INTESTINAL OBSTRACTION-HOMSCINTESTINAL OBSTRACTION-HOMSC.ppt

INTESTINAL OBSTRACTION-HOMSC.ppt

1. INTESTINAL INTESTINAL
OBSTRUCTIONOBSTRUCTION
Aug-2013Aug-2013
AddisAddis

2. Presentation OutlinePresentation Outline

IntroductionIntroduction

ClassificationClassification

CausesCauses

PathophysiologyPathophysiology

Strangulation ObstructionStrangulation Obstruction

TreatmentTreatment

Small bowel VolvulusSmall bowel Volvulus

Adhesion obstructionAdhesion obstruction

Paralytic IleusParalytic Ileus

3. IntroductionIntroduction

Intestinal obstructionIntestinal obstruction
Small bowel Small bowel  80% of obstruction 80% of obstruction
20% of acute abdomen admissions20% of acute abdomen admissions
 5% of all surgical admissions5% of all surgical admissions
Large bowel Large bowel  20% of obstruction 20% of obstruction

4. ClassificationClassification

Generally classified into mechanical and non mechanical by Generally classified into mechanical and non mechanical by
mechanism mechanism

Mechanical ObstructionMechanical Obstruction
By location By location  small bowel; High or Low small bowel; High or Low
 Large bowelLarge bowel
By pathophysiology By pathophysiology Simple, closed loop or strangulatedSimple, closed loop or strangulated
The obstruction may be complete or partial, acute or chronicThe obstruction may be complete or partial, acute or chronic

5. Causes Of ObstructionCauses Of Obstruction
MechanicalMechanical
Intraluminal =>impaction, foreign bodies, bezoars, gall stones, ascariasisIntraluminal =>impaction, foreign bodies, bezoars, gall stones, ascariasis
Intramural => Inflammatory strictures, Neoplasm's, Congenital malformationsIntramural => Inflammatory strictures, Neoplasm's, Congenital malformations
Extramural => bands/adhesions, hernia, volvulus, intussusceptionsExtramural => bands/adhesions, hernia, volvulus, intussusceptions
Non mechanicalNon mechanical
Paralytic Ileus Paralytic Ileus
Mesenteric vascular occlusionMesenteric vascular occlusion
Pseudo-obstructionPseudo-obstruction

6. Relative frequency of causes of intestinal Relative frequency of causes of intestinal
obstructionobstruction

Developed Countries Developing CountriesDeveloped Countries Developing Countries
Adhesions 40% Adhesions 40% Obstructed herniaObstructed hernia
Inflammatory 15%Inflammatory 15% Primary volvulusPrimary volvulus
Carcinoma 15% Carcinoma 15% Adhesions/ Bands; post-op, inflammatory Adhesions/ Bands; post-op, inflammatory
Obstructed hernia 12%Obstructed hernia 12% IntussusceptionsIntussusceptions
Fecal impaction 8% AscariasisFecal impaction 8% Ascariasis
Pseudo-obstruction 5% Large Bowel -- Volvulus, MalignancyPseudo-obstruction 5% Large Bowel -- Volvulus, Malignancy
Miscellaneous 5%Miscellaneous 5%

7. Mechanism of Mechanical obstructionMechanism of Mechanical obstruction

VolvulusVolvulus

IncarcerationIncarceration

ObstructionObstruction

IntussusceptionIntussusception

9. PathophysiologyPathophysiology

Normally 8-9 liter enter small intestineNormally 8-9 liter enter small intestine Electrolyte content (mmol/LElectrolyte content (mmol/L))
Oral intake 2oooml Oral intake 2oooml Sodium Sodium PotassiumPotassium ChlorideChloride
saliva 1500mlsaliva 1500ml
Gastric secretion 2500ml 60Gastric secretion 2500ml 60 10 100 10 100
Bile 500mlBile 500ml 145 5 100 145 5 100
Pancreatic secretion 1500ml 140 5 75Pancreatic secretion 1500ml 140 5 75
Small intestine secretion 1000ml Small intestine secretion 1000ml

 small intestine absorption 7500ml 110 5 100small intestine absorption 7500ml 110 5 100
 1500ml to colon1500ml to colon

