Term
| Nausea, retching, vomiting |
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Definition
o Nausea: sensation or urge to vomit
o Retching: rhythmic spasmodic movements without explusion of gut contents
o Vomiting (emesis): forceful oral expulsion of GI contents |
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Term
| regurgitation vs. rumination |
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Definition
Regurgitation: effortless return of gastric contents into mouth
Rumination: regurgitation with rechewing or reswallowing |
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Term
| anorexia vs. early satiety |
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Definition
Anorexa: loss of appetite
Early satiety: feeling full quickly without completing a full meal |
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Term
| do the symptoms other than nausea/vomiting respond to anti-emitic therapy? |
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Definition
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Term
| What's the pathophys of vomiting/nausea? |
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Definition
o Emetic receptor sites: stimuli act on peripheral and central neural structures
o Initiation of vomiting program: brainstem nuclei (single location of initiation, despite multiple sensory locations) stimulate motor events of vomiting
o Nausea: unknown pathways – requires conscious perception |
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Term
| What's the chemoreceptor trigger zone and what is it responsive to? |
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Definition
• Area postrema as the chemoreceptor trigger zone
o Base of 4th ventricle
o Responsive to blood borne stimuli: medications (opiates, digoxin), chemotherapy, hormones/metabolic factors (pregnancy, thyroid disease, uremia), bacterial toxins (S. aureus) |
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Term
| What are the • Muscular components of vomiting i.e. the stereotypical set of response coordinated by brainstem => vomiting) |
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Definition
o Increased intraabdominal and intrathoracic pressure – driving force for vomiting
o Open diaphragmatic hiatus
o Open glottis
o Disrupted gastric peristalsis (so contents don’t travel distally)
o Retrograde contractions from jejunum to stomach |
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Term
| Name 5 general mechanisms of peripheral stimulation of vomiting |
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Definition
blockage
irritation/inflamm
activation of sensory nerves from periphery
impaired motor function
FBDs |
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Term
| What are 3 causes of irritation/inflamm? |
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Definition
| analgesic drugs, gastroenteritis, pancreatitis |
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Term
| what is the type of impaired motor function caused by: collagen vascular disease (scleroderma), amyloidosis, hereditary, paraneoplastic (lung cancer) |
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Definition
| These are the primary causes of intestinal pseudoobstruction: disorder characterized by symptoms of intestinal obstruction with evidence of delayed small intestinal transit |
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Term
| Diabetes/idiopathic and postsurgical complications contribute primarily to which type of impaired motor function? |
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Definition
| gastroparesis - disorder characterized by symptoms of gastric retention with evidence of delayed gastric emptying |
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Term
persistent or recurrent regurgitation of recently ingested food with remastication and swallowing and regurgitation not preceded by retching (effortless)
• Diagnosis supported by lack of nausea, cessation with acidic regurgitation, regurgitation of recognizable food |
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Definition
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Term
| bothersome nausea several times weekly, not usually associated with vomiting, absence of organic or metabolic disease |
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Definition
| Chronic idiopathic nausea |
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Term
| Cyclic vomiting syndrome |
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Definition
| stereotypical episodes of vomiting regarding onset (acute) and duration (<1wk); >=3 discrete episodes in the past year; absence of N/V between episodes; symptom onset >6 months |
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Term
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Definition
| on average, at least one vomiting episode per week; absence of eating disorder, self-induced vomiting, rumination, major psychiatric disease; no CNS or metabolic cause to explain symptoms |
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Term
| What are possible abnormalities in the stomach that can => delayed emptying in gastroparesis? |
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Definition
Fundus - altered compliance
Antrum - reduced fasting/fed contractions
Pylorus - inc tone and phasic contractions
Intestine - duod/jej burst contractions |
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Term
| What is the contribution of abnormal myoelectric function to gastroparesis? |
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Definition
impaired pacemaker control of gastric contractions (slow wave)
Pacemaker in body region of stomach generates electrical slow wave that cycles continuously at 3 cycles/min
Regulates frequency and direction of contractions
Produced by ICC (distinct cells from neurons, smooth muscle)
Abnormal slow wave frequencies in many patients with gastroparesis, functional vomiting, pregnancy, motion sickness |
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Term
vomiting patterns in terms of time - what does it mean?
