peritonitis

Question 1

definition of peritonitis

Answer 1

inflammation of the peritoneal lining of the abdominal cavity

can be localised to one part or generalised

generalised can be primary or secondary

Question 2

aetiology of localised peritonitis

Answer 2

appenidicitis

cholecystitis

diverticulitis

salpingitis

Question 3

aetiology of primary generalised peritonitis

Answer 3

bacterial infection of the peritoneal cavity without obvious focus responsible

possibly via haematogenous or lymphatic spread, or ascending infection from the female genital tract

more common in people with ascites - eg liver cirrhosis (SBP) or children with nephrotic syndrome

Question 4

aetiology of secondary generalised peritonitis

Answer 4

due to bacterial translocation and spread, evolving from a localised focus

or nonbacterial due to spillage of bile, blood, gastric contents eg perforated peptic ulcer, pancreatic secretions - chemical peritonitis that often becomes secondarily infected

Question 5

epidemiology of peritonitis

Answer 5

primary peritonitis rare - usually in adolescent females

localised and secondary generalised peritonitis are common in surgical patients

Question 6

sx of peritonitis

Answer 6

parietal pain from peritonitis is usually continuous, sharp, localised,

exacerbated by movement and coughing (because parietal peritoneum is supplied by somatic A-d fibres arising from spinal nerves T7-L2

in those with liver disease and ascites, symptoms can be vague eg increased confusion due to encephalopathy

Question 7

signs of peritonitis

Answer 7

general state should be assessed

vital signs,

signs of dehydration or compromised perfusion eg due to hypovolaemia, sepsis, or circulatory failure

Question 8

signs of localised peritonitis

Answer 8

tenderness on exam with involuntary guarding - reflex contraction of overlying abdominal wall muscles

rebound tenderness - sudden removal of a palpating hand = pain due to movement of the inflamed peritoneum, similarly demonstrated as percussion tenderness or pain evoked by coughing

Question 9

signs of generalised peritonitis

Answer 9

pt very unwell - systemic signs of toxaemia or sepsis eg fever, tachycardia

pt lies still with shallow resp effort - movement exacerbate pain

prostration - lying stretched out

abdo is rigid with generalised tenderness,

bowel sounds are reduced or more typically absent due to paralytic ileus

rectal exam allows direct palpation of the pelvic peritoneum - demonstrating anterior tenderness

Question 10

pathology of peritonitis

Answer 10

peritoneum consists of a single layer of flatterned mesothelial cells over loose areolar tissue containing rich network of capillaies, lymphatics, nerve endings and immune competent cells (lymphocytes and macrophages)

secondary is usually polymicrobial with synergistic growth of aerobic and anaerobic organisms - often arising from bowel flora

primary - monomicrobial (eg streptococcus, pneumococcus)

when inflammed the peritoneum loses glistening appearance and becomes erythematous, with production of copious serous inflammatory exudate, rich in WBC, protein and inflam mediatirs

greater omentum becomes adherent to the inflammed organ creating a barrier to spread of infection

Question 11

investigation for peritonitis

Answer 11

• blood
  
  • FBC, UE, LFT, amylase, CRP, clotting, G&S or crossmatch, blood cultures, preg test, ABG (looking for acidosis or resp failure)
• imaging
  
  • eract CXR - for pneumoperitoneum
  • AXR - bowel obstruction, localised ileus with a sentinal loop of intraluminal gas visible
  • USS or CT abdo if suspect abscess (swelling, swinging fever, high WCC)
  • laproscopy
• if ascites
  
  • ascitic tap and cell count (diagnostic of SBP if >250neutropjils/mm3)
  • gram stain and culture

Question 12

management of local peritonitis

Answer 12

depend on the underlying cause eg appendicectomy

cholecystitis, salpingitis and most cases of acute diverticulis can be treated by IV AB

Question 13

management of generalised peritonitsi

Answer 13

pt at risk of sepsis and shock

need IV fluid resus and correction of volume and electrolyte imbalance - there is often severe hypovolaemia seciondary to 3rd space losses

IV AB

urinary catheter, NG tube, CVP line to monitor fluid balance

urgent laparotomy should be performed to remove the infected or nectroic tissue, treat the cause and perform peritineal washing with copious irrigation to remove all seropurulent exudate

an exception is non-necrotising pancreatitis

primary peritonitis is treated with AB - but dx not apparent until after attempted operation

Question 14

management of spontaneous bacterial peritonitis

Answer 14

medical treatment with quinolone antibiotic or cefuroxime and metronidazole combination

Question 15

early complication of peritonitis

Answer 15

septic shock

resp or multiorgan failure

paralytic ileus

wound infection

tertiary peritonitis - persistance of intra-abdo infection

abscesses

portal pyaemia/hepatic abscesses

Question 16

late complications of peritonitis

Answer 16

incisional hernia

adhesions

Question 17

prognosis of peritonitis

Answer 17

locallised usually resolves

generalised has a higher mortality- 30-50%

concurrent development of septic shock and ultiorgan dysfucntion can increase mortality rate to >70%

primary peritonitis has a good prognosis with appropriate AB

overall mortality of pts with SBP may exceed 30% if dx and treatment are delayed

Question 18

spontaneous bacterial peritonitis (SBP)

Answer 18

considered in any patient with ascites who deteriorates suddenly

e coli, klebsiella, streptococci

treatment - penicillin, tazobactam 4.5g/8hr for 5d

prophlaxis for high risk pts (low albumin, high PT/INR, low ascitic albumin) or those who have had a previous episode eg ciprofloxacin 500mg PO daily