Colorectal Flashcards
(138 cards)
1
Q
what is intestinal obstruction
A
obstruction of the normal movement of bowel contents
2
Q
pathophysiology of intestinal obstruction
A
obstruction of bowel segment –> proximal bowel dilates and distal bowel collapses –> dilatation leads to increased peristalsis of bowel to relieve obstruction –> leads to secretion of large volumes of electrolyte-rich fluid into bowel (‘third-spacing’) + colicky pain
3
Q
What are causes of small bowel obsturction
A
HAT
Hernia
Adhesion
Tumour
4
Q
What are causes of large bowel obstruction
A
CVS
Cancer
Volvulus
Strictures (from diverticulitis)
5
Q
What are big risks with bowel obstruction
A
Hypovolaemia > AKI (due to third spacing) –> dehydration and renal impairment
Bowel Perforation –> faecal peritonitis
Bowel Ischaemia –> gangrene
6
Q
What is third spacing
A
fluid stuck in the bowel rather than intravascular space –> hypovolaemic shock
7
Q
What are classical symptoms of bowel obstruction
A
severe abdominal pain, colicky, widespread
Vomiting (bilious)
Distension
Absolute constipation
8
Q
What are signs of bowel obstruction
A
Signs of underlying cause e.g. surgical scars, cachexia from malignancy, hernia
Abdominal distension with generalised tenderness
May see visible peristalsis
Tinkling bowel sounds
Tympanic sound on percussion
Assess fluid status due to third-spacing
9
Q
Features of strangulating obstruction
A
toxic appearance + fever and tachycardia
colicky pain, becoming continuous as peritonitis develops
tenderness and abdominal rigidity more marked;
bowel sounds becoming reduced or absent, reflecting peritonism;
raised white cell count, mostly neutrophils, which is usual with infarcted bowel
10
Q
intestinal obstruction differential diagnosis
A
- pseudo-obstruction
- paralytic ileus
- toxic megacolon
- constipation
11
Q
routine urgent bloods for intestinal obstruction?
A
o FBC o U&Es = electrolyte imbalances o CRP o LFTs o G&S o VBG: = 1. Bowel ischaemia ( raised lactate) 2. metabolic alkalosis (secondary to dehydration or excessive vomiting)
12
Q
2 initial (scans) investigation that they often get with bowel obstruction
A
Abdominal XR (to look at bowel distension) Erect CXR (to check for free fluid under diaphragm)
13
Q
Whart is definitive Ix for bowel obstruction
A
CT abdo-pelvis with IV contrast
14
Q
What will the abdo x ray show for small bowel vs large bowel obstruction
A
small bowel: >3cm, central, valvulae conniventes
large bowel: >6cm (colon), >9cm (sigmooid), peripheral,haustrae
15
Q
what are the indications for surgical management of bowel obstruction
A
Suspicion of intestinal ischaemia or closed loop obstruction
Cause requiring surgical correction e.g. strangulated hernia or obstructing tumour
If patient fails to improve with conservative measures after > 48 hours
16
Q
What is the conservative management approach for bowel obstruction
A
- NBM immediately
- Drip and Suck =IV fluid resus and electrolyte replacement AND NG tube with free drainage
- analgesia +/- anti-emetics
- monitor vital signs, fluid balance and urine output (urinary catheter)
17
Q
what is the surgical management of intestinal obstruction
A
Generally involves laparotomy to correct underlying cause
Exploratory surgery if unclear cause
Adhesiolysis for adhesions
Hernia repair
Emergency resection of the obstructing tumour
18
Q
What is volvulus
A
Twisting of intestinal loop around its mesenteric attachment > closed loop bowel obstruction
19
Q
What are complications of volvulus
A
Bowel has compromised blood supply > rapid ischaemia, necrosis and perforation risk
20
Q
what are two different types of volvulus
A
sigmoid (80%) vs caecal (20%)
21
Q
Explain characteristic patient of sigmoid volvulus
and what occurs
A
Older, chronic constipation
sigmoid bowel twists around mesentery > large bowel obstruction
22
Q
What is the cause of a caecal volvulus
A
abnormality in development (falure of peritoneal fixation) that makes the volvulus at risk of twisting»_space; small bowel obstruction due to proximal large bowel obstruvtive cause
23
Q
imaging of volvulus
A
