General surgery in the GI tract Flashcards
what is the general approach to acute abdomen?
PC – Pain assessment (SOCRATES)*, associated symptoms
PMHx, DHx, SHx
Range of investigations (depending on presentation):
Bloods: VBG, FBC, CRP, U&Es (renal profile), LFTs +amylase
Urinalysis + Urine MC&S
Imaging: Erect CXR, AXR, CTAP (ct abdomen adn pelvis), CT angiogram, USS
Endoscopy
Management:
ABCDE approach (airways breathing circulation disability (GCS, eyes etc)
Conservative management
Surgical management
what are the differential diagnoses for RUQ pain?
Bilary Colic Cholecystitis/Cholangitis Duodenal Ulcer Liver abscess Portal vein thrombosis Acute hepatitis Nephrolithiasis RLL pneumonia
what are the differential diagnoses for epigastrium pain?
Acute gastritis/GORD Gastroparesis Peptic ulcer disease/perforation Acute pancreatitis Mesenteric ischaemia AAA (Abdominal Aortic Aneurysm) Aortic dissection Myocardial infarction
what are the differential diagnoses for LUQ pain?
Peptic ulcer Acute pancreatitis Splenic abscess Splenic infarction Nephrolithiasis LLL Pneumonia
what are the differential diagnoses for RLQ pain?
Acute Appendicitis Colitis IBD Infectious colitis Ureteric stone/Pyelonephritis PID/Ovarian torsion Ectopic pregnancy Malignancy
what are the differential diagnoses for suprapubic/central pain?
Early appendicitis Mesenteric ischaemia Bowel obstruction Bowel perforation Constipation Gastroenteritis UTI/Urinary retention PID
what are the differential diagnoses for LLQ pain?
Diverticulitis Colitis IBD (Inflammatory Bowel Disease) Infectious colitis Ureteric stone/Pyelonephritis PID/Ovarian torsion Ectopic pregnancy Malignancy
how does bowel ischaemia present?
Sudden onset crampy abdominal pain
Severity of pain depends on the length and thickness of colon affected
Bloody, loose stool (currant jelly stools)
Fever, signs of septic shock
what are risk factors for bowel ischaemia?
Age >65 yr Cardiac arrythmias (mainly AF), atherosclerosis Hypercoagulation/thrombophilia Vasculitis Sickle cell disease Profound shock causing hypotension
what are the differences between acute mesenteric ischaemia and ischemic colitis?
Acute Mesenteric Ischaemia:
Small bowel
Usually occlusive due tothromboemboli
Sudden onset (but presentation and severityvaries)
Abdominal pain out of proportion of clinical signs
Ischaemic Colitis:
Large bowel
Usuallydue to non-occlusive low flow states, or atherosclerosis
More mild and gradual (80-85% of the cases)
Moderate pain and tenderness
what investigations are done for bowel ischaemia?
Bloods:
FBC: neutrophilic leukocytosis
VBG: Lactic acidosis (means it late stage and the bowel is dead already)
Imaging -CTAP/CTAngiogram:
Detects:
Disrupted flow
Vascular stenosis
‘Pneumatosis intestinalis’ (transmural ischaemia/infarction)
Ischaemic colitis: Thumbprint sign (unspecific sign of colitis)
Endoscopy:
For mild or moderate cases of ischaemic colitis (oedema, cyanosis, ulceration of mucosa)
what is conservative management of bowel ischaemia?
Mild to moderate cases of ischaemic colitis (not suitable for SB ischaemia):
IV fluid resuscitation
Bowel rest(nil my mouth)
Broad-spectrum ABx - colonic ischaemia can result in bacterial translocation & sepsis
NG tube for decompression - in concurrent ileus (no peristalsis)
Anticoagulation
Treat/manage underlying cause
Serial abdominal examination and repeat imaging
what is surgical management of Bowel ischaemia?
Indications: Small bowel ischaemia Signs of peritonitis orsepsis Haemodynamic instability Massive bleeding Fulminant colitis with toxic megacolon
Exploratory laparotomy:
Resection of necrotic bowel +/-open surgicalembolectomy
or mesenteric arterial bypass
Endovascular revascularisation:
Balloon angioplasty/thrombectomy
In patients without signs of ischaemia
how does acute appendicitis present?
Initially periumbilical pain that migrates to RLQ (within 24hours)
Anorexia, nausea +/- vomiting, low grade fever, change in bowel habit
Important clinical signs:
McBurney’s point - tenderness in the RLQ (lateral 1/3 of a hypothetical line drawn from the right ASIS to the umbilicus)
Blumberg sign - rebound tenderness especially in the RIF
Rovsing sign - RLQ pain elicited on deep palpation of the LLQ
Psoas sign - RLQ pain elicited on flexion of right hip against resistance
Obturator sign - RLQ pain on passive internal rotation of the hip with hip & knee flexion
what investigations are done for acute appendicitis?
