Appendix Flashcards
What is the appendix?
Under-developed distal cecum
Located where tenia join at cecum
True diverticula - outpouch of the distal cecum
Most common location of Appendix?
McBurney’s point - RLQ
When does appendicitis most frequently occur? Age?
2nd and 3rd decades of life
Incidence highest in 10-19 year old age group
Male > Female
Pathogenesis of Appendicitis
Inflammation -> Ischemia -> Perforation -> Peritonitis/Abscess
-pts usually present BEFORE perf and abscess
Appendicitis pathogenesis related to what?
An obstructed process at the lumen of the appendix
- obstruction by fecolith, stricture, foreign body
- dietary factors (low fiber, highly refined CHO) - junk food
- bacterial proliferation
- obstruction by tumor
- infective trigger and seasonal variation
- lymphoid hyperplasia
What organisms are involved in gangrenous and perforated appendicitis?
E. Coli, Peptostrepto, B. Fragilis, and Pseudomonas
Common presentation of appendicitis
Periumbilical pain that moves to right iliac fossa pain
Colicky (waning) pain that changes to dull constant pain
Periumbilical pain -> 1 or 2 episodes of vomiting -> right iliac fossa pain
ALSO HAVE ANOREXIA AND NAUSEA PROGRESSION
Hx workup for appendicitis
- abd pain
- N/V
- low grade fever
- anorexia
- malaise
- diarrhea
Family hx and appendicitis
1/3 of children have a 1st degree relative with similar story
Appendicitis Physical Work-up
FEVER IS LOW GRADE
- McBurney’s Point Tenderness
- Rovsing’s sign
- Psoas Sign (RLQ pain with passive right hip extension)
- Obturator Sign
- Pointing Sign
Appendicitis Lab Workup
CBC w/diff
Electrolytes
LFT’s
Urinalysis
Appendicitis Imaging
Abd X-ray
U/S - let’s you know if inflammation at site of appendix
CT scan
Appendicitis Tx
- NOTHING BY MOUTH (NPO)
- TREATMENT IS SURGICAL (but have to prepare)
To prepare do IVF and IV Abx broad spectrum (3rd ceph or Gentamycin or Metro+Flagyl)
When do you NOT operate for Appendicitis?
Peritonitis
Presence of appendicular mass
Resolved - elective at a later time
IF NO SX’S DON’T OPERATE
What must you do before appendicitis surgery?
Need to stabilize pt - give IVF and broad spectrum Abx
Appendicitis/Appendectomy complications
- perforation
- abscess intro-abdominal
- fecal fistula
- DVT
- Hernia
Complications of surgery:
- bleeding
- wound infection (MOST COMMON)
- bowel injury
What is the most common complication of appendix surgery?
Wound infection
What is the blood supply of the small intestine?
Superior Mesenteric Artery
-source of blood supply for Duodenum, jejunum, ileum, cecum, ascending colon and proximal 2/3 transverse colon
Superior Mesenteric artery supplies what?
Duodenum, jejunum, ileum, cecum, ascending colon, and proximal 2/3 transverse colon
Signs of Small Bowel Obstruction
- Abd distention
- Tinkering bowel sounds
- possible bilious vomiting
- colicky central abd pain
Evidence of small bowel strangulation/ischemia or perforation
Peritonism and fever
When does a small bowel obstruction occur?
When the normal flow of intestinal contents is interrupted
what is the most common cause of SBO in the U.S.?
Postop adhesions
What is the most common cause of SBO in developing world?
Hernias
Other causes of SBO
Malignant tumors (primary and metastatic deposits)
Intussusception (bowel folds in on itself)
Volvulus (bowel twists)
Crohn’s disease
Gallstones (gallstone ileum) - can come out and cause SBO
What are the types of SBO?
Intraluminal (w/in the lumen)
Intramural
Extramural
Simple
Closed Loop
Strangulated
What causes intraluminal SBO?
- foreign bodies
- bezoars
- gallstones
- parasites
What causes intramural SBO?
