Assessments Unit 4 Flashcards
What layer of the smooth membrane secretes serous fluid to enclose the cavity and reduce friction?
Serosa
List the GI layers from outer to inner
The serosa, longitudinal muscle layer, circular muscle layer, submucosa, and mucosa
List the layers of the mucosa from outer to inner
muscularis mucosae, lamina propria, and epithelium
What 2 muscle layers work together to propagate gut motiliy?
The longitudinal and circular muscle layers
What innervates GI organs up to the proximal transverse colon?
The celiac plexus
What innervates the descending colon and distal GI tract?
Inferior hypogastric plexus
What does the myenteric plexus do? The submucosal plexus?
Myenteric = lies in between smooth muscle layers and regulates the smooth muscle
Submucosal = transmits information from the epithelium to the enteric and CNS
In the mucosa layer, what contains blood vessels/nerve endings? Where are GI contents sensed, enzymes are secreted, nutrients are absorbed, and waste is excreted?
Vessels/nerves = Lamina Propria
GI content = epithelium
What 2 systems make up the GI ANS?
The extrinsic nervous system and enteric nervous system (this system is independent of the CNS and controls motility, secretion and blood flow)
Describe the effects of the SNS and PNS on the GI system
SNS = inhibitory and decrease GI motility
PNS = excitatory and increases/activates GI motility
What cells of the enteric nervous system help carry out motiliy?
the interstitial cells of Cajal (ICC cells), GI pacemakers and smooth muscle cells
What is the primary anesthesia concern with an upper GI endoscopy (EGD)?
We have to share the airway with the endoscopist
What is the primary anesthesia concern with a colonoscopy?
Dehydration -> potential BP problems
What does High Resolution Manometry (HRM) measure?
Pressures along the esophagus; diagnoses motility disorders
What does a barium GI series measure?
Swallowing function and GI transit
What does small intestine manometry measure
Contraction pressure and motility of the small intestine. Evaluatescontractions during three periods: fasting, during a meal, and post-prandial.Normally the recording time consists of 4 hrs fasting, followed by ingestion of a meal, and 2 hrs post-meal
What does a lower GI series evaluate?
Using a barium enema, it outlines the intestines and allows for detection of colorectal anatomical abnormalities
What categories are the diseases of the esophagus grouped into?
Anatomical, mechanical and neurologic
What are anatomical causes of esophageal disease?
Diverticula, hiatal hernia, and changes assoc w/ chronic acid reflux. These abnormalities interrupt the normal pathway of food,which changes the pressure zones of the esophagus
What are mechanical causes of esophageal disease?
Achalasia (esophagus doesn’t contract properly), esophageal spasms, and ahypertensive LES
What are neurologic causes of esophageal disease?
Stroke, vagotomy or hormone deficiences
What are the most common s/sx of esophageal disease?
Dysphagia, heartburn, GERD
What are the 3 types of Achalasia?
Type I: minimal esophageal pressure, responds well to myotomy
Type II: entire esophagus pressurized; responds well to treatment, has best outcomes
Type III: esophageal spasms w/premature contractions; has worst outcomes
What is Achalasia?
Outflow obstruction of neurotransmitters causing inadequate LES tone and a dilated hypomobile esophagus (such as unopposed cholinergic stimulation = LES can’t relax)
What are some treatments for Achalasia?
All are palliative: nitrates, CCBs to relax LES Endoscopic botox injections
Pneumatic dilation * most effective nonsurgicaltx
Laparoscopic Hellar Myotomy *best surgical tx
Peri-oral endoscopic myotomy (POEM)- endoscopic division of LES muscle layers (40% develop pneumothorax or pneumoperitoneum)
Esophagectomy- only considered in the most advanced dz states
What is the best surgical treatment of Achalasia?
Laparoscopic Hellar myotomy
Treatment for diffuse esophageal spasms?
