General Surgery in the GI Tract

Question 1

What is the general approach to a patient presenting with acute abdominal pain?

Answer 1

PC = use SOCRATES for pain assessment

[Site, Onset, Character, Radiation, Association, Time course, Exacerbating/Relieving factors, Severity / Scale)

PMHx, DHx, SHx

Investigations

Management

Question 2

What are some investigations that could be performed for acute abdominal pain?

Answer 2

Investigations ordered depend on the presentation

Bloods: VBG, FBC, CRP, U&Es (urea and electrolytes - renal profile), LFTs + amylase

Urinalysis + Urine MC&S - always do these, many acute abdominal issues come from UTIs

Imaging:

Erect CXR, AXR, CTAP (CT abdo and pelvis), CT angiogram (suspected bleeding or infarction of intraabdominal blood vessel), USS

Endoscopy

Question 3

What are the management approaches for acute abdominal pain?

Answer 3

ABCDE approach - airways, breathing, circulation, disability, exposure

Conservative management

Surgical management

Question 4

What are the differentials for RUQ / right hypochondriac pain?

Answer 4

Bilary Colic
Cholecystitis/Cholangitis
Duodenal Ulcer
Liver abscess
Portal vein thrombosis
Acute hepatitis
Nephrolithiasis
RLL pneumonia

List not exhaustive

Question 5

What are the differentials for epigastric pain?

Answer 5

Acute gastritis/GORD
Gastroparesis
Peptic ulcer disease/perforation
Acute pancreatitis
Mesenteric ischaemia 
AAA (Abdominal Aortic Aneurysm) Aortic dissection
Myocardial infarction

List not exhaustive

Question 6

What are the differentials for LUQ / left hypochondriac pain?

Answer 6

Peptic ulcer
Acute pancreatitis
Splenic abscess
Splenic infarction
Nephrolithiasis
Left Lower Lobe Pneumonia

List not exhaustive

Question 7

What are the differentials for RLQ / right iliac pain?

Answer 7

Acute Appendicitis
Colitis
IBD
Infectious colitis
Ureteric stone/Pyelonephritis
PID/Ovarian torsion
Ectopic pregnancy
Malignancy

List not exhaustive

Question 8

What are the differentials for suprapubic / central pain?

Answer 8

Early appendicitis
Mesenteric ischaemia
Bowel obstruction 
Bowel perforation 
Constipation 
Gastroenteritis
UTI/Urinary retention
PID - pelvic inflammatory disease

List not exhaustive

Question 9

What are the differentials for LLQ / left iliac pain?

Answer 9

Diverticulitis
Colitis
IBD (Inflammatory Bowel Disease)
Infectious colitis
Ureteric stone/Pyelonephritis
PID/Ovarian torsion
Ectopic pregnancy
Malignancy

List not exhaustive

Question 10

How do patients with bowel ischaemia present clinically?

Answer 10

Sudden onset crampy abdominal pain

Severity of pain depends on the length and thickness of colon affected (positive correlation)

Bloody, loose stool (currant jelly stools)

Associated fever, signs of septic shock

Question 11

What are the risk factors for bowel ischaemia?

Answer 11

Age >65 yrs
Cardiac arrythmias (mainly AF) and history of atherosclerosis
Hypercoagulation/thrombophilia
Vasculitis
Sickle cell disease 
Profound shock causing hypotension

Question 12

What are the 2 types of bowel ischaemia?

Answer 12

1. Acute mesenteric ischaemia

2, Ischaemic collitis

Question 13

What are the main features of acute mesenteric ischaemia?

Answer 13

Small Bowel

Usually occlusive and secondary due to thromboemboli (SMA) - AF (atrial fibrillation) makes this more likely as cardiac arrythmia can throw small clots to block the SMA

Sudden onest (but presentation and severity varies)

Abdominal pain can be out of proportion of clinical signs
e.g. extreme pain but nothing clinically wrong OR something major clinically but patient feels well

Question 14

What happens if the clot completely occludes / obstructs the SMA?

