Lecture 1: N/V Flashcards
How long is the digestive tract?
33 ft
What are the 6 primary functions of the GI system?
- Ingestion
- Mechanical digestion and propulsion
- Chemical Digestion
- Secretion
- Absorption
- Defecation
What is considered the middle part of the GI system and what occurs in it?
- Duodenum, jejunum, and ileum
- Most digestion and absorption occurs here!
How does the GI system increase its surface area?
- Ridges
- Folds
What is emesis?
- Retching
- Follows nausea
- Expulsion of GI contents
What is rumination syndrome?
Chewing and swallowing food that has been regurgitated
What are the 3 things that control the motor function of the gut?
- Parasympathetic and sympathetic nervous systems
- Enteric brain neurons
- Smooth muscle cells
How many cycles occur per minute in the gastric cycle?
3 cycles per minute of smooth muscle contraction in the stomach.
Nausea shifts this
What are the two irregular rhythms of stomach motility?
- Tachygastria
- Bradygastria
What are the 4 sources that can stimulate vomiting?
- Afferent vagal fibers from GI viscera (GI distention
- Fibers of the vestibular system (sea-sickness, dizziness)
- Higher CNS centers (smells, sights, emotion)
- Chemoreceptor trigger zone (area posterna)
What virus is most likely implicated with vomiting 24-48 hrs post ingestion?
Norwalk-like viruses
What does acute onset of N/V w/ severe pain suggest for etiology?
- Peritoneal inflammation
- Acute gastric/intestinal obstruction
- Pancreatobiliary disease
What does persistent N/V suggest for etiology?
- Pregnancy
- Gastric outlet obstruction
- Gastroparesis
- Intestinal dysmotility
- Psychogenic disorders
- CNS/Systemic disorders
What does morning N/V suggest for etiology?
- Pregnancy
- Uremia
- Alcohol intake
- Increased ICP
What improves cannabinoid hyperemesis syndrome usually?
A hot bath
If a person constantly vomits right after meals, what is the suspected etiology and how might you check?
- Bulimia
- Perform a TEETH exam!
What does feculent vomiting suggest?
Intestinal obstruction
What should abdominal XRAY show for SBO? Ileus?
- SBO: Intestinal air-fluid levels with reduced colonic air.
- Ileus: Diffusely dilated air-filled bowel loops.
Order Flat and upright XRAY if sus of mechanical obstruction.
How does EGD often present?
Normal
What complications should we be wary about in someone with persistent vomiting?
- Volume depletion/dehydration
- Lyte disturbances
- Aspiration
- Mallory-Weiss tear
- Boerhaave syndrome (Esophageal rupture)
What two things should we always check in someone vomiting?
- Volume status
- Lyte status
What food type should we avoid in someone vomiting that we are attempting to PO test?
Lipids
Lipids delay gastric emptying
What is the overall goal of replacement fluid therapy?
- Correct volume status
- Correct lyte abnormalities
What is unique about replacing mild hypovolemia?
Positive fluid balance is preferred.
Infusing slightly more fluid than the rate of loss.
What electrolyte abnormality should NOT be corrected fast?
Natremias
What is the MOA of zofran/ondansetron?
Serotonin 5-HT3 receptor agonist
Blocks stimulation of vomiting center in medulla.
When is zofran NOT used for N/V?
- First trimester!!!
- QT prolongation
Cleft palate defect could occur.
What kind of patients should zofran use be cautionary in?
Hepatic impaired.
What is the MC SE of zofran?
HA
What are the preferred medications for N/V in pregnancy?
- Scopolamine
- Meclizine
- Doxylamine
Anticholinergics/anthistamines
Any of these + vit B6 (pyridoxine) + doxylamine = recommended
How does promethazine work?
1st gen H1 blocker.
Used for acute N/V only.
What are the serious SEs of promethazine?
- Respiratory depression
- Extrapyramidal SEs
- Bradycardia
What are the BBWs for promethazine?
- Respiratory depression
- Tissue necrosis/injury
Who is promethazine specifically contraindicated in?
Children under 2 due to risk of respiratory depression.
Gotta be a pro to take promethazine
How does metoclopramide work and when do we use it?
- Prokinetic
- Used as adjunct for N/V, gastroparesis, and refractory GERD.
Meto makes you move
What are the main serious SEs of metoclopramide?
- Extrapyramidal SEs
- Neuroleptic malignant syndrome
- Lowers seizure threshold
Malignant meto
What is the BBW of metoclopramide?
Tardive dyskinesia
When is metoclopramide contraindicated?
- Seizure d/o
- GI obstruction
Taper med off.
When is lorazepam commonly administered for N/V?
Prior to chemo along with zofran
What history might preclude us from using promethazine for a N/V patient?
COPD
Promethazine causes respiratory depression.
What is preferred medication therapy for N/V during pregnancy?
Vit B6 + doxylamine
UTD says this is the first-line therapy before the anticholinergics but u can add scopolamine or meclizine i guess
