GI Flashcards
test 4
1
Q
GI tract is ___% of total body mass
A
5%
2
Q
What are the main functions of the GI tract? (5)
A
-motility
-digestion
-absorption
-excretion
-circulation
3
Q
What are the layers of the GI tract? outer –> inner
A
Serosa (most outer)
Longitudinal muscle layer
Circular muscle layer
submucosa
mucosa (most inner)
4
Q
What are the layers of the mucosa layer of the GI tract? outer –> inner
What do they do?
A
Muscularis Mucosae (outer): move the villi
Lamina propria (middle): contains blood vessels, nerve, endings, and immune cells
Epithelium (inner): GI contents are sensed, enzymes are secreted, and nutrients are absorbed
5
Q
Which two layers of the GI tract propagate gut motility? How?
A
Longitudinal muscle layer: contracts to shorten the length
Circular muscular layer: contracts to decrease the diameter
6
Q
The GI tract is innovated by the ________ nervous system. What does this include?
A
autonomic
Includes:
-Extrinsic nervous system (SNS & PNS)
-Enteric nervous system: independent nervous system –> controls, motility, secretions, and blood flow
7
Q
The enteric nervous system contains the _____ & ______ plexuses. Describe them
A
myenteric:
-Lies between smooth muscle layers
-regulates the smooth muscle
-controlled motility (by enteric neurons & cells of Cajal)
submucosal:
Transmit info from the epithelium to the enteric and central nervous system
-controls, absorption, secretion, mucosal blood flow
both respond to SNS & PNS
8
Q
What does the Celiac Plexus innervate?
A
Proximal GI organs to the transverse colon
9
Q
What does the hypogastric plexus innervate?
A
Descending colon & distal GI tract
10
Q
What are the ways you can block the celiac plexus? (4)
A
-Trans-crural
-intraoperative
-endoscopic ultrasound guided
-peritoneal lavage
11
Q
GI Procedures: Upper GI endoscopy
A
Endoscope placed thru esophagus –> stomach –> pylorus –> duodenum
challenges: sharing airway w/ endo
-done w/o ETT
-performed outside of main OR (limited equipment/supplies)
12
Q
GI Procedures: Colonoscopy
A
Done w or w/o anesthesia
challenges: pt dehydrated from bowel prep and NPO
13
Q
GI Procedures: High resolution manometry (HRM)
A
Pressure catheter measures pressures along entire esophageal length
Used to diagnose motility disorders
14
Q
GI Procedures: Barium swallow
A
Assessment of swallowing function & GI transit
15
Q
GI Procedures: gastric emptying study
A
Fast for 4+ hours –> consumes meal with radio tracer –> freq imaging done for 1-2 hours
16
Q
GI Procedures: small intestine Manometry
A
Catheter measures contraction, pressures, and motility of the small intestine
Evaluate contractions during three period periods: fasting, during a meal, and post meal
17
Q
GI Procedures: lower GI series
A
Barium enema, outlines the intestines and is visible on radiograph
detects colon/rectal abnormalities
18
Q
What the different esophageal groups? (3) What is included in them.
A
Anatomical: diverticula, hiatal hernia, and changes associated with chronic acid reflux
Mechanical: achalasia, esophageal spasms, hypertensive LES
Neurologic: stroke, vagotomy, hormone deficiencies
19
Q
What are the most common symptoms of esophageal disease?
A
Dysphagia (difficulty swallowing)
-heartburn
-GERD
20
Q
What are the different types of dysphagia?
A
Oropharyngeal: common after head/neck surgery
Esophageal: based on physiology
-esophageal dysmotility: occurs when/ both liquids & solids
-mechanical esophageal dysphasia: occurs w/ solid food only
21
Q
What are the signs of GERD?
A
Gastroesophageal reflux disease
effortless return of gastric contents into pharynx
Symptoms: heartburn
Nausea
“lump in throat”
22
Q
Describe Achalasia
A
Neuromuscular disorder of the esophagus
Outflow obstruction dt in adequate LES tone and a dilated hypomobile esophagus –> food unable to move forward
Symptoms: dysphagia, regurgitation, heartburn, chest pain
Dx: esophageal manometry or esophagram
23
Q
Long-term Achalasia is associated with an increased risk of ________
A
Esophageal cancer
24
Q
What are the 3 classes of Achalasia? Describe them.