Inflammation causes a stricture
Crohn’s
Intussusception
Volvulus
What causes extramural SBO?
Something on outside that may clamp down and cause SBO
- bands/adhesions
- hernia
What is a simple SBO?
Above the obstruction:
-peristalsis increases -> intestine dilates -> reduction in peristaltic strength -> flaccidity and paralysis
Below the obstruction:
-normal peristalsis and absorption until it becomes empty and it contracts and becomes immobile
Strangulated SBO
Leads to impaired venous return and increased congestion
Have impaired arterial blood supply
Free peritoneal fluid
Edema of the intestinal wall
Ischemia and gangrene
What is abdominal distention? What is the gas and fluids from?
Distention = the accumulation of GAS AND FLUIDS
Gas -> swallowed air, bacterial overgrowth, diffusion from blood
Fluids -> ingested fluids, saliva, gastric and intestinal juices, bile and pancreatic secretions
What does a distended abdomen sound like?
Tympanic
SBO hx of pt
- abd pain
- N/V
- no passage of flatus/stool
- prior surgery
- prior SBO
SBO PE signs
- abd distention
- abd tenderness
What will CBC w/diff be for SBO?
Elevated WBC suggests ischemia, lower Hgb and MCV could suggest tumor
What will Chem 7 look like for SBO?
- electrolyte losses, acute renal failure
- elevated LFTs
- amylase - pancreatitis w/ileus
What will ABG show for SBO?
Metabolic status of patient, evidence of intestinal ischemia
-metabolic acidosis is a LATE CHANGE
Lactate and SBO
Will be elevated if necrosis or perforation, but can be misleading and need to follow it
SBO and imaging
- abd x-ray
- CT SCAN WITH ORAL CONTRAST
SBO and CT scan contrast to use?
DO CT CAN WITH ORAL CONTRAST THAT IS WATER SOLUBLE ONLY!!!
What is CT scan w/contrast for SBO useful in identifying?
Useful in identifying pts with SBO that are unlikely to resolve with conservative measures
If the CT contrast fails to reach cecum by 4 hrs, what does that indicate?
Surgical intervention is likely necessary
After give contrast for CT scan for SBO imaging, when is surgery necessary?
When the contrast fails to reach the cecum by 4 hrs
Can the CT contrast for SBO be therapeutic?
Yes, in adhesional SBO due to osmolar effect
-can help adhesion and resolve the SBO
what are the indications for urgent surgery in SBO?
Evidence of strangulation:
- Peritonism
- Leukocytosis
Perforation
Irreducible hernia
SBO treatment
NPO - give bowel rest
IVF - IMPORTANT
Abx if have perf, sick, or going to OR
NGT - to evacuate the stomach
Surgery (lap procedures best)
NGT tx for SBO
To evacuate the stomach (not the jejunum)
Decreases nausea, vomiting, distention, aspiration
what does NGT tx for SBO decrease?
nausea, vomiting, distention, aspiration
when do you not take a pt to surgery for SBO?
- post-op
- carcinomatosis - little deposits of cancer and pts get a lot of SBOs
- recurrent SBO
- post-radiation
adhesion tx for SBO
conservative at first
volvulus tx for SBO
derotate and operate
abscess or peritonitis tx for SBO
drain and treat
mesenteric ischemia tx for SBO
operate (go to OR b/c have necrotic bowel now)
intussusception tx for SBO
Pneumatic or Barium reduction then OR
-Use air to help bowel unfold on itself
what is ileus? what do you hear on auscultation?
GUT HAS STOPPED MOVING
hear NO bowel sounds on auscultation
what do you start with when treating ileus?
Start with correction of underlying medical conditions, electrolytes, acid base abnormalities
what do most treatments of ileus involve?
watchful waiting with supportive treatment
what study may you need to do for ileus tx?
May need to do a contrast study to rule out any mechanical obstruction if not improving
what should you stop the use of when have ileus?
Discontinue any medication which slow the gut (ex: opiates)
what meds/what should be treated when have ileus?