sigmoid: AXR > COFFEE BEAN SIGN (+ normal LBO signs)
caecum: on AXR has normal SBO signs
CT ABDO PELVIS WITH CONTRAST > WHIRL SIGN
24
Q
Management of sigmoid volvuluis
A
-
decompress with sigmoidoscope + flatus tube insertion
leave flatus tube in for up to 24h
if decompression fails repeatedly or peritonism: laparotony
25
Describe large bowel anatomy
Appendix > caecum > ascending colon > right colonic flexure > transverse colon > left colonic flexure > descending colon > sigmoid > rectum > anus
26
what is does a right hemicolectomy remove and when is it used?what type of anastamosis
the caecum and ascending coon
used for tumours in this caecum and proximal ascending colon
iliocolic anastamosis
27
what does an extended right hemicolectomy remove and when is it used?what type of anastamosis
caecum ascending colon and transverse colon
for tumours in distal descending colon or transverse oolon
iliocolic anastamosis
28
what is a left hemicolectomy used for, what does it remove? what is anastamosis
descending colon
for tumours in descending colon
colocolic anastamosis
29
what is hartmann's procedure remove
recto-sigmoid colon with formaytion of end colostomy
30
when is hartmann's used for
obstrution or perforation secondary to sigmoid tumour or diverticulitis -- EMERGENCY
31
what colorectal procedures leave you with a stoma
Hartmsnn's
AP resection
Anterior resection
32
where and what stoma do you get with Hartmann's
single lumen colostomy in LIF
33
what is an AP resection
Abdominal Perineal Resection
| aka BARBIE BUTT PROCEDURE
34
What does an AP resection remove
sigmoid, rectum, anal sphinctersand mesorectal nodes
| Perineal incision: anus removed
35
what stoma do you get with AP resection
single lumen colostomy in LIF
36
what are indications forAP resection
rectal cancer LESS THAN 4-5 cm from anal verge ==> LOW RECTAL TUMOUR
(Anal Proximity tumour!!)
37
what are indications for anterior resection
rectal cancer MORE THAN 4-5 cm from anal verge ==> MID/HIGH RECTAL TUMOUR
you resect part of rectum and sigmoid colon
38
what stoma are you left with in anterior resection
DOUBLE LUMEN loop ileostomy in RIF
39
what are classical symptoms of colorectal cancer
change in bowel habit
PR bleed
WL, fatigue
ANaemia
40
what is the most important ix to get in suspected colorectal cancer
COLONOSCOPY
41
what colorectal cancer screening currently exists in UK
offerec **every 2 years** to those **aged 60-75 years** old
* **Faecal immunochemical test** (FIT)
uses antibodies against human Hb to detched blood in faece
42
what happens if FIT +ve
colonoscopy offered
43
How do you manage colorectal cancer
resection +-neoadjuvant chemo/radiotherapy
44
what is the most common type of abdominal hernia
INGUINAL hernia
45
what is the risk in a man of having an INGUINAL hernia
1 in 4
46
What are the two types of inguinal hernia?
INDIRECT vs DIRECT hernia
47
Explain INDIRECT hernia
Common in young boys
peritoneal sac protrudes through deep ingluinal ring > inglluinal canal > superficial ring > testes
due to weakness of deep inguinal ring (which is where structures pass during development to reach external genitalia=
48
Explain DIRECT inguinal hernia
DIRECT inguinal hernia
still more common in men, but this time RF are age, lifting heavy weights
peritoneal sac enters through weakening in abdominal wall eventually into inguinal canal (through superficial ring)
49
where are ingluinal hernias found
Above and medial to pubic tubercle
50
where are femoral hernias found
Below and lateral to pubic tubercle
51
Explain how femoral hernias occur
weakness in abdominall wall causes protrusion of intestinal content through femoral canal
52
WHo are femoral hernias most common in
WOMEN
| due to large pelvis (which means tissues are more stretched)
53
What are femoral hernias at high risk of
strangulation and obstruction
54
What type of hernia respods to cough impulse
INGUINAL
55
what is incarceration of a hernia
hernia CANNOT be reduced
56
what is strangulation of a hernia
hernia becomes ischaemic due to compromised blood supply
57
What do you do if hernia is incarc / strangulated?