Nitroglycerin, antidepressants and PD-Is (phospho-diesterase inhibitors)
List the types of Esophageal Diverticula
Pharyngoesophageal (Zenker diverticulum): bad breath d/t food retention
Midesophageal: may be caused by old adhesions or inflamed lymph nodes
Epiphrenic (supradiaphragmatic): pts may experience achalasia
Describe a hiatal hernia
Herniation of stomach into thoracic cavity, occurs through the esophageal hiatus in the diaphragm (could be related to weakening in anchors of GE junction to the diaphragm)
What is the mortality rate of esophageal cancer?
Very high because of the abundance of lymph nodes for the cancer to metastasize to
What are the most common esophageal cancers?
Adenocarcinomas are the most common, squamous cell carcinoma comprise the rest
What are some risk factors for esophageal adenocarcinoma?
GERD, Barrets esophagus (esophageal changes with repeated exposure to stomach acid) and obesity
What is the definition of GERD?
Incompetence of the gastro-esophageal junction, leading to reflux
What are the reflux contents from GERD?
HCL, pepsin, pancreatic enzymes and bile
What are the 3 mechanisms of GE incompetence?
Transient LES relaxation, elicited by gastric distention
LES hypotension (normal LES pressure-29mmHg, avg GERD pressure-13 mmHg)
Autonomic dysfunction of GE junction
What are some pre-op interventions for GERD?
H2 blockers, PPIs prior to surgery, sodium citrate, reglan (good for DM, obese and pregnancy)
During induction/intubation, what has become a controversial intervention?
Cricoid pressure
What can increase intraop aspiration risk (a lot of things are listed)?
Emergent surgery, Full Stomach, Difficult airway, Inadequate anesthesia depth,, Lithotomy, Autonomic Neuropathy, Gastroparesis, DM, Pregnancy, ↑ Intraabdominal pressure, Severe Illness, Morbid Obesity
What hormones increase strength/frequency of GI contractions? Inhibit?
Increase = gastrin and motilin
Decrease = gastric inhibitory peptide
What is the most common cause of non-variceal upper GI bleeding? More common in men or women?
PUD, men, has 10% risk of perforation without treatment
What are the s/sx of gastric outlet obstruction? Treatment?
Recurrent vomiting, dehydration & hyperchloremic alkalosis,
Tx = NGT, IV hydration; Normally resolves in 72h
What is a potential outcome of chronic gastric outlet obstruction?
Repetitive ulceration & scarring may lead to fixed-stenosis and chronic obstruction
What are the 5 types of gastric ulcers?
Type I: Along the lesser curvature close to incisura; no acid hypersecretion
Type II: Two ulcers, first on gastric body, second duodenal; usually acid hypersecretion
Type III: Pre-pyloric with acid hypersecretion
Type IV: At lesser curvature near gastroesophageal junction; no acid hypersecretion
Type V: anywhere in stomach, usually seen with NSAID use
What types of gastric ulcers have hypersecretion of acid?
Type II and III
What type(s) of gastric ulcers are related to NSAID use?
Type V
Tx of gastric ulcers?
Antacids, H2 blockers, PPIs, prostaglandin analogues, cytoprotective agents
H. Pylori treatment?
Tripple therapy (2 abx and a PPI) for 14 days
What is Zollinger Ellison syndrome?
Non B cell islet tumor of the pancreas, causing gastrin hypersecretion (gastrin stimulates gastric acid secretion). Normally, gastric acid suppresses further gastrin release (negative feedback), this loop is not present in ZE syndrome. More common in men ages 30 - 50
What is the cancer concern with Zollinger Ellison syndrome?
up to 50% of patients have gastrinomas that are metastatic
Tx and Pre-op of Zollinger Ellison?
PPIs and surgical resection of gastrinoma.
Pre-op = correct lytes and increase gastric pH with meds, RSI
What are reversible vs irreversible causes of small bowel dysmotility?
Reversible: mechanical obstructions (hernia, adhesions), bacterial overgrowth, ileus, e-lyte abnormalities and critical illness
Irreversible: structural or neuropathic.