10. Pathophysiology-Mechanical ObsPathophysiology-Mechanical Obsnn

Proximal Bowel => Increreased peristalsis Proximal Bowel => Increreased peristalsis  dilatation (fluid and air) dilatation (fluid and air)
reduction in peristaltic strength ----reduction in peristaltic strength ----Flaccidity and ParalysisFlaccidity and Paralysis


Distal bowel=> Normal Peristalsis and absorption Distal bowel=> Normal Peristalsis and absorption  Empty Empty  contracted contracted
and immobileand immobile
Simple ObstructionSimple Obstruction
Fluid and Electrolyte loss (ECFFluid and Electrolyte loss (ECF))
Bacterial proliferation ; Feculent vomitus in distal SBOBacterial proliferation ; Feculent vomitus in distal SBO
N.B. Ischemic changes progressing to necrosis and perforation may occur at site of N.B. Ischemic changes progressing to necrosis and perforation may occur at site of
obstructionobstruction
IN LBO, when the ileocaecal valve remains competent, the caecum may burstIN LBO, when the ileocaecal valve remains competent, the caecum may burst
Closed loop obstructionClosed loop obstruction
Blood Vessels enter intestinal wall tangentially => Tension on them increases rapidly with Blood Vessels enter intestinal wall tangentially => Tension on them increases rapidly with
bowel distentionbowel distention

11. PathophysiologyPathophysiology
Strangulated ObstructionStrangulated Obstruction

Blood and Plasma loss in strangulated obstruction Blood and Plasma loss in strangulated obstruction  shock shock

Hypoxia of intestinal mucosa (luminal hypoventilation and decreased blood flow)Hypoxia of intestinal mucosa (luminal hypoventilation and decreased blood flow)
Decreased absorption, increased secretion Decreased absorption, increased secretion
Decreased mucosal resistance Decreased mucosal resistance  Auto-digestion + Bacterial invasion Auto-digestion + Bacterial invasion 
Inflammation, Ulceration Inflammation, Ulceration  Bacterial and Endotoxin translocation Bacterial and Endotoxin translocation

The peritoneal fluid exudate changes from a clear plasma like fluid intoThe peritoneal fluid exudate changes from a clear plasma like fluid into
blood tinged and then foul, dark exudationblood tinged and then foul, dark exudation

Frank gangrene and perforationFrank gangrene and perforation

12. Clinical FeaturesClinical Features

Abdominal PainAbdominal Pain

VomitingVomiting

Abdominal DistensionAbdominal Distension

Absolute ConstipationAbsolute Constipation

Dehydration –Tachycardia, Hypotension, oliguria Dehydration –Tachycardia, Hypotension, oliguria

Features of Peritonism –Strangulation or PerforationFeatures of Peritonism –Strangulation or Perforation
C.F. vary according toC.F. vary according to
Site of the obstructionSite of the obstruction
Onset and duration of the obstructionOnset and duration of the obstruction
Underlying pathologyUnderlying pathology
Presence / absence of strangulation Presence / absence of strangulation
Constipation is a rule in intestinal obstruction doesn't apply inConstipation is a rule in intestinal obstruction doesn't apply in
Richter's hernia, gallstone obturation, obstruction associated with pelvic abscess, partial Richter's hernia, gallstone obturation, obstruction associated with pelvic abscess, partial
obstruction (diarrhea may occur)obstruction (diarrhea may occur)

13. Causes Of StrangulationCauses Of Strangulation

External –hernial orificesExternal –hernial orifices
--adhesions / bands--adhesions / bands

Interrupted blood flow -volvulusInterrupted blood flow -volvulus
- Intussusceptions- Intussusceptions

Increased intraluminal pressureIncreased intraluminal pressure
-Closed loop obstruction-Closed loop obstruction

