Intro to GI Flashcards
Layers of the GI Tract
- Innermost mucosa: provides a barrier against foreign particles, captures them in its sticky mucus and clears them out
- Submucosa: supports the mucosa, as well as joins the mucosa to the bulk of underlying smooth muscle
- Muscularis: propel food through the gut by contractile peristaltic waves initiated and regulated by various neural and hormonal events
- Serosa: carries blood vessels and nerves to the wall of the digestive tube
Hepatobiliary Tree/Biliary System
a system of vessels that directs these secretions from the liver, gallbladder and pancreas through a series of ducts into the duodenum
Hepatic duct for bile secretion to gallbladder, and joins with pancreatic duct which both empty into duodenum of small intestine
3 Arteries that support GI
- Celiac
- Hepatic
- Superior Mesenteric
- Inferior Mesenteric
What does the celiac artery supply?
Stomach, spleen, pancreas
What does the superior mesenteric artery supply?
Pancreas, small intestine, colon
What does the inferior mesenteric artery supply?
colon
How is blood returned to the heart from GI circulation?
All drained into portal vein, filtered in the liver, leave liver via hepativ veins to IVC
6 Functions of GI Tract
- Ingestion and propulsion of food
- Secretion of mucous, water, enzymes
- Digestion of food to meet body’s nutritional requirements
- Absorption of nutrients into the blood stream
- Motility
- Elimination of waste products
Stomach role
Storage and digestion of food
Gallbladder role
Stores bile for fat digestion
Liver role
Over 400 functions: Produces bile
Pancreas role
Production of insulin, secretes enzymes for CHO, protein digestion
Spleen role
Production RBC, storage antibodies
Small intestine role
Movement, digestion, absorption (nutrients, lytes, water)
Large intestine role
Movement, absorption (water), elimination
When would you not engage in light palpation during a GI assessment?
when you do not want to precipitate rupture: AAA (auscultate bruit, pulsatile bulge), appendicitis
Kehr’s Sign
Referred pain in left shoulder
Classic sign of spleen hemorrhage causing intraperitoneal bleeding
progressive onset – reassessment important
Cullen’s Sign
Periumbilical ecchymosis
Intraperitoneal bleeding
progressive onset – reassessment important
Grey Turner’s Sign
Bruising to flank
Retroperitoneal bleeding
progressive onset – reassessment important
Why is CBC important in GI diagnostics?
infection, active/chronic bleeding
Why are coagulation studies important in GI diagnostics?
function of liver is to produce vitamin K; shows functional ability
Why are electrolyte studies important in GI diagnostics?
disturbances common in GI issues; low calcium = absorption issue
Why are BUN/creatinine studies important in GI diagnostics?
alterations with water absorption; if GI unable to retain (diarrhea) can end up with prerenal AKI
Why are H Pylori Studies important in GI diagnostics?
leading cause of peptic ulcer disease
What is an MRI/MRCP?
magnetic resonance cholangiopancreatography (gallbladder and pancreas specific)
What is an endoscopy used for?
used to visualize interior of hollow organs
* EGD (Esophagogastroduodenoscopy)
* ERCP (Endoscopic retrograde cholangiopancreatography – to see and remove gallstone)
* Small bowel endoscopy
* Colonoscopy
* Sigmoidoscopy
What is a barium swallow used for?
assess aspiration risk, any issue from mouth/esophagus (strictures)
6 Priorities of GI System
- Pain
- Impaired nutrition
- Hypovolemia
- Constipation/diarrhea
- Electrolyte imbalances
- Infection
Defense Mechanisms due to lack of sterility of GI system
- Saliva
- Gastric acid
- Mucosa: Goblet cells and tight epithelial junctions
- Peristalsis
- Normal flora (aka friendly bacteria)
Key to remember about sterility of GI
the peritoneum IS sterile
Because of this, any relationship the GI organs have with the peritoneum is dangerous = peritonitis = infection / sepsis
Intestinal fistula defintion, result, and management
when small intestine communicates with any other organ
Decreased nutrient absorption, less digested food – doesn’t stay in track as long as it should
Management:
* Control fluid and electrolytes: decreased absorption
* Skin integrity: r/t nutrient deficiency and surgery
* Facilitate wound healing: r/t nutrient deficiency and surgery
Abscess definition and management
enclosed pocket of infection
Management= antibiotics (broad)
* Cover anaerobes, gram +ve and
* gram –ve
* Prevent growth, rupture, merging with another organ (especially peritoneal space – sterile), sepsis
Peptic Ulcer Disease Causes and Definition
Erosion of mucosa in the stomach or duodenum as the result of increased mucosal injurious substances (acid and toxins) and lack of gastroprotective factors (mucous, blood flow, epithelial cells, prostaglandins)
Causes: H. Pylori, NSAID Use, Ischemia
Treatment of PUD
- Antibiotics
- PPI
- H2 Antagonist
- Bismuth Subsalicylate
- Sucralfate
- Antacids
- Avoid alcohol/tpbacco
- Sx if severe bleeds
What Occults Blood Indicates
Not readily visible – needs a stool sample lab test
What Hematemesis Indicates
Bright red or “coffee grounds” emesis. – upper GI bleed
What melena indicates
Black tarry foul smelling. Upper GI bleed; black because it has travelled whole system
What hematochezia indicates
Bright red or maroon “BRBPR – bright red blood per rectum ”. Lower GI bleed
Management of Acute GI Bleeds
Remember your ABC’s!
Assess what is going on and severity of blood loss
Resuscitate – hemodynamic instability becomes priority!
The Patient May Need:
* Oxygen
* Crystalloid volume resuscitation
* Vasosconstricting drugs for substantial bleed (vasopressin)
* Blood Transfusions for substantial bleed
* Correcting of the underlying problem; surgical
What is a small bowel obstruction?
Mechanical or non-mechanical occlusion of the lumen
* Paralytic Ileus: Loss of intestinal peristalsis (complication of surgery, opioids, electrolyte disturbances); non mechanical obstruction
Gas, fluid, food, etc. will accumulate proximal to the occlusion
Alterations in fluid balance, including third-spacing into the peritoneum
May lead to hypovolemia
Cues of small bowel obstruction
Abdominal distention/rigidity, vomiting, fluid loss, tenderness/pain
* Elevated BUN, Hct, increased osmolality as fluid shifts into the peritoneum (dehydration)
* Electrolyte imbalances
* Xray, CT, ultrasound
Taking action for small bowel obstruction/ileus
IV fluids and symptom therapy
NPO; no point in putting things in when it cannot be absorbed
Fluid and electrolyte replacement
NG tube (to decompress if backed up)– not routine*
Support nutrition parenterally