Structural = scleroderma, connective tissue disorders, IBD
Neuropathic = pseudo-obstruction in which the intrinsic and extrinsic nervous systems are altered and the intestines can only produce weak, uncoordinated contractions
How frequent are giant migrating complexes in the intestine?
6-10x a day
What are the 2 primary s/sx of colonic dysmotility?
altered bowel habits and intermittent cramping
What are the clinical diagnostic criteria of IBS (ROME II criteria)?
abdominal discomfort along with 2 of the following features:
defecation relieves discomfort
pain is associated w/abnormal frequency (> 3x per day or < 3xper week)
pain is associated with a change in the form of the stool
What are the 2 most common inflammatory disorders?
RA is first, IBD is 2nd
What labs reflect ulcerative colitis?
Increased platelets and erythrocyte sedimentation rate, decreased H/H and albumin
What GI complication is triggered by e-lyte disturbances?
Toxic megacolon. 1/2 resolve, the other 1/2 require colectomy (perforation is a dangerous complication with 15% mortality)
What is Crohn’s disease?
Acute or chronic inflammatory process that may affect any/all of the bowel.
S/sx = weight loss, fear of eating, anorexia and diarrhea (patients are afraid to eat d/t pain)
What differentiates early vs late stage Crohn’s?
Early = diarrhea
Late = chronic bowel obstruction
What are common secondary s/sx of Crohn’s?
1/3 Crohn’s pts have an additional symptoms s/a arthritis, dermatitis, kidney stones
IBD treatment?
Medical: 5-Acetylsalicylic acid (5-ASA)- mainstay for IBD *antibacterial & anti-inflammatory, PO/IV Glucorticoids during flares, Antibiotics (Rifaximin, Flagyl, Cipro), Purine analogues
Surgery = last resort, removal of more than 1/2 the small intestine can cause short bowel syndrome which requires TPN permanently
Where do most carcinoid tumors originate?
The GI tract, any portion
What is carcinoid syndrome?
Massive release of serotonin and vasoactives = flushing, diarrhea and HTN or hypotension. Puts a lot of strain on the right heart (left is spared)
Pre-op treatment for carcinoid syndrome?
Octreotide to attenuate volatile hemodynamic changes
How much serotonin is secreted from carcinoid tumors in the foregut, midgut and hindgut?
Fore = low
Mid = high
Hind = rare
What carcinoid tumors are most likely to cause carcinoid syndrome?
Midgut carcinoid tumors -> release tachykinins
ETOH and gallstones are the most common causes of acute pancreatitis, what are some lesser known causes?
Immunodeficiency syndrome and hyperparathyroidism
Hallmark labs of acute pancreatitis?
Increased serum amylase and lipase
Tx of acute pancreatitis?
Pain control, rehydrate, NPO to rest pancreas, tube feed
Is upper or lower GI bleed more common?
Upper
How much blood loss creates hypotension/tachycardia in a GI bleed?
25% loss
Orthostatic hypotension indicates a HCT of what?
Less than 30%
Most common population for lower GI bleed? Causes?
Elderly, diverticulosis, tumors, colitis
Treatment of an ileus?
Fix e-lytes, hydrate, mobilize, NGT suction, enemas. Can give 2 - 2.5 mg of neostigmine but this requires cardiac monitoring
Describe the trend of the GI tract recovering from anesthesia
Small intestine recovers first, followed by the stomach within 24 hours, then the colon 30-40 hours after
Do NMBDs affect the GI tract?
No, NMBDs only affect skeletal muscle
What hormone stimulates glycogenolysis and gluconeogenesis, and inhibits glycolysis?
Glucagon
List the 3 types of DM
DM IA = 1a diabetes is caused by a T-cell–mediated autoimmune destruction of β cells within pancreatic islets, leading to minimal or absentcirculating insulin levels
DM IB = diabetes is a rare disease of absolute insulin deficiency, which is not immune mediated
DM II = diabetes is also not immune mediated and results from defects in insulin receptors and post-receptor intracellular signaling pathways
When does hyperglycemia with DM I generally start to occur?
