The Acute Abdomen + Peritonitis Flashcards
1
Q
What is peritonitis
A
Inflammation of the peritoneum
2
Q
What is primary
A
No cause found at laparotomy
3
Q
What is secondary peritonitis
A
Underlying disease
4
Q
What is localised
A
Certain part of abdomen
e.g. abscess
5
Q
What is generalised [3]
A
Affects whole abdomen
>2 quadrants
Tenderness diffuse and inflammation widespread
6
Q
What causes peritonitis
A
- Inflammation / obstruction +- perforation of
- GI / biliary / female tract
- Ulcer / gall bladder / appendix / IBD / malignancy - Perforation of abdominal wall
- Haematogenous spread of infection
- Post-op - anastomotic leak
- Ischaemia
- Kidney / liver failure
- PD
7
Q
Peritonitis symptoms [5]
A
Sudden severe abdominal pain
Lying still
Loss of appetite, Vomiting
Fever
8
Q
How does colic present to peritonitis [2]
A
muscular spasm of a hollow viscous (gut, ureter, salpinx, uterus, bile duct or gallbladder)
Restlessness
Waxing and waning (except gallbladder colic which is dull and constant)
9
Q
What are signs of peritonitis [5]
A
Guarding Rebound tenderness Percussion tenderness - use to localise Rigid abdomen No bowel sounds
10
Q
What are bowel sounds like in obstruction
A
High pitched
11
Q
How do you investigate peritonitis [7]
A
Urine dip, beta-HCG Bloods - FBC, U+E, LFT, CRP ABG (lactate) CXR - erect (free air), abdominal (Rigler's sign) USS / CT (perforation) Gastrograffin (anastomotic leak) Laparoscopy
12
Q
What is contraindicated in peritonitis investigation?
A
Endoscopy
13
Q
Immediate management of peritonitis [9]
A
ABCDE & treat underlying cause IV access & bloods IV fluid resuscitation Ensure tissue perfusion and oxygenation SEPSIS 6 Catheter NG tube Analgesia Anti-emetic
14
Q
What antibiotics do you use in peritonitis? [2]
Subsequent mx of peritonitis [3]
A
CEFUROXIME and METRONIDAZOLE or GENT + MET
Drain abscess
Surgery - repair peritoneum
Treat cause
15
Q
What are complications of peritonitis [4]
A
Abscess formation
Localized ileus
Sepsis
Septic shock
16
Q
When does peritonitis not localise [3]
A
Contamination too rapid
Abscess ruptures
Immunocompromised
17
Q
What is the acute abdomen?
A
Severe abdo pain which results in patient being referred for urgent surgical opinion
18
Q
What are emergencies/ difficult to Dx conditions
A
Mesenteric ischaemia
Acute pancreatitis
Leaking/ ruptured AAA
Peritonitis after ruptured appendix
19
Q
Pancreatitis
A
Presents with peritonitis signs but does not require laparotomy to Dx
20
Q
How does AAA present [3]
A
Retroperitoneal back pain
Shock
Sudden collapse
21
Q
Why is appendix rupture difficult
A
Unusual distribution of pain
22
Q
What is somatic pain
A
Arise from abdominal wall
Peritoneum irritated
Intercostal nerves supply
Localised pain which tracks where fluid goes
23
Q
What is visceral pain
A
Arise for organ / gut
Insensitivite to mechanical or thermal
Sensitive to distension / ischaemia / spasm
Autonomic
24
Q
What are signs of organ rupture [3]
A
Shock
Abdo swelling
Mild peritonitis signs
25
What suggests abscess or localized peritonitis [3]
Swinging fever
Swelling
Increased WCC
26
What will be seen on examination [2]
Guarding
| Rebound tenderness
27
What should you do prior to surgical referral in an acute abdomen? [6]
```
Urine dip + MSSU
Bloods & culture
ABG
Pregnancy test
ECG
Imaging
```
28
What bloods [8]
```
FBC
U+E
LFT
CRP
Amylase / lipase (pancreas)
Lactate (mesenteric ischaemia)