A
Type 1: minimal esophageal pressure; responds well to myotomy
Type 2: entire esophagus pressurized; respond well to treatment, has best outcomes
Type 3: esophageal spasms with premature contractions; has worse outcomes
25
What is the Tx for Achalasia?
**All Tx is palliative**
Meds: Nitrates, CCB <-- relaxes LES
Endoscopic botox injections
**Pneumatic dilation** most effective non Sx Tx
**Laprascopic Heller Myotomy** best Sx Tx
Esophagectomy -- advanced cases
26
What considerations should we have with all esophageal diseases?
Increased risk of aspiration
RSI or awake intubation
27
Describe Esophageal Spasms.
Spasms in distal esophagus dt autonomic dysfunction
Dx: on esophagram
Symptoms: mimics angina
Tx: NTG, Antidepressants, PDI
28
Describe Esophageal Diverticula and their types
Outpouching in the wall of the Esophagus
Pharyngoesphageal (Zenker): bad breath dt food retention
Midesophageal: caused by old adhesions or inflamed lymph nodes
Epiphrenic: may experience achalasia
29
Describe Hiatal hernia
Herniation of stomach into thoracic cavity thru Esophageal hiatus in diaphragm
Symtomps: asymptomatic; associated with/ GERD
30
Describe Esophageal cancer
Symptoms: **progressive dysphagia & weight loss**
Most are adenocarcinomas -- in lower Esophagus
Squamous cell carcinoma -- are remainder
Tx: Esophagectomy (curative or palliative) -- high risk of recurrent laryngeal nerve injury
31
Describe GERD & 3 mechanisms of incompetence
Incompetence of the gastro-esophageal junction --> reflux
mechanisms of incompetence
1. Transient LES relaxation --> gastric distention
2. LES hypotension (normal 29, GERD 13)
3. Autonomic dysfunction of GE junction
symptoms: heartburn, dysphagia, mucosal injury
**Associated w/ Barret metaplasia & adenocarcinoma**
Tx: Avoid trigger foods
Meds: antacids, H2 blockers, PPIs, Reglan
Sx: Nissen Fundoplication, Toupet, LINX
32
What does reflux contents include?
HCL
Pepsin
Pancreatic enzymes
bile
33
What Preop interventions should we have w GERD?
34
What factors increase intraop aspiration
Emergent Sx
Full stomach
Diff airway
Inadequate anesthesia depth
Lithotomy
Autonomic Neuropathy
Gastroparesis
DM
Pregnancy
Increased intraabdominal pressure
Sever illness
morbid obesity
35
Food is broken down into _____ and must be ____mm particles before entering into the _________
chyme
1-2 mm
duodenum
36
How does neurohormonal control modulate GI movement?
Gastrin & motilin: increase strength/freq on contractions
Gastric inhibitory peptide: inhibits contractions
37
Describe Pepic Ulcer Disease
**Most common cause of nonvariceal upper GI bleed**
**associated w/ Helicobacter Pylori**
symptoms: burning epigastric pain **exacerbated w/ fasting (no food) & improved w/ meals**
Perforations signs: severe pain dt secretions in peritoneum --> mortality dt shock >48h
38
Describe Gastric Outlet Obstruction
Acute or chronic
Acute: dt edema & inflammation inpyloric channel at beginning of duodenum
symptoms: vomitting, dehydration, hyperchloremic alkalosis
Tx: NTG, IVF (resolves w/i 72h)
Chronic: dt repetitive ulceration & scarring
39
What is the triple therapy Tx for H. Pylori?
2 abx + PPI for 14 days
40
Describe Zollinger Ellison Syndrome
Non B cell pancreatic tumor --> gastrin hypersecretion
(Normally gastric acid neg feedback loop to inhibit excess gastrin secretion, but that is absent)
symptoms: peptic ulcer disease, erosive esophagitis, diarrhea
Male>female
30-50yo
Tx: PPI
Sx: Resection of gastrinoma
Considerations: correction electrolytes, increase gastric pH, RSI
41
Describe the small intestines
Mixes nutrients with/ digestive enzymes --> reducing particle size & increasing solubility
circulates contents & exposes them to the mucosal wall to maximize absorption
Segmentation controlled by enteric NS
Motility controlled by extrinsic NS
42
What are reverible causes of small bowel dysmotility?
Mechanical obstruction: hernias, malignancy, adhesions, volvuluses
Bacterial overgrowth --> alteration in absorption
Ileus, electrolyte abnormalities, critical illness
43
What are nonreverible causes of small bowel dysmotility?