hours, minutes, and early morning |
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Definition
Hours after eating: gastric obstruciotn, gastroparesis
Minutes after eating: rumination, psychological causes
Early morning: hormonal (e.g. pregnancy), increased ICP |
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Term
| what are the main consequences of persistent vomiting? |
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Definition
| dental disease, neck or facial petechiae (if vomiting is violent), Na or K depletion, metabolic alkalosis, GI bleeding from violent vomiting itself (Mallory-Weiss tear at GE junction, hemorrhagic gastropathy) |
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Term
| Lab tests to be done on vomiting patietn? |
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Definition
Electrolytes: hypokalemia, metabolic alkalosis
Metabolic: BUN/creat (renal insuff can cause N/V), glucose (DM can cause N/V, pregnancy test
Complete blood count
• Anemia: bleeding, malignancy, chronic disease
• Leukocytosis: inflammation
• Leukopenia: viral infection
Special tests: liver and pancreas chemistries, thyroid chemistries, cortisol (testing for Addison’s), rheumatologic and paraneoplastic serologies |
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Term
| Measuring gastric emptying...Which tests? |
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Definition
Gastric scintigraphy (nuclear med test): radioactive test that assesses gastric emptying over time (e.g. 64% retained at 1 hr, 24% retained at 2hr etc.)
Breath tests: can measure gastric empyting by measuring rate at which C-13 (from tagged food) is exhaled as CO2 (from breakdown of tagged food)
Wireless motility capsule: pH sensor and pressure sensor (measure contractions)
GI Manometry: done less often because pts don’t tolerate well. Used to detect small bowel abnormalities. Catheter placed with pressure ports in antrum and duodenum
• Can help find and differentiate myopathic causes and neuropathic causes of small intestinal pseudoobstruction
o Myopathic: familial visceral myopathies, advanced scleroderma, dermatomyositis, muscular dystrophies, advanced amyloidosis
o Neuropathic: familial visceral neuropathies, DM, early scleroderma, early amyloidosis, Chagas disease, paraneoplastic neuropathy
Of research interest: MRI, Ultrasound, Single photon emission tomography (SPECT) |
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Term
| T/F: Eating bigger meals that are higher in fat to fulfill satiety is an effective way to prevent vomiting. |
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Definition
False: o Non-medication therapy of N/V
Frequent small meals
Ingest foods that empty rapidly: liquids, low fat, low fiber
Early IV fluids for: dehydration and electrolyte disturbance, unable to drink fluids, extreme age |
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Term
| Name the two classes of drugs that act at the vestibular apparatus. What do these drugs do? |
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Definition
H1 Histamine antagonists, muscarinic cholinergic antagonists
• Muscarinic cholinergic antagonists
o E.g. scopolamine, hyosycamine
o Main site of action: vesibular apparatus
o Uses: motion sickness, labyrinthine diseases
• Histamine (H1) antagonists
o E.g. dimenhydrinate (Dramamine), promethazine
o Site of action: vestibular apparatus
o Uses: motion sickness, labyrinthine diseases |
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Term
| thiethylperazine is a drug that is a useful antiemetic. Where does it act and what class is it in? |
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Definition
area postrema
dopamine antagonists |
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Term
| a cancer patient has come to you for some help w/ her nausea a/w her acute chemo treatment. which classes of drugs can you use for her? where does it work? |
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Definition
NK1 antags - best suited for acute and delyaed chemo-induced nausea and vomiting. works at the BRAINSTEM.
dopamine antags, 5HT3 antags, Cannaboid receptor are for chemo-EMESIS |
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Term
| ondasetron and granisetron are drugs used for (acute/delayed) chemo-induced emesis and act on the area postrema and ________ |
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Definition
| these are 5HT3 antags for ACUTE emesis, and also act on the peripheral sensory nerves |
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Term
| If you want to reduce the sensation at stomach, what can you use? |
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Definition
| TCAs for FUNCTIONAL vomiting (acts at sensory nerves, cns) |
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Term
| metoclopramide and erythromycin are drugs in ____ and ____ class, and cause ____________. However the drawbacks of erythromyicin are ______ and _______. |
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Definition
Prokinetics: drugs that lead to accelerated stomach emptying
• Metoclopramide:
o Mechanism: 5-HT4 agonist, dopamine antagonist, 5-HT3 antagonist
o Both prokinetic (antidopaminergic) and antiemetic effects
o 25-40% intolerable side effects (dystonia, hyperprolactinemic, tardive dyskinesia)
• Erythromycin:
o Mechanism: motilin agonist (somatch and duodenum)
o Pure prokinetic
o Narrow therapeutic range – cause nausea and vomiting at high doses
o May induce tachyphylaxis |
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Term
| What are two surgical therapies for gastroparesis? |
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Definition
• Pyloric injection of botulinuum toxin for gastroparesis
• Implantable neurostimulator for gastroparesis
o Uncontrolled studies show reduced N/V
o Does not accelerate gastric emptying |
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