Lecture 18- GI emergencies 1/2 Flashcards
Causes of peritonitis
- Ascites
- Cirrhosis
- Perforated appendicitis
- Perforated peptide ulcer
- Perforated diverticulitis
- Volvulus
- Cancer
what is peritonitis
Inflammation of the serosal membrane that lines the abdominal cavity
the peritoneal cavity is usually
sterile
primary peritonitis is
spontaneous
secondary peritonitits
- Breakdown of peritoneal membrane leading to foreign substances entering cavity
inflammation in both primary and secodnary peritonitis is
uniform
- Peritonitis can be
infectious or sterile
Peritoneal cavity-
space between the visceral and parietal layers of the peritoneum
viceral and parietal components of the periotneum are
continous
visceral periotneum
any part of the serosal memrbane that is not lining the abdominal wall
parietal peritoneum
any part of the serosal memrbane that is lining the abdominal wall
peritioneal cavity contains
no viscera, only a small amount of fluid
peritoneal cavity can be divided itno 2 sec tions
greater and lesser sac
greater and lesser sac conencted by the
foramen of winslow
what is a mesentry
The mesentery attaches the intestines to the abdominal wall, and also helps storing the fat and allows the blood and lymph vessels, as well as the nerves, to supply the intestines.
primary peritonitis is also called
spontaneous bacterial peritonitis (SBP)
spontaneous bacterial peritonitis (SBP) is most commonly seen in
- patients with end stage liver disease (pts with cirrhosis)
- what is Spontaneous bacterial peritonitis (SBP)
is an infection of ascitic fluid that cannot be attributed to any intra-abdominal, ongoing inflammatory, or surgical correctable condition
Ascites
Pathological collection of fluid within peritoneal cavity
- In cirrhosis what causes ascites
- caused by a combination of
- Portal hypertension
- Causing increase hydrostatic pressure in veins draining the gut
- Decreased liver function resulting in less albumin production
- Decreased intravascular oncotic pressure
- The result is net movement of fluid into the peritoneal cavity
- Portal hypertension
symptoms of Primary peritonitis- spontaneous bacterial peritonitis (SBP)
- Abdominal pain, fever and vomiting
- Usually symptoms are mild (slightly milder than regular peritonitis)
Diagnosis of SBP
Aspirating ascitic fluid- neutrophil count >250 cell/mm3
Secondary peritonitis
Secondary (surgical) peritonitis is a result of an inflammatory process in the peritoneal cavity secondary to inflammation, perforation, or gangrene of an intra-abdominal or retroperitoneal structure
pathophysiology of secondary peritonitis
- Peritoneal cavity is normally sterile
- If viscera perforates then the contents will enter the peritoneal cavity
- Common cause of secondary bacterial peritonitis include
- Peptic ulcer
- Appendicitis
- Diverticulitis
- Post surgery
- Non-bacterial causes of secondary peritonitis
- Tubal pregnancy that bleeds (peritoneal cavity is not enclosed in females)
- Ovarian cyst
- Blood is highly irritant to peritoneal cavity
Symptoms of secondary peritonitis
- Abdominal pain
- Lying very still
- Knees flex
- Shallow breathing
- May come on gradually or acutely
- Diffuse abdominal pain common in perforated viscera
Treatment of secondary peritonitis
*
- Control infectious source- surgery
- Eliminate bacteria and toxins- Abx
- Maintain organ system function
- Intensive care
define bowel obstruction
Mechanical or functional problem that inhibits the normal movement of gut contents
- Can effect large and small bowel
- All ages affected
Common causes of bowel obstruction in children
- Intussusception
- Intestinal atresia- failure to recanalize bowels during development
Common causes of bowel obstruction in adults
- Adhesion
- Incarcerated hernias
Small bowel obstruction
Symptoms
- Nausea and vomiting (bilious) are most common early symptoms
- Abdominal distension
- Absolute constipation (late)
causes of small bowel obstruction
- Intra-abdominal adhesion
- hernias
- IBD
- Intra-abdominal adhesion
*
abnormal fibrous bands between organs or tissues or both in the abdominal cavity that are normally separated
- Arises after more than 50% of abdominal surgeries
- Greater omentum involved in 90%, bowel in 50%
- Damage to mesothelium (direct trauma, post op infection)
- Capillary bleeding leading to exudation of fibrinogen
Other consequences of adhesions
Abdominal pain
Infertility
small bowel obstruction caused by which sort of hernia
incarcerated groin hernias
IBD and small bowel obstruction
- Crohns- repeated episodes of inflammation causing narrowing
Diagnosis of small bowel obstruction
- History- abdominal pain is crampy intermittent- colic pain
- Physical exam- abdominal distension, increased /absent bowel sounds, presence of hernia
- Imaging
how would smalll bowel obstruction look on CT
- 3cm or more= distended small bowel
- central position of bowel
- plica circulares clear- lines across hole of bowel
Intussusception
When one part of the gut telescopes into an adjacent section
causes of intussusception
- Not understood well
- Potential motility issue
- Lead point (a mass that precipitates the telescoping action)
- Mechels diverticulum
- Enlarged lymph nodes
- Intussusception can extend quite far –
even prolapse out of the rectum
when do you get oedema in intussusception
- As soon as the lymphatic and venous drainage is impaired you get oedema
- Enough oedema can impede arterial supply (infarction)
symptoms of intussusception
Symptoms
- Abdominal pain
- Vomiting
- Haematochezia- bright red blood passed PR
Treatment of intussusception
- Air enema- pressure can pop the bowel into the right place
- surgery
Large bowel obstruction
Typically affects
older people
common causes of large bowel obstruction
- Colon cancer – mechanical obstruction
- Diverticular disease (20%)- sigmoid colon
- Volvulus- sigmoid and caecal (5%)
symptoms of large bowel obstruction
Symptoms often appear gradually if caused by cancer but abrupt with volvulus
- Change in bowel habit (cancer)
- Abdominal distension
- Crampy abdominal pain
- Nausea/vomiting (later)
how would a large bowel obstruction look on a CT
- more peripheral
- can seehuastra which doesnt go the whole way across
- 3/6/9 rule
-3/6/9 rule
. The upper limit of 3 cm applies to the small intestinal loops, 6 cm for the colon and 9 cm for the cecum (blind intestine).
Volvulus
- Derived from latin ‘to twist’*
- Part of the colon twists around its mesentery
where are volvulus most common
- Most common is sigmoid colon (60%) and caecum (can technically be anywhere)
volvulus can result in
obstruction
obstruction of the sigmoid colon
- Can result from overloaded sigmoid colon (constipation)
- Extra mass elongates the sigmoid (relatively small mesenteric attachment)
- High fibre diet can also lead to sigmoid and twisting
- Results in large and small bowel obstruction
- Sign of sigmoidal volvulus
Coffee bean sign
Small vs large bowel obstruction
Age
*
- Small bowel obstruction more common in younger age group
- Large bowel obstruction in older age group
in bowel obstruction what is important
Competence of the ileo-caecal valve is of great importance
- If it is competent then the colon cannot decompress proximally
- Closed loop obstruction- ischaemia and perforation more likely
abdominal pain in small bowel obstruction
colicky 3-4 mins
abdominal pain in large bowel obstruction
colicky 10-15 mins
vomiting in small bowel obstruction
early
vomiting in large bowel obstruction
late
constipation in small bowel obstruction
late
constipation in large bowel obstruction
early