Glucose
Calcium
```
29
Why is it important to do ECG
Diseases above diaphragm
30
What imaging before surgery? [6]
```
USS / CT
AXR
CXR
CT if time
CT angio (if bruits detected)
CT-KUB (renal stone)
```
31
What do you do before surgery
```
ABC
Resuscitate
NBM if scan / surgery
Fluid If needed
X-match and transfuse
Analgesia
Anti-emetic
IV Ax
Thrombo-prophylaxis
NG aspiration
Nutrition
```
32
What is seen on a CT scan if perforation
Air between abdominal wall and skin
| Same as hernia
33
What are common causes of acute abdomen
```
Acute appnedicitis
Obstruction
Urinary tract
Biliary tract
Trauma
Malignancy
Perforated ulcer / gall stone
Pancreatitis
```
34
What causes epigastric pain [6]
```
Gastritis
Peptic ulcer
Biliary colic
Pancreatitis
Perforation
Diseases above diaphragm
```
35
What diseases above diaphragm [5]
```
Inferior MI
PE
DKA
Poison
Pneumonia
```
36
What should you do for diseases above [3]
CXR
ECG
Blood glucose
37
What causes umbilical pain [7]
```
Crohns
Small bowel obstruction
Appendicits
Adhesions
Malignancy
Mesenteric ischaemia
Ruptured AA
```
38
What causes hypogastric/suprapubic pain [5]
```
Constipation
Diverticulitis
Colon cancer
Volvulus
Testicular/ovarian
```
39
What causes RLQ / LLQ pain
```
Appendicits
Ruptured ectopic
Renal stone
Pyelonephritis
Hernia
Mesenteric adenitis
Perforation
Diverticulitis
Testicular / ovarain torsion
PID
```
40
What causes LUQ pain
```
Pneumonia
Ruptured spleen
Ruptured AA
Pyelonephritis
Renal colic
```
41
What causes RUQ pain
```
Appendicits
Pneumonia
Acute cholecystitis
Cholangitis
Choledohcolithathis
Hepatitis
Biliary colic
Ulcers
Pyelonephritis
Renal colic
```
42
Surgical causes abdominal distension
```
Pregnancy
Obstruction
Volvulus
Ascites
Retention
Ovarian cancer
Constipaiton
```
43
What factors make obstruction more likely? [2]
Surgery Hx due to adhesions
| Cancer
44
When is ascites likely [2]
Alcohol
| CF
45
What are 5Fs
```
Fat
Faeces
Flatus
Fetus
Fluid
```
46
Define appendix
a prominent lymphoid tissue which regresses with age
47
What causes appendicitis
What bacteria cause appendicitis
Obstruction - fecalith, bezoar, filarial worms, lymphoid hyperplasia
Infection
Enterus vemicularis
48
Pathogenesis of appendicitis [5]
- Fills with mucous and swell
- eventually causing thrombosis, occlusion of small vessels and stasis of lymphatic flow.
- Appendix becomes ischaemic and necrotic
- Bacteria leak out through walls and pus forms around the appendix.
- Eventual rupture
49
Presentation Appendicitis
Symptoms [3]
Signs [5]
Symptoms
- Periumbilical pain that moves to RIF
- Anorexia - pain usually proceeds any vomiting
- Usually constipated +/- diarrhea
Signs
- Tachycardia, fever,
- furred tongue, foetor
- lying still, positive cough test
- Guarding, rebound tenderness,
- McBurney's point, Rovsings sign
50
What is Murphys triad
Investigations: appendicitis [5]
Murphys triad
- Pain, vomiting, fever
- FBC (neutrophilic leucocytosis)
- CRP
- Urine test - neutrophils + leucocyte (no nitrites), pregnancy test
- USS >6cm diameter + rule out gynae
- CT (not routine)
51
Appendicitis management
Simple appendicitis [2]
Perforated appendicitis [2]
Simple appendicitis: laparoscopic appendectomy, prophylactic IV abx (metronidazole and cefuroxime)
Perforated appendicitis: copious abdominal lavage and appendectomy
52
What are the differentials for appendicitis [8]
What should you beware in elderly?