Primary – mesenteric infarction Primary – mesenteric infarction

14. Strangulation ObstructionStrangulation Obstruction

Severe Continuous abdominal painSevere Continuous abdominal pain

FeverFever

Tachycardia after resuscitationTachycardia after resuscitation

Peritoneal signsPeritoneal signs

LeukocytosisLeukocytosis
Distinction b/n simple and strangulated obstructionDistinction b/n simple and strangulated obstruction
Individually present equally in both groupsIndividually present equally in both groups
If all are absent strangulation is unlikelyIf all are absent strangulation is unlikely
If bowel is strangulated two or more of above will be present in at least 90% of casesIf bowel is strangulated two or more of above will be present in at least 90% of cases
N.B. Clinical and lab investigations are unreliable orN.B. Clinical and lab investigations are unreliable or
impossible to Dx strangulated obstruction while the bowel is in impossible to Dx strangulated obstruction while the bowel is in
reversible ischemic state reversible ischemic state

15. DiagnosisDiagnosis

Clinical Clinical Aim is to DetermineAim is to Determine
Is bowel obstruction present ?Is bowel obstruction present ?
Where is the location ?Where is the location ?
What is the cause ?What is the cause ?
Are any complications present ? E.g.. Dehydration, shock, strangulationAre any complications present ? E.g.. Dehydration, shock, strangulation

HistoryHistory
AgeAge
The four cardinal features of obstructionThe four cardinal features of obstruction
Past Hx -- abdominal surgeryPast Hx -- abdominal surgery
-- medical illnesses: cardiac arrhythmias, IBD, radiation-- medical illnesses: cardiac arrhythmias, IBD, radiation

P/EP/E
V/S Tachycardia – dehydration/hypovolemia; V/S Tachycardia – dehydration/hypovolemia;
Hypotension – severe dehydrationHypotension – severe dehydration
Fever – strangulation, peritonitis, inflammatory processFever – strangulation, peritonitis, inflammatory process

16. DiagnosisDiagnosis
Abdomen Abdomen Inspection, auscultation, palpation and percussionInspection, auscultation, palpation and percussion
Surgical scarsSurgical scars
Distension ---distribution, step-ladder pattern, visible peristalsisDistension ---distribution, step-ladder pattern, visible peristalsis
Hernia orificesHernia orifices
Bowel soundsBowel sounds
Guarding and tendernessGuarding and tenderness
DRE --- masses, stool, bloodDRE --- masses, stool, blood
InvestigationsInvestigations
Hematology; Hematology; WBC, Hct, Blood group, electrolytesWBC, Hct, Blood group, electrolytes
Radiology; Radiology; Erect abdominal and CXRErect abdominal and CXR
Contrast study in partial SBO of uncertain causeContrast study in partial SBO of uncertain cause

17. Plain abdominal filmPlain abdominal film
 Usually confirms the clinical diagnosisUsually confirms the clinical diagnosis
 Define more accurately the site of obstructionsDefine more accurately the site of obstructions
 Doesn't Dx the etiologyDoesn't Dx the etiology

X-ray findingsX-ray findings
Small bowel larger than 3 cm in diameterSmall bowel larger than 3 cm in diameter
Gas and fluid levelsGas and fluid levels
Paucity of gas in the colonPaucity of gas in the colon

Strong clinical diagnosis + normal x-ray Strong clinical diagnosis + normal x-ray  should suggest strangulation should suggest strangulation

May be normal in early obstructions, high obstructions, mid gut volvulus May be normal in early obstructions, high obstructions, mid gut volvulus

Generalized haze in advanced strangulated obstructionGeneralized haze in advanced strangulated obstruction

18. TreatmentTreatment

Principles of RxPrinciples of Rx
1. GI drainage1. GI drainage
2. Fluid and Electrolyte replacement2. Fluid and Electrolyte replacement
3. Relief of Obstruction3. Relief of Obstruction

Resuscitation / Pre-op careResuscitation / Pre-op care
Volume replacementVolume replacement
Correction of electrolyte imbalanceCorrection of electrolyte imbalance
NGT suction – reduces nausea, vomiting, distention, risk of aspirationNGT suction – reduces nausea, vomiting, distention, risk of aspiration
Catheterize - monitor urine outputCatheterize - monitor urine output
Pre-op antibioticsPre-op antibiotics

