GI Disturbances Flashcards
What part of the pharynx do each of the nerves innervate?
–Trigeminal nerve
–Glossopharyngeal nerve
–Superior laryngeal nerve
–Recurrent laryngeal nerve
–Branches of Vagus nerve
–Trigeminal nerve - nasopharynx
–Glossopharyngeal nerve - posterior third of tongue and oral pharynx
–Superior laryngeal nerve – tongue base and inferior epiglottis to the vocal cords
–Recurrent laryngeal nerve – vocal cords distally
–Branches of Vagus nerve – remaining larynx and trachea
T/F: Local and general anesthesia depress sensation of the upper airway innervation.
True
What does the damage or impairment of the oropharynx innervation increase the risk of?
Pathology of the oropharynx, such as pharyngeal tumor, CVA and metabolic toxin will increase aspiration of pneumonia.
What is the anatomical location of the esophagus?
-originates at the pharynx (~C6, behind the cricoid cartilage) and ends at the cardia of the stomach (~T11)
* consists of :
upper (cervical) esophagus: C6-T1
Thoracic esophagus
Abdominal esophagus: T11-T12
What are the 2 muscle layers of the esophagus and what is the composition of the muscles?
Outer: longitudinal layer
Inner: circular muscular layer
- Striated (skeletal) muscle dominates top 1/3rd of the esophagus.
- Striated and smooth muscles in the middle 1/3rd
- Smooth muscle in the distal 1/3rd
What is the space the esophagus pass through to enter the diaphragm?
Right crus
What two drainage system is found outside of the esophagus?
Regional lymphatics and thoracic duct
Name the different blood vessels that supply blood to the esophagus.
Inferior thyroid artery - cervical (upper) esophagus and its sphincter
bronchial arteries from the thoracic aorta - thoracic esophagus
left gastric artery and left inferior phrenic artery - lower part of the esophagus and its sphincter
Describe the two intrinsic plexuses for the esophagus and their locations.
*Myenteric (Auerbach) plexus lies between the longitudinal and circular muscles and provides motor innervations mainly by parasympathetic (CN X) and some by sympathetic nervous system.
*Submucosal (Meissner) plexus connects the mucosa to the circular muscle and has only parasympathetic fibers and provides secretomotor innervation to the mucosa nearest the lumen of the gut.
–This system is a continuum that extends from the esophagus to the anus
Describe the extrinsic innervation of the esophagus?
-Sympathetic
•Acts on myenteric plexus to
modulate rather than control
motor activity
-Parasympathetic
- Cranial nerves IX, X, XI
- Causes esophageal
muscular contraction (peristalsis)
•Causes relaxation of LES
-Somatic
What stimulates the upper esophageal tone?
- inspiration
- esophageal distention
- gagging
- valsalva maneuver
- acidity of gastric contents
What reduces the upper esophageal tone?
- Distention
- Belching
- Vomiting
What studies can be done to diagnose or find the underlying cause of dysphagia?
–Barium contrast studies
–Upper endoscopy
•Biopsy and cytology
How is esophagus affected in chronic alcoholism?
- Impaired esophageal peristalsis
- LES hypotonia
- Degeneration of the Auerbach plexus
- Mallory Weis Tear
- Barrett Esophagus
What is achalasia and what diseases can cause it?
•Failure of the Lower esophageal sphincter tone to relax during swallowing accompanied with a lack of peristalsis
–Diabetes
–Stroke
–Amyotrophic lateral sclerosis (Lou Gehrig’s disease)
–Connective tissue diseases
- Amyloidosis
- Scleroderma
What are the surgical options for the treatment of achalasia?
penumatic dilation
Heller myotomy or endoscopic myotomy
What is Barrett esophagus and what can cause it?
•Normal squamous epithelium changes to metaplastic columnar epithelium
–Chronic exposure to acidic gastric contents – GERD (Assume GERD if the patient has Barrett esophagus.)
–Chronic alcohol abuse
–Smoking
•Closely associated with the eventual development of esophageal carcinoma
What is GERD and its management modality?
Loss of LES tone and the ensuing reflux of gastric contents
•Current management modality is medical therapy.