EMERGENCY surgery
58
what do you do if hernia is not strangulated / incarc?
depends on type of hernia
if inguinal: ruotine repair, even if asymptomatic
if femoral: urgent repair (due to high risl of strangulation)
59
What are the two approaches to femoral hernia repair
if eLective: Lockwood Low approach (low incision over hernia with herniotomy/herniorrhaphy)
if eMergency: McEvedy High approach (via inguinal region to inspect and resect non viable bowel)
60
What are the types of surgery you can use for hernia repar
herniotomy: ligation + excision of hernial sac
herniorrhaophy: repair of abdo wall defect
hernioplasty: mesh implant
61
what incisions do you leave for herni repain
McBurney (oblique)
| Lanz (transverse)
62
how do you differentiate between direct and indirect inguinal hernia
1. reduce the hernia
2. press on deep inguinal ring
3. Ask patent to cough
if the hernia is DIRECT: it will protrude
if hernia is INDIRECT: it will NOT protrude as you are blocking its way out
63
what does pain suggest in jaundice?
PAINFUL jaundice = gallstone disease
| painLESS jaundice = pancreatric cancer
64
what is toxic megacolon
acute colonic distension (dilatation >6cm on AXR) + systemic symptoms of infection (fevers, shock)
65
causes of toxic megacolon
- IBD (most common - most likely UC)
- C diff
- Ischaemic colitis
- bowel cancer
- volvulus
66
risk with toxic megacolon
likely to PERFORATE >> death
67
Ix toxic megacolon
SEPSIS 6
Ix: FBC, CRP, UE, LFT, stool sample
AXR and abdo CT
68
Mx of toxic megacolon
```
NBM
Drip and suck
start IV Abx
Involve surgeons early
If no improvement within 72 hours / deterioraton: take for emergency laparotomy
```
69
what is gastrointestinal perforation
Perforation of the wall of the GI tract with spillage of bowel contents
70
most common causes of GI perforation
peptic ulcers and sigmoid diverticulum
71
infective causes of GI perforation
Diverticulitis
Cholecystitis
Appendicitis
Meckel’s diverticulum
72
ischaemic causes of GI perforation
mesenteric ischaemia
| obstructing lesions --> bowel distension --> ischaemia OR malignancy
73
clinical features of GI perforation
**PAIN - Rapid onset and Sharp**
**Systemically unwell**
**Malaise**
**Vomiting**
**Lethargy**
74
symptoms of Large Bowel perforation
Peritonitic abdominal pain
| IMPORTANT: make sure you rule out ruptured AAA
75
symptoms of Gastroduodenal perforation
**Sudden-onset severe epigastric pain** - worse on movement
Pain becomes **generalised**
Gastric malignancy - may have accompanying **weight loss and nausea/vomiting**
76
symptoms of Oesophageal perforation
severe pain following an episode of violent vomiting
| Neck/chest pain and dysphagia develop soon afterwards
77
signs of gastrointestinal perforation
**signs of shock**
**fever**
**pallor**
**dehydration**
Features of **peritonitis**: **lie still, tensing, guarding, rigidity, rebound tenderness, absent bowel sounds**
**Loss of liver dullness** (due to overlying gas)
78
investigations for GI perforation