19. Surgical RxSurgical Rx

TimingTiming: : Immediate, urgent, delayed/electiveImmediate, urgent, delayed/elective
Depends on 1. Duration of obstruction i.e. severity of fluid, electrolyte and Depends on 1. Duration of obstruction i.e. severity of fluid, electrolyte and
acid-base abnormalityacid-base abnormality
2. The opportunity to improve vital organ function2. The opportunity to improve vital organ function
3. Consideration of the risk of strangulation3. Consideration of the risk of strangulation
ImmediateImmediate

strangulated obstructions; As soon as hemomodynamically stablestrangulated obstructions; As soon as hemomodynamically stable

Closed loop obstructions; Non sigmoid volvulus, incarcerated herniasClosed loop obstructions; Non sigmoid volvulus, incarcerated hernias

Simple, complete obstructions; After resuscitation is completeSimple, complete obstructions; After resuscitation is complete

20. Surgical RxSurgical Rx
UrgentUrgent

Lack of response to non operative therapy within 24 to 48 hrsLack of response to non operative therapy within 24 to 48 hrs

Early post-op technical complications; abscess, intussusceptions, narrow Early post-op technical complications; abscess, intussusceptions, narrow
anastomosis, stomal obstructionsanastomosis, stomal obstructions
ConservativeConservative

Adhesive partial small bowel obstructionsAdhesive partial small bowel obstructions

Early post-op obstructionsEarly post-op obstructions

Partial SBO due to inflammatory conditionsPartial SBO due to inflammatory conditions
Delayed / Elective operationsDelayed / Elective operations

Deflated sigmoid volvulusDeflated sigmoid volvulus

Recurrent adhesive / stricture related SBORecurrent adhesive / stricture related SBO

Partial colonic obstructionsPartial colonic obstructions

Bowel obstructions without previous abdominal operationsBowel obstructions without previous abdominal operations

21. Surgical RxSurgical Rx

Operative assessment is directed toOperative assessment is directed to
1. The site of obstruction1. The site of obstruction
2. The nature of obstruction2. The nature of obstruction
3. Viability of the gut; color, motility, arterial pulsation3. Viability of the gut; color, motility, arterial pulsation

Principles of surgical interventionPrinciples of surgical intervention
1.management of segment at site of obstruction1.management of segment at site of obstruction
2. The distended proximal bowel2. The distended proximal bowel
3.Underlying Cause of obstruction3.Underlying Cause of obstruction

22. Surgical ProceduresSurgical Procedures
1. 1. Procedures not requiring opening bowelProcedures not requiring opening bowel
- Lysis of adhesions/ bands- Lysis of adhesions/ bands
- Manipulative and reduction; incarcerated hernia, intussusceptions, - Manipulative and reduction; incarcerated hernia, intussusceptions,
volvulusvolvulus
2. Enterotomy for removal of cause of obstruction2. Enterotomy for removal of cause of obstruction
3. Resection; obstructing lesion, strangulated (non viable) bowel3. Resection; obstructing lesion, strangulated (non viable) bowel
4.Short-circuiting anastomosis4.Short-circuiting anastomosis
5.Formation of a cutaneous stoma5.Formation of a cutaneous stoma

23. Post-op CarePost-op Care

Fluid and electrolyte:Fluid and electrolyte:
Deficit, Maintenance, Continued third space losses Deficit, Maintenance, Continued third space losses

NGT decompression until return of bowel functionNGT decompression until return of bowel function

Input / output monitoringInput / output monitoring

AntibioticsAntibiotics

Observation for complicationsObservation for complications

24. PrognosisPrognosis
MortalityMortality

SBOSBO Simple obstruction =2% , Most in the elderly with co morbiditiesSimple obstruction =2% , Most in the elderly with co morbidities
Strangulated obstruction Strangulated obstruction  surgery within 36hrs = 8% surgery within 36hrs = 8%
 surgery after 36hrs = 25%surgery after 36hrs = 25%
Recurrent small bowel obstruction occurs in 10 – 20% of patients treated by Recurrent small bowel obstruction occurs in 10 – 20% of patients treated by
adhesiolysisadhesiolysis