```
Gastroenteritis
IBS, Crohns
Constipation
Peptic ulcer
UTI
Ectopic pregnancy
PID
Mesenteric adenitis
```
Beware of underlying malignancy in elderly
53
Describe an atypical presentation of appendicitis [2]
Retrocaecal retroperitoneal appendix > flank or RUQ pain, PR painful
Can occur in pregnancy
54
Complications of appendicitis
- Perforation
- Appendix mass - when inflamed appendix becomes covered in omentum, could also be in tumor
- Appendix abscess
55
What is ischaemic colitis [2]
| Presentation [3]
Ischaemic colitis describes an acute but transient compromise in the blood flow to the large bowel. This may lead to inflammation, ulceration and haemorrhage.
Bloody diarrhea + abdo pain
56
Where is common site
Splenic flexure
57
How do you Dx [2] and treat [2]
CT = 1st line
AXR
Supportive
Surgery if peritonitis / perforation / haemorrhage
58
What is mesenteric ischaemia?
| Aetiology
Typically small bowel in contrast to ischaemic colitis
| Due to embolism of SMA etc
59
What are the symptoms [4]
| Mesenteric ischemia
Sudden onset abdo pain out of proportion of physical exam findings
Rectal bleeding
Diarrhoea
Fever
60
What are RF for bowel ischaemia / mesenteric [7]
```
Age
Smoking, Cocaine
Hypertension, DM
Malignancy
Endocarditis, AF** (mesenteric)
Surgery
Abdominal aneurysm
```
61
How do you treat mesenteric ischaemia
Urgent surgery - laparotomy
| High mortality
62
What is a volvulus [2]
Torsion of bowel resulting in a closed loop obstruction that can cause strangulation or incarceration
63
Where is volvulus common
Sigmoid
| Can occur gastric / caecal
64
What are symptoms of volvulus [3]
Describe presentation of small intestine, caecal, sigmoid
1. Absolute constipation
2. Abdo pain + bloating
3. N+V
Small intestine: SBO symptoms
Caecal: LBO symptoms
Sigmoid: sudden left sided abdominal pain with abdominal distention
65
What is bowel volvulus associated with [5]
Elderly, Constipation
Neuro: Duchennes / PD
Schizophrenia
Chagas disease
Caecal - preg / adhesions / fistula, Crohns
66
How do you Dx and Rx [3]
AXR
| Central distended bowel in cecum
67
Tx of volvulus
Caecal [2]
Sigmoid [2]
Caecal
- Laparotomy for resection of affected segment
- +/- anastomosis
Sigmoid
- Emergency sigmoidoscopy, rectal tube insertion and
- Laparotomy for sigmoidectomy +/- anastomosis
68
Gastric volvulus
Aetiology
Risk factors [2]
Aetiology: twisting of stomach more than 180 degrees
Risk factors:
- Congenital eg pyloric stenosis
- Acquired (surgery)
69
Gastric volvulus
Symptoms [3]
Ix [2]
Mx [2]
Symptoms:
- Vomiting, pain, failure to pass NGT
- saliva regurgitation
- dysphagia
Ix: erect CXR, AXR (gastric dilation, double fluid level)
Mx: resuscitation, laparotomy
70
What is a diverticulum
Outpouching of gut wall
Usually at site of entry of arteries
Intraluminal pressure forces mucosa to herniate through gut at weak points
71
Where is common site for diverticulum
Sigmoid colon as this is where the luminal pressures are highest
72
What is diverticular disease
What is diverticulosis
Symptomatic diverticulum
The state of having diverticula which are asymptomatic
73
What are the symptoms of diverticular disease [7]
Pain LLQ
Relieved by defecation
N+V, bloating, flatulence
Altered bowel habit
Dysuria - bladder irritation due to inflamed bowel
PR bleeding
Pneumaturia or faecaluria may suggest colovesical fistula while vaginal passage of faeces or flatus may suggest a colovaginal fistula.
