GI/Liver Flashcards
What are the guidelines for NPO status pre-operatively in a healthy patient?
no chewing gum or candy after midnight
clear liquids up to 2 hours before
breast milk up to 4 hours before
light meal, milk or formula up to 6 hours before
(only really applicable in ASA class 1 or 2 patients)
What are some factors that make a patient at high risk for aspiration?
age extremes ascites or ESLD metabolic disorders like DM, ESRD or hypothyroid hiatal hernia/GERD mechanical obstruction like intestinal obstructions or pyloric stenosis prematurity pregnancy obesity neurologic disease
What kinds of patients are at the GREATEST risk of aspiration?
high anxiety pre-op
obesity
pregnancy (esp after 14 weeks)
hiatal hernia
What are some common treatments for aspiration prophylaxis?
h2 antagonists
sodium citrate (bicitra)
reglan
omeprazole
H2 Antagonists – special considerations?
act as competitive antagonists at the H2 receptors at the gastric parietal cells to decrease acid secretion
best if given the night before surgery and then repeated 1 hour before surgery
ex. cimetidine and famotidine
metoclopramide – special considerations
acts as a dopamine antagonist to increase pressure at the lower esophageal sphincter to speed up gastric emptying
prevent or alleviates N/V
CONTRAINDICATED in intestinal obstruction
sodium bicitrate (bicitra) – special considerations
its a non-particulate antacid used to raise gastric pH (30 mL of volume which may contribute to aspiration risk)
give it 15 minutes before surgery and it will last for 3 hours
not indicated if the patient has no risk factors for aspiration, per ASA
What are some physiologic risk factors for aspiration pneumonitis?
pH 25 mL in 70 kg patient
What are the manifestations of aspiration pneumonitis?
potentially the only sign intra-op might be a persistent desat with the tube definitely in the right place
bronchospasm, cyanosis, tachycardia, dyspnea
how are aspiration syndromes characterized?
by volume aspirated, type of material aspirated, pH of the material
What is the treatment for Barrett’s Esophagus?
H2 blockers, PPIs, nissen fundoplication
what are S&S of barrett’s esophagus?
dysphagia, reflux esophagitis, heartburn, LES dystonia, weight loss
How would you modify the anesthetic plan in the case of a patient with Barrett’s Esophagus?
prepare for an RSI
What are the S&S of a hiatal hernia?
retro-sternal discomfort
reflux after meals
What is the usual cause of peptic ulcer disease?
H. Pylori
What are some typical treatments for peptic ulcer disease?
H2 antagonists, PPIs, antimicrobial therapy, antacids
Who is at high risk for a peptic ulcer?
chronic NSAID use, age 45-60, ETOH
What are the S&S of peptic ulcer disease?
vomiting blood epigastric pain abdominal tenderness and rigidity perforation weight loss anorexia metabolic disturbances
What are some examples of malabsorption syndromes?
celiac’s disease
protein malabsorption syndromes
fat malabsorption syndromes
small bowel perforation or obstruction
What is the clinical significance of malabsorption syndromes?
metabolic disturbances that change electrolytes and fluid status
What are some S&S of malabsorption syndromes?
unexplained weight loss fatty stools diarrhea anemia fatigue Vit K deficient bleeding edema/ascites
What is the clinical significance of Crohn’s disease pre-anesthetically?
deficient in multiple vitamins and minerals such as B12, phosphorous, folic acid, zinc, iron, K+
hypoalbuminemia
anemia
What are the S&S of ulcerative colitis?
intermittent bloody diarrhea fever/malaise anorexia abdominal pain weight loss
What are some anesthetic considerations for a patient with large colon dysfunction, such as Crohn’s and uclerative colitis?
patient may be on chronic steroids and would require a stress dose pre or intra op
prepare for immune suppression r/t meds and higher infection risk
What is carcinoid syndrome?
a small tumor that has originated in the GI tract or bronchi and will produce hormones that can be secreted in the blood and cause systemic effects
What are some S&S of carcinoid syndromes?
cutaneous flushing, diarrhea, palpitations, bronchospasm, dyspnea, hypotension, hypertension, orthostasis
*may want to consider a 12 lead EKG if there are S&S of a dysrhythmia
What is the problem with having a carcinoid syndrome?
the tumors secrete hormones such as bradykinin, serotonin, dopamine and and histamine
What are some helpful lab values when taking care of a patient with severe GI or liver disease?