When 80-90% of B cell function is lost
What are the 3 main abnormalities with DM II?
↑hepatic glucose release cause by a reduction in insulin’s inhibitory effect on liver
Impaired insulin secretion
Insufficient glucose uptake in peripheral tissues
What are 3 causes of insulin resistance?
Abnormal insulin molecules
Circulating insulin antagonists
Insulin receptor defects
With HgbA1c, what are the values for normal, prediabetic and diabetic?
Normal = less than 5.7
Pre = 5.7-6.4
DM = 6.5 or greater
What DM II treatment has significant cardiac concerns?
Sulfonylureas
Per the DM lecture there is a chart that lists what can decrease A1C, what are the 2 initial therapy’s listed?
Lifestyle modifications and metform
How often is Insulin needed in DM I and II?
DM I = 100% of the time
DM II = 30%
What can repetitive hypoglycemic episodes lead to?
Hypoglycemia awareness - dangerous as the patient become desensitized to hypoglycemia
What types of insulin are lente and ultralente?
Lente = intermediate
Ultralente = long acting
What type of DM is DKA more common in ?
DM I
What lab values are consistent with DKA?
BG greater than 300, pH less than 7.3, bicarb less than 18, serum osmolarity less than 320 (pt is very dehydrated) and moderate to high ketone levels
DKA treatment?
Fluids, Insulin: Loading dose 0.1u/kg Regular + low dose infusion @ 0.1u/kg/hr, bicarb and fix e-lytes
HHNK or hyperglycemic hyperosmolar syndrome is fairly similar to DKA, what can differentiate the two?
HHNK generally has MUCH higher sugar levels and the level of acidosis is generally not as severe as DKA. HHNK generally has fewer or no ketones
What type of DM is more likely to cause ESRD? What can slow the progression of proteinuria?
DM I and an ACE/ARB can slow disease progression
Treatment of DM related peripheral neuropathy?
BG control, NSAIDs, antidepressants and anticonvulsants
Prevention of DM related retinopathy?
Glycemic control and control BP
What are some GI complications of DM? Treatment/management?
GI: ↓gastric secretions & motility, eventually causing gastroparesis
S/sx: N/V, early satiety, bloating, epigastric pain
Tx: glucose control, small meals, prokinetics
What is an insulinoma? Diagnosis? Preop treatment?
Rare, benign insulin-secreting pancreatic islet tumor
Diagnosis = Whipple triad (Hypoglycemia w/fasting, Glucose <50 w/sx and S/sx relief w/glucose)
Pre-op: Diazoxide can inhibit insulin release from B cells (other drugs: verapamil, phenytoin, propranolol, glucorticoids, octreotide)
What nerves are in close proximity to the thyroid gland and prone to injury with thyroid surgery?
The recurrent laryngeal nerves
What is the T4/3 ratio, and the primary proteins they bind to?
10:1, and bind to thyroxine-binding globulin (80%), pre-albumin (10–15%), and albumin (5–10%).
Describe the basic process of hormonal control of the thyroid starting from the hypothalamus
TRH is released -> TSH is now released form the anterior pituitary -> TSH promotes synthesis/secretion of T3/4
How does TSH affect thyroid gland size?
Increased TSH = larger gland
Less TSH = smaller or atrophied gland
What is the normal TSH level?
0.4 - 5.0 milliunits/L
What do thermal thyroid scans of warm vs hot vs cold indicate?
Warm = gland is normal
Hot = hyperfunctioning
Cold = hypofunctioning
The majority of hyperthyroidism pathologies are attributed to what 3 disease processes?
Graves disease
toxic multinodular goiter
toxic adenoma
What population is graves more common in?
Females aged 20-40, more common to female to men in a 7:1 ratio
First line treatment for Graves?
antithyroid drug, either methimazole or propylthiouracil (PTU)
In an emergent case, what drugs would you give to a Graves patient?
