GI Endoscopy

Question 1

What are the uses of endoscopy?

Answer 1

Diagnostic - observation, sampling (fluid, brush cytology, FNA, biopsies)
Therapeutic - FB removal, stricture dilation, gastrotomy tube placement

Question 2

What are the benefits of endoscopy?

Answer 2

Minimally invasive
Low morbidity/mortality (mainly anaesthetic related!)
Easy/quick recovery time

Question 3

What are the limitations of endoscopy?

Answer 3

Cannot visualise whole GI tract - cannot biopsy
Assess appearance (morphology) and not function
Mucosal evaluation only - visual/histopathological
Cannot evaluate extra-GI disease

Question 4

What are the contraindications to endoscopy?

Answer 4

Known GI surgical disease e.g. perforation, mass lesion
Inadequate investigation e.g. extra-GI disease
Unsuitable for anaesthesia e.g. inadequate cardiopulmonary/hepatic/renal function
Coagulopathy
Inadequate preparation

Question 5

Describe gastric overdistension as a complication of GI endoscopy.

Answer 5

Affecting endoscopist - challenging pyloric intubation, increased antro-pyloric motility
Affecting anaesthetist - caudal vena cava compression (reduced venous return, CO, BP), diaphragmatic splinting (reduced tidal volume)

Question 6

What complications can we see during endoscopy?

Answer 6

Acute bradycardia +/- AV block
Aspiration
Bacteraemia - transient during colonoscopy, prophylactic antibiotics if at risk
GI perforation
Haemorrhage - mucosal/laceration of major vessels

Question 7

What equipment is required for endoscopy?

Answer 7

Light source
Air/water insufflator
Suction pump
Endoscope - insertion tube
Forceps

Question 8

What are the advantages of fibre-optic endoscopes?

Answer 8

Portable - wide range of sizes
Moderate cost

Question 9

What are the disadvantages of fibre-optic endoscopes?

Answer 9

Faceted image (‘honeycomb’)
Fragile
Size of endoscope dictates image quality (decreased quality with decreased diameter)
Eye piece vs video

Question 10

Describe video-endoscopy.

Answer 10

Mechanically identical to fibre-optic
Non-coherent illumination
CCD detects image to screen (more hygienic as no eye-piece)
Excellent image
Image control buttons
Expensive
Not protable
Smallest diameter not possible

Question 11

Describe insertion tubes for endoscopes.

Answer 11

Diameter - 5.5-9.5mm for gastro-, 10-13 for colono-
Steering - uni/multiplanar
Accessory (biopsy) channel

Question 12

Why is retroflexion of a GI endoscope important?

Answer 12

Visualise cardia
FB retrieval

Question 13

What are some endoscopy accessories?

Answer 13

Cytology brush
Biopsy forceps
Lavage tubes
Sheathed needles

Question 14

Describe biopsy forceps.

Answer 14

Reusable / non-reusable
Elipsoid (oval) / round
Fenestrated / whole
With spike / no spike
Swing jaw / fixed angle
Alligator / smooth
Rotatable / non-rotatable

Question 15

How do we prep patients for gastroscopy?

Answer 15

Confirm endoscopy indicated - exclude extra-GI/surgical diseases, consider contraindications
12 hour fast - improved visualisation/manouverability, reduce risk of reflux/aspiration

Question 16

How do we prep patients for colonoscopy?

Answer 16

Fast 24-48hrs
Oral lavage
Multiple ‘high’ enemas

Question 17

Describe oral lavage prior to endoscopy.

Answer 17

PEG electrolytes solutions
Day prior to endoscopy
Oral vs stomach tube vs NO-tube (cats)

Question 18

What are some risks associated with oral lavage?

Answer 18

Tracheal intubation
Aspiration
Trauma

Question 19

Describe ‘high’ enemas prior to endoscopy.

Answer 19

Warm water - avoid cleaners/laxatives
1-2hrs before colonoscopy

Question 20

How do we position patients for endoscopy?

Answer 20

Left lateral - standard, pylorus/ascending colon
Right lateral - G-tube, FB removal
Mouth gag (cats!), ET tuebe secured to mandible/maxilla