Case 11: Central/lower abdominal pain Flashcards
dermatomes for the foregut
T5-T9
dermatomes for the midgut
T10-T11
dermatomes for the hindgut
L1-L2
what small bowel diameter suggests bowel obstruction
over 3cm
what caecum diameter suggests bowel obstruction
over 9cm
what colon diameter suggests bowel obstruction
over 6cm
which structures will cause central abdominal pain
intra-abdominal structures- midgut
retroperitoneal structures- duodenum, pancreas, aorta
abdominal wall- hernia, muscle, skin
referred pain- from back, base of lung, inferior heart
rarely medical causes- DKA, porphyria
what are the midgut structures
form the opening of the bile duct to proximal 2/3 of transverse colon:
distal duodenum
jejunum
ileum
caecum
appendix
ascending colon
proximal 2/3 transverse colon
how does referred pain happen
the visceral pain of the organ is referred to the site on the skin which is supplied by that dermatome
where is foregut pain perceived
epigastric region
where is midgut pain perceived
umbilical region
where is hindgut pain perceived
suprapubic/hypogastric region
possible diagnoses for continuous abdominal pain radiating to the back
symptomatic abdominal aortic aneurysm (AAA)
pancreatitis
possible diagnoses for colicky abdominal pain which is now constant
bowel obstruction with/without hernia
IBS
possible diagnoses for colicky abdominal pain associated with diarrhoea
gastroenteritis
IBD
possible diagnoses for central abdominal pain which has now shifted to the right iliac fossa
appendicitis
rarely perforated duodenal ulcer
possible diagnoses for sudden severe pain radiating to the back, flank and/or groin
AAA until proven otherwise
renal colic
possible diagnoses for severe generalised pain with shoulder tip pain
diaphragm irritation by free fluid/blood within the abdomen
typical presentation of AAA
central abdominal pain
no link to food
palpable pulsatile/expansile mass especially if tender
typical presentation of acute appendicitis
classic central (visceral) abdominal pain that localises to right iliac fossa when the inflamed appendix irritates the peritoneum locally
typical presentation of duodenal perforation
background of epigastric pain and clear relationship to eating
can cause high central abdominal pain and leak of duodenal content will track across the root of mesentery into right iliac fossa localising the pain to that side
what does colicky pain that becomes constant suggest
that there is a partial obstruction of a hollow viscus (bowel, bile duct, ureter) which has become complete
needs urgent intervention to prevent perforation or major complications
what suggests infection/inflammatory process in one organ
pyrexia
localised tenderness
guarding
what is mcburneys point
point of maximum tenderness in appendicitis (base of the appendix)
1/3 the line between the anterior superior iliac spine to umbilicus
important interventions for appendicitis
analgesia (morphine)
NBM
IV fluids- to maintain hydration and to treat hypotension
antibiotics for the sepsis
what can septic shock also present with with acute abdominal pathology
hypothermia
what part of the large intestine is the appendix attached to
caecum
official name for appendix and why
vermiform appendix- means worm shaped
what is the most common surgical emergency for the abdomen
appendicitis
causes of appendicitis
most common is obstruction:
fecalith- faecal rock
undigested seeds
pinworm infection
lymphoid hyperplasia
what leads to the pathophysiology of appendicitis
there is an increase in pressure- prolonged increase in pressure can compress the blood vessels suppling the appendix which can lead to ischaemia)
gut flora multiplies (e.coli, bactericides fragilis)
immune system causes an increased which cell count
fever, nausea and vomiting
why might you get peritonitis with appendicitis
the increase in pressure can weaken the walls of the appendix
this can lead to the appendix rupturing
the contents which are full of bacteria can irritate the peritoneum causing peritonitis
this will cause guarding and rebound tenderness especially at mcburneys point
what is a AAA
dilation of the abdominal aorta
the diameter is over 3cm
what is the mortality of a ruptured abdominal aortic aneurysm
80 percent
are men or women more at risk of AAA
men are affected more often and at a younger age
risk factors for AAA
men
increasing age
smoking
hypertension
family history
existing cardiovascular disease
screening process for AAA
all men at 65 are offered an ultrasound to detect an asymptotic AAA
women aren’t routinely offered screening as they are at a much lower risk (may be screened at 70 if they have lots of risk factors)
how does referral for AAA work following screening
if diameter is more than 3cm refer to vascular
urgent referral if more than 5.5cm
typical presentation of AAA
most asymptomatic
