Final, Lecture 2 Flashcards
Where the vomiting center lies
Medulla
4 Inputs to the vomiting center
GI tract,
cerebral cortex/thalamus,
vestibular region,
chemoreceptor trigger zone
Nausea/Vomiting Triggers
General Anesthetics Histamine Serotonin Dopamine Opioids Acetylcholine Inflammatory mediators involved n nociceptive pathways
Risk factors for N/V
Female
Nonsmoker
History of motion sickness
Anesthetic agents that INCREASE the threshold for PONV
Propofol
Midazolam
General mechanism for antiemetics
Receptor antagonists at the vomiting center
Most commonly used antiemetic classes
Serotonin antagonists Dopamine antagonists Anticholinergics Glucocorticoids Histamine antagonists Neurokinin 1 antagonists
Antiemetics we give at OSU
Ondansetron (Zofran) - Serotonin antagonist
Dexamethasone (Decadron) - Glucocorticoids
Dosing for OSU antiemetics
Dexamethasone and Ondansetron - 4 mg IV
Antiemetic patch used
Scopolamine
Antiemetic that can cause gangrene
Promethazine (phenergan)
Management of Vomiting pt
Tredellenberg position
Turn on their RIGHT
Supplemental O2
Auscultate
Must be measured Continually during GA
Oxygenation
Ventilation
Circulation
Temperature
DEF: Oxygenation
Transport of oxygen from atmosphere to the alveoli and eventually the tissues
How to measure oxygenation
Pulse oximetry
Color of mucosa, skin, blood
Primary determinants of oxygen content
Hemoglobin concentration and oxygen saturation of Hb
Pulse oximetry shows
% of total hemoglobin saturated w/ O2
Normal oxygenation reading
95-100%
How pulse oximeter works
Shoots red and infrared lights through finger to see ratio of deoxy to oxy hemoglobin
More infrared light absorbed means
More oxyhemoglobin
Ventilation
Observe chest excursions
Auscultate breath sounds or monitor end-tidal volume
DEF: Ventilation
Process of moving air into and out of lungs
DEF: Capnography
Measures carbon dioxide concentration in exhaled air
Typical partial pressure of CO2
40 mmHg
Capnogram waveform phases
Phase 1 - exp begins but at first just CO2 less dead space air
Phase 2 - mix of CO2 and dead space air exp
Phase 3 - exhaled gas almost entirely alveolar
Phase 0 - inspiration
Shark fin appearance Capnogram
Bronchospasms- asthma, COPD
Circulation monitoring
Continually, document BP and HR every 5 min
Continuously w/ EKG if have heart hx
Normal hemoglobin levels
12-14 for females, 14-15 for males
Anemia affect on hemoglobin
Lowers Hb levels
Normal amount of O2 a Hb can carry
1.34
PP of 02 in blood at 90% pulse oximetry reading
60 mmHg - this is the low threshold for hypoxia- will get beeping
pO2 if pulse oximetry reads 97%
97 mmHg - normal
Cause Hb dissociation curve to shift to right
Acidic environment (Dec pH)
Inc in metabolism
Inc CO2
Inc 2,3 GTP
End tidal volume you want to maintain during CPR
10 mmHg CO2
Type of hypertension more common in younger people
Diastolic Hypertension- due to exaggerate cathecholamines
Isolated Systolic HT
Seen in elderly people with stiffening of arteries
Most common symptom of high BP
Headache
EKG Lead 1
Right shoulder (-) to left shoulder
EKG Leade 2
Right shoulder to left leg
EKG Lead 3
Left shoulder to left leg
Colors of EKG things
White on right, smoke over fire on left
PONV
Prior motion sickness
Opioids
Non-smoker
Female
