GI Disorders - Exam IV Flashcards
1
Q
The GI tract constitutes ____ of the total human body mass
A
5%
2
Q
What are the main functions of the GI tract?
A
- motility
- digestion
- absorption
- excretion
- circulation
3
Q
Outermost to innermost layers of the GI tract
A
serosa - longitudinal muscle layer - circular muscle layer - submucosa - mucosa
4
Q
Mucosa layers (outermost to innermost)
A
muscarlis mucosae, lamina propria, epithelium
5
Q
The ____ is a smooth membrane of thin connective tissue and cells.
What does it do?
A
Serosa - it secrets serous fluid to enclose the cavity and reduce friction b/w muscle movements
6
Q
The ____ ____ ____ contracts to shorten the length of the intestinal segment.
A
longitudinal muscle layer
7
Q
The ____ ____ ____ contracts to decrease the diameter of the intestinal lumen.
A
Circular muscle layer
8
Q
What 2 layers work together to propagate gut motility?
A
- longitudinal muscle layer
- circular muscle layer
9
Q
Innervation of the GI organs up to the proximal transverse colon are supplied by the ____.
A
Celiac Plexus
10
Q
Innervation of the descending colon & distal GI tract comes from the ____ ____ ____.
A
Inferior hypogastric plexus
11
Q
How can the celiac plexus be blocked?
A
- transcrural
- intraoperative
- endoscopic ultrasound-guided
- peritoneal lavage
12
Q
The ____ ____ lies b/w the smooth muscle layers.
What does it do?
A
Myenteric plexus - it regulates the smooth muscle
13
Q
The submucosal plexus transmits information from the ____ to the ____ & ____.
A
Epithelium
Enteric
Central Nervous Systems
14
Q
What is the muscalaris mucosa & what does it do?
A
A thin layer of smooth muscle in the mucosa of the GI tract
Functions to move the villi.
15
Q
What is the lamina propria? What does it contain?
A
The middle layer of the mucosa of the GI tract.
It contains blood vessels & nerve endings.
16
Q
True or False - there are immune & inflammatory cells in the mucosa of the GI tract.
A
True
17
Q
What happens in the epithelium of the GI mucosa?
A
- where the GI contents are sensed
- enzymes are secreted
- nutrients are absorbed
- waste is excreted
18
Q
What is the GI tract innervated by?
A
Autonomic nervous system
19
Q
The extrinsic nervous system has ____ & ____ components.
A
SNS & PNS
20
Q
The extrinsic SNS is primarily ____ & ____ GI motility
A
inhibitory & decreases
21
Q
The extrinsic PNS is primarily ____ & ____ GI motility.
A
excitatory & activates
22
Q
What is the independent nervous system in the GI tract?
What does it control?
A
Enteric Nervous System
Controls motility, secretion, & blood flow
23
Q
The enteric system is comprised of the ____ ____ & ____ ____.
A
Myenteric Plexus & Submucosal Plexus
24
Q
What does the myenteric plexus control? How is it carried out?
A
Controls motility
carried out by:
* enteric neurons
* interstitial cells of Cajal (aka ICC cells, GI pacemakers)
* smooth muscle cells
25
What does the submucosal plexus of the enteric nervous system control?
absorption, secretion, & mucosal blood flow
26
What do the myenteric plexus & submucosal plexus respond to?
Sympathetic and parasympathetic stimulation
27
Upper GI Endoscopy
* May be diagnostic or therapeutic
* Endoscope placed into esophagus, stomach, pylorus, and duodenum
* done w/ or w/o anesthesia
27
Anesthesia challenges with upper GI endoscopy
1. sharing airway w/ endoscopist
2. procedure performed outside of the main OR - don't have all the bells & whistles
28
Colonoscopy
* may be diagnostic or therapeutic
* w/ or w/o anesthesia (rare)
29
Anesthesia Challenges w/ Colonoscopy
* pt dehydration d/t bowel prep & NPO status
* renal & CHF pts can be problematic when they are dry
* MAC (monitored anesthesia care) - BP drops w/ propofol
30
High Resolution Manometry (HRM)
* pressure catheter measures pressure along the entire esophageal length
* used to Dx motility disorders
* anti-reflux procedures
31
GI series w/ ingested Barium
* radiologic assessment of swallowing function
* GI transit
* series of pictures taken under fluoroscopy
32
Gastric emptying study
* pt fasts for at least 4 hours
* consumes a meal (eggs) w/ a radiotracer dye in it
* used to dx gastroparesis/problems emptying the stomach
33
Small Intestine manometry
* catheter measures contraction pressures & motility of small intestine
* evaluates contractions during 3 periods:
(fasting, during a meal, post-prandial)
* recording time: 4hrs fasting, ingestion of meal, 2hrs post-meal
* abnormal results grouped into myopathic or neuropathic causes
34
Lower GI series
* involves the admin of a barium enema
* barium outlines the intestines & is visible on radiograph
* allows for detection of colon & rectal abnormalities
35
Examples of anatomical causes of esophageal disease:
What do they interrupt?