Answer 14

Lose all the bowel from the DJ (duodenojejunal) flexure to the splenic flexure - all the small bowel + 3/4 of large bowel

Question 15

What are the main features of ischaemic Collitis?

Answer 15

Large bowel

Usually due to non-occlusive low flow states or atherosclerosis

More mild and gradual (80-85% of cases)

Moderate pain and tenderness

Question 16

What investigations should be performed for suspected bowel ischaemia?

Answer 16

Bloods =
FBC: neutrophilic leukocytosis (abnormally high number of neutrophils)
VBG (venous blood gases): Lactic acidosis (low pH from build up of lactic acid due to late stage mesenteric ischaemia = dead bowel)

Imagings =
CTAP/CT Angiogram:
Detects - disrupted flow, vascular stenosis, ‘Pneumatosis intestinalis’ (transmural ischaemia/infarction), and Ischaemic colitis: Thumbprint sign (unspecific sign of colitis)

Endoscopy =
For mild or moderate cases of ischaemic colitis (detects oedema, cyanosis, ulceration of mucosa)

Question 17

What is the conservative management approach to an ischaemic bowel and when is it used?

Answer 17

Suitable only for mild to moderate cases of ischaemic collitis (not suitable for small bowel ischaemia)

IV fluid resuscitation
Bowel rest - nil by mouth
Broad-spectrum antibiotics - as colonic ischaemia can result in bacterial translocation and subsequent sepsis
NG tube for decompression - in concurrent ileus
Anticoagulation
Treat/manage underlying cause
Serial abdominal examination and repeat imaging - check for changes(e.g. perotonitis inside the abdomen) / progress of treatment

Question 18

When is surgical management used for ischaemic bowel?

Answer 18

Almost a necessity in most patients

Required in:
Small bowel ischaemia
Signs of peritonitis or sepsis
Haemodynamic instability
Massive bleeding
Fulminant colitis with toxic megacolon

Question 19

What are the two types of surgical management?

Answer 19

Exploratory laparotomy =
Explore everything from the DJ flexure to the rectum
Resect necrotic bowel with or without open surgical embolectomy (baloon catheter in SMA) or mesenteric arterial bypass

Endovascular revascularisation =
Balloon angioplasty/thrombectomy
In patients without signs of ischaemia

Question 20

How does acute appendicitis present clinically?

Answer 20

Initially periumbilical pain that migrates to RLQ (within 24hours)

Usually associated with anorexia, nausea +/- vomiting, low grade fever, change in bowel habit (due to inflamed appendix located next to the rectum, irrtating it, hence altering the bowel habit)

Good way to test for anorexia - ask to get them a meal, if they refuse, likely to be appendicitis

Question 21

What are the important clinical signs in acute appendicitis?

Answer 21

McBurney’s point = usually where the appendix lies (lateral 1/3 of a hypothetical line drawn from the right ASIS to the umbilicus), tenderness in the RLQ

Blumberg sign = rebound tenderness especially in the RIF (right iliac fossa) - press down and suddenly release = patient suddenly jump

Rovsing sign = RLQ pain elicited on deep palpation of the LLQ - press down on the left iliac fossa but they report pain in the right iliac fossa due to moving of the perotineum causing irritation on the other side

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

Question 22

What investigations should be carried out for suspected acute appendicitis?

Answer 22

Bloods =
FBC: neutrophilic leukocytosis
Increased 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 laparotomy = only used in persistent pain and inconclusive imaging

Question 23

What is the diagnostic tool used for acute appendicits?

Answer 23

Alvardo score = consists of 6 clinical items:
(brackets represent points awarded for each sign)

RLQ Tendereness (2)
Fever (1)
Rebound tenderness (1)
Pain migration (1)
Anorexia (1)
Nausea +/- vomiting (1)
WCC > 10,000 (2)
Neutrophilia (left shift) (1)

≤4 Unlikely
5-6 Possible
≥7 Likely

Question 24

What is the conservative management for acute appendicitis?