bloods: **FBC** (raised WCC), **U&E**, **CRP** (raised), **LFT**, **clotting**, **G&S**, **amylase** (raised but not very high as in pancreatitis)
**urinanalysis**: exclude renal and tubo-ovarian pathology
imaging: **erect CXR, AXR, CT scan (gold standard)**
79
how does perforation show on CXR
free air under diaphragm BILATERALLY (pneumoperitoneum)
80
how does perforation show on AXR
**RIGLER SIGN** = both sides of bowel wall can be seen due to free intra-abdominal air acting as an additional contrast
**PSOAS SIGN** : loss of sharp delineation of psoas muscle border due to fluid in retroperitoneum
81
gold standard investigation for gastrointestinal perforation
CT scan:
| - Confirms free air and shows location of perforation, and potentially underlying cause
82
conservative management for GI perforation
- **ABCDE**
- Resuscitation: **Oxygen, IV Fluids, Analgesia**
- IV broad spectrum antibiotics: With anaerobic cover ~ E.g. **cefuroxime + metronidazole**
- **NBM**
- **Nasogastric tube insertion**
83
surgical intervention for GI perforation
1. **Identify site of perforation**
2. Management of perforation
Gastroduodenal: **repair perforation ulcer with omental patch**
Large bowel: **resect perforated diverticular via Hartmann’s procedure**
Oesophagus: **repair ruptured oesophagus**
3. Thorough washout (**peritoneal lavage**)
84
Complications of GI perforation
**infection**: peritonitis + sepsis --> septic shock, multi organ dysfunction and death
**haemorrhage**
85
what is MESENTERIC ADENITIS
inflammation of the mesenteric lymph nodes - due to infecton (adenovirus, EBV, beta haem step)
86
how does MESENTERIC ADENITIS present
Similar to appendicitis - except for HIGH FEVER
87
what does laparotomy show on mesenteric adenitis
enlarged mesenteric lymph nodes
88
What is meckels' diverticulitis - and how does it present
ectopic gastric mucosa
```
RIF pain (worse after eating)
bleeding (IDA)
```
89
what investigation is important if anal fistula in Chrons
get an MRI to check track of fistula
90
what does an ileostomy drain?
the SMALL BOWEL (ILEO = ileum)
91
Where is an ileostomy typically?
RIF
92
What does an ileostomy shape typically loook like?
SPOUTED
| due to the acidic nature with high enzyme contents, which irritates the surrounding skin. A spout minimises this
93
what is output of ileostomy like?
LIQUID to SEMI-LIQUID output (as this is small bowel content)
Usually high output, so 500ml - 1L/day
94
where is a colostomy usually located
LIF
95
what is the shape of a colostomy look like
FLUSH to the skin
96
what does the content of a colostomy looko like
```
Semi solid to solid (faecal matter)
low output (200-300ml)
```
97
when do you do a double lumen (loop) stoma
both ends connect out
| this is temporary, to allow distal bowel to rest. Wll then be reversed
98
complications of stoma
immediate: bleeding, necrosis from poor blood supply
early: high outpput causing dehydration and micronutrient lot, obsructon, retraction
late: obstruction, prolapse (out of skin), parasternal hernia (contained within the skin), skin irritation, psych
99
what do you do if at GP, seen pt >60 with IDA?