Hct, albumin, serum electolytes, BUN
Nutritional deficiencies are associated with what poor outcomes?
prolonged hospital stays poor wound healing higher infection rate respiratory failure death
What is a relatively accurate indicator of malnutrition?
serum albumin
What are some normal physiologic functions of the liver?
acts as a reservoir of blood immune globulin production creation of clotting factors mediates endocrine functions metabolism of nutrients excretion of bilirubin metabolizes drugs
What are some specific risk factors to ask about if liver disease is suspected?
jaundice? hx of blood transfusions? drug or alcohol use? current medications + herbals? family history of liver disease? travel history? occupational history?
What are some physical exam findings that might be common in liver disease?
easy bruising, anorexia, weight gain, weight loss, N/V, ascites, pruritis, GI bleeding
When might the patient have an increased risk for intra-op morbidity and mortality?
based on high Child-Turcotte-Pugh scores and MELD scores.
These tests look at encephalopathy, ascites, bilirubin, albumin, PT/INR, primary biliary cirrhosis
When would you want to order liver function tests?
in the case of significant liver disease, overt jaundice symptoms, weight changes >15%, severe drinking problem, prolonged or unusual bleeding, patient has an overt GI bleed, patient admitted to the hospital in the last year?
What are some examples of liver function tests?
AST/ALT GGT AP serum albumin serum bilirubin prothrombin time
What are some specific assessments that the CRNA could look at to assess the severity of liver disease?
hand tremor (could represent encephalopathy) dependent edema hx of blood transfusions presence of hepatitis ascites or jaundice
What general lab studies might be required in a patient with severe liver disease?
CBC, BMP, clotting studies albumin glucose liver enzymes serum ammonia levels blood alcohol level or a tox screen if acute use is suspected
ABG?
How is a patient’s CV system affected if they have liver disease?
increased levels of vasodilators higher cardiac output decreased SVR AV shunting portal HTN
a pre-op EKG is warranted in severe liver disease
What are the respiratory effects of liver disease?
ascites can decrease FRC and decrease diaphragmatic movement
shunting can cause V;Q mismatch
How can liver disease impact intraop fluid status?
ascites and edema can cause wide swings in BP and general fluid status, so treat volume loss accordingly based on central filling pressures in severe cases
What are some general CNS considerations for a patient with liver disease?
encephalopathy is common and so patient may have decreased LOC or altered mentation
What are some common symptoms to assess for in a patient with GI or liver dysfunction?
nutritional changes, weight loss, N/V, blood in stool, GI bleed, abdominal pain or distention, abdominal mass, dysphagia, gastric acidity, reflux, jaundice, easy bruising, pruritis, ascites, hepatomegaly or splenomegaly, palmar erythema, gynecomastia, ecchymosis or spider angiomas
What are some expected findings in cholestatic disease?
increased peripheral vasodilation
increased CO
increased portal venous pressure
decreased portal venous blood flow
What is the main anesthetic consideration when taking care of a patient with cholestatic disease?
patient is at a predisposition for a Vitamin K deficiency, and long term disease can cause liver dysfunction resulting in abnormal protein synthesis
*should treat with exogenous Vit K and FFP if the patient starts bleeding
In acute hepatitis, pre-operative evaluation should focus on…
S&S of encephalopathy, bleeding, jaundice, ascites, hemodynamic instability
What might be some good lab results to review in a patient with hepatitis?
albumin, birlirubin, PT/INR, electrolytes, BUN/Cre, glucose, H&H, liver enzymes, ABG
What are some risk factors for non-alcoholic fatty liver disease?
NIDDM and obesity
What is the timeline for alcohol withdrawal?
6-8 hours – tremors
24 hours – hallucinations and grand mal seizures
72 hours – DTs
What are the main anesthetic considerations when caring for a patient who is withdrawing from alcohol?
treat with benzodiazepines
prepare to leave the patient intubated and possible dispo to the ICU
What are the hemodynamic changes in a patient with cirrhosis?
high CO
low PVR
*will probably need a cardiac clearance pre-op
What are some S&S of cirrhosis?
esophageal varices intrapulmonary shunting V/Q mismatch arterial hypoxemia ascites and edema coagulation disorders hormone disorders encephalopathy portal HTN
How does liver disease affect the clotting cascade?
affects it at all 3 stages:
- hemostasis
- coagulation
- fibrinolysis
What clotting factors are deficient in liver disease?
2, 5, 7, 9, 10
How are platelets affected in liver disease? why?
altered function and decreased # of circulating platelets
*because they are derived from thrombopoetin, which is a protein normally synthesized in the liver
What is the importance of Vit. K?
its a fat-soluble vitamin absorbed in the small intestine only in the presence of bile salts. it’s necessary for the production of Factors 2-7-9-10. deficiencies cause prolonged PT/PTT.
When can a Vit. K deficiency develop?
patients on parenteral nutrition, biliary obstruction, pancreatic insufficiency, malabsorption, GI obstruction and rapid GI transit
