Test 3 aka Final Flashcards
• Identify four standard monitors for the intubated patient undergoing general anesthesia
- Oxygenation- oxygen analyzer, pulse ox
- Ventilation- capnography, ETCO2
- Circulation- ECG, BP q5min
- Body Temp- should be READILY AVAILABLE
• Describe the role of the oxygen analyzer in avoiding a hypoxic mixture of gases
located in the inspired limb and is calibrated to RA 21%; measures downstream from flowmeters
• Identify the single monitor which provides the most clinical information
pulse oximetry
• List wavelengths of oxygenated and deoxygenated blood and describe how this
generates pulse oximeter readings
Oxygenated- 960 nm (katrins notes say 990)
Deoxygenated- 660 nm
Differ in their absorption of red and infrared light; change in light absorption when passing through vascular bed during arterial pulsation is the basis for oximetric readings
List three clinical scenarios which may result in decreased oxygen saturation
V/Q mismatch, disconnect, inadequate MV, misplaced ET tube, diffusion abnormality
List eight locations which may be used to monitor oxygen saturation
finger, nose, earlobe, forehead, lip, tongue, cheek (couldn’t find an eighth one)
List eight factors affecting pulse oximeter accuracy
electrocautery, motion/venous pulsations, ambient light/radiant warmers, nail polish/acrylic nails, low perfusion, CO/Methemoglobin, methylene blue(false low), hypothermia, tourniquet, IABP/CPB
• Identify monitoring standards for accuracy, signal adequacy and mandatory alarms (in reference to saturation)
Accuracy b/t 70-100% mandatory alarm for sat <85% (must be stated if accurate below 65%), indication for signal inadequacy, indication if lag time for data, indication if affected by motion
• List four uses for pulse oximetry besides measuring oxygen saturation
Estimate of SBP, monitoring peripheral circulation, locating arteries, warning of fluid extravasation
• Identify the most commonly used technology used for anesthesia gas monitoring
Infrared analysis
• Describe how infrared technology works in relation to measuring anesthesia gas concentration
Based on the principle that gases with 2 or more dissimilar atoms have specific infrared light absorption; the amount of IR light absorbed is proportional to the concentration of the absorbing molecules; gas concentration may be determined by comparing IR light absorption to known standard
• Compare and contrast limitations of non- diverting and diverting gas monitors
Nondiverting- “mainstream”, sensor located directly in gas stream, more accurate, no gas removed, must be placed close to patient (cumbersome), expensive
Diverting- requires water trap for condensation, accuracy decreases with increasing RR and longer sampling lines, requires TV 150 ml, must be beyond HME, particulate matter may clog line, if FGF high may have dilution, larger gradient but less cumbersome
• List four limitations of IR technology
Gas interference, oxygen may interfere with CO2 accuracy, overlap of CO2 and nitrous IR peaks, mixture of agents causes erroneous readings, interference from water vapors
• Discuss accuracy standards for capnometry
CO2 reading will be within 12% of the actual value or 4 mmHg, manufacturer must disclose any interference by inhalation anesthetics,
• Describe mandatory alarms for capnometry
capnometer must have a high CO2 alarm for both inspired and exhaled CO2, mandatory alarm for low exhaled CO2
List four factors associated with a decrease in ETCO
2
hyperventilation, respiratory obstruction, poor mask/LMA fit, malposition of ETT, embolism/hypoperfusion, diffusion issue, cardiac arrest
List four critical clinical events detectable by gas analysis
machine malfunction, disconnect, vaporizer malfunction, circuit leaks, ETT cuff leak, hypoventilation, MH, Airway obstruction, Air embolism, circuit hypoxia
List four sources of heat loss during anesthesia
Radiation, evaporation, convection, conduction
Identify four deleterious effects associated with hypothermia during anesthesia
shivering, decreased metabolism of drugs, prolonged emergence, increased bleeding, N/V, poor wound healing
Identify five clinical scenarios associated with a higher risk of hypothermia
elderly/neonates/peds, burn patients, pts with spinal cord injuries, open abdomen/chest, cold room
Identify the most effective method of keeping the patient warm
Increase ambient temperature
Identify the BIS range associated with a surgical plane of anesthesia
BIS 40-60
List four potential monitoring sites for nerve stimulators
Ulnar nerve (most sensitive), median nerve, tibial nerve, posterior tibial nerve, peroneal nerve, facial nerve, mandibular nerve
• Compare and contrast nerve stimulator monitoring for depolarizing and nondepolarizing
muscle relaxants
Nondepolarizing- decreased twitch height, fade during tetany, fade during TOF, T4/T1 <0.7, post-tetanic potentiation, absence of fasciculations, antagonism of block by Achase
inhibitors, augmentation by NDMR
No slide on depolarizing*
