I&M: Introduction to Noninvasive Perioperative Monitoring Flashcards
Noninvasive, invasive?
Puncturing skin? Inserting instrument or foreign material into body?
Noninvasive - BP, EKG
Invasive - arterial line
Continuous, continual?
Repeated regularly and frequently in steady rapid succession (continual)?
Prolonged without interruption (continuous)?
Continual - BP, twitch (every 15min)
Continuous - pulse ox, capnogram, EKG, arterial line
Iatrogenic
Harm to the patient caused by provider
Artifact
Interference, altered data
ASA Standards
- Qualified anesthesia person in room at all times
2. Patient’s oxygen, ventilation, circulation and temp shall be monitored
Pulse oximeter
Non-invasive measurement of arterial blood using two wavelengths of light: 660nm (red) - deoxyhemoglobin, 940nm (infrared) - oxyhemoglobin. The difference in light absorption during systolic pulsation determines reading.
Waveform gives idea of tissue perfusion–small waves may indicate weak blood flow.
Normal saturation: 97-100%
Oxy-hemoglobin dissociation curve
Slippery slope when pulse-ox reading reaches ~90%. PaO2 is ready to drop exponentially.
ALSO, there is a slight delay between what’s happening with patient and what’s on the monitor.
Right shift - decreased Hb-O2 affinity ↑H+, ↑PCO2 ↑Temp
Left shift - increased Hb-O2 affinity ↓H+, ↓PCO2 ↓Temp
Ventilation
Can be monitored with ETCO2, chest excursion, auscultation of breath sounds, movement in reservoir bag. ETCO2 can be measured with capnography, capnometer, mass spec.
Capnography also experiences slight delay between what’s happening with the patient and what’s on the monitor.
Circulation
EKG, BP and HR (at least every 3-5min)
At least one of the following: pulse palpation, auscultation of heart sounds, arterial line, pulse oximetry
Blood pressure cuff
MAP = DBP + 1/3PP PP = SBP-DBP
Can be placed on upper arm, forearm, calves
Don’t place cuff on arm with AV graft or fistula, surgical field, or where lymph node dissection has occurred (mastectomy)
EKG
Usually monitor leads II and V in adults and lead II in children. Lead II is the vecter between the W lead and the R lead.
White - right
Black over Red - smoke over fire
Green = grounding - can really go anywhere
Brown - axillary 5th intercostal space
Temperature
Normal body temperature regulation is inhibited by anesthesia –> patients get cold. Patient can be kept warm with a bair hugger kept at ~40C
Thermistors can be placed in nose, esophagus, rectum, on skin, oropharynx, armpit.
Other common monitors
Foley bags - determine urine output
Acceptable = 0.5-2.0ml/kg/hr
Nerve stimulator - commonly placed on ulnar or facial nerve to monitor paralysis
Esophageal stethoscope - positioned right behind the heart, so can listen to heard and lungs during anesthesia; can also be used as temperature probe