1. diverticula
2. hiatal hernia
3. changes associated w/ chronic acid reflux
* they interrupt the normal pathway of food & change pressure zones of esophagus
36
Examples of mechanical causes of esophageal disease
1. achalasia
2. esophageal spasms
3. Hypertensive LES (lower esophageal sphincter)
37
Examples of neurological causes of esophageal disease
1. stroke
2. vagotomy
3. hormone deficiencies
38
Most common Sx of Esophageal Disease
1. dysphagia
2. heartburn
3. GERD
39
Dysphagia
Difficulty swallowing
2 types
40
Oropharnygeal dysphagia
common after head & neck surgeries
41
Esophageal Dysphagia - 2 types
Classified based on physiology
* esophageal dysmotility: sx occur w/ both liquids & solids
* mechanical esophageal dysphagia: sx only occur w/ solid food
41
GERD (Gastroesophageal Reflux Disease)
Pt experiences effortless return of gastric contents into pharynx
Sxms: heartburn, nausea, "lump in throat"
42
What is Achalasia?
* one of the most common esophageal diseases
* neuromuscular disorder of esophagus
* outflow obstruction d/t inadequate LES tone & dilated hypomobile esophagus
43
Causes of Achalasia:
1. loss of ganglionic cells of the esophageal myenteric plexus
2. absence of inhibitory neurotransmitters of the LES
3. Unopposed cholinergic LES stimulation (LES can't relax)
4. Esophageal dilation w/ food unable to pass into stomach
43
What do people w/ achalasia have an increased risk of long-term?
esophageal cancer
43
Diagnosis for Achalasia
esophageal manometry
esophagram
43
Symptoms of Achalasia:
* dysphagia
* regurgitation
* heartburn
* chest pain
* hard time getting food to pass adequately
44
Type 1 Achalasia
minimal esophageal pressure
* responds well to myotomy
45
Type 2 Achalasia:
entire esophagus pressurized
* responds well to treatment
* has the best outcomes
46
Type 3 Achalasia
esophageal spasms w/ premature contractions of the esophagus
* has the worst outcomes
47
Achalasia Tx
* ALL TREATMENTS PALLIATIVE
* Meds: nitrates, CCBs - relax LES
* endoscopic botox injections
* pneumatic dilation - most effective (balloon dilation)
* Laparascopic Hellar Myotomy - best surgical tx
* peri-oral endoscopic myotomy (POEM)
* esophagectomy - only for advanced dx
48
POEM: peri-oral endoscopic myotomy & risks
* endoscopic division of LES muscle layers
* 40% develop pneumothorax or pneumoperitoneum
49
All achalasia pts are ____.
What is indicated b/c of this?
* high risk for aspiration
* RSI or awake intubation (full stomach)
50
Diffuse Esophageal Spasms
* spasms that occur in the distal esophagus
* d/t autonomic dysfunction
* occur more in elderly
* Dx: esophagram
* pain mimics angina
51
Tx for diffuse esophageal spasms
NTG, antidepressants, PDE-I's
52
What are Esophageal Diverticula
outpouchings in the wall of the esophagus
53
Pharyngoesophageal Diverticula
* Zenker Diverticulum
* cause bad breath d/t food retention in the pockets of their throat
54
Midesophageal Diverticula causes
* deeper down
* caused by old adhesions, inflamed lymph nodes
55
Epiphrenic Diverticula
* Surpadiaphragmatic
* pts may experience achalasia
56
All diverticula pts are ____ ____.
What is indicated d/t this?
aspiration risks
* removal of particles before putting them to sleep & RSI
57
Hiatal Hernia
herniation of the stomach into the thoracic cavity
* occurs through the esophageal hiatus in the diaphragm
58
Cause of hiatal hernia:
weakening in anchors of GE junction to the diaphragm
59
Sxms of Hiatal Hernia
* may be asymptomatic
* often have GERD
60
How does esophageal caner present?
Progressive dysphagia & weight loss
61
Why does esophageal cancer have a poor survival rate?
