60-64 IleusandBowelObstruction.

Question 1

What are the types of bowel Obstruction (6)

Answer 1

Mechanical obstruction

Functional obstruction.

Simple obstruction

Strangulation obstruction

Open-loop obstruction

Closed-loop obstructions

Question 2

Mechanical obstruction definition

Answer 2

Mechanical obstruction.
means that luminal contents cannot pass through the gut tube because the lumen is blocked.

Question 3

definition of

Functional obstruction.

Answer 3

There are neurogenic or functional obstructions in which luminal contents are prevented from passing because of disturbances in gut motility that prevent coordinated peristalsis from one region of the gut to the next.

Question 4

simple obstruction definition

Answer 4

the intestinal lumen is partially or completely occluded without compromise of intestinal blood flow.

may be complete, meaning that the lumen is totally occluded

or

incomplete, lumen is narrowed but permitting distal passage of some fluid and air.

Question 5

Strangulation obstruction.

• def
• ceonsequences

complete/ incomplete obstruction

Answer 5

In strangulation obstruction, blood flow to the obstructed segment is compromised and tissue necrosis and gangrene are imminent.

Strangulation usually implies that the obstruction is complete.

Question 6

Open-loop obstruction. def

Answer 6

open-loop obstruction occurs when intestinal flow is blocked but proximal decompression is possible through vomiting.

Question 7

Closed-loop obstructions

• def
• is decompression possible

Answer 7

closed-loop obstruction occurs when inflow to the loop of bowel and outflow from the loop are both blocked. This obstruction permits gas and secretions to accumulate in the loop without a means of decompression, proximally or distally

Question 8

classification of Intestinal obstruction

Answer 8

Dynamic- Peristalsis against a mechanical obstruction

• intraluminal
• intramural
• Extraluminal

Adynamic – absent or non propulsive peristalsis

Question 9

Dynamic classification of Bowel Obstruction

Answer 9

Intraluminal

• Foreign bodies, Gallstones,
• Parasites, Enteroliths, Intussuseption
• Swallowed objects

Intramural

• Congenital: Meckels, Atresia, Stenosis,
• Inflammatory: crohns, Diverticulitis, Radiation enteritis
• Traumas: Intramural/Extramural
• Tumors: mg/ benign

Extraluminal

• Adhesions
• Meckels bands
• Hernia
• Volvulus
• External Mass Effect

Question 10

Adynamic /functional obstruction - absent or non propulsive peristalsis

( func obs has disturbances in gut motility )

Answer 10

1. paralytic ileus (neuourigenic)
2. Mesenteric Vascular Occlusion
3. Pseudo-obstruction

Question 11

Pathophysiology of Intestinal Obstruction

Answer 11

When a loop of bowel becomes obstructed, intestinal gas and fluid accumulate.

Stasis of luminal content favors bacterial overgrowth!! → alters intestinal fluid transport properties and motility, and causes variations in intestinal perfusion and lymph flow. →

altered flow leads to Changes in hydrostatic and osmotic pressures on the blood and lumen sides of the mucosa. →

pressure changes lead to favor flow of extracellular fluid into the lumen. →

Perfusion is compromised as luminal pressures increase,bacteria invade, and inflammation leads to edema within the bowel wall.

Question 12

complications of closed-loop obstructions

Answer 12

closed loop obstructinos evolve rapidly compared to open loop

blood supply of the obstructed loop is compromised→ gangrene and perforation → free perforation w/ Peritonitis ( clinically leads to a rigid abdomen) ​

Toxins from necrotic tissue and bacterial overgrowth are released into the systemic circulation → shock ensures

Question 13

conplications of open-loop obstructions

Answer 13

dosent evolve as quickly since proximal jeujenum can be decompressed by vomitting

Question 14

Complications / charaacteristics clinical sx of Proximal obstruction

Answer 14

vomiting →loss of gastric, pancreatic, and biliary secretions, → electrolyte disturbances.

• sx of Elyte disturbance
• dehydration,
• metabolic alkalosis
• hypochloremia -( gastric)
• hypokalemia -(bile)
• hyponatremia -(hypovolemic hyponatremia)

Question 15

Characteristics Complications of Obstructions of the distal ileum

• speed of progression
• most marked comp

Answer 15

this type of obs leads to slowly progressing distention of the small intestine.

distal jejunal obstruction tend to present with complications resulting from

1. Loss of intestinal contents from vomiting, as well as
2. distention of Lower abdom seg
3. compromise of intestinal wall perfusion.

Question 16

General sx of intestinal obstruction

Answer 16

Abdominal pain. - first symptom - colicky in the early stages → severe, constant as the process progresses

• Prox obstruction - with an acute onset of pain (less than 1 day)
• Distal - indolent course (a few days)
• strangulated in contact with the inner abdominal wall → well-localised severe pain

Nausea and vomiting.- follows the pain - emphasis must placed on the nature

• bilious emesis - proximal obstruction
• feculant* emesis - *Distal obstruction

Constipation - at ANY LEVEL = absolute constipation for both stool and gas.

Question 17

Physical findings of Intestinal Obstruction

Answer 17

Inspection

• Distension!! - lower the obstruction in the small bowel, the greater the distension.
• Visible peristalsis may occasionally in a thin patient

Palpation

• mass - suggests a specific cause for the obstruction,
  
  • irreducible mass - strangulated hernia
• tenderness and guarding - strangulation / perforation

Percussion

• tympanitic note - presence of gas-filled loops of bowel
  
  • absent - if Slow evolution of complications ( Distal ileal obstruction)

Auscultation

• Early → Increased Frequency of high-pitched, tinkling bowel sounds that resemble water lapping the side of a small boat
• Late → absent bowel sounds → PERITONITIS from PERFORATED LOOP!!