When do you use conservative management?

Answer 24

Conservative Management =
IV Fluids, Analgesia, IV or PO Antibiotics
In abscess, phlegmon or sealed perforation - resuscitation + IV antibiotics +/- percutaneous drainage

Only used when =
After negative imaging in selected patients with clinically uncomplicated appendicitis
Usually when patient presents late with mass/abscess/phlegmon formation in their RIF (right iliac fossa) = CT-guided drainage and IV antibiotics as surgery to now take appendix out is a major undertaking so it is far better to treat conservatively

Question 25

What is an interval appendicectomy and why is it used after conservative management of acute appendicitis?

Answer 25

Take out appendix electively on a scheduled date Although late presentations are treated conservatively initially due to risk of surgery complications After consevative management, most patients are later revisted with an interval appendicectomy as rate of recurrence after conservative management of abscess/perforation is 12-24%, so appendix is taken out later electively before it causes further issues

Question 26

What are the benefits of laparoscopic over open appendicectomy ?

Answer 26

``` Less pain Lower incidence of surgical site infection Decreased length of hospital stay Earlier return to work Overall costs Better quality of life scores ``` Most patients are home the next day = quick recovery time

Question 27

What are the steps of laparoscopic appendicectomy?

Answer 27

Trocar placement (usually at 3 port sites) Exploration of RIF & identification of appendix Elevation of appendix + division of mesoappendix (containing artery) Based secured with endoloops and appendix is divided - so first you mobilise the appendix, then you lasso around the base and tighten Retrieval of appendix with a plastic retrieval bag - to avoid infection spreading in the abdo cavity and port site Careful inspection of the rest of the pelvic organs/intestines Pelvic irrigation (lavage / wash out) + Haemostasis Removal of trocars + wound closure

Question 28

What is bowel / intestinal obstruction?

Answer 28

Restriction of normal passage of intestinal contents

Question 29

What are the 2 main groups of intestinal obstruction?

Answer 29

1. Paralytic (adynamic) ileus - occurs when the abdomen is full of pus that irritates the bowel, the bowel stops peristalsis and this does not get better until the infection is gone 2. Mechanical - a physical obstruction causing fluids and waste to build up in the portion of the bowel prior to the obstruction

Question 30

What are the 4 components to classifying a mechanical intestinal obstruction?

Answer 30

1. Speed of onset 2. Site 3. Nature 4. Aetiology

Question 31

What of each of the components below highlight about the mechanical intestinal obstruction? 1. Speed of onset 2. Site 3. Nature 4. Aetiology

Answer 31

1. Speed of onset = acute, chronic or acute-on-chronic 2. Site = high or low - Roughly synonymous with small or large bowel obstruction 3. Nature = simple VS strangulation - Simple = bowel occulded without damage to blood supply (bowel still perfused and healthy) - Strangulation = blood supply of involved segment of intestine is cut off (e.g. in strangulated hernia, volvulus, intussusception - e.g. a polyp that is taken down by peristalsis causing the bowel to turn inside out like the sleeve of a jacket) 4. Aetiology = - Causes in the lumen = faecal implantation, gallstone 'ileus' (gallstone erodes through the gallbladder into the bowel) - 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

Question 32

What are the main causes of small bowel obstruction?

Answer 32

Adhesions (60%) - patient usually has PMH of previous abdominal surgery Neoplasia (20%) - primary (rare), metastatic or extraintestinal e.g. can happen in ovarian peritoneal disease with peritoneal deposited tumour can catch a part of the small bowel Incarcerated hernia (10%) - external (Within abdominal wall) or internal (mesenteric defect) Crohn's disease (5%) - acute (oedema) or chronic (strictures) Other (5%) - intussusception, intraluminal (foreign body, bezoar)

Question 33

What are the main causes of large bowel obstruction?

Answer 33