74
What are RF for diverticular disease [5]
```
Lack of fibre
Age
Obesity
Smoking
NSAID
```
75
How do you Dx diverticular disease [6]
FBC: raised WCC
CRP: raised
Erect CXR: may show pneumoperitoneum in cases of perforation
AXR: may show dilated bowel loops, obstruction or abscesses
CT: this is the best modality in suspected abscesses
Colonoscopy: should be avoided initially due to increased risk of perforation in diverticulitis
76
How do you treat diverticular disease in the community [4]
Antibiotics (oral)
Liquid diet
Analgesia
77
What are complications of diverticular disease [5]
```
Diverticulitis
Haemorrhage
Fistula (colovesical)
Perforation
Peritonitis, Abscess
```
78
What is diverticulitis
Inflammation of a diverticulum
| Beware in immunocompromised who present late
79
What are signs of diverticulitis [5]
- Low grade pyrexia
- Tachycardia
- Tender LIF: in 20% there will be a tender palpable mass due to inflammation or an abscess
- Possibly reduced bowel sounds
- Guarding, rigidity and rebound tenderness may suggest complicated diverticulitis with perforation
80
How long should you wait before you admit patients with diverticulitis?
```
If no improvement in 72h:
Admit
Analgesia
NBM
Iv fluid
Abx: IV ceftriaxone, metronidazole
Surgery for peritonitis / perforation
```
81
2 investigations you should not do in acute diverticulitis as risk of perforation?
Colonoscopy
| Barium enema
82
```
Management of
Abscess [2]
Perforation [2]
Hemorrhage [2]
Fistulae [1]
```
Abscesses: abx +/- US or CT guided drainage
Perforation: laparotomy and Hartmann’s procedure (temporary colostomy and partial colectomy)
Haemorrhage:
- mx as per any rectal bleed; may require transfusion and elective embolization (diathermy and local adrenaline)
- or colonic resection after colonoscopy or angiography
Fistulae: elective colonic resection
83
Intestinal obstruction define
Failure of downward passage of intestinal contents
84
Causes of intestinal obstruction
Mechanical vs pseudo obstruction
85
Mechanical causes of intestinal obstruction. Give definitions of each [2]
Simple vs strangulated
o Simple obstruction: lumen obstructed without interference of blood supply
o Strangulation: obstruction with persistent interference of blood supply
86
Simple causes of intestinal obstruction. Classify into 3 [4]
- Lumen: gallstones, impacted feces
- Mural: strictures
- Extra-mural: adhesions
87
Causes of strangulated intestinal obstruction [5]
```
Strangulated hernia
Intussusception
Late adhesive obstruction
Volvulus
Vascular adhesions
```
88
Pseudo-obstruction [4]
Systemic/metabolic causes
Drugs
Spinal trauma, brain injury
Hirschsprung disease
89
Describe some systemic/metabolic causes that can cause pseudo [2]
Describe some drugs that can cause pseudo [3]
Systemic/metabolic causes
Dehydration, low K/Na/Ca
Hypoxia, DKA, uremia
Drugs
TCA, Lithium, GA
90
Pathophysiology
Simple obstruction
1. Explain what happens to the intestine [4]
Intestinal:
Above obstruction
- initial increased peristalsis and distention with air and fluid later
- peristalsis ceases as bowel becomes flaccid and paralyzed
Below obstruction
- collapse, paralysis and pallor
At obstruction:
- perforation may eventually occur causing peritonitis
91
Pathophysiology
Simple obstruction
2. Explain what happens to fluid and electrolyte balance
3. Explain what happens to gut flora
Third space loss
- Failure of absorption of GI secretions in bowel
- proximal to obstruction site
- thus fluid sequesters into ECF
- hypovolemia, dehydration
Bacterial proliferation:
- bacterial accumulate proximal to obstruction
- impairment of barrier fx of mucosa