IV BBs, glucocorticoids, and PTU usually necessary (BBs don’t affect the abnormality but may relieve symptoms by impairing the conversion of T4 to T3)
What is the other name of severe hypothyroidism?
Myxedema
What are the 2 most common causes of hypothyroidism?
Ablation of the gland by radioactive iodine or surgery and idiopathic though likely autoimmune in nature with antibodies blocking TSH receptors
What autoimmune disorder creates a goiter and hypothyroidism in middle-aged women?
Hashimoto thyroiditis
What type of hypothyroidism responds to TRH with an elevation in TSH?
Primary hypothyroidism
If TRH does not cause an increase in TSH, what gland is not working?
Pituitary gland
Drug of choice to treat hypothyroid?
L-thyroxine (synthroid)
What can trigger a myxedema coma?
Most common in elderly women (who have had hypothyroidism for awhile) triggered by infection, trauma, cold and CNS depressants
What is the primary treatment of myxedema coma?
L-thyroxine (synthroid) or L-triiodothyronine
In most cases, a goiter is associated with what kind of thyroid dysfunction? Treatment?
A compensated euthyroid state. TX = synthroid
With goiters/thyroid tumors, what could indicate an increased risk of airway obstruction?
Preop hx of dyspnea in upright or supine position is predictive of possible AW obstruction during GA
What are the most serious complications from thyroid surgery?
Laryngeal nerve injury (bilateral injury may warrant a trach), hypoparathyroidism from inadvertent damage (look for hypocalcemia in the first 48 hours post op) and hematoma compressing the trachea (again, emergency trach)
What hormone stimulates the adrenal cortex to produce cortisol, which facilitates the conversion of NE to EPI in the adrenal medulla?
ACTH (adrenocorticotropic hormone)
Describe the process of the cortex to convert NE into epi
Hypothalamus releases CRH -> Anterior pituitary releases ACTH -> adrenal cortex converts NE into epi
What 2 adrenal hormones cause sodium retention and K excretion?
Aldosterone and cortisol
What is the ratio of pheochromocytoma Ne/Epi ratio?
85:15 NE:EPI which is inverse of normal for the body, 15:85 NE:EPI
DOC for pheochromocytoma?
Phenoxybenzamine
What are the 2 forms of Cushing syndrome (hypercortisolism)?
ACTH-dependent: high plasma ACTH stimulates the adrenal cortex to produce excessive cortisol
ACTH-independent: excessive cortisol production by abnormal adrenocortical tissue that is not regulated by CRH and ACTH
What is a common cause of ACTH-dependent and independent Cushing’s (hypercortisolism)?
Independent = small cell lung carcinoma
Dependent = benign or malignant adrenocortical tumors
S/sx of Hypercortisolism (Cushings)?
Sudden weight gain, usually central w/↑facial fat(moon face), ecchymoses, HTN, glucose intolerance,muscle wasting, depression, insomnia
What test can differentiate hypercortisolism (Cushing) from ectopic ACTH syndrome?
High-dose dexamethasone suppression test
What is the treatment of choice in hypercortisolism (Cushing)?
transsphenoidal microadenomectomy if microadenoma is resectable (if not, 85-90% resection of the anterior pituitary)
What is Hyperaldosteronism (Conn Syndrome)?
Excess secretion of aldosterone from a functional tumor (aldosteronoma) that acts independently of a physiologic stimulus
What nonspecific s/sx may indicate Hyperaldosteronism (Conns)?
HTN, hypokalemia, hypokalemic metabolic acidosis
What diagnostic criteria is highly suggestive of hyperaldosteronism (Conns)?
Spontaneous hypokalemia in presence of systemic HTN
Treatment of Hyperaldosteronism (Conns)?
Competitive aldosterone antagonist (Spironolactone), K+ replacement, antihypertensives, diuretics, tumor removal, possible adrenalectomy
What lab value is suggestive of hypoaldosteronism?
