Intra-abdominal sepsis Flashcards
Peritonitis definition
inflammation of the serosal membrane that lines the abdominal cavity (infection or irritants)
What causes primary peritonitis?
haematogenous - immunocompromised state
What causes secondary peritonitis?
perforation
What causes tertiary peritonitis?
persistent or recurrent infection after adequate therapy
What is generalised peritonitis?
rigidity
rebound tenderness
guarding
in all 4 abdominal quadrants
What is localised peritonitis?
peritoneal signs limited to 1 or 2 abdominal quadrants
may not look unwell
Abdominal signs of peritonitis
abdomen that moves with respiration
cough peritonism
percussion tenderness
rebound tenderness
Common causes of secondary peritonitis
pancreas - pancreatitis, trauma, iatrogenic
small bowel - ischaemic bowel, incarcerated hernia, closed loop obstruction, Crohn’s, malignancy, meckel diverticulum, trauma
large bowel + appendix - ischaemic bowel, diverticulitis, malignancy, Crohn’s, UC, appendicitis, colonic volvulus, iatrogenic
uterus, salpinx + ovaries - pelvic inflammatory disease, malignancy, trauma
Causes of pain in RUQ
cholecystitis
pyelonephritis
ureteric colic
hepatitis
pneumonia
Causes of pain in LUQ
gastric ulcer
pyelonephritis
ureteric colic
pneumonia
Causes of pain in RLQ
appendicitis
ureteric colic
inguinal hernia
IBD
UTI
gynaecological
testicular torsion
Causes of pain in LLQ
diverticulitis
ureteric colic
inguinal hernia
IBD
UTI
gynaecological
testicular torsion
Causes of epigastric pain
peptic ulcer disease
cholecystitis
pancreatitis
myocardial infarction
Causes of pain in peri-umbilical region
small bowel obstruction
large bowel obstruction
appendicitis
abdominal aortic aneurysm
What is acute mesenteric ischaemia?
group of diseases characterised by an interruption of blood supply to varying portions of the small intestine, leading to ischaemia and secondary inflammatory changes
causes intestinal necrosis
life-threatening
Aetiology of acute mesenteric ischaemia
mesenteric arterial embolism - AF, MI, endocarditis, vascular grafts
non-occlusive mesenteric ischaemia - systemic shock, hypoperfusion, hypovolaemia
mesenteric arterial thrombosis - advanced age, traumatic injury, peripheral artery disease
mesenteric venous thrombosis - coagulopathy
Risk factors for acute mesenteric ichaemia
smoking
dyslipidaemia
hypertension
AF
vasculopathy
Presentation of acute mesenteric ischaemia
generalised abdominal pain out of proportion to clinical findings
diffuse + constant pain
nausea + vomiting
non-specific tenderness with no specific clinical signs
generalised or localised peritonitis
embolic sources - eg. AF, heart murmurs - clues for underlying cause
What imaging is diagnostic of acute mesenteric ischaemia?
CT scan with IV contrast
oedematous bowel, loss of bowel wall enhancement
pneumatosis
free air
free fluid
Acute mesenteric ischaemia management
urgent initial resuscitation
NBM
analgesia
antiemetic
catheter
broad spectrum IV abx
excision of necrotic/non-viable bowel if revascularisation not possible
Appendicitis pathophysiology
direct luminal obstruction (faecolith, lymphoid tissue, malignancy)
Appendicitis presentation
migratory pain (central to RLQ)
anorexia
malaise
nausea
vomiting
percussion tenderness over McBurney’s point
localised peritonism RIF
Appendix perforation presentation
hypotension
tachycardia
pyrexia
Specific signs on examination in appendicitis
Rovsing’s sign = RIF pain on palpation of LIF
Psoas sign = RIF pain with extension of right hip - suggestive of retrocaecal appendix abutting the psoas muscle
What 2 things should be ruled out in suspected appendicits?