- bacterial translocation
92
Pathophysiology: strangulation [4]
Vascular:
• Impaired venous return: bowel and mesentery are congested
• Impaired arterial supply: affected segment becomes black
Dehydration:
- Serosanguinous fluid accumulates in peritoneal cavity
- Blood also is lost to 'third space'
93
Whats the main difference in pathophysiology of simple vs strangulated obstruction
o Simple obstruction: death occurs due to peritonitis and fluid and electrolyte imbalance
o Strangulation: death occurs either due to peritonitis or hypovolemic shock and sepsis
94
Dynamic vs adynamic intestinal obstruction
o Dynamic: increasing peristalsis working against obstructing agent
o Adynamic: peristalsis absent or ineffective with no effective propulsive waves
95
State in each scenario which bowel will be dilated or collapse:
SBO
LBO with competent ileocecal valve
LBO with incompetent ileocecal valve
o SBO: obstruction confined to small bowel and large bowel NOT dilated or collapsed
o LBO:
Competent ileocecal valve: small bowel is NOT dilated; large bowel becomes progressively dilated so perforation risk increases; perforation can occur at obstruction site or more commonly at cecum due to ischaemic change
Incompetent ileocecal valve: small AND large bowel BOTH dilated
96
Presentation of bowel obstruction [4]
Vomiting
Colicky pain
Bloating (abdominal distention)
Constipation (not always present)
97
Describe pain and vomiting in SBO [5]
o Pain:
- generalised and colicky
- each attack lasts a few minutes
- then gradually disappears with periods of relief between attacks
o Vomiting:
- early vomitus is partly digested food
- then becomes bile stained and then feculent due to enteral bacterial growth
98
What would indicate that its a jejunal obstruction [3]
generalised and colicky, [1] each attack lasts a few minutes and then gradually disappears [1] with periods of relief between attacks [1]
99
What would indicate an ileal obstruction [2]
- early vomitus is partly digested food, then becomes - bile stained and then feculent due to enteral bacterial growth
100
Compare abdominal distention in jejunal vs ileal obstruction
Compare abdominal distention in LBO with competent and incompetent ileocecal valve
Jejunal: minimal
Ileal: central
LBO with competent ileocecal valve: flank distension
LBO with incompetent ileocecal valve: generalised distension
101
Explain the difference between absolute and partial obstruction by constipation [2]
Absolute obstruction: no stool or flatus
Partial obstruction: continued passage of flatus and/or stool beyond 6-12h after symptom onset
102
SBO subtypes: high [3], middle [3] low [3]
| Describe differences in presentations
* High: frequent vomiting, no distension, intermittent pain but not classical crescendo type
* Middle: moderate vomiting and distension, intermittent crescendo colicky pain w/ free intervals
* Low: late and feculent vomiting, marked distension, variable pain (may not be classical crescendo type)
103
Bowel obstructions presenting without absolute constipation [4]
* Richter’s hernia: antimesenteric wall of bowel herniates through a small defect and progresses more rapidly to gangrene than other hernias
* Gallstone ileus
* Acute mesenteric ischaemia
* Intestinal obstruction associated with pelvic abscess
104
Signs of intestinal obstruction
| go through abdominal exam
• General: dehydration, tachycardia and shock
• Inspection: scars from previous surgery (adhesions), visible non-reducible hernia, visible peristalsis, stepladder appearance due to distended loops over each other
• Palpation: NO tenderness or rigidity in simple obstruction
