Flashcards in GI Pathophysiology Deck (73):
True or false: this was the worst lecture all year
What is responsible for vasoconstriction of arterial blood flow to the G.I. tract?
Sympathetic nervous system
What two things enhance mechanical activity of the GI tract?
Distention and parasympathetic nervous system stimulation
What is the normal pH range for gastric fluid?
What are some symptoms of vagal stimulation during an abdominal procedure?
Decreased blood pressure
Increased bowel mobility
What can you do when there is vagal stimulation during an abdominal procedure?
Tell the surgeon to quit dicking around
What two things put the patient at high risk for aspiration pneumonitis?
Volume > 25 mL
pH < 2.5
What is the relationship between the pH and volume and severity of aspiration pneumonitis?
Dose-dependent relationship in the severity of AP for both volume and acidity that reaches the lung
What are some potential reasons for reduced airway reflexes and thus increased risk for perioperative AP?
Pregnancy, obesity, GERD, MS, MD, MG, ALS, (Stroke)
What are some methods for reducing the risk of regurgitation and pulmonary aspiration?
Decrease volume and acidity
H1 and H2-blockers
What are the fasting guidelines for clear liquids in adults and children?
Adults >3 hours
Kids >2 hours
What are the ASA fasting recommendations for breastmilk and nonhuman milk/light meals preoperatively?
Breast milk >4 hrs
Light meals >6 hrs
Why is gum not allowed preoperatively?
It increases gastric volume and decreases pH
How could gum potentially be helpful post-op?
Prevent post-op ileus
What is peristalsis?
Wavelike movements of the bowel in a forward direction
How long is the average adult esophagus?
8 inches or 20 cm
What is the purpose of the upper esophageal sphincter?
Prevents aspiration of gastric contents into the lung and swallowing of air
What effect do most anesthetic agents have on UES tone?
What is the exception?
Most anesthetic agents decrease you UES tone
What is zenker's diverticulum?
Diverticulum of the mucosa of the pharynx just above the cricopharyngeal muscle
What type of maneuver cannot be performed on patients with a zenker's diverticulum?
Selleck (cricoid pressure)
What leads to gastroesophageal reflux?
Decrease in lower esophageal sphincter tone
What is the resting pressure of lower esophageal sphincter tone?
At what point is LES pressure problematic?
Normal: 15-30 mmHg
Problem: <10 mmHg
What is barrier pressure?
Difference between gastric pressure and LES pressure
What effect does cricoid pressure have on LES tone?
List some factors that decrease LES tone
List some factors that increase LES tone
What is an EGD?
What is heartburn?
Incompletely closed lower esophageal sphincter allows acidic stomach contents to reflux into the esophagus
What is gastroesophageal reflux disease (GERD)?
When reflux occurs frequently or is bothersome
What is Barrett's esophagus?
Regular reflux of stomach acids irritates the esophagus, which may lead to histological changes and progress to malignancy
What is achalasia?
The LES does not relax properly
What is true of all general anesthetics in patients with achalasia?
What is esophageal stricture?
A narrowing of the esophagus
What are the risk factors for esophageal cancer?
Smoking, heavy drinking, chronic reflux
What is esophageal varices?
Dilated veins in the distal esophagus are at risk for serious bleeding
What is the main cause of esophageal varices?
What is the treatment for portal hypertension and hepatic encephalopathy?
TIPS Transjugular intrahepatic portosystemic shunt
In the event of an upper G.I. perforation early diagnosis and surgical management within what timeframe is best?
Within 12 hours
Upper GI perforation is associated with what mortality if delayed 24 hours?
24 hrs --> 50%
48 hrs --> 90%
What is the function of the stomach?
Food storage and initial digestion
NOT Nutrient absorption
How is the stomach innervated?
What is the pyloric sphincter?
Opening from the stomach into the small intestine
What is the surgical treatment option for GERD and hiatal hernias?
What is a nissen fundoplication?
When the upper portion (fundus) of the stomach is wrapped around the lower esophagus
What happens to FRC, PIP, PaCO2, and PaO2 during Laparoscopic procedures?
At what intra-abdominal pressure is there a decrease in venous return?
Why is there a potential for shoulder pain during laparoscopic procedures?
Referred pain from stimulation to the phrenic nerve
Where does most digestion and absorption occur?
Parasympathetic simulation will have what effect on small intestine activity?
How much chyme is produced on a daily basis?
1 to 2 L/day
What effect do hypokalemia, peritonitis and laparotomy have on small intestine activity
All decrease activity for up to 48 hours
What is celiac disease?
Autoimmune disorder that destroys the villi in the small intestines
Causes a reaction to eating gluten
What is Crohn's disease?
Autoimmune inflammatory bowel disease
How much can the gallbladder store?
Opioid effect what structure in the gallbladder?
How can this affect be reversed?
Sphincter of oddi
Reversed with glucagon or narcan
What is cholelithiasis?
Gallstones can lead to rupture
What are some potential causes of pancreatitis?
Alcohol abuse, blockage, trauma, autoimmune, hyperparathyroidism cystic fibrosis
Propofol can cause at high doses
What is one of the most common causes of emergency abdominal surgery?
What is an ERCP?
Endoscopic retrograde cholangiopancreatography
-View the entrance of the common bile duct
Where are water and electrolytes absorbed?
Where is feces stored?
Colonic secretions have what type of pH?
What type of inflammatory bowel disease usually begins in the rectal area and may involve the entire large intestine?
What is diverticulosis?
Small pouches in the lining off the colon, or large intestine, that bulge outward through weak spots
What is diverticulitis?
When the patches of diverticulosis become inflamed
What are some complications associated with diverticulosis?
Bleeding, abscess, perforation, peritonitis, fistula, obstruction
What is important to know about carcinoid tumors?
They secrete hormones
60% of carcinoid syndrome cases present as what?
Carcinoid heart disease
-Right sided involvement (Tricuspid regurge and pulmonary valve involvement)
What is important for the management of carcinoid syndrome?
Block histamine and serotonin receptors
Avoid histamine releasing drugs
Monitor electrolytes and glucose
What are the life-threatening causes of agitation during a MAC case?
What are the four categories used to gauge the depth of a MAC case?
What effect does glucagon have on the sphincter of oddi?
What are some of the pros and cons for using ketamine during MAC anesthesia?
Pros: Analgesia, CV stability
Cons: Patient may move, hallucinate, drool