Colorectal cancer - usually occurs on left hand side to cause obstruction as on the right hand side a small tumour can be compensated by bowel expansion and so will require a significantly larger tumour Volvulus - twist of the bowel on itself like a balloon at the sigmoid or caecal part of the colon Diverticulitis - inflammation, strictures Faecal impaction - Hirchsprung disease - birth defect and commonly presents in infants / children, characterised by absence of nerve cells / ganglions in a sengment of the bowel, so that part of the bowel cannot carry out peristalsis leading to long term obstruction

Question 34

What are the 4 main signs of a patient presenting with a bowel obstruction?

Answer 34

Abdominal pain Vomiting Abdolute constipation Abdominal Distension

Question 35

How do patients present clinically with small bowel obstruction?

Answer 35

Abdominal pain = colicky, central pain Vomiting = early onset vomiting (i.e. the higher up the obstruction, the wuicker the vomiting starts due to fluid build up) - large amount and bilious Absolute constipation = late sign, as everything in the large bowel can still come through Abdominal distention = less significant

Question 36

How do patients present clinically with large bowel / colon obstruction?

Answer 36

Abdominal pain = colicky or constant pain Vomiting = late onset - the back pressure needs to travel up most of the GI tract to initiate comiting - initally billous progress to faecal vomiting (i.e. what they're vomiting looks a lot like faeces Absolute constipation = early sign Abdominal distention = early sign and significant

Question 37

What are some other signs patients with any type of bowel obstruction present with clinically?

Answer 37

Other signs = Dehydration - from the vomiting Increased high pitched tinkling bowel sounds (early sign), or absent bowel sounds (late sign due to stopping of peristalsis) Diffuse abdominal tenderness - intervene asap

Question 38

What are the three important factors for diagonisisng bowel obstruction?

Answer 38

Diagnosed by the presence of symptoms Examination should always include a search for hernias and abdominal scars (looking for strangulated bowel), including laparoscopic portholes Is it simple (viable bowel) or strangulating (non-viable bowel = faster intervention required)?

Question 39

What features suggest it is a strangulation rather than a simple obstruction?

Answer 39

Change in character of pain from colicky to continuous Tachycardia Pyrexia Peritonism - localised inflammation of the peritoneum Bowel sounds absent or reduced Leucocytosis Increased C-reactive protein

Question 40

What is the mortality rate of strangulating obstruction with peristonitis?

Answer 40

Up to 15%

Question 41

What are common hernial sites?

Answer 41

Epigastric Umbilical Incscional - from previous operation, skin has healed but muscle below has a defect so bowel can come through that Inguinal - at the groin, usually defects in the abdominal wall Femoral

Question 42

What is most important about the defect causing the hernia?

Answer 42

Size Large defect = bowel can go in and out without any problems The smaller the hole, the greater the chance of the hernia obstructing and strangulating

Question 43

What are the 3 different types of hernia?

Answer 43

Neck of sac Strangulated hernia = compromised blood flow, venous return is first to go, so as blood stops going out, it compresses the arterial blood coming in leading to ischaemic bowel Richter's hernia = just a small amount of bowel caught, so there is still continuity of the small and large bowel but there is that small portion of ischaemic bowel that needs to be removed

Question 44

What are the investigations that can be carried out for a suspected bowel obstruction?

Answer 44

Bloods = WCC/CRP = usually normal (if raised suspicion of strangulation / perforation) U&E = electrolyte imbalance from vomiting VBG (venous blood gas) from vomiting shows HypoCl- (hypochloraemic), HypoK+ (hypokalaemia) = metabolic alkalosis VBG if strangulation = metabolic acidosis (lactate) Imaging = Erect CXR / AXR (chest / abdominal x-ray) - SBO (small bowel obstruction) = Dilated small bowel loops >3cm proximal to the obstruction (central) - LBO (large bowel obstruction) = dilated large bowel >6cm (if caecum >9cm) predominantly peripheral CT abdo/pelvis = shows transition point (helpful for surgery), dilatation of proximal loops – IV or oral contrast if possible

Question 45

What does a small bowel obstruction on an abdominal x-ray show?