Abundant lymphatics in the area leads to lymph node metastasis
62
What are the 2 common types of esophageal cancer?
1. Adenocarcinomas (lower esophagus) - r/t GERD, barrett's esophagitis, obesity
2. Squamous cell carcinoma
63
64
Is an esophagectomy curative or palliative?
Can be either
65
How can an esophagectomy be performed?
* transthoracic
* transhiatal
* minimally invasive
66
There is a high risk of ____ ____ ____ with esophagectomy surgeries.
Recurrent laryngeal nerve injury
* 40% resolve spontaneously
67
68
Pt concerns r/t esophagectomy
1. pts malnourished pre-op and for months post-op
2. pancytopenia & dehydration if h/o chemo/radiation
3. post-esophagectomy pts are high risk of aspiration for life
69
GERD
Incompetence of gastro-esophageal junction - leads to reflux
* 15% of adults
70
Sxms of GERD
* heartburn, dysphagia, mucosal injury
71
Reflux contents include ____, ____, ____ ____, & ____.
1. HCl
2. pepsin
3. pancreatic enzymes
4. bile - associated w/ Barret metaplasia & adenocarcinoma
72
73
3 mechanisms of GE incompetence
1. Transient LES relaxation - elicited by gastric distention
2. LES hypotension
3. Autonomic dysfunction of GE junction
74
What is the normal LES pressure?
GERD pressure?
* measured using manometry
* LES normal - 29mmHg
* GERD - 13mmHg
75
Treatment of GERD
1. Avoid trigger foods
2. Meds: antacids, H2 blockers, PPIs
3. Surgery
76
What is a Nissen Fundoplication?
wrap stomach around esophagus so the stomach muscles tighten where the LES is
77
78
What is a Toupet?
Similar to Nissen - not as high up
79
What is a Linx procedure?
* newer procedure - magnets that open and close around sphincter - less invasive
80
Pre-op Interventions: GERD
1. Cimetidine, Ranitidine - decrease acid production & increase pH
2. PPIs night before and morning of
3. sodium citrate - nonparticulate PO antacid (OB c-section)
4. Metoclopramide - gastrokinetic agent; 3rd line - reserved for DM, obese, pregnant
5. Aspiration precautions -- RSI, cricoid pressure controversial
81
Factors that increase intra-op Aspiration risk: LONG ASS LIST
1. emergent surgery - full stomach (digestion halted w/ traumas)
2. full stomach
3. difficult airway
4. inadequate anesthesia depth
5. lithotomy
6. autonomic neuropathy
7. Gastoparesis - DM
8. Pregnancy
9. Increased intraabdominal pressure
10. severe illness
11. morbid obesity
81
82
What is the stomach & what does it do?
* J-shaped sac that serves as a reservoir for large volumes of food
* mixes & breaks down food to form chyme
* slows emptying into the small intestine
83
How small must solids be broken down to before entering the duodenum?
1-2mm particles
84
How is the motility of the stomach controlled?
intrinsic & extrinsic neural regulation
85
SNS stimulation ____ these contractions via the ____ ____.
inhibits, sphlanchnic nerve
86
PNS stimulation to the vagus nerve increases the ________________ of the stomach.
number & force of contractions
87
The intrinsic nervous system provides ____ for motility.
Coordination
88
What is the neurohormonal control of the stomach?
1. Gastrin & Motilin - increase the strength & frequency of contractions
2. Gastric inhibitory peptide - inhibits contractions
89
What is the most common cause of non-variceal upper GI bleeding?
Peptic Ulcer disease
* 10% women, 12% men
* 15,000 deaths/yr
90
91
PUD may be associated with ____.
Helicobacter Pylori
92
93
Sxms of PUD:
burning epigastric pain w/ fasting & improved w/ meals
94
95
There is a ____ risk of perforation in PUD pts who don't receive treatment
10%
96
97
PUD Perforation Symptom
1. sudden/severe epigastric pain - acidic secretions leaking into peritoneum (EMERGENCY)
98
What causes moratlity r/t PUD perforation?
Shock or perforation >48hrs
99
Gastric Outlet Obstruction onset
* Can be acute or chronic
* acute d/t edema & inflammation in pyloric channel at the beginning of the duodenum
100
Pyloric obstruction sxms
recurrent vomiting, dehydration & hypochloremic alkalosis
101
Repetitive ulceration & scarring may lead to ____ - ____ & ____ ____.