Bloods:
FBC: neutrophilic leukocytosis
↑ed CRP
Urinalysis: possible mild pyuria/haematuria
Electrolyte imbalances in profound vomiting
Imaging:
CT: gold standard in adults esp. if age > 50
USS: children/pregnancy/breastfeeding
MRI: in pregnancy if USS inconclusive
Diagnostic Laparoscopy:
In persistent pain & inconclusive imaging
alvarado score is used to assess likelihood of appendicitis
what is conservative management of acute appendicitis?
Consists of:
IV Fluids, Analgesia, IV or PO Antibiotics
In abscess, phlegmon or sealed perforation, Resuscitation + IV ABx +/- percutaneous drainage
Indications:
After negative imaging in selected patients with clinically uncomplicated appendicitis
In delayed presentation with abscess/phlegmon formation, CT-guided drainage(as it would be a big undertaking to operate)
Consider interval appendicectomy - rate of recurrence after conservative management of abscess/perforation is 12-24%
what is surgical management of acute appendicitis?
Laparoscopic vs Open appendicectomy: Less pain Lower incidence of surgical site infection ↓ed length of hospital stay Earlier return to work Overall costs Better quality of life scores
Steps of Laparoscopic Appendicectomy:
- Trocar placement (usually 3)
- Exploration of RIF & identification of appendix
- Elevation of appendix + division of mesoappendix (containing artery)
- Based secured with endoloops and appendix is divided
- Retrieval of appendix with a plastic retrieval bag
- Careful inspection of the rest of the pelvic organs/intestines
- Pelvic irrigation (wash out) + Haemostasis
- Removal of trocars + wound closure
how are bowel obstructions classified?
Intestinal obstruction - restriction of normal passage of intestinal contents.
Two main groups:
Paralytic (Adynamic) ileus
Mechanical.
Mechanical intestinal obstruction classified by:
Speed of onset: acute, chronic, acute-on-chronic
Site: high or low
roughly synonymous with small or large bowel obstruction
Nature: simple vs strangulating
Simple - bowel is occluded without damage to blood supply.
Strangulating - blood supply of involved segment of intestine is cut off (e.g. in strangulated hernia, volvulus, intussusception)
Aetiology:
Causes in the lumen - faecal impaction, gallstone ‘ileus’
Causes in the wall - Crohn’s disease, tumours, diverticulitis of colon
Causes outside the wall –
Strangulated hernia (external or internal)
Volvulus
Obstruction due to adhesions or bands.
what is the aetiology of bowel obstructions?
small bowel:
Adhesions (60%)- Hx of previous abdominal surgery
Neoplasia (20%)- Primary, Metastatic, Extraintestinal
Incarcerated hernia (10%)- External (abdominal wall), Internal (mesenteric defect)
Crohn’s Disease (5%)- Acute (oedema), Chronic (strictures)
Other (5%)- Intussusception, intraluminal (foreign body, bezoar)
large bowel:
Colorectal carcinoma
Volvulus - Sigmoid, Caecal
Diverticulitis - Inflammation, strictures
Faecal impaction
Hirschsprung disease - commonly found in infants/children
how do small bowel obstructions present?
pain:
colicky central
vomiting:
Early onset
Large amount
Bilious
absolute constipation:
late sign
abdominal distention:
less significant
other signs:
Dehydration
Increased high pitched tinkling bowel sounds (early sign), or absent bowel sounds (late sign)
Diffuse abdominal tenderness
how do large bowel obstructions present?
pain:
colicky or constant
vomiting:
Late onset
Initially bilious
Progresses to faecal vomiting
absolute constipation:
early sign
abdominal distention:
early sign and significant
other signs:
Dehydration
Increased high pitched tinkling bowel sounds (early sign), or absent bowel sounds (late sign)
Diffuse abdominal tenderness
how are bowel obstructions diagnosed?
3x Important points to remember about intestinal obstruction:
Diagnosed by the presence of symptoms
Examination should always include a search for hernias & abdominal scars, including laparoscopic portholes
Is it simple or strangulating? (simple, bowel is still viable)
Features suggesting strangulation are: Change in character of pain from colicky to continuous Tachycardia Pyrexia Peritonism Bowel sounds absent or reduced Leucocytosis ↑ed C-reactive protein
Strangulating obstruction
with peritonitis
has a mortality of up to 15%
what investigations are done for bowel obstruction?
Bloods:
WCC/CRP usually normal (if raised suspicion of strangulation/perforation)
U&E: electrolyte imbalance
VBG if vomiting: HypoCl-,HypoK+ metabolic alkalosis
VBG if strangulation: Metabolic Acidosis (lactate)
Imaging:
Erect CXR/AXR-
SBO: Dilated small bowel loops >3cm proximal to the obstruction (central)
LBO:Dilated large bowel >6cm (if caecum >9cm) predominantly peripheral
CT abdo/pelvis→ Transition point, dilatation of proximal loops – IV +/- oral contrast if possible
what are the x ray signs for small bowel obstruction?
Ladder pattern of dilated loops & their central position
Striations that pass completely across the width of the distended loop produced by the circular mucosal folds.