LBO LBO Uncomplicated colonic resections = 10%Uncomplicated colonic resections = 10%
In the presence of fecal peritonitis = 40%In the presence of fecal peritonitis = 40%

25. Primary VolVulus of Small intestinePrimary VolVulus of Small intestine

Developed World: Rare, except in babies and small childrenDeveloped World: Rare, except in babies and small children

Developing World: common, particularly in young menDeveloping World: common, particularly in young men

Accounts 18-51% of SBO in Africa and AsiaAccounts 18-51% of SBO in Africa and Asia

Etiology is poorly understoodEtiology is poorly understood
 Diet; Study in Afghanistan Muslims showed tenfold increase during Diet; Study in Afghanistan Muslims showed tenfold increase during
the Ramadan festival (Duke and Yar)the Ramadan festival (Duke and Yar)
 Increased gut motility; Parasitic infectionsIncreased gut motility; Parasitic infections
Secondary small bowel volvulus : Most frequently related conditionsSecondary small bowel volvulus : Most frequently related conditions
are Bands, adhesions, Meckel`s diverticulum,internal hernia and pregnancyare Bands, adhesions, Meckel`s diverticulum,internal hernia and pregnancy

26. Primary Volvulus of Small BowelPrimary Volvulus of Small Bowel

The small gut rotates on its mesentery 5 – 10cm from the ilieocaecal junctionThe small gut rotates on its mesentery 5 – 10cm from the ilieocaecal junction

Most of the small gut may rotate apart from its top and distal endsMost of the small gut may rotate apart from its top and distal ends

Symptoms of acute obstruction become rapidly those of strangulationSymptoms of acute obstruction become rapidly those of strangulation

In a strangulated closed loop, there may be no fluid levels In a strangulated closed loop, there may be no fluid levels  x-ray may look x-ray may look
normalnormal

Rx is immediate operation Rx is immediate operation

27. Adhesion Intestinal ObstructionAdhesion Intestinal Obstruction

Obstruction may result from a single band or multiple dense adhesionsObstruction may result from a single band or multiple dense adhesions

Cause ; Post-op, Inflammatory, congenital, post blunt traumaCause ; Post-op, Inflammatory, congenital, post blunt trauma

Develops in 5% of abdominal operationsDevelops in 5% of abdominal operations
Healing without adhesion formationHealing without adhesion formation
Peritoneal injury Peritoneal injury  disrupted microvasculature beneath mesothelium disrupted microvasculature beneath mesothelium
extravastion of serum and cellular elementsextravastion of serum and cellular elements coagulates producing fibrinous coagulates producing fibrinous
bands ban abutting surfacesbands ban abutting surfaces
 Neutrophil, later macrophage infiltratesNeutrophil, later macrophage infiltrates
Activated fibrinolitic path -- lyses fibrinous bands within 72 hrsActivated fibrinolitic path -- lyses fibrinous bands within 72 hrs
 By 5By 5
thth
day re-epithelializaion ( indistinguishable from normal peritoneum) day re-epithelializaion ( indistinguishable from normal peritoneum)
The new mesothelium is derived from the metaplasia of subperitneal perivascular The new mesothelium is derived from the metaplasia of subperitneal perivascular
connective tissueconnective tissue

28. Adhesion Intestinal ObstructionAdhesion Intestinal Obstruction
Healing with adhesion/band formationHealing with adhesion/band formation


Inequilibrium b/n fibrin deposition and fibrinolysisInequilibrium b/n fibrin deposition and fibrinolysis  persistence of fibrinous persistence of fibrinous
adhesions/strands adhesions/strands  Invaded by fibroblasts (collagen synthesis) Invaded by fibroblasts (collagen synthesis)  fibrous fibrous
adhesions/bandsadhesions/bands