Fixed-stenosis & chronic obstruction
101
Tx for gastric outlet obstruction
1. NGT (decompress the stomach)
2. IV hydration
3. normally resolves in 72h
102
Type I Gastric Ulcer location
Along the lesser curvature close to incisura; no acid hypersecretion
103
Type II Gastric Ulcer
2 ulcers - 1st on gastric body, 2nd duodenal
* usually acid hypersecretion
104
Type III Gastric Ulcer
Pre-pyloric with acid hypersecretion
105
Type IV Gastric Ulcer
At lesser curvature near gastroesophageal junction
* no acid hypersecretion
106
Type V Gastric Ulcer
Anywhere in the stomach
* usually seen w/ NSAID use
107
Common causes of gastric ulcers include:
NSAIDs, H. Pylori, ETOH
108
Tx for gastric ulcers:
* Antacids, H2 blockers, PPIs
* Prostaglandin Analogues, cytoprotective agents
109
H. Pylori Tx:
Triple Therapy
* 1 Abx
* PPI
* 14 days
110
111
What is Zollinger Ellison Syndrome?
Non B cell islet tumor of the pancreas - causes gastrin hypersecretion
* gastrin stimulates gastric acid secretion
* gastric acid normally inhibits further gastrin release - this is absent in ZE syndrome!
112
113
Sxms of Zollinger Ellison Syndrome
very high stomach acid levels leading to -
* PUD, erosive esophagitis, diarrhea
114
115
Incidence of ZE Syndrome
* 0.1-1% of PUD pts
* males > females
* ages 30-50
116
Up to 50% of pts w/ gastrinomas are ____ at the time of diagnosis.
metastatic
117
Tx of ZE syndrome
PPI & Surgical resection of gastrinoma
118
Pts w/ ZE syndrome have: (3 things)
1. increased gastric fluid volume
2. possible electrolyte imbalances
3. endocrine abnormalities
119
Pre-op Considerations for ZE Syndrome
* correct electrolytes
* increase gastric pH w/ meds
* RSI
120
What does small intestinal motility do? What is the purpose of this?
mixes contents of the stomach w/ digestive enzymes
* further reduces particle size & increases solubility
121
What is the major function of the small intestine?
circulate the contents & expose them to the mucosal wall
* maximizes the absorption of water, nutrients, & vitamins - before entering large intestine
122
The circular & longitudinal muscle layers coordinate to achieve ____.
Segmentation
123
What is segmentation?
Isolation of a segment of intestine when 2 nearby areas contract
124
What is the purpose of segmentation?
Allows the contents to remain in the intestine long enough for essential substances to be absorbed into circulation
125
What is Segmentation controlled by?
Mainly by the enteric nervous system &
modulation of motility by the extrinsic nervous system
126
Reversible causes of small bowel dysmotility:
1. Mechanical Obstruction: hernias, malignancy, adhesions, volvuluses
2. bacterial overgrowth - alterations in absorptive function
3. ileus, electrolyte abnormalities, critical illness
127
Structural Irreversible Causes of small bowel dysmotility
Scleroderma, connective tissue disorder, IBD
128
Neuropathic Irreversible causes of small bowel dysmotility
1. pseudo obstruction - intrinsic & extrinsic nervous systems are altered
2. intestines produce weak, uncoordinated contractions
3. Cannot move food forward - bloating, nausea, vomiting, abd. pain
4. food stuck in intestines & grows bacteria
129
130
What is the large intestine?
acts as a reservoir for waste & indigestible material before elimination
* it exctracts remaining electrolytes & water
131
Physiology of the large intestine
1. distention of ileum - relaxes ilocecal valve to allow intestinal contents to enter colon
2. subsequent cecal distention will contract ileocecal valve
3. colon exhibits giant migrating complexes
132
Giant migrating complexes serve to produce -
how often does this occur?
mass movements across the large intestine
6-10x/day
133
Colonic Dysmotility manifests as what 2 symptoms?
1. altered bowel habits
2. intermittent cramping
134
What are the most common diseases associated with colonic dysmotility?
IBS
IBD
135
Rome II criteria for IBS
Abdominal discomfort w/ 2 of -
* defecation relieves discomfort
* pain associated w/ abnormal frequency (>3x per day or < 3x/week)
* pain associated w/ a change in the form of the stool
136
In IBD - the contractions & giant migrating complexes are suppressed d/t colonic wall compression by the inflamed mucosa. True or False?
False
* the giant migrating complexes remain & are increased in frequency
137
What can the increased frequency of giant migrating complexes in IBD lead to?
further compresses the inflamed mucosa
* hemorrhage, thick mucus secretion, significant erosions