Question 18

N.B. what does it mean When mechanical obstruction is indicated by other clinical findings but bowel sounds are absent?

Answer 18

advanced condition or there is peritonitis which has resulted from perforation of an involved loop!

Question 19

What is the Imaging modality of choice for Intestinal obstruction

what is the appearance of inestinal obstruction on this imaging modality ]

Answer 19

Plain abdominal X-rays taken in the erect and/or supine positions are the standard and most reliable means of diagnosis.

Characteristic appearance of small-bowel ob‐struction is a number of distended, gas- and fluid-filled loops of bowel with, in the erect posture,

Question 20

Wat are the 5 Queations that MUST be answered through clinical dg, labs and Imaging in order to determine whether the Management of Intestinal Obstriction will be CONSERVATIVE or SURGICAL

Answer 20

1. Is the pain proportional to the physical findings?
2. How rapidly are the symptoms and signs evolving (minutes, hours,or more slowly)?
3. Does the patient suffer from dehydration and serum electrolyte and pH imbalances?
4. Is the obstruction complete or incomplete?
5. Is there a possibility of strangulation?

Question 22

Indications of

Non-operative management / CONSERVATIVE of Intestinal Obstruction

Answer 22

1. firm evidence that there is not a threat to the viability of the bowel and thus no risk of strangulation or perforation)
2. incomplete obstruction of the small bowel with features which suggest non-progression;
3. adhesive obstruction is the only instance a Complete obstructio is permitted .

Question 23

what does Conservative management of Intestinal obstruction actually involves

Answer 23

• proximal decompression by a nasogastric tube with aspiration either continuously or on a regular intermittent basis,
• Homeostasis-> water and electrolyte replacement,
• monitoring -> repeated (4-6-hourly) evaluation of the clinical state-abdominal pain, development of tenderness, changes in bowel sounds and in cardiovascular status,
• repeated reassessment -> plain X-rays or contrast studies and haematological and biochemical

Question 24

Indications for Operative management.of Intestinal Obstruction

Answer 24

irreducible Mass

• established or suspected strangulation;
• causes requiring surgical removal (e.g. tumor)

complete bowel obstruction+ tenderness

• -indicative of closed-loop obstruction with possible perforation,

failure of resolution after a period of non-operative management,

Question 25

WHat procedures preceede operatvie management of Intestinal Obstruction

Answer 25

1. gastric suction,
2. water and electrolyte replacement.

Question 26

what is the only indication of urgent operation (w/o pre op procedures) of Intestinal obstruction

how is it managed in the operative field

Answer 26

only indication for urgent operation is when strangulation or other causes of non-viability of the bowel are likely.

1. At operation, the obstruction is relieved
2. underlying cause removed. if possible!
3. Dead or damaged intestine must be excised.

Occasionally an irremovable obstruction (e.g. a fixed neoplasm) is bypassed.

Question 27

Paralytic ileus definition

Answer 27

Type of adynamic obstruction with no peristaltic waves d/2 neuromuscular failure of auerbach/ meissner’s plexus

• doesn’t involve a physical blockage.
• Muscle or nerve problems disrupt the normal coordinated muscle contractions of the intestines

Question 28

Types of paralytic ileus = PIRM paralysis

whichi is self limiting

which leads to adhesions

which fractures can cause ileus

which elecytolyte imbalances causes ileus

Answer 28

1. Post operative ileus & pharmacologic- Sefl limiting, prolonged after 24 hrs iif protein is low
2. Infective ileus - aka Intra-abdom Sepsis - causes local or general ileus and can lead to adhesions
3. Reflex ileus -(neurogenic) - Fractures of the Spine or rip cuasing RP heamorrhage
4. Metabolic ileus - uremia or hypokalemia

Question 29

PP pf paralytic ileus

Answer 29

disorganized electrical activity leads to paralysis of intestinal segments. This lack of coordinated propulsive action leads to the accumulation of gas and fluids within the bowel

Question 30

post op ( Abdominal or pelvic surgery) paralytic ileus

Answer 30

Normal resumption of bowel activity after abdominal surgery follows a predictable pattern:

• small bowel typically regains function within hours;
• stomach regains activity in 1-2 days; a
• colon regains activity in 3-5 days.

Question 31

Pharmacological Paralytic Ileus

Answer 31

medications that affect muscles and nerves,

• TCA’s , such as amitriptyline and imipramine (Tofranil), and
• OPIODS such as those containing hydrocodone (Vicodin) and oxycodone (Oxycontin)

Question 32

Risk factors for Paralytic ileus

Answer 32

• Abdominal or pelvic surgery, which often causes adhesions — a common intestinal obstruction
• Crohn’s disease, which can cause the intestine’s walls to thicken, narrowing the passageway
• Cancer in your abdomen, especially if you’ve had surgery to remove an abdominal tumor or radiation therapy

Question 33

Clinical picture of Paralytic ileus

Answer 33

Sx

distention, fullness, and bloating. - Abdominal cramping is usually not present.

effortless vomiting, and poor appetite. Patients may or may not continue to pass flatus and stool.

phys exam

tympanic on percussion

absent or hypoactive bowel sounds

imaging

x-ray - air fluid lvls

CT w/ Gastrofinn - gold for postop ileus

Question 34

RX of ileus

Answer 34

• Most cases of postoperative ileus resolve with watchful waiting and supportive treatment
  • Naso -gastric-tube decompression
  • food restriction until bowel sounds return
  • intravenous hydration
  • NSAIDS may improve ileus by reducing local inflammation
  • discontinue meds causing Ileus (opiods)
• surgery (laparoscopic) if conservative fails

Question 35

complicatoins of paralytic ileus

Answer 35

same as other intestinal obsructions

NECROSIS from loss of perfusion

PERITONITIS after perforation