• Auscultation:
o Early: loud, high pitched and frequent intestinal sounds
o Late: silent abdomen (ileus or peritonitis)
• Hernial orifices: features of strangulated external hernia
• PR: empty rectum, cause of obstruction (tumour, faecal impaction)
105
Red flags for strangulation [6]
• Pain: more severe and never completely absent between attacks
• Shock: present and progressive
• Tenderness and rigidity: localised and rebound tenderness
• NG suction fails after 1-2h: fails to relieve pain
• Raised WCC
• ABG: metabolic acidosis
- External hernia feels tense, tender, irreducible with no expansible impulse on cough
106
Ix: bloods [4]
FBC (leucocytosis in peritonitis or strangulation),
U&E and creatinine (electrolyte disturbance in SBO),
LFT (liver mets in LBO),
Clotting (abnormal in sepsis due to strangulation or peritonitis)
107
X-ray Imaging:
CXR [1]
AXR SBO [3]
AXR LBO [3]
o Erect CXR: pneumoperitoneum (free air under diaphragm) indicating perforation
```
SBO:
- dilated small bowel loops with fluid levels (minimal in proximal, large in distal)
- vavulae conniventes - lines extend all the way across
- maximum normal diameter is 35mm
LBO:
- large bowel loops
- haustra extend 1/3 of the way across
- maximum normal diameter is 55mm
```
108
Investigations: contrast studies [2]
What can CT abdominal show? [3]
o Contrast studies:
1) Gastrograffin follow through: if small bowel loops on AXR; may have therapeutic effect in adhesions; if contrast seen in large bowel at 24h this indicates non-surgical resolution of obstruction
2) Gastrograffin enema: if large bowel loops seen on AXR
o CT abdo: confirms dx [1] if transition point seen and identifies obstruction level [1] and staging if secondary to malignancy[1]
109
Immediate management [4]
| What to avoid at this stage?
Drip and suck
1. NG tube - symptomatic relief from vomiting and abdo pain and reduces aspiration risk
2. Fluid resus - isotonic fluids; assess response by pulse and urine output; correct K+ abnormalities if found
Avoid prokinetic anti-emetics e.g. metoclopramide
110
Early surgery indications [5]
```
Obstructed hernia,
suspected strangulation,
SBO in virgin abdomen,
failure or conservative mx in adhesive SBO,
obstructing tumour on CT
```
111
Surgical: general obstruction [1]
For obstructed hernia
For obstructing tumor
Laparotomy or laparoscopy: cause of obstruction identified and corrected
Obstructed hernia: explored and viable bowel reduced into abdo cavity with non-viable bowel resected
Obstructing tumour:
Hartmann’s procedure: resection of rectosigmoid colon with an END COLOSTOMY and rectal stump
112
When is conservative management indicated?
Incomplete SBO
113
Intussusception adult
Ax [2]
Pathogenesis
Ax:
- large polyp, sub mucous lipoma
- polypoid tumors, inverted Merckels diverticulum
Pathogenesis:
- telescoping of one segment into another
- polyp/tumour leading point
- usually colocolic
114
Intussusception adult
Sxs [2]
Ix
Mx
Abdominal lump/mass
Incomplete obstruction
Ix: CT (target sign)
Mx: laparotomy for resection of affected segment +/- anastomosis
115
Gallstone ileus
Ax [3]
Ix [2]
Mx [2]
- Gallstone fistulae allows gallstone to become impacted in terminal ileum
- Dynamic obstruction
- SBO, history of biliary colic
- Ix:
1. AXR (air in biliary tree)
2. CT
- Mx:
Laparotomy
Laparoscopy with enterotomy to remove stone
116
Paralytic ileus
| Aetiology [4]
- Post-op (major abdo surgery)
- Infective (generalized peritonitis)
- Reflex (post spinal #)
- Fluid & electrolyte abnormalities
117
Paralytic ileus
Symptoms [3]
Signs [3]
Symptoms:
- Vomiting, increased gastric NGT aspirate
- Progressive abdominal distention