Hyperkalemia in the absence of renal insufficiency
Treatment of hypoaldosteronism?
liberal sodium intake and daily administration of fludrocortisone
What are the 2 types of adrenal insufficiency?
Primary: Adrenal glands unable to produce enough glucocorticoid, mineralocorticoid, and androgen hormones (usually d/t autoimmune adrenal destruction)
Secondary: hypothalamic-pituitary disease or suppression leading to failure in the production of CRH or ACTH
What test indicates adrenal insufficiency?
Cortisol stress test: baseline cortisol is less than 20 ug/dL and remains less than 20 after ACTH stimulation
Treatment of adrenal insufficiency?
Steroids
What are the 3 most common causes of primary hyperparathyroidism?
benign parathyroid adenoma (90%)
carcinoma (<5%)
parathyroid hyperplasia
Treatment of hyperparathyroidism?
Surgical removal of abnormal portions of gland
What is secondary hyperparathyroidism?
compensatory response of the parathyroid glands to counteract a separate disease process producing hypocalcemia.
What is unique about secondary hyperparathyroidism in regards to calcium levels?
Because secondary hyperparathyroidism is adaptive, it rarely produces hypercalcemia
Secondary hyperparathyroidism treatment?
controlling the underlying disease, normalizing phosphate levels in pts with renal disease by administering a phosphate binder
What is the most common cause of low or absent PTH?
inadvertent removal of parathyroid glands, as may occur during thyroidectomy
Most dangerous complication of parathyroid damage/removal?
Low calcium related laryngospasm
What is the most common cause of chronic hypocalcemia?
Chronic renal failure
Hypoparathyroidism Tx?
Calcium replacement, vitamin D
What are the 6 hormones the anterior pituitary secretes? What 2 are stored but not made by it?
GH, ACTH, TSH, FSH, LH, and prolactin. Vasopressin and oxytocin are stored in the AP (made by the hypothalamus)
What lab value indicates acromegaly? Treatment?
Elevated IGF-1 (insulin like growth factor). Tx = surgical excision of the adenoma, if surgery is not feasible, use a somatostatin analogue
Airway concerns with acromegaly?
Distorted facial anatomy can interfere with ventilation, large tongue/epiglottis = higher chance of airway obstruction, glottic opening may be narrowed, use of a smaller ET tube and fiber optic intubation is common
What is diabetes insipidus?
the absence of vasopressin (ADH) c/b destruction of posterior pituitary (neurogenic DI) or failure of renal tubules to respond to ADH (nephrogenic DI)
How do you differentiate nephrogenic vs neurogenic DI?
Desmopressin
In neurogenic it causes urine-concentration, but has no effect in nephrogenic
Neurogenic vs nephrogenic DI treatment?
Neuro = DDAVP
Nephro = low salt/protein diet, diuretics and NSAIDs
What is SIADH?
Some stimulus is making the body secrete more ADH (many potential causes). This causes urine to become very concentrated
SIADH treatment?
fluid restriction, salt tablets, loop diuretics & ADHantagonists-Demeclocycline
What is the defined value for HTN?
BP of 130/80 or greater of either SBP or DBP
What is isolated systolic, isolated diastolic and combined BP values?
IS = SBP greater than 130, DBP less than 80
ID = SBP less than 130, DBP greater than 80
Combined = 130/80 or greater in both
What is the widened pulse pressure in HTN a risk factor for?
CV morbidity as it correlates with vascular remodeling and stiffness
What are some common causes of secondary HTN in middle aged adults?
hyperaldosteronism, thyroid dysfunction, OSA, Cushings, and pheochromocytoma
What are the common causes of secondary HTN in children?
renal parenchymal disease or coarctation of the aorta
What is the common cause of secondary HTN in adolescents?
Coarctation of the aorta
Common causes of secondary HTN in young adults?
Thyroid dysfunction, fibromuscular dysplasia and renal parenchymal disease
Common causes of secondary HTN in the elderly?
Atherosclerotic renal artery stenosis, renal failure, hypothyroidism