Consider NSAIDs, treat pain, and reduce inflammation
Emesis and distention - use NGT for decompression
what is mesenteric ischemia?
Ischemia of the small bowel, usually secondary to an acute cause involving the SMA or SMV
what is ischemic colitis?
Ischemia of the colon, rarely with a known acute precipitating cause
what is the most common etiology of ischemic bowel disease?
SMA occlusion
-Embolism: MI, A-fib, Endocarditis, Valve d/o
-Thrombosis: Atherosclerosis – plaque rupture
ischemic bowel disease etiologies
SMA Occlusion
Nonocclusive Mesenteric Ischemia (NOMI)
Mesenteric Venous Thrombosis (MVT)
Nonocclusive Mesenteric Ischemia (NOMI)
cause of ischemic bowel disease
Atherosclerosis + shock + vasopressors
No blockage, just no blood flow to small bowel
Mesenteric Venous Thrombosis (MVT)
cause of ischemic bowel disease
Primary clotting disorder -> clot off mesenteric vein
what is the classical presentation of ischemic bowel disease?
Rapid onset of severe, unrelenting periumbilical pain
***Pain out of proportion to findings on physical exam
what is the imaging test of choice for ischemic bowel disease?
Mesenteric angiography – TEST OF CHOICE!!!
-Can identify the type of Acute Mesenteric Ischemia
ischemic bowel disease imaging
Plain films
-Thumb printing, thickened bowel (<40% sensitivity – not sensitive)
CT
-Thickened/dilated bowel, intramural hematoma, pneumatosis (64% sensitivity)
- **Mesenteric angiography – TEST OF CHOICE!!!
- Can identify the type of Acute Mesenteric Ischemia
ischemic bowel disease treatment
Resuscitation with fluids/blood products
Anticoagulation (If there’s a clot causing obstruction)
Infusion of a vasodilator (if trying to increase blood flow)
- Glucagon systemically OR
- Papverine through a catheter
infarcted bowel disease signs?
peritoneal signs, fever
infarcted bowel disease tx
EMERGENT LAPAROTOMY
- restore interrupted blood flow w/arteriotomy or bypass graft
- resection of infarcted bowel
- second look in 24-48hrs
- vasodilators and pressor use
what is the most frequent form of mesenteric ischemia?
ischemic colitis
what part of colon does ischemic colitis affect?
watershed areas
- rectosigmoid junction
- left colon (splenic flexure)
Not a lot of blood flow to these areas so any disruption even to one vessel could be catastrophic
ischemic colitis common in who?
elderly population
common presentation of ischemic colitis
LEFT SIDED PAIN OUT OF PROPORTION IN OLDER PATIENT
ischemic colitis etiologies
- Low-flow state (hypotension)
- Embolus (A-fib) – sets you up for clots
- Post MI (hypotension, mural thrombus)
- Post AAA reconstruction
- Closed loop construction – left side with intact ileocecal valve
- Volvulus
- Mesenteric Vein Thrombosis
what is the most common hx for a pt with ischemic colitis?
abdominal pain
what is dx of ischemic colitis based off of?
clinical setting
- PE
- Labs (r/o that it’s not from infectious cause)
ischemic colitis labs for dx
- Rule out that it’s not from infectious cause (entero or invasive bacteria)
- Stool cultures for suspected infectious cause
- Metabolic acidosis
- Elevated white count >20,000
what is the study for choice for ischemic colitis?
CT
- May be normal initially
- Thickening of bowel wall in segmental pattern and mesenteric stranding in area that is ischemic
- Pneumatosis and gas in mesenteric veins in advanced stages
ischemic colitis tx
Supportive
- IVR, bowel rest, empiric abx (mod-severe cases)
- NGT (ileus)
- hold meds that can promote ischemia (ex: clotting meds)
- optimize cardiac and pulmonary function
Laparotomy w/resection
what is toxic megacolon?