- No pain
Signs:
- False shifting dullness
- No bowel sounds, occasional high pitched intestinal sounds
- Due to fluid passage from one intestinal segment to another
118
Paralytic ileus
Investigation
Management
AXR (dilated large and small bowel loops)
Mx:
- NGT, IV fluids, correction of electrolyte imbalance
- TPN if indicated
- Manage underlying cause
119
Ogilvie's syndrome
Epidemiology
Ax
Associated features [6]
```
AKA large bowel pseudo-obstruction
Epidemiology: elderly
Ax: idiopathic
Associated features:
- Recent surgery
- Severe pulmonary or CV disease
- Electrolyte imbalance
- Medications
- Malignancy
- Systemic infection
```
120
```
Ogilvie's syndrome
What type of bowel obstuction
Presentation
Ix [3]
Mx
```
Adynamic obstruction
Presents with symptoms of LBO
Ix
• Bloods: U&E and creatinine (hyponatraemia, hypokalaemia, hypomagnesaemia), calcium (hypo or hypercalcaemia)
• AXR: generalised dilatation large bowel loops with visible air in the rectum
• CT abdo: generalised dilatation of large bowel loops with NO transition point or identifiable obstruction
Mx: supportive w/ mx of underlying cause
121
Acute mesenteric ischaemia- causes: [5]
Arterial - thrombosis or embolism
Non-occlusive
Venous
Other
122
```
Acute mesenteric ischaemia- causes 2 :
Thrombotic [3]
Embolic [4]
Non-occlusive [3]
Venous [2]
Other [4]
```
• Arterial (thrombotic or embolic): superior mesenteric artery (SMA)
o Thrombosis: atherosclerosis, polycythaemia, OCP
o Embolism: arrhythmia, post-MI mural thrombus, AAA, thoracic aortic aneurysm
• Non-occlusive: low cardiac output, recent cardiac surgery, renal failure
• Venous: mesenteric vein thrombosis (younger pts, hypercoagulable state, smaller segments) due to portal HTN
• Other: trauma, vasculitis, RT, strangulation (e.g. volvulus or hernia)
123
Acute mesenteric ischaemia:
Collateral arteries [3]
Ischaemia [4]
Usually small bowel
Collateral arteries:
- Small intestine supplied by coeliac artery and SMA
- Collateral arteries exist between SMA and IMA but this is limited at watershed areas
Ischemia:
- Hypoperfusion leads to ischemia
- Bowel necrosis > septic peritonitis
- SIRs, multi-organ dysfunction (bacterial translocation through gut wall)
- Reperfusion injury can also occur
124
Where are the watershed areas?
Splenic flexure
| Rectosigmoid junction
125
Acute mesenteric ischaemia:
Sxs [3]
Ix [6]
Mx
Sxs:
- classic triad:
- acute severe abdo pain
- no abdo signs signs (but marked tenderness and rigidity later on)
- rapid hypovolaemia and shock
Ix:
- Bloods
- ABG
- CXR
- AXR
- CT abdo pelvis triple phase with IV contrast
- Invasive arteriography or CT/MR angiography
126
Acute mesenteric ischaemia:
- Bloods [3]
- ABG
- CXR
- AXR [3]
- CT [3]
* Bloods: FBC (elevated Hb due to plasma loss, leucocytosis), amylase (moderately raised), lactate (elevated)
* ABG: metabolic acidosis with raised anion gap (lactic acidosis)
* CXR: pneumoperitoneum if perforation
* AXR: gasless abdo in early stages, then air fluid level and bowel dilatation due to ischaemia
* CT: oedematous bowel progressing to loss of bowel wall enhancement and pneumatosis intestinalis (can see on AXR too)
127
Acute mesenteric ischaemia:
Initial management
Surgical options
Initial:
- NGT
- IV fluid resus
- IV ceftriaxone, metronidazole
- Heparin
- Catheter
Exploratory laparotomy or invasive angioplasty
128
Exploratory laparotomy for acute mesenteric ischemia [3]
- SMA embolectomy may salvage bowel in early stages
- but most often resection with stoma formation
- ITU with sedation post-op with planned re-look laparotomy at 24-48h to check viability of remaining bowel
