Clinical Monitoring Flashcards
(21 cards)
What is a scope of practice defined by the AANA?
Responsibility associated with anesthesia practice using a collaborative method with other healthcare providers
What are AANA Standards?
Minimum rules & responsibilities
- Expected behavior
What are AANA guidelines?
Statements to assist an anesthesia provider with clinical decision making
What are the standards for monitoring? (5)
- Monitor, evaluate, and document patient’s condition
- Alarm on & audible
- Continuous attendance unless relived by another anesthesia professional
- Professional judgement may determine additional monitoring per patient condition, type of surgery or anesthetic
- Oxygenation = Continuous monitoring of oxygenation by clinical observation & pulse oximetry
- Mitigate fire risk = prevent events from occurring
Ventilation Regulation
- Continuously monitor using clinical observation & ETCO2
- Intubation via chest excursion, auscultation, & expired CO2
Cardiovascular Regulations
- Continuously monitor HR & CV status
- Monitor & evaluate circulation to maintain homeostasis
Thermoregulation Regulations
- Monitor when expect change in temp to maintain normothermia using active measures
- Recognize malignant hyperthermia (increased temp is a late sign, 1st sign is a spike in ETCO2)
Neuromuscular Regulations
- Monitor depth blockade & degree of recovery
Anesthesia monitors
You are a monitor:
- Sight, hearing, touch
- Stethoscope, sphygmomanometer (BP), electrocardiograph
Supplemental:
- Pulse ox
- Expired gas analyzer
- Evoked potential monitors
- Transesophageal echocardiograph
What is the difference between Error, Reliability, and valid
Error = deviation from the “Gold Standard”
Reliability = is it measuring the parameter the same way every time?
Valid = is it measuring what you intend it to measure?
- zeroing an A-line to make sure it is measuring what we think it is measuring
Who gets a pulse ox?
Everyone gets pulse ox despite the level of anesthesia
- Part of WHO safe surgery checklist
What is oximetry?
The measurement of the O2 saturation of Hgb in a sample
- uses pulsatility of arterial blood flow
- looks at the ratio of absorbed red & infrared light in tissue using the Beer Lambert Law
- Probe is a combo of light emitter & photo decor.
Where does the pulse ox signal get read?
The pulse ox is read during the pulse of the artery b/c that is the only time we have variation between the deoxygenated Hgb & the oxygenated Hgb
- the Alternating Current = pulsatile arterial blood flow
- Direct Current = absorption from tissue, venous, capillary, and non-pulsatile arterial blood
Deoxygenated Hgb = absorbs more red light (660 nm) - darker
Oxygenated Hgb = absorbs more infrared light (940 NMB)
AC660/DC660 R= ————————- AC940/DC940
What are the general ratios of absorption of light
- Red/IR ratio of 0.5 = 100%
- Red/IR ratio of 1.0 = 85%
- Red/IR ratio of 2.0 = 50%
- per regulation - accuracy of the pulse ox has to be within 4%
What 2 factors determine oxygen delivery
(Do2) Oxygen Delivery = Arterial O2 content x Cardiac output
Arterial O2 content = (1.34 x SaO2 x Hgb) + 0.0031 x PaO2
- 1.34 mL/g is the O2 binding capacity of Hgb
- SaO2 is the Hgb O2 saturation
- Hgb is the concentration of Hgb in the arterial blood
- 0.0031 is the solubility of O2 in the blood
- PaO2 is the arterial partial pressure of O2 (mmHg)
O2 saturation is a major component of O2 content & a major component of oxygen delivery in the body
What are the 4 species of Hemoglobin
- Oxygenated Hgb
- Deoxygenated Hgb
- Met Hgb
- CO Hgb
O2Hgb can be functional or fractional SaO2
- Functional is the pulse ox reading
- Fractional SaO2 = the amount of O2Hgb as a fraction of the total amount of Hgb
- to obtain fractional SaO2 you have to use co-oximetry
- know which Hgb are occupied by oxygen
- House fire & smokers have more CO
What is the pulse ox response time
Pulls data for 5- 8 seconds before displaying
A Desaturation reading takes even longer to show up
- Ear up to 20 sec
- Finger up to 35 sec
- Toe up to 73 sec
- Ear/Forehead least sensitive to low amp states
Advantages of Pulse Ox (10)
- No contraindications to use
- Accurate when O2 sat > 70%
- Convenient
- Continuous
- Noninvasive
- Not affected by anesthetic vapors
- May indicate decreased cardiac output
- Tone modulation (makes you respond)
- Probe variety
- Battery operated
What are the limitations of the Pulse ox
- Erratic performance with dysrhythmia
- Delayed hypoxia event detection
- Does not provide:
- Tissue oxygenation
- Acid/base status
- Presence of other dysHgb
- Hyperoxia (does not go above 100%)
- Septic patients have decreased tissue oxygenation d/t edema & extracellular fluid
When might the Pulse ox be inaccurate (7)
- Saturation < 70% (look up table did not collect data < 70)
- Hypotension
- Motion artifact (hypothermia)
- Variant Hgbs (COHgb & MetHgb) - nitrates (ICU patients), local anesthesia, malaria drugs)
- Intravascular dyes (methylene blue, indigo carmine, indocyanine green
- shows a temporary decreased sat that is false
- Nail polish (black, dark blue, purple)
- Intra-aortic balloon pump & continuous flow devices = no pulsatile flow
What is Photoplethysmography
Waveform tracing sensitive to changes in fluid volume & intravascular pressure - tries to determine if they will respond to fluid expansion or presser
Variation in amplitude = predicts fluid responsiveness in mechanically ventilated patients
- Reliability compromised in negative pressure ventilation and presence of arrhythmias - Spontaneous breathing patient changes the intrathoracic response w/ barorecptors