Answer 45

Ladder pattern of dilated loops & their central position (easier to see on supine than erect xray) Striations that pass completely across the width of the distended loop produced by the circular mucosal folds

Question 46

What does a large bowel obstruction on an abdominal x-ray show?

Answer 46

Distended large bowel tends to lie peripherally (easier seen on erect xray) Show haustrations of taenia coli - do not extend across whole width of the bowel.

Question 47

What information can CT scans show regarding bowel obstructions?

Answer 47

Can localize site of obstruction Detect obstructing lesions & colonic tumours May diagnose unusual hernias (e.g. obturator hernias).

Question 48

What are the 3 types of management for a bowel obstruction?

Answer 48

Supportive Conservative Surgical

Question 49

What is the supportive mangement for bowel obstruction?

Answer 49

NBM (nil by mouth), IV peripheral access with large bore cannula - IV Fluid resuscitation (basic rate depends on weight) IV analgesia (For colicky pain), IV antiemetics, correction of electrolyte imbalances NG tube for decompression (vital for removing chance of aspiration pneumonia), urinary catheter for monitoring output (influences IV fluid replacement) Introduce gradual food intake if abdominal pain and distension improve

Question 50

What do you need to be careful of for small bowel obstruction with the commonest cause is secondary to adhesions?

Answer 50

The more fluid you pump into it, the more it twists on that area = worsening of obstruction

Question 51

What is the conservative treatment for bowel obstruction?

Answer 51

Faecal impaction = stool evacuation (manual, enemas, endoscopic) Sigmoid volvulus: rigid sigmoidoscopic decompression - pass tube through bowel and suck all the fluid out causing it collapse, giving it a chance to straighten it out SBO: oral gastrograffin (highly osmolar iodinated contrast agent) can be used to resolve adhesional small bowel obstruction

Question 52

When is surgical management used, and what are the indications of surgical management for bowel obstruction?

Answer 52

Used when bowel obstruction does not resolve OR patient has developed signs of ischaemia Haemodynamic instability or signs of sepsis Complete bowel obstruction with signs of ischaemia Closed loop obstruction - intervene quicly before it becomes ischaemic e.g. strangulated hernia Persistent bowel obstruction >2 days despite conservative management

Question 53

What are the surgical management operation options available?

Answer 53

Exploratory Laparotomy / Laparoscopy - find the cause and remove it, ensure all bowel left is viable Restoration of intestinal transit (depending on intra-operational findings) Bowel resection with primary anastomosis or temporary/permanent stoma formation (when it is not safe to join the 2 ends of the bowel straight away after the resection of the non-viable bowel)

Question 54

What is endoscopic stenting and when is it used?

Answer 54

Non-surgical management of distal obstruction - stend placed endoscopically to prevent constriction or collapse of tubular organ Reserved for patients with tumours

Question 55

How does GI perforations present clinically?

Answer 55

Sudden onset severe abdominal pain associated with distention Examination shows diffuse abdominal guarding, rigidity, rebound tenderness Pain aggravated by movement Nausea, vomiting, absolute constipation (due to ileus i.e. irritation of chemicals of the bowel rather than mechanical obstrution) Fever, Tachycardia, Tachypnoea, Hypotension Decreased or absent bowel sounds

Question 56

What are the 4 main perforations of the GI tract?

Answer 56

Perforated peptic ulcer Perforated diverticulum Perforated appendix Perforated malignancy

Question 57

What are the features of perforated peptic ulcer?

Answer 57

Sudden epigastric or diffuse pain Referred shoulder pain - diaphragm irritation - as phrenic nerve innervates shoulder HPC / PMH of NSAIDs, steroids, recurrent epigastric pain

Question 58

What are the features of perforated diverticulum?

Answer 58

LLQ pain | Constipation

Question 59

What are the features of perforated appendix?

Answer 59

Present a phlemons (inflammation of soft tissue under skin) Migratory pain Anorexia Gradual worsening RLQ pain

Question 60

What are the features of perforated malignancy?

Answer 60