–Proton Pump Inhibitors (PPIs)
–Histamine-2 (H2)-blocking agents
What is hiatal hernia?
Protrusion of a portion of the stomach into the thoracic cavity through a weak spot in the diaphragm.
What is the medical management and surgical treatment for a hiatal hernia?
H2 blockers
Nissen fundoplication
What is esophageal diverticulum and its three classifications?
An esophageal diverticulum is a pouch that protrudes outward in a weak portion of the esophageal lining. This pocket-like structure can appear anywhere in the esophageal lining between the throat and stomach and is named according to its location.
- Zenker (Upper Esophagus): most common
- Traction (Middle esophagus)
- Epiphrenic (Lower esophagus)
What are the causes of esophageal carcinoma?
–Advanced age
–Cachectic (general ill health with malnourishment)
–Suffering from age related disease process
–Suffering from metastasis disease process
–May have associated history of alcohol and tobacco use/abuse
–History of preoperative radiation
- Bone marrow suppression
- Intrathoracic and pulmonary fibrosis
- Increased friability of tissues
–History of chemotherapy
What are some chemotherapy complications for Daunorubicin, Doxorubicin/Adriamycin and Bleomycin?
•Daunorubicin and Doxorubicin/Adriamycin:
–Chemotherapy-induced cardiomyopathy
•Bleomycin
–Pulmonary fibrosis (most serious complication)
–Increases sensitivity for oxygen toxicity. This can cause post-op pulmonary fibrosis following supplemental oxygen therapy during general anesthesia.
–Restrictive defect
What are the two section of the stomach and their functions?
–Fundus
- Thin-walled and distensible
- Upper abdomen
- Primary function is storage (4 hours); hence no peristalsis
–Distal Stomach
- Thick-walled
- Mixing of food
- Slow release of chyme through pyloric sphincter into the duodenum (peristalsis)
Where is the duodenum located?
The duodenum extends from the pylorus to the ligament of treitz, in a sharp curve that almost completes a circle. It is so named because it is about equal in length to the breadth of 12 fingers, or about 25 cm. It is largely retroperitoneal and the position is relatively fixed. The stomach and duodenum are closely related in function and in pathogenesis and manifestation of disease.
Describe the anatomy of the gastric wall.
- Serosa - External layer (connective tissue)
- Muscularis externa
–Outer: longitudinal
–Middle: circular
–Inner: oblique
- Submucosa
- Muscularis mucosae (thin smooth muscle)
- Mucosa
What are the cells that occupy the surface of gastric mucosa?
mucous cells
parietal cells
G cells
ECL cells
Chief cells
What do the G cells produce in the gastric mucosa?
-G cells produce gastrin hormone in response to gastric distension. The hormone stimulates histamine release from the enterochromaffin-like cells (ECLs). Histamine release acts as a powerful stimulant of acid production from the parietal cells.
H2 antagonists block histamine release from the ECLs.
True / False
False.
H2 antagonists block the H2 receptors at the parietal cells and prevent histamine from binding to the receptors.
What is the effect of a vagotomy?
diminshes parietal cell response to gastrin and histamine.
Describe the innervation of the stomach.
•Major innervation is Autonomic
–Two branches of the vagus nerve
- Right vagus becomes right posterior (celiac) branch
- Left vagus becomes left anterior (hepatic) branch
List the common stomach disorders/diseases.
- Peptic ulcer Disease
- Gastric ulcer Disease
- Gastric neoplastic disease
Describe Peptic Ulcer Disease (PUD).
•Caused by the erosion of protective mucous layer of the stomach and duodenum
–Chronic oversupply of gastric hydrochloric acid and pepsin
–Subsequent ulceration over time with lesions of varying depth
- Beyond mucosal layer into submucosa and muscularis epithelial layer into the serosal layer
- If the LES is incompetent, ulcerative involvement of the esophagus may also occur
Describe Therapeutic Pharmacology for Peptic Ulcer Disease.