Structural: Scleroderma, connective tissue disorder, IBD
Neuropathic: pseudo-obstruction dt extrinsic NS dysfunction
44
Describe the large intestine
Reservoir for waste & indigestible material before elimination
Extracts remaining electrolytes & water
Exhibits **giant migrating complexes** movements in a healthy person **6-10x daily**
45
What are the 2 primary symptoms of large intestine dysmotility?
altered bowel habits
intermittent cramping
46
What are the most common large intestine dymotility diseases?
IBD
IBS
47
Describe IBD
Inflammatory Bowel Disease
Contractions are suppressed dt inflammation but giant migrating complexes remain the same --> compresses infamed mucosa --> erosions & hemorrhage
Seen in Ulcerative Colitis & Crohns
48
Describe UC
Ulcerative Colitis
Mucosal disease or part of all/part of colon
Severe cases: hemorrhagic, edematous, ulcerated
symptoms: diarrhea, rectal bleeding, crampy abd pain, N/V, fever, wt loss
Labs: increases platelets, increased ery. sed. rate, decreased H/H, decreased albumin
**Hemorrhage requiring 6u of blood in 24/48hr = sx colectomy**
**Toxic Megacolon**: triggered by electrolyte disturbances
-colon perforation dangerous complication
49
Describe Crohn's Disease
Acute/Chronic
Can affect all/part of bowel
Presistent inflammation--> fibrosis --> narrowing & stricture formation
**Most common site = terminal ileum** --> RUQ pain
Symptoms: wt loss, fear of eating, anorexia, diarrhea --> diarrhea decreases, chronic bowel obstruction
(1/3 pts: arthritis, dermatitis, kidney stones)
obstruction & inflammation --> loss of absorption surfaces --> malabsorption
50
What is Tx for IBD?
Medical: **5-Acetylsalicyclic acid (5-ASA)** - main drug abx/afx
-Glucorticoids
-Abs: Rifaximin, Flagyl,, Cipro
-Purine analogues
Sx: Last resort
-Resection
**-small intestine limited to <1/2 length
-more than this leads to "short bowel syndrome" requiring TPN**
51
Most Carcinoid tumors originate in the _______. What do they secrete?
GI tract
Peptides & vasoactive substances: gastrin, insulin, somatostatin, motilin, neurotensin, tachykinins, glucagon, serotonin
52
Describe Carinoid syndrome
Occurs in 10% of ppl w/ carcinoid tumors
symptoms: flushing, diarrhea, HTN/HoTN, bronchoconstriction, R heart endocardial fibrosis (L heart more protected dt lungs clearing some substances)
Dx: urinary/plasma serotonin levels
CT, MRI
Tx: avoid serotonin
serotonin antagonists
somatostatin analogues
**Preop: OCETROTIDE**
53
Describe Acute Pancreatitis
Inflammatory disorder
Common causes: Gallstones & alcoholism
-also seen in immunodeficient syndrome, hyperparathyroidism, increased Ca++
symptoms: **excruciating epigastric pain --radiates to back**, N/V, abd distention, steatorrhea, ileus, fever, tachycardia, hypotension
**Hallmark labs: increased serum amylase & lipase**
Dx: contrast CT, MRI, endoscopic US
Tx: aggressive IVF, **NPO** to rest pancreas, enteral feeding, opioids
Sx: ERCP
Complications: 25% pts -- shock, ARDS, RF, necrotic pancreatic abscess
54
What prevents autodigestion of pancreas?
Proteases packages in precursors form
-Protease inhibitors
-Low intra-pancreatic calcium, which decreases trypsin activity
**failure of any of these mechanisms can trigger pancreatitis**
55
Describe Upper GI bleeds
More common than lower GI bleeds
>25% blood loss --> hypotension & tachycardia
Orthostatic hypotension = HCT <30%
Melena = bleed above cecum
Dx: EDG
Tx: Mechanical balloon tamponade last resort of uncontrolled variceal bleeding
56
Describe Lower GI bleeds
More commin in elderly
Causes: diverticulosis, tumors, colitis
Dx: Sigmoidoscopy, colonoscopy
Tx: presistent bleeding = angiography w/ embolic therapy
57
Describe an Ileus
Loss of peristalsis --> massive dilation/distention of colon
(no mechanical obstruction)
Causes: electrolyte disorder, immobility, excessive narcotics, anticholinergics
Tx: Restore electrolyte balance, hydrate, mobilize, NG suction, enemas
Meds: Neostigmine 2-2.5 mg over 5 mins --> immediate results (requires cardiac monitoring)
Untreated --> ischemia or perforation
58
What are anesthesia considerations for bowel diseases?