can be detected during routine screening, after rupture, or an incidental finding on x-ray, ultrasound or CT
non-specific abdominal pain
pulsatile and expansile mass
diagnosis of AAA
ultrasound
a CT angiogram will be performed to get a more detailed picture and it helps guide elective surgery
classification of AAA
normal= less than 3cm
small= 3-4.4cm
medium= 4.5-5.4cm
large= over 5.5cm
management of AAA
treat reversible risk factors- smoking cessation, healthy diet and exercise, optimise hypertension, diabetes and hyperlididaemia
follow-up scans- yearly if 3-4.4cm or every 3 monthly if 4.5-5.4cm
elective repair- if symptomatic, growing more than 1cm per year or if over 5.5cm
how is the surgery for AAA done
a graft is inserted
can be either open repair (laparotomy)
or
endovasuclar aneurysm repair (EVAR) which is inserted via the femoral arteries
DVLA advice for AAA
must inform the DVLA if over 6cm
must stop driving if over 6.5cm
presentation of ruptured AAA
severe abdominal pain which radiates to the back and groin
haemodynamic instability:
hypotension
tachycardia
pulsatile and expansile mass
collapse
loss of consciousness
what blood pressure technique is done when managing ruptured AAA
permissive hypotension
(don’t want to increase BP as it will lead to more blood spilling into the abdominal cavity)
common misdiagnosis of ruptured AAA
renal colic
diverticulitis
GI bleed
MI
muscular or mechanical back pain
how can clinical examination for AAA be limiting
only picks up 40-50%
can be difficult in obese
false positives in thin individuals due to transmitted pulse vs expansile mass
what happens to the legs with ruptured AAA
bilateral leg ischemia (if in one leg think of dissection or significant peripheral vascular disease)
in which patients should you always suspect ruptured AAA
men older than 60 with first presentation of renal colic
what is a hernia
protrusion of an organ through its containing wall and into a different cavity (can be acquired or congenital)
what is the most common type of hernia
inguinal
other types of hernias
umbilical/paraumbilical
femoral
incisional
epigastric
what is a reducible hernia
hernia can be manually pushed back or reduced into the abdominal cavity
what is a irreducible hernia
the hernia sac and its content cannot be pushed back into the abdomen
what is a stangulated hernia
the neck of the sac is quite tight leading to cut off the blood supply to the organ that herniated
what is a obstructed hernia
the bowel loop trapped within the sac causes bowel obstruction, with further oedema it can become strangulated
what investigation is always done when there is peritonitis
CT
what is conservative management of appendicitis
can be treated with antibiotics but has a significant failure rate due to ongoing sepsis and also has high recurrence rate
may be an option for those not fit for surgery or those who are pregnant with mild symptoms and no sepsis
complications of appendectomy that the patient needs to be counselled on
conversion to open surgery
post-operative wound infection or intra-abdominal collection
bleeding
others- pain, postoperative ileus, lower respiratory tract infections/pneumonias, DVT, PE, adhesions and incisional herniasconversion to open surgery
what would warrant and urgent referral for ovarian cancer
2 week wait if:
ascites
pelvic/abdominal mass (which is not obviously uterine fibroids)
what is the CA125 blood test
protein in the blood
raised levels may indicate/help monitor ovarian, fallopian tube, or primary peritoneal cancer
when would CA125/ultrasound be indicated
in women (especially 50+) who experience the following frequently (more than 12 times per month):
persistant abdominal distention
early satiety and/or loss of appetite
pelvic/abdominal pain
increased urinary urgency and/or frequency
new onset symptoms suggestive of IBS (IBS rarely presents for the first time in women of this age)
unexplained weight loss
fatigue
changes in bowel habit (though colorectal cancer will be the most likely malignant cause)
what would prompt urgent referral for investigation of colorectal cancer
any age with abdominal/rectal mass
40 and over with unexplained weight loss and abdominal pain
50 and over with unexplained rectal bleeding
60 and over with iron deficiency anaemia
symptoms and signs of strangulated hernia
acute, severe pain delectable on examination as a non-reducible mass in groin or anterior abdominal wall
what is overflow diarrhoea and what would you find on examination
can occur in severe constipation
there would be impacted stool in the rectum
what age most commonly presents with inflammatory bowel disease
15-40
signs and symptoms of inflammatory bowel disease
abdominal pain
bloating
bloody diarrhoea
weight loss
extreme tiredness
pathophysiology of irritable bowel syndrome
functional disorder of the bowel