•H2-receptor Antagonists
–Blocks secretion of hydrochloric acid
–Promotes healing of duodenal ulcers
–Reduces cytochrome P-450 enzyme activity in the liver (prolonged drug metabolism)
*Famotidine is the least likely H2 antagonist offender
•Proton pump inhibitors
–Most effective antisecretory agent
In addition to the H2 blockers and PPI, what are othe pharmacology therapy of peptic ulcer disease?
- Sucralfate
- Antibiotics
- Misoprostol
How does sucralfate help manage PUD?
•Sucralfate
–Aluminum salt of sulfated sucrose
–Binds to ulcer and Increases (coats) the gastric mucous layer
–Promotes the healing process
–Devoid of side effects
How does misoprostol help manage PUD?
–Synthetic prostaglandin: acts on parietal cells in the stomach wall to inhibit acid secretion
–Secondary therapy to prevent ulcers in patients requiring NSAIDs
How does gastritis associated with gastric mucosal acidosis affect peri-operative morbidity and mortality?
Peri-operative morbidity and mortality are increased
What are the exocrine functions of the pancreas?
External digestive function:
- Secretes 1500-3000ml of pancreatic juice daily
- Clear, colorless liquid with a pH of 8.3
- Ionic composition is Na+, K+, bicarb, chloride
- Principle function is to adjust duodenal pH
- Promotes optimal function of pancreatic enzymes
What is the e__ndocrine function of the pancreas?
Internal hormonal function:
-Direct (non-ductal) production of insulin and glucagon to meet the physiologic need.
What are the S/S of acute pancreatitis?
severe abdominal pain
fever
N/V
jaundice
hypotension
ileus
external distortion of stomach on radiographs
What are the common causes pancreatitis?
- Alcohol abuse
- Direct or indirect trauma
- Ulcerative penetration from adjacent structures
- Infectious processes
- Biliary tract disease
- Metabolic disorders
- Drug side effect
What is the management of acute pancreatitis?
- Nasogastric suction
- Maintenance of intravascular volume (NPO)
- Anticipation of respiratory insufficiency
- Analgesia
- Nutritional support
- Common bile duct exploration
What are the S/S of chronic pancreatitis?
–Incapacitating upper abdominal pain radiating to the back (Continuous or intermittent in nature)
–Pancreatic calcification
–Steatorrhea
–40% have diabetes from loss of pancreatic function
What are the common causes of chronic pancreatitis?
- Chronic alcoholism
- Chronic, significant biliary tract disease
- Long term effects of pancreatic injury
What are the surgical procedures of pancreatitis?
- Drainage of pseudocyst
- Pancreatojejunostomy
- Puestow procedure: It involves a side-to-side anastomosis of the pancreatic duct and the jejunum
What is biliary tract (tree) and what comprise it?
- Excretory conduit for the liver
- Composed of:
–Intrahepatic ducts
–Coalescence of the intrahepatic ducts and the right and left hepatic ducts
–The common hepatic duct
–The gallbladder
–The cystic duct
–The common bile duct
What causes the sphincter of Oddi to dilate?
Glucagon
How much bile does the gallbladder store?
30ml - 50ml
What causes the gallbladder to contract and release bile?
Regulation of gallbladder contraction is primarily hormonal through the action of cholecystokinin which is released from duodenum and mediated by presence of intraluminal amino acids and fats
•Vagal stimulation also plays a role – secondary to cholecystokinin.
What are the three main functions of bile?
–Emulsify and enhance absorption of ingested fats and fat-soluble vitamins.
–Provide an excretory pathway for bilirubin, drugs, toxins, and immunoglobulin A (IgA)
–Maintain duodenal alkalization
What is Murphy’s sign?
Inspiratory effort accentuates the pain in cholecystitis
What is cholecystitis and what is the clinical presentation?
•Acute obstruction of the cystic duct.
- Patients present with acute, severe, midepigastric pain that often radiates to right abdomen.
- Jaundice suggests complete obstruction of the cystic duct.
What is choledocholithias?
-an obstruction of common bile duct
symptoms are similar to cholecystitis
What are the signs of Charcot Triagle and what does it indicate?