Higher anxiety = GI inhibition
Volatile agents inhibit GI function & motility
Dont use nitrous in abd Sx or when bowel is distended
Neostigmine will increase PNS activity
-Sugammadex has no affect on GI motility
Opioids that work on the mu receptor --> delays gastric emptying & glower GI transit (constipation)
59
What are the main functions of the GI tract?
Motility, digestion, absorption, excretion, and circulation
60
List the layers of the GI tract from outermost to innermost.
* Serosa
* Longitudinal muscle layer
* Circular muscle layer
* Submucosa
* Mucosa
61
What is the role of the longitudinal muscle layer in the GI tract?
Contracts to shorten the length of the intestinal segment
62
What is the role of the circular muscle layer in the GI tract?
Contracts to decrease the diameter of the intestinal lumen
63
What does the mucosa of the GI tract consist of?
* Muscularis mucosa
* Lamina propria
* Epithelium
64
What types of nervous systems innervate the GI tract?
* Extrinsic nervous system (SNS & PNS components)
* Enteric nervous system
65
What is the primary role of the celiac plexus?
Innervates the proximal GI organs to the transverse colon
66
What is the function of the myenteric plexus?
Regulates smooth muscle activity
67
What does the submucosal plexus control?
Absorption, secretion, and mucosal blood flow
68
True or False: The extrinsic SNS primarily activates GI motility.
False
69
What is an upper gastrointestinal endoscopy used for?
Diagnostic or therapeutic purposes
70
What is the primary symptom of achalasia?
Dysphagia
71
What are the three classes of achalasia?
* Type 1: minimal esophageal pressure
* Type 2: entire esophagus pressurized
* Type 3: esophageal spasms with premature contractions
72
Fill in the blank: The most common cause of non-variceal upper GI bleeding is _______.
Peptic Ulcer Disease
73
What is Zollinger Ellison Syndrome?
A non-B cell pancreatic tumor causing gastrin hypersecretion
74
What are common symptoms of gastroesophageal reflux disease (GERD)?
* Heartburn
* Dysphagia
* Mucosal injury
75
What is the treatment for GERD?
* Avoidance of trigger foods
* Antacids, H2 blockers, PPIs
* Surgical options like Nissen Fundoplication
76
What is the major function of the small intestine?
To circulate contents and maximize absorption
77
What are reversible causes of small bowel dysmotility?
* Mechanical obstruction
* Bacterial overgrowth
* Ileus
* Electrolyte abnormalities
* Critical illness
78
What is the primary role of the large intestine?
Acts as a reservoir for waste and extracts remaining electrolytes and water
79
What is inflammatory bowel disease (IBD)?
The second most common inflammatory disorder after rheumatoid arthritis
80
What is the most common symptom of esophageal disease?
Dysphagia
81
What are the three mechanisms of gastroesophageal incompetence in GERD?
* Transient LES relaxation
* LES hypotension
* Autonomic dysfunction of GE junction
82
What is the role of gastrin in the GI system?
Stimulates gastric acid secretion
83
What are the symptoms of achalasia?
* Dysphagia
* Regurgitation
* Heartburn
* Chest pain
84
What is the treatment for esophageal spasms?
* Nitroglycerin
* Antidepressants
* PDE inhibitors
85
What is the common presentation of esophageal cancer?
* Progressive dysphagia
* Weight loss
86
What is the lifetime prevalence of peptic ulcer disease?
10% in women, 12% in men
87
What are the symptoms of gastric outlet obstruction?
* Recurrent vomiting
* Dehydration
* Hyperchloremic alkalosis
88
What is the most common cause of gastric ulcers?
Excessive NSAIDs, H. Pylori, and alcohol
89
What is the role of the colon in digestion?
Acts as a reservoir for waste and extracts electrolytes and water
90
What are the symptoms associated with colonic dysmotility?
* Altered bowel habits
* Intermittent cramping
91
What are the two types of colonic dysmotility diseases?
* Irritable Bowel Syndrome (IBS)
* Inflammatory Bowel Disease (IBD)
92
What is the primary symptom of colonic dysmotility?