testicular torsion
ectopic pregnancy
Appendicitis differential diagnosis
gynaecological - ectopic pregnancy, ovarian torsion, cyst rupture, PID
renal - kidney stones, UTI, pyelonephritis
gastrointestinal - IBD, Meckel’s, diverticular disease
urological - testicular torsion
other - mesenteric adenitis, gastroenteritis
Appendicitis investigation
MSU - leukocytes may be present as appendix next to bladder
B HcG - rule out ectopic
FBC/UE/CRP/Coag
Appendicitis management
IV fluids
analgesia
antiemetics
NBM
IV ABX
laparoscopic appendicectomy (gold standard)
Diverticulitis definition
inflammation due to micro-perforation of a diverticulum
What is the diverticulum?
sac-like protrusion of the colon
Diverticulitis risk factors
low fibre, high fat, red meat diet
obesity
smoking
NSAIDs
steroids
opiates
Diverticulitis presentation
LLQ abdominal pain
change in bowel habits (diarrhoea or constipation)
nausea/vomiting
dysuria - frequency + urgency
Diverticulitis signs on examination
tenderness to palpation
localised peritonism
fever
tachycardia
hypotension
bowel sounds normally hypoactive
generalised peritonitis
Diverticulitis investigation
FBC, UE, LFT, CRP
CT abdomen pelvis with IV contrast - bowel wall thickening, pericolic fat stranding, pericolic fluid, small abscesses confined to colonic wall
colonoscopy - 6-8 weeks after symptoms to rule out malignancy, IBD
Diverticulitis management
IV ABX
analgesia
antiemetic
bowel rest
Diverticulitis complications
POFAB
perforation:
- intestinal perforation - localised or generalised peritonitis
obstruction - stricturing disease
fistula - colovesical fistula
abscess - pelvic abscess
bleeding - PR bleed
Types of small bowel obstruction
partial or complete
non-strangulated or strangulated
Aetiology of small bowel obstructions
post-surgical adhesions
incarcerated hernias
malignancy
IBD
stool impaction
foreign bodies
volvulus
Small bowel obstruction presentation
intermittent or progressive abdominal pain, distension, nausea, vomiting
constipation/obstipation with or without flatus, loose bowel movements
surgical scars, hernias, IBD hx, malignancy
Small bowel obstruction examination signs
temperature
tachycardia
tenderness (3 Ts)
abdominal tenderness, generalised/localised peritonism
bowel sounds - reduced + high-pitched
Small bowel obstruction CT signs
dilated small bowel
transition point
small bowel faeces sign
closed loop obstruction
secondary features of strangulation - enhancement of bowel, pneumatosis, portal venous gas, mesenteric stranding, free fluid, free air
Small bowel obstruction management
fluids
electrolyte correction
analgesia
antiemetic
NBM
NG decompression
catheter
strict fluid balance
antibiotics if signs of perforation
gastrograffin
surgery
Is the peritoneal cavity closed or open?
closed in men
open in women - via cervix + vagina
Intraperitoneal organs
stomach
liver
gallbladder
transverse colon
jejunum
ileum
caecum
What is spontaneous bacterial peritonitis (SBP)?
infection of ascitic fluid which arises in the absence of any other source of sepsis within the peritoneum or adjacent tissues
What organisms mainly cause spontaneous bacterial peritonitis?
E Coli
Streptococci
Enterococci
typically monobacterial
Main risk factors for SBP
alcoholism
cirrhosis
Common causes of pyrexia in a surgical patient
7Cs:
chest (infection)
cut (wound infection)
catheter (UTI)
collections (abdomen, pelvis etc)
calves (DVT)
cannula (infection)
central line (infection)
Which antimicrobials target gram-negative organisms?
amoxicillin
gentamicin
co-amoxiclav
cefuroxime
ciprofloxacin
piperacillin/tazobactam
Which antimicrobials target gram-positive organisms?
amoxycillin
gentamicin
co-amoxyclav
piperacillin/tazobactam
vancomycin
Which antimicrobials target anaerobes?
metronidazole
co-amoxiclav
piperacillin/tazobactam