Adequate blood supply is critical for normal fibrinolysis to occurAdequate blood supply is critical for normal fibrinolysis to occur

Ischemia -Ischemia -leads to organization of the fibrin-cellular matrixleads to organization of the fibrin-cellular matrix
Ischemia may result from excessive handling, crushing, lygation,Ischemia may result from excessive handling, crushing, lygation,
suturing, cauterizing or striping of the peritoneumsuturing, cauterizing or striping of the peritoneum

Foreign body rxn causes excessive formation of fibrin coagulumForeign body rxn causes excessive formation of fibrin coagulum

Infection; proteolytic enzymes Infection; proteolytic enzymes  ischemia and tissue damage ischemia and tissue damage

29. Adhesion Intestinal ObstructionAdhesion Intestinal Obstruction
TreatmentTreatment
Conservative: NPO, NGT, iv fluids, analgesicsConservative: NPO, NGT, iv fluids, analgesics
Success rate Success rate  90% in early adhesive obstruction and partial obstruction 90% in early adhesive obstruction and partial obstruction
70% over all70% over all
Risks Risks  Strangulation already exists but undetected Strangulation already exists but undetected
Progression of complete obstruction to strangulationProgression of complete obstruction to strangulation
 3 hourly examination by the same clinician3 hourly examination by the same clinician
Crucial to be alert to changes in patients conditionCrucial to be alert to changes in patients condition
Repeat abdominal x-ray in 6 hrsRepeat abdominal x-ray in 6 hrs
IF strangulation suspected IF strangulation suspected  Immediate operation Immediate operation
Complete obstruction Complete obstruction  ? ?

30. Adhesion Intestinal ObstructionAdhesion Intestinal Obstruction
Duration of conservative RxDuration of conservative Rx; Controversial; Controversial
Majority; fairly prompt response within the first 8-12 hrsMajority; fairly prompt response within the first 8-12 hrs
Only 5-15% of patients who doesn't show significant improvement within 48 hrs Only 5-15% of patients who doesn't show significant improvement within 48 hrs
continue to improvecontinue to improve
Oral water soluble contrast study: If contrast seen in the colon within 24hrsOral water soluble contrast study: If contrast seen in the colon within 24hrs
Positive predictive value Positive predictive value 100%100%
Negative predictive value Negative predictive value  98% 98%

31. Non Mechanical obstructionsNon Mechanical obstructions
Paralytic IleusParalytic Ileus
Failure of transmission of peristaltic waves due to neuromuscular failureFailure of transmission of peristaltic waves due to neuromuscular failure
Mediated via the hormonal component of sympathoadrenal systemMediated via the hormonal component of sympathoadrenal system
Causes - Post-operative ; clinical significance if prolonged after 3-5 daysCauses - Post-operative ; clinical significance if prolonged after 3-5 days
- Infection- Infection
- Reflex ileus- Reflex ileus
- Metabolic ; uremia and hypokalemia- Metabolic ; uremia and hypokalemia
- Drugs; Narcotics- Drugs; Narcotics
C.F - Abdominal distensionC.F - Abdominal distension
- Vomiting ; gastric and bilious, never feculent- Vomiting ; gastric and bilious, never feculent
- discomfort from distension, not colicky pain - discomfort from distension, not colicky pain

32. Non Mechanical obstructionsNon Mechanical obstructions
Paralytic IleusParalytic Ileus

Dx - clinical, x-ray, U/sDx - clinical, x-ray, U/s
RX – PreventionRX – Prevention
-- NGT -- NGT
-- Rx primary cause-- Rx primary cause
-- Close attention to fluid and electrolyte balance-- Close attention to fluid and electrolyte balance
-- Peristaltic stimulants ; Rarely ; Adrenergic blocking with cholinergic -- Peristaltic stimulants ; Rarely ; Adrenergic blocking with cholinergic
stimulationstimulation
-- Laparotomy; when ileus is prolonged and threatens life-- Laparotomy; when ileus is prolonged and threatens life
To exclude a hidden cause and facilitate decompressionTo exclude a hidden cause and facilitate decompression

33. 
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