URGENT referral to colorectal team for COLONOSCOPY +- OGD
100
what is the method of inheriitance of FAP
Autosoml DOMINANT
| mutation of APC gene
101
what occurs in FAP
mutation of APC gene
hundreds of colonic adenomas develop
so the cancer risk is 100%
102
how do you manage FAP
annual flexi-sigmoidoscopy from age of 15
if no polyps found > 5 yearly colonoscopy from 20y
if polyps found > resection
103
method of inheritaance of Peutz-Jeguers
autosomal DOMINANT
104
presentation of Peutz-Jeguers
multiple benign intestinal hamatomas + PIGMENTATION PATTERN
can cause episodic obstruction or intussusception
risk of GI cancer and risk of breast, ovarian, cervical, pancfreatic and testicular cancers
105
how do you screen for peutz jeugers
intestinal endoscopy every 2-3 yeas
106
cancers associuated with HNPCC
COLORECTAL + Endometrial, gastric, pancreatic cancer
107
which geneit condition needs prophylactic surgery
HNPCC
108
what situations require a 2ww colorectal referral
- over 40 with WL and abdo pian
- over 50 with rectal bleed
- over 60 with IDA
- FOB+ve
109
what are the two commonest post op complications of colorectal tumour resection
ileus
| anastamotic dehiscence
110
what occurs with ileus after colorectal tumour resection
peristalsis stops > electrolytes and fluid dissolve into lumen > low electrolytes in blood and dehydrated picture despite normla fluid balance
111
how do you manage ileuas
NG tube + fluids
112
how does an anastamotic dehiscence present
day 6, fever, septic picturw
113
which area of the gut has the WORSE perfusion
the splenic flexure (between transverse and descending colon=)
114
mangement of caecal volculus
lapatotomy (right hemicolectomy often needed)
115
what key sx does rectal intussusception (internal rectal prolapse) present with
obstructed defecation -- associated with childbirth
116
what kinds of surgery are commonly done with chron's disease
perianal fistula = seton suture
perianal disease = proctectomy
terminal ileum = iliocaecal resection
117
which procedure must you avoid in chroons and why
avoid ILIOANAL POUCH
| high risk of failure
118
what is a total proctocolectomy
complete removal of large inteestine (colon) and rectum (procto)
119
what is a subtotal colectomy
removal of colon but NOT of rectum
120
what is the indication for ilio-anal pouch
used for UC after a SUBTOTAL COLECTOMY
can only be performed if the rectum is still in place (as patient still needs to pass stool. by themselves > still need to have rectal continence)
avoids a stoma! :)
121
what surgery is classically done in UC patient in emergency situation
subtotal colectomy + loop ileostomy
later consider ilioanal pouch to avoid stoma bag
122
ilioanal pouch complications
anastomotic dehiscence
pouchitis
poor physiological function with seepage and soiling.
123
what marker is used to monitor the response to treatment in colorectal cancer?
CEA
124
what is the important finding that you see in the rest of the bowel with a caecal volvulus
no other gas findings in the rest of the bowel
| becuase NOTHING can get through
125
where are primary anal fissures (due to constipation) most likely located
90% are posterior
| 10% anterior
126
what do lateral anal fissures inidicate
that the anal fissure is the secondary conodition > look for the cause!
127
how do you manage a pt with mild diverticulitis
and what do you do if they do not improve
oral abx, send home
if do not improve within THREE DAYS
admit for CEF AND MET IV
128
sx of acute diverticulitiis (esp location of pain)
Severe LIF pain (as sigmoid colon is where colon narrows down)
bloody stool
fever
urinary sx (diverticular fistulation into bladder)
129
explain dukes staging for colorectal cancer
Dukes A: confined to mucosa
B: through bowel wall
C: lymph node invasion
D: distant mets
130
when do you need to do a laparotomy in sigmoids volvulus
```
if PERITONITIC (so skip sigmoidoscopy)
or if REPEATED FAILED ATTEMPTS
```
131
what is the key sx difference between haemorrhoids and anal fissures in MCQ land
haemorrhoids are painless (unless thrombosed)
132
ix for anal fissure
* DRE/under anaesthesia
* Proctoscopy
133
mx of anal fissure
* Acute (<6weeks):
1. dietary advice
2. bulk-forming laxatives
* Chronic (>6 weeks):
1. topical GTN or topical diltaziem
2. refer for lateral sphincterotomy of botulinum toxin
134
triad of gastric volvulus
vomiting
pain
failed attempts at passing NG tube
135
what kind of stoma should you aim for in distal bowel cancer
a loop ileostomy
| to allow rest of distal bowel prior to reversal
136
when would you use IV iron compared to PO
when:
- oral replacement is ineffective or intolerable
- ferritin is very low and needs to be replaced very quickly
137
what investigation must you do to ensure that anastamosis has healed
GASTROGAFFIN contrast enema
138
things to look for on examination of bowel obstruction (besides classic signs)
Signs of underlying cause e.g. surgical scars, cachexia from malignancy, hernia
Abdominal distension with generalised tenderness
May see visible peristalsis
Tinkling bowel sounds
o Tympanic sound on percussion
o
o
o Assess fluid status due to third-spacing
o If peritonitis: absent bowel sounds, guarding, rebound tenderness
