of stoma in 6-8 weeks.Important note:

A consent for stoma is important before any laparotomy for intestinal obstruction.

Bowel preparation, consent for stoma and prophylactic antibiotics are mandatory before elective colonic operations.

Now let us test our knowledge with some clinical scenarios in bowel obstruction……

Clinical scenario 1

32 years old male c/o gradual central coliky abdominal pain since 10 hours associated with nausea, he had a projectile greenish vomitus 2 hours ago. He passed normal stool today. No past medical history but he had appendectomy one year ago. No previous similar conditions.

What is the likely diagnosis ?

Acute adhesive intestinal obstruction

what are the important points in physical exam?

32 years male c/o gradual central colicky abd.pain since 10 hours. He is nauseated, and had a greenish projectile vomitus 2 hours ago, and passed normal stool today.No associated fever.No passed medical problems or similar attaks.He had appendectomy one year ago.Physical exam:

Pulse 82/m, Bp110/82, tem.37.2cAbdomen is moving freely with respiration, mildly distended, healthy midline scar, no visible peristalsis, intact hernia orifices , no tenderness, no masses , tympanic percussion, hyper active bowel sounds and PR.

exam was normal

what is your impression now ?

Acute simple (uncomplicated) adhesive int. obst.

What are the required investigations?

CBC , Urea, Cr , Electrolytes , ABG (met.alkalosis)

CxR ,plain abd.X-R

Gastrografin follow through vs contrast CT.

How would you manage this case?

Conservative treatment: admission

Npo IV fluids

Analgesia Foley cath

Regular check of symptoms , vital signs and abdominal exam to rule out complications .

Indications for surgery:Ischemia , strangulation , failure of conservative treatment (up to 5 days).

Scenario 2

42 years old lady presented to the emergency room with coliky pain at the centre of the abdomen since 2 days associated with nausea and frequent greenish vomitus. She did not pass flatus or stool since yesterday. She had laparoscopic cholecystectomy and para-umbilical hernia repair 3 years ago followed by recurrence of the para-umbilical swelling 2 years later.

What is your differential diagnosis?

1 .simple obstruction (adhesion) 2 .closed loop obstruction (hernia)

What further information from history & physical exam you need?

42 years old lady presented to the emergency room with coliky pain at the centre of the abdomen since 2 days associated with nausea and frequent greenish vomitus. She did not pass flatus or stool since yesterday. she had laparoscopic cholecystectomy and para-umbilical hernia repair 3 years ago followed by recurrence of the para umbilical swelling 2 years later which became irreducible and painful since 2 days.

Examination revealed: pulse 110/m, BP100/70 temp 38c .

Abdomen: distended and tympanic, multiple scars, a para-umbilical swelling which is hot and tender.

Hyper active bowel sounds.

Now what is your most likely diagnosis?

Strangulated recurrent para-umbilical hernia

How would you manage?

Investigations:Lab:

CBC, U/E, Cr. INR ,blood cross match ECG

Imaging: CxR

plain x ray abd.(erect & supine) CT scan

Preparation: Admission

NPO NG tube

Foley catheter IV fluids (REPLACE ELECTROLYTES)

Antibiotics Consent

Laparotomy:assesment of obstructed segment of intestine :

Resection for established gangrene & asessment of viability in doubtful one after releasing the obstructing ring, warming and given 100% oxygen to

patient.(return of colour, pulsation and peristalses) .

Scenario 3

65 yars old male presented to ER c/o sudden ,sever, coliky lower & left side abdominal pain since 3 hours, associated with nausea but no vomiting.He is habitual constipator on occasional laxatives for long time.no past med. History but he was admitted 6 months ago with similar problem,offered surgery which he refused.

What are the likely differential diagnosis?

Scenario 3

Sigmoid volvulus Acute diverticulitis

Left renal colic

What further history & examination is important ?

Scenario 365 years old male presented to ER c/o sudden ,sever, coliky lower

abdominal pain since 3 hours, associated with nausea but no vomiting.He is habitual constipator on occasional laxatives for long time. No history of diarrhea or bleeding per rectum .No loin pain , no dysuria or hematuria. No past med. History but he was admitted 6 months ago with similar problem for which he had colonoscopy and then offered surgery after 5 days which he refused.Physical exam:Pulse 92/m, RR 27/m, BP 130/90 mmHg ,temp 36.9c.

Abdomen :no scars or hernias.It is hugely distended, non tender.Renal angle is free. Bowel sounds are audible.

what is the diagnosis now?

Sigmoid volvulus (un complicated)

What is the diagnostic modality?

•Omega sign

Un complicated : colonoscopic deflation.

Complicated (ischemia or perforation):resection.

SCENARIO 4

70 years old male admitted to hospital c/o gradual painless abdominal distention for 10 days and constipation for 3 days. No nausea or vomiting.He is hypertensive on Nitralix and diabetic on Daonil.

What is your differential diagnosis?

1 .Colonic carcinoma 2. Colonic pseudo-obstruction

( Ogilvie syndrome ) 3.Fecal impaction

What further history is important?

70 years old male admitted to hospital c/o gradual painless abdominal

distention for 10 days and constipation for 3 days.No nausea or vomiting. He had recent H/O tenesmus and passage of stool mixed with fresh blood.He has reduced appetite and lost 15 kg over two months.He is hypertensive on Nitralix and diabetic on Daonil. No family history of similar problem.Physical examination revealed:

Cahexia , normal vita signs , pallor , no jaundice. Distended , tympanic ,non tender abdomen. No masses or organomegally and

no scars. PR: no masses. There were little stool mixed with blood.

What is your most likely diagnosis now?

Colonic carcinoma

How would you investigate?

Blood: CBC, U/E, LFT, Cross matching, CEA

Radiology: CxR why?

plain abdomen why? CT abdomen why?

Colonoscopy & biopsy. ( incomplete v.s complete obstruction)

How do you manage early carcinoma sigmoid colon ?

•Incomplete obst.

•Complete obst.

Incomplete obstruction: bowel preparation then resection &

primary anastomosis.

Complete obstruction: Defunctioning temporary transverse

colostomy , then few days later resction, primary anastomosis and closure of colostomy.

Thanks