Altered bowel habits and/or intermittent cramping
93
What are the most common diseases associated with colonic dysmotility?
* IBS
* IBD
94
What occurs in Inflammatory Bowel Disease (IBD) regarding contractions?
Contractions are suppressed due to inflammation, but the giant migrating complexes remain
95
What can increased frequency of giant migrating complexes lead to in IBD?
Significant erosions and hemorrhage
96
What is IBD's rank among inflammatory disorders?
2nd most common inflammatory disorder (after RA)
97
What are the two main types of Inflammatory Bowel Disease?
* Ulcerative Colitis
* Crohn's Disease
98
What is a common symptom of Ulcerative Colitis?
* Diarrhea
* Rectal bleeding
* Crampy abdominal pain
* N/V
* Fever
* Weight loss
99
What laboratory findings may be present in Ulcerative Colitis?
* ↑ platelets
* ↑ erythrocyte sedimentation rate
* ↓ H&H
* ↓ albumin
100
What complication of Ulcerative Colitis may require surgical colectomy?
Hemorrhage requiring 6+ units of blood in 24-48 hours
101
What is Toxic Megacolon?
A complication triggered by electrolyte disturbances
102
What is a dangerous complication of Crohn's Disease?
Colon perforation with a mortality rate of 15%
103
What is the most common site affected by Crohn's Disease?
Terminal ileum
104
What are common symptoms of Crohn's Disease?
* Weight loss
* Fear of eating
* Anorexia
* Diarrhea
105
What is the mainstay medical treatment for IBD?
5-Acetylsalicylic acid (5-ASA)
106
What are the surgical considerations for treating IBD?
* Resected segment should be as conservative as possible
* Small intestine resection should be limited to <1/2 length
107
What is the risk of >2/3 small intestine resection?
Short bowel syndrome, requiring TPN
108
Where do most carcinoid tumors originate?
GI tract
109
What is Carcinoid Syndrome?
Occurs in 10% of patients with carcinoid tumors, leading to large amounts of serotonin and vasoactive substances in systemic circulation
110
What are symptoms of Carcinoid Syndrome?
* Flushing
* Diarrhea
* Hypertension/Hypotension
* Bronchoconstriction
111
What is the primary treatment for Carcinoid Syndrome?
Avoid serotonin triggers and use serotonin antagonists & somatostatin analogues
112
What is the hallmark symptom of Acute Pancreatitis?
Excruciating epigastric pain that radiates to back
113
What are common causes of Acute Pancreatitis?
* Gallstones
* Alcohol abuse
114
What laboratory findings are indicative of Acute Pancreatitis?
* ↑ serum amylase
* ↑ lipase
115
What imaging techniques are used for diagnosing Acute Pancreatitis?
* Contrast CT
* MRI
* Endoscopic US (EUS)
116
What is the treatment for Acute Pancreatitis?
* Aggressive IVF
* NPO to rest pancreas
* Enteral feeding (preferred over TPN)
* Opioids
117
What is the most common type of GI bleeding?
Upper GI bleeding
118
What indicates a significant blood loss in GI bleeding?
>25% blood loss will lead to hypotension and tachycardia
119
What does melena indicate?
Bleed is above the cecum
120
What is the preferred diagnostic procedure for upper GI bleeding?
EGD
121
What characterizes an ileus?
Massive dilation of the colon without mechanical obstruction
122
What are some causes of ileus?
* Electrolyte disorders
* Immobility
* Excessive narcotics
* Anticholinergics
123
What is the treatment for ileus?
* Restore electrolyte balance
* Hydrate
* Mobilize
* NG suction
* Enemas
124
What are the main functions of the GI tract?
* Motility
* Digestion
* Absorption
* Excretion
* Circulation
125
What are the layers of the GI tract wall from outermost to innermost?
* Serosa
* Longitudinal muscle
* Circular muscle
* Submucosa
* Mucosa
126
What systems innervate the GI tract?
The autonomic nervous system, which includes SNS and PNS
127
What is the effect of volatile anesthetics on GI activity?
Depresses electrical, contractile, and propulsive GI activity
128
What is the effect of nitrous oxide on the GI system?
Diffuses into gas-containing cavities faster than nitrogen can diffuse out
129
What are the effects of opioids on GI motility?
Reduced GI motility and constipation
130
What increases PNS activity and bowel peristalsis?
Neostigmine (AchE-I)