Fever (Chills)
Jaundice
upper quadrant pain
–Indicative of acute ductal obstruction r/t cholelithiasis
–Patients also have weight loss, anorexia, and fatigue
•Diagnostic studies demonstrate a dilated biliary tree.
What type of pain will be most seen with post op laparascopic cholecystectomy ?
right shoulder pain
What are the anesthesia considerations for a cholecystectomy?
–Post-op pain
–Nausea and vomiting
–Peritoneal irritation from CO2
–Intravascular volume restoration
What are the anesthesia considerations for a laparoscopic surgery?
- Abnormal gastroesophageal junction competence from high intra-abdominal pressure/aspiration risk
- Altered ventilatory dynamic caused by large volume of intra-abdominal carbon dioxide/hypercapnia
- Decreased venous return from increased intra-abdominal pressure/patient position
- Manipulation of abdominal viscera may cause bradycardia and hypotension
- Bleeding at trocar insertion site/inadvertent breech of large vessel ~ hemorrhage
- Venous CO2 embolism
Name the structures of the small intestine, beginning with the proximal structure to the stomach.
–Duodenum ~ 20cm
–Jejunum ~ 100cm
–Ileum ~150cm
(tethered by the mesentery)
What are the three major classes of nutrients that enter the digestion in the small intestine?
- Proteins
- lipids (fats)
- carbohydrates
What is absorption and by what mechanism does it occur?
*It is the passing of food from the small intestine into the blood vessels.
*Diffusion.
What epithelial cells line the inner wall of the small intestine?
simple columnar epithelial tissues
What are the three functional zones of the esophagus?
–Upper esophageal sphincter (UES)
–Esophageal body
–Lower esophageal sphincter (LES)
Differentiate rugae and plicae circulares
Rugae Plicae circularis
Folds in the stomach folds in the small intestine
Temporary permanent
For distension and contraction for absorption
What are some of the diseases of the small intestine.
•Malabsorption Syndromes
–Celiac sprue/Gluten-sensitive enteropathy
–Fat malabsorption
–Protein malabsorption
•Maldigestion Syndromes
–Deficient pancreatic secretion
- Upper GI bleeding
- Small bowel obstruction
How long is the large intestine?
3-5 feet
Describe the wall of the large intestine.
–Composed of longitudinal muscle and numerous outpouchings (haustrations) throughout its length
What is the arterial supply of the large intestine?
–Superior mesenteric artery
–Inferior mesenteric artery
–Internal iliac artery
Describe the diseases of the large intestine.
•Inflammatory Bowel Disease
–Chrohn’s Disease
–Ulcerative colitis
- Diverticulitis (inflammation) /Diverticulosis (pouches)
- Abdominal Compartment Syndrome
- Colonic polyps
- Colon Cancer
- Colon volvulus
- Ischemic Bowel
- Appendicitis
What are the anesthesia considerations for intestinal surgery?
- Aspiration Risk
- Fluid and electrolyte status
- History of steroid use ~ perioperative coverage
- Avoid Nitrous Oxide
- TPN (we do not stop since it’s calculated based on 24hr)
- Bowel prep (dehydration)
- Malnutrition and anemia
- Thermoregulation – SCIP 36*C
- Post op ileus (do not give Reglan)
What is a spleen?
- The spleen is a non-vital organ located in the left upper quadrant of the abdominopelvic region.
- It is the largest lymphatic organ, acting as a site of lymphocyte proliferation and in immune surveillance and response.
- In the fetus, it is a hematopoietic organ.
- Organs and structures that border the spleen are the diaphragm, stomach, left kidney, pancreas and left colic flexure.
Describe the tissues that make up the esophageal mucosal lining.
Squamous epithelium
Columnar epithelium: distal 1-2 cm that connects to the stomach (same tissue as the stomach)
What separates the two layers of the esophageal muscles and what is its function?
The myenteric plexus of Auerbach (A): a tangled network of nerve fibers involved in the secretion of mucus and in peristalsis of the smooth muscle of the esophagus.
This is mainly a parasympathetic (vagus nerve) plexus along with some postganglionic sympathetic nerves.
Which nervous system is primarily responsible for the digestive system?
Parasympathetic nervous system (Rest and Digest)