``` HPC of: Change in bowel habit Weight loss Anorexia PR Bleeding ```

Question 61

What are the investigations carried out for a suspected GI perforation?

Answer 61

Bloods = FBC = neutrophil leukocytosis Possible elevation of urea and creatinine (checking renal function) VBG (venous blood gas) = lactic acidosis Imaging = Erect CXR = - Subdiaphragmatic free air (pneumoperitoneum) CT abdo/pelvis - Pneumoperitoneum, free GI content, localised mesenteric fat stranding can exclude common differential diagnoses such as pancreatitis

Question 62

What other conditions can present as a GI perforation (i.e. what else would be on your differential diagnoses?)

Answer 62

Acute cholecystitis Appendicits MI Acute pancreatitis

Question 63

What is the supportive / conservative management given to the patient on presentation of a suspected GI perforation?

Answer 63

``` NBM & NG tube IV peripheral access with large bore cannula - IV Fluid resuscitation Broad spectrum antibiotics IV PPI Parenteral analgesia & antiemetics Urinary catheter ```

Question 64

What is the conservative management for GI perforation presentation without sepsis?

Answer 64

Conservative management in localised peritonitis without signs of sepsis = very rare IR - guided drainage of intra-abdominal collection Serial abdominal examination and abdominal imaging for assessment - look for any changes, and do not hestitate to shift management to surgical But most people require an operation

Question 65

What are the stages of surgical management for GI Perforation with generalised perotonitis with/without signs of sepsis?

Answer 65

Exploratory laparotomy/laparascopy Primary closure of perforation with or without omental patch (most common in perforated peptic ulcer) Resection of the perforated segment (e.g. in a perforated diverticulum) of the bowel with primary anastomosis or temporary stoma Obtain intra-abdominal fluid for MC&S (microscopy culture and sensitivity), peritoneal lavage If perforated appendix: Lap or open appendicectomy If malignancy: intraoperative biopsies if possible

Question 66

What are some common biliary and pancreatic causes of an acute abdomen?

Answer 66

Biliary Colic Acute Cholecystitis Acute Cholangitis Pancreatitis

Question 67

What are the symptoms, investigations and management options for biliary colic?

Answer 67

Symptoms = Postprandial RUQ pain with radiation to the shoulder. Nausea Investigations = Normal blood results USS: cholelithiasis (often people already know they have gallstones) Management = Analgesia, Antiemetics, Spasmolytics Follow up for elective cholecystectomy

Question 68

What are the symptoms, investigations and management options for acute cholecystitis?

Answer 68

Symptoms = Acute, severe RUQ pain Fever Murphy's sign Investigations = Elevated WCC/CRP USS: thickened gallbladder wall Management = Fluids, ABx, Analgesia, Blood cultures Early (<72 hours) or elective cholecystectomy (4-6 weeks)

Question 69

What are the symptoms, investigations and management options for acute cholangitis?

Answer 69

Symptoms = Charcot's triad: jaundice, RUQ pain, fever Investigations = Elevated LFTs, WCC, CRP, Blood MCS (+ve) USS: bilary dilatation Management = Fluids, IV antibiotics, Analgesia ERCP (within 72hrs) for clearance of bile duct or stenting

Question 70

What are the symptoms, investigations and management options for pancreatitis?

Answer 70

Symptoms = Severe epigastric pain radiating to the back Nausea +/- vomiting Hx of gallstones or EtOH use Investigations = Raised amylase/lipase High WCC/Low Ca2+ CT and US to assess for complications/cause - only useful after a few weeks when there are changes ``` Management = Admission score (Glasgow-Imrie) Aggressive fluid resuscitation, O2 Analgesia, Antiemetics ITU/HDU involvement ```