related to the way the bowel and the brain interact, causing increased sensitivity of the bowel to normal stimuli and abnormal motility
most common age diagnosis of IBS
20-40
are men or women more likely to have IBS
women are twice as more likely to be affected by men
symptoms of IBS
diarrhoea
constipation
alternation between both of the above
abdominal pain
diurnal bloating
mucus in the stool
tiredness
what can affect the symptoms of IBS
hormonal fluctuations during the menstrual cycle- often worse during the progesterone dominant premenstrual phase
emotional stress is a trigger
can also occur after an episode of gastroenteritis
pathophysiology of diverticulitis
diverticula are small bulges/pouches in the lining of the large intestine- usually incidental findings on scans/colonoscopy and occur with advancing age
occurs when these pouches becomes infected/inflamed
what is diverticulosis
presence of diverticula (they are asymptomatic and not inflamed)
signs and symptoms of diverticulitis
severe pain ofter in LLQ
bloating
fever
bloody diarrhoea
severe pain which worsens over several days
pathophysiology of coeliac disease
autoimmune condition triggered by sensitivity to gluten, repeated gluten exposure causes inflammation of the small intestine
signs of symptoms of coeliac disease
abdominal pain
bloating
tiredness
diarrhoea
constipation
anaemia
weight loss
skin rashes (specifically dermatitis herpetiformis)
pathophysiology of lactose intolerance
deficiency in lactase enzyme which is produced by the small intestine (breaks down sugar lactose which is found in diary products)
symptoms of lactose intolerance
usually occur within 30 minutes after eating diary products
diarrhoea
crampy abdominal pains
bowel gas
bloating
epidemiology of lactose intolerance
primary lactase deficiency is most common in adults of African, asian, hispanic o American Indian descent
secondary lactase deficiency can occur as a result of other conditions affecting the function of the small intestine including crohns and after a severe episode of gastroenteritis
bile acid diarrhoea pathophysiology
bile acids are produced in the liver, stored in the gallbladder and secreted into the small intestine after meals
they are mostly reabsorbed in the ileum and returned to the liver in a cycle known as enterohepatic circulation
when they are not adequately reabsorbed, chronic diarrhoea along with bloating and cramping pain can result
what is bile acid diarrhoea most commonly misdiagnosed as
irritable bowel syndrome with predominant diarrhoea
epidemiology of bile salt diarrhoea
affected 1 in 100 people in the UK
investigations for bile salt diarrhoea
SeHCAT scan- artificial bile is swallowed and an initial scan determines how much is present in the body
a further scan one week later shows how much of the original amount has been retained via enterohepatic circulation
treatment for bile salt diarrhoea
low fat diet and bile acid sequestrants (drugs that bind to bile acids in the small intestine and prevent irritation of the colon)
what is faecal calprotectin and what does it help distinguish between
is a biomarker of bowel inflammation
distinguishes between IBS (normal levels) and inflammatory bowel disease (elevated levels even if CRP is normal)
anaemia may be seen in which 2 gastrointestinal diseases
coeliac
IBD
what is toxic megacolon
extreme dilation of a segment of the diseased colon caused by paralysis of the colon
results in complete obstruction
what on coeliac serology suggests coeliac disease
tissue transglutiamse antibody (tTGA)
endomysial antibody (EMA)
(are both antibodies formed in response to eating gluten)
what biopsy may be done to confirm coeliac disease
duodenal biopsy
what should be recommended as first line management for IBS
reduce caffeine (caffeine stimulates bowel motility)
reduce fizzy drinks (fizzy drinks exacerbate symptoms of bloating and bowel gas)
regular exercise (reduces stress and improves overall wellbeing)
loperamide
what is loperamide
anti-motility drug
used first line with diarrhoea associated with IBS
opiate receptor agonist (binds to u) in the colon
decreases the smooth muscle tone in the intestinal wall
hardly crosses BBB so has no central effects
what is a Low FODMAP diet
if general lifestyle and dietary advice does not help with IBS this can be recommended
fermentable olgiosaccharides
dissacharides
monosaccharides
polyols
(these are a group of carbohydrates that are incompletely digested and absorbed in the small intestine, have an osmotic effect, retaining water as they pass into the colon, they are then fermented which produces gas, extra gas and water can cause these unpleasant symptoms)
examples of FODMAPs
fructose
lactose
sorbitol
fructans
galactans
(fruit is abundant so they are asked to limit fresh fruit consumption)
