passmed Flashcards
Ischaemia to lower GIT can cause what 3 conditions
- Acute mesenteric ischaemia
- Chronic mesenteric ischaemia
- Ischaemic Colitis
Bowel ischaemia: common predisposing factors
- incr age
- AF - esp Mes Isch
- Other causes of emboli - endocarditis, malignancy
- CVD RF - smoking, HTN, diabetes
- Cocaine - isch colitis sometimes seen in young pts after cocaine use
Bowel ischaemia: common features
- abdominal pain - in acute mesenteric ischaemia this is often of sudden onset, severe and out-of-keeping with physical exam findings
- rectal bleeding
- D
- F
- bloods typically show an elevated WBC assoc with a lactic acidosis
Acute mesenteric ischaemia cause, pres, Ix + Mx
CAUSE: typically caused by an EMBOLISM resulting in occlusion of an artery which supplies the SMALL BOWEL, for example the SMA. Classically patients have a hx of AF.
PRES: abdo pain is typically severe (morphine might not even help), of sudden onset and out-of-keeping with physical exam findings.
IX: AMI causes RAISED LACTATE = VBG = 1st line ix
MX: urgent surgery is usu req
-poor prognosis, especially if surgery delayed
Chronic mesenteric ischaemia
relatively rare clinical diagnosis due to it’s non-specific features and may be thought of as ‘intestinal angina’. Colickly, intermittent abdominal pain occurs.
Ischaemic Colitis: define, Ix, Mx
= ACUTE but TRANSIENT compromise in the blood flow to the LARGE BOWEL –> inflamm, ulceration and haemorrhage
-It is more likely to occur in ‘WATERSHED’ areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries.
IX: ‘THUMBPRINTING’ may be seen on AXR due to mucosal oedema/haemorrhage
MX: - usually supportive
- surgery may be required in a minority of cases if conservative measures fail.
- Indications would include generalised peritonitis, perforation or ongoing haemorrhage
HNPCC inheritance + mutations
ADom
- most common form of inherited colon cancer (also causes endometrial C)
- 90% dev C - often proximal colon
- mutations in DNA mismatch repair
- genes: MSH2 (60%), MLH1 (30%)
HNPCC what criteria to aid dx
Amsterdam Criteria:
- at least 3 fam members with colon c
- cases span at least 2 generations
- at least 1 case dx before 50Y
FAP inheritance + gene
rare ADom
- mutation in TSG = APC - Chromosome 5
- develop colon carcinoma from 100s of polyps (also duodenal T)
- variant of FAP = Gardners Syndrome (=polyps + osteomas of skull + mandible, retinal pigmentation, thyroid C + epidermal cysts on the skin
oesophageal C - adenocarcinoma
most common type in UK/US
location - LOWER THIRD - near gastrooesophageal jtn
RF: GORD, Barrets O, Smoking Achalasia, Obesity
oesophageal C - SCC
most common in developing world
location - UPPER 2/3 of oesophagus
RF: smoking, alcohol, achalasia, Plummer-Vinson Syndrome, diets rich in nitrosamines
oesophageal C - Mx
surgical resection = IVOR LEWIS TYPE OESOPHAGECTOMY (often with adjuvant chemo)
-biggest surgical challenge= anastomotic leak - with intrathoracic anastomosis –> mediastinitis
C.Diff – > pseudomembranous colitis causes, features + dx
G+ rod –> prod exotoxin –> PSM Colitis
- C.diff cause = clindamycin, 2nd/3rd gen cephalosporins PPIs
- feat: D, abdo pain, RAISED WCC, severe toxic megacolon
- dx: detect CDT in stool
- exposure: C.diff antigen positivity shows exposure to bacteria NOT current infection
C.DIff usual MX - V, F, V+M
1st - oral VANC 10d
2nd - oral fidaxomicin
3rd - oral vanc +/- IV metro
C.Diff recurrence Mx
recurs in 20%, incr to 50% after 2nd ep
- WITHIN 12w of sx resolution: oral fidaxomicin
- AFTER 12w of sx resolution: oral vanc OR fidaxomicin
C.Diff LIFE THREATENING Mx
- ORAL vancomycin AND IV metronidazole
- specialist advice - surgery may be considered
Hereditary Haemochromatosis blood findings - 2 RAISED 1 LOW - Chromsome 6 - A.REC
RAISED - transferrin saturation + ferritin
LOW - TIBC
NB. ferritin is v sensitive for IRON OVERLOAD
perianal fistulae define
inflamm tract bet anal canal + perianal skin
perianal fistulae gold std ix
MRI
-determine if there is an abscess and if fistula simple (low) or complex (high - passes through or above muscle layers)
perianal fistulae mx
(symptomatic) - MED - oral metronidazole , infliximab = anti - TNF
SURG - seton or fistulotomy
oesophageal disorders 1: Plummer Vinson syndrome TRIAD. (DIG) + Tx
- Dysphagia (secondary to oesophageal webs)
- IDA
- Glossitis
- Tx: IRON supplementation + DILATATION of WEBS
oesophageal disorders 2: Mallory Weiss Syndrome