Total or segmental non-obstructive colonic dilatation plus systemic toxicity
-Grossly inflamed colon usually due to infection
BAD AND VERY RARE
toxic megacolon etiologies
- IBD – Crohn’s, UC
- Bacterial – C. Diff, Salmonella, Shigella, Campylobacter, Yersinia
- Parasitic – E. histolytica, Cryptosporidium
- Viral – CMV colitis
toxic megacolon pathogenesis
Mucosal inflammation leads sequentially to the release of inflammatory mediators and bacterial products, increased inducible nitric oxide synthase, generation of excessive nitric oxide, and colonic dilatation
Severe inflammation of the smooth muscle layer which paralyzes the colonic smooth muscle, thereby leading to dilatation
possible precipitating agents of toxic megacolon
- Hypokalemia
- Antimotility agents
- Opiates
- Anticholinergics
- Antidepressants
- Barium enema and colonoscopy
dx of toxic megacolon
Abdominal distention and acute or chronic diarrhea
Radiographic evidence of colonic distention with at least 3 of the following:
- Fever >38 C
- HR >120 beats/min
- WBC >10,500/microL
- Anemia
At least one of the following:
- Dehydration
- Altered sensorium
- Electrolyte disturbances
- Hypotension
toxic megacolon imaging
x-ray and CT scan
toxic megacolon labs
CBC, Chem 7, stool WBC and cultures including C. diff
what is the first line tx of toxic megacolon?
Non-operative
what is the non-operative tx of toxic megacolon?
- Includes fluid resuscitation
- Correction of lab abnormalities
- Antibiotics broad spectrum for IBD (Vanco and Flagyl for C Diff)
- Intravenous corticosteroids (IBD)
- NPO
- Bowel decompression with a NGT if needed
who is surgery reserved for, for treatment of toxic megacolon?
Surgery reserved for patient who don’t improve on non-operative management
what is the surgery of choice for toxic megacolon?
subtotal colectomy with end-ileostomy (up to 50% mortality)
what is the 4th leading cause of cancer mortality? most common in? age?
pancreatic cancer
M>F
rarely seen before age 45
pancreatic cancer risk factors
- Chronic pancreatitis (a lot of insult to the pancreas)
- Smoking
- Diabetes mellitus
- Family history
pancreatic cancer pt hx
Jaundice – tumors in the head of the pancreas
Weight loss
Pain – tumors in body and tail of the pancreas
(If tumor in head, no complaints of pain – JUST JAUNDICE)
Recent onset of atypical DM
pt with jaundice has tumor where in pancreas?
head of the pancreas
pt with pain has tumor where in pancreas?
body and tail of the pancreas
pancreatic cancer physical exam
Palpable mass/Ascites late in disease
Courvoisier’s sign (non-tender palpable gallbladder with jaundice)
what is Courvoisier’s sign?
sign for pancreatic cancer
-non-tender palpable gallbladder with jaundice
pancreatic cancer labs
LFTs and cancer antigen 19-9 test
pancreatic cancer imaging
- CT scan
- MRI
- Ultrasound
- EUS (endoscopic ultrasound)
what is the treatment of choice for pancreatic cancer?
SURGERY - ONLY CURATIVE APPROACH
done for stage I-IIB
types of surgery of pancreatic cancer
Whipple (tumor in head)
Distal pancreatectomy (tumor in body or tail)
what is the most common pathology of pancreatic cancer?
ductal adenocarcinoma
at the time of dx of pancreatic cancer, what as occurred?
metastasis to peripancreatic lymph nodes
common places of pancreatic cancer metastasis?
Metastases to the liver (up to 80%), peritoneum (60%), lungs and pleura (50-70%), and adrenal glands (25%)
can you resect pancreatic tumor after stage IIb?
no!!!
benign pancreatic tumors
Serous cystadenoma -> cured by surgical removal alone
premalignant pancreatic lesions
Intraductal papillary-mucinous neoplasms (IPMN)
Mucinous Cystadenoma
-Remove them, not cancer, but high likelihood that will become malignant
endocrine tumors of pancreas
- Gastrinoma
- Insulinoma
- VIPoma
- Glucagonoma
- Somatostatinomas