severe vomiting –> painful mucosal lacerations at the gastrooesophageal jtn –> haematemesis
-common in alcoholics
oesophageal disorders 3: Boerhaave Syndrome
severe vomiting –> oesophageal RUPTURE
Ascites define
ABN ACCUMULATION of fluid in ABDOMEN
Ascites with SAAG>11g/L (indicates portal HTN) CAUSES x3 main - think FAILURES
LIVER - (most common)
-ALD, acute liver failure, liver mets
HEART-
-RHF, constrictive pericarditis
OTHER -
-Budd Chiari Syndrome, Portal vein thrombosis, veno-occlusive disease, myxoedema
Ascites with SAAG<11g/L x4 main
HYPOALBUMINAEMIA
- nephrotic syndrome
- severe malnutrition eg Kwashiorkor
MALIGNANCY
-peritoneal carcinomatosis
INFECTIONS
-TB peritonitis
OTHER
- pancreatitis
- bowel obstruction
- biliary ascites
- post op lymphatic leak
- serositis in CTD
Ascites Mx x6
- reduce dietary SODIUM
- Fluid restrict (if sodium <125)
- aldosterone antagonists eg SPIRO
- drainage if tense (therapeutic abdominal paracentesis)
- prophylactic ABx (reduce risk of SBP)
- TIPS (in some pts)
obesity or T2DM with abnormal LFTs
NAFLD
which meds should be held in C.Diff infection
anti motility and anti-peristaltic drugs eg opiods as it can predispose to toxic megacolon due to slowing of clearance of C.Diff
-ABx should also be held to allow normal intenstien flora to be re-established
prophylaxis of variceal haemorrhage
PROPANOLOL - reduced rebleeding + mortality cf to placebo
ENDOSCOPIC VARICEAL BAND LIGATION (EVL) - done at 2 weekly intervals until all varices eradicated - PPI cover to prevent EVL- induced ulceration
peptic ulcer disease RFs - 3 main categories + 4 drugs
- H.PYLORI - 95% DU, 75% GU
- DRUGS - NSAIDs, SSRIs, CSteroids, Bisphosphonates
- ZOLL-ELLINSON - xs gastrin usu gastrin secr T
duodenal vs gastric features
DUODENAL - more common -epigastric pain WHEN HUNGRY, RELIEVED BY EATING
GASTRIC - epigastric p WORSENED BY EATING
coeliac disease immunisation
- often hv degree of FUNCTIONAL HYPOSPLENISM
- offer PNEUMOCOCCAL VACCINE + BOOSTER every 5 years (Risk of overwhelming pneumococcal sepsis)
what on blood tests shows severity of C.Diff infection
WCC count > 15x 10^9 / L
hepatocellular disease: lab tests
ALT - raised at least 2x
ALP - normal
ALT/ALP - 5+
Cholestatic disease: lab tests
ALT - normal
ALP - raised at least 2x
ALT/ALP: <2
Mixed disease: lab tests
ALT: raised at least 2 fold
ALP: raised at least 2 fold
ALT/ALP: 2-5
ALP produced by what in biliary system
cells lining BILE DUCT
-so levels in blood rise in OBSTRUCTIVE disease
IBS NICE Mx
Pain - ANTISPASMODICS
Constipation - LAXATIVES (bulk forming 1st = Isphagula Husk) but avoid lactulose (increase gas production, makes sx worse), if not responding try linaclotide
Diarrhoea - LOPERAMIDE 1st line
Migraine mx of nausea
prokinetic eg METACLOPRAMIDE
- relieves gastric stasis that can slow transity + absorption of drugs during acute migrain attack
- can be used even in absence of N+V
- low risk ST (advise <5d tx)
pancreatic cancer sign on CT
DOUBLE DUCT
-either pancreatic or ampulla vater cancer
= DILATED CBD + DILATED PD
chrons does what to goblet cellss
INCREASES
mx of asymptomatic gallstones in the GB vs in the CBD
Asymptomatic gallstones = located in the GB are COMMON and do not require TX
-BUT, if stones are present in the CBD there is an INCR risk of Cx eg cholangitis or pancreatitis + surg mx should be considered
risks of ERCP x4
Bleeding
Duodenal perforation
Cholangitis
Pancreatitis
in pts with severe colitis, what Ix is used for dx
FLEXI SIG + BIOPSY
-colonoscopy avoided due to perf risk
how to convert ml + ABV% into units
Alcohol units = volume (ml) * ABV / 1,000
mx of alcoholic hepatitis
Selected management notes for alcoholic hepatitis:
GLUCOCORTICOIDS (e.g. prednisolone) are often used during acute episodes of alcoholic hepatitis
-Maddrey’s discriminant function (DF) is often used during acute episodes to determine who would benefit from glucocorticoid therapy
-it is calculated by a formula using prothrombin time and bilirubin concentration
PENTOXYPHYLLINE is also sometimes used
-the STOPAH study (see reference) compared the two common treatments for alcoholic hepatitis, pentoxyphylline and prednisolone. It showed that prednisolone improved survival at 28 days and that pentoxyphylline did not improve outcomes
what is the prophylaxis of oesophageal bleeding
non-cardioselective beta blocker (NSBB) eg PROPANOLOL
colorectal cancer occurs most commonly in what part
RECTUM > SIGMOID > CAECUM
