Week 6: Anesthesia Monitoring Flashcards
The purpose of monitoring
- Assist with data collection regarding patient’s physiologic status.
- Guide the administration of the anesthetic
-Enhance situational awareness
-Extend the senses
-Not a substitute for a qualified provider.
Standard I
Qualified anesthesia personnel shall be present in the room throughout the conduct of all general, regional, and monitored anesthesia care (MAC).
** the ASA and AANA standards for basic anesthetic monitoring.
Standard II
During all anesthetics, the patient’s:
- oxygenation, -
- ventilation,
- circulation, and
- temperature shall be continually evaluated.
** the ASA and AANA standards for basic anesthetic monitoring.
purpose of oxygenation monitoring
To ensure adequate oxygen concentration in the inspired gas and the blood during all anesthetics.
Methods to ensure oxygenation.
Inspired gas:
- Oxygen analyzer with LOW concentration limit alarm.
Blood oxygenation:
- Pulse oximeter with pitch and threshold alarm.
- Adequate visual inspection.
Purpose of monitoring ventilation
To ensure adequate ventilation throughout anesthetic
Oxygen concentration in the blood is objectively measured by a blood gas/ lab. That is the saturation of arterial blood gas, the ___________.
SaO2
FiO2 monitoring can be waived under certain circumstances – T/F?
True
** it is a monitor it is not YOU. Monitors themselves are not the providers.
As AANA stardard of care, BP cycles intervals should occur under _______ or less. What are the common options?
<5 minutes.
Options 2.5, 3, 5
Methods of ensuring adequate ventilation:
- Auscultation, reservoir bag, chest excursion .
- Quantitative measure of expired gas and capnography.
- Ability to detect disconnection from ventilator.
How to ensure adequate circulatory function during all anesthetics?
- EKG and HR,
- BP ( cycles cannot exceed <5 minutes)
- palpation of a pulse
- Auscultation of heart sounds.
- monitoring of a tracing of intra-aterial pressure.
- ultrasound peripheral pulse monitoring.
- pulse oximetry (also monitors HR)
The skin temperature monitor adjusts quickly but it only monitors the area where you place it at. T/F
False; not quick enough.
To aid in the maintenance of appropriate body temperature during all anesthetics when clinically significant changes in body temperature are intended, anticipated or suspected.
4 methods to achieve this:
Temperature monitoring.
- skin (least accurate)
- nasal
- esophageal
- pulmonary artery catheter (GOLD STANDARD)
Form of human error occurring when a practitioner is desensitized to alarms or alerts.
Alarm Fatigue
** deaths have been attributed to alarm fatigue.
AANA Practice ________ indicates that alarm limit parameters and audible warning systems should be used,
Standard V
** the ideal monitoring device should elicit the minimal number of false alarms.
Four Stages of Oxygen Transport
- Lungs **
- Arterial blood **
- Tissue
- Venous blood
How can you check lungs O2 (inspired/expired gas)?
- noninvasive:
noninvasive:
- FIO2 meter (fuel cell, polarographic, paramagnetic).
- Mass spectrometer
- Raman spectrometer
- Magnetoacoustic
** no invasive way
How can you check arterial blood O2?
- noninvasive:
-invasive:
noninvasive:
- pulse oximeter
invasive:
-intraarterial optode
-clarke electrode
How can you check tissue O2?
- noninvasive:
-invasive:
noninvasive:
- transcutaneous PO2
- niroscope
- cerebral oximeter
- skin color
invasive:
- organ surface PO2 (ex. liver, brain)
- intramuscular fiberoptic
How can you check venous blood O2?
-invasive:
Fiberoptic pulmonary artery oximeter (SvO2)
** no non-invasive way.
Oxygen Analyzers (FiO2 meters) goal:
Goal is to detect hypoxia or hyperoxia
Oxygen Analyzers (FiO2 meters) - what does it monitor?
Monitors the fraction of inspired oxygen (FiO2) -controlled by CRNA.
where is Oxygen Analyzers (FiO2 meters) placed?
Placed in the inspiratory arm to ensure oxygen going to the patient
Fuel (_______) cell
Polarographic (_______) electrode.
Both are what type of analysis ?
Galvanic;
Clark
Electrochemical analysis
3 main methods of Oxygen Analyzers (FiO2 meters):
Electrochemical analysis
- Fuel (Galvanic) cell
- Polarographic (Clark) electrode.
- Paramagnetic analysis (Pauling).
This electrochemical analysis must be calibrated:
Fuel (Galvanic) cell.
Why can’t these be used to ensure oxygenation?
-Fail-safe valve
-Second-stage O2 pressure regulator
-O2 pipeline supply
because they all belong to the intermediate system.
Low O2 concentration alarms given hypoxic mixtures due to:
- Pipeline crossover
- Incorrectly filled storage tanks
- Failure of the proportioning system
High O2 audible and visual concentration alarms are used:
- Used with neonates
- On the inspiratory limb of the breathing system.
- Used to monitor inspired and end-expired oxygen.
- Preoxygenation and end-tidal oxygen greater than 90%, airway fire (<30%).
Fuel (Galvanic) Cell Oxygen Analyzer
Fundamentally an oxygen battery. (Oxygen is the fuel)
**It must be calibrated daily.
** The components may need intermittent replacement.
Fuel (Galvanic) Cell Oxygen Analyze is a breath by breath analysis. T/F
False - it is a metric of AVERAGE O2 in the inspiratory limb
where is Fuel (Galvanic) Cell Oxygen Analyzer placed?
Usually located in the inspired limb of the anesthesia circuit.
Fuel (Galvanic) Cell Oxygen Analyzer takes how long to respond?
Is slow (~30 sec) to respond
Fuel (Galvanic) Cell Oxygen Analyzer includes a ________ concentration alarm.
low O2
In a fuel (Galvanic) cell oxygen analyzer, ____________ compensation is required for accurate measurement. It also creates its own _________ potential.
Temperature;
Polarizing
Describe how the Fuel (Galvanic) Cell Oxygen Analyzer works:
Oxygen in the gas sample permeates a membrane and enters a ___________.
An electrical potential is established between a noble metal (e.g., gold, platinum) ______ and _______ (e.g., lead, zinc).
The measured _________ between the electrodes is proportional to the oxygen _______(PO2) of the gas sample.
KOH solution;
Cathode; & Anode
voltage; tension
how does the Polarographic (Clark) Electrode work?
Oxygen diffused via a membrane and electrolytes to the cathode and a similar reaction occurs like the fuel cell.
The current is proportional to the number of oxygen molecules surrounding the electrode.
The main difference between the Polarographic (Clark) electrode and the fuel cell is that it requires an:
EXTERNAL polarizing potential (a battery)
What is the name of the relationship between flow, pressure and resistance?
Ohm’s Law
Ohm’s Law and what does each letter mean?
I = V/R
I is current (flow) in amperes;
V is voltage (pressure) in volts;
R is resistance in ohms.
Molecular oxygen has two electrons in unpaired orbits, it is:
paramagnetic
** the result of an unpaired electron having a magnetic dipole moment
This electrochemical analysis must be calibrated:
Fuel (Galvanic) cell.
to 21%
When a sample and a reference O2 streams are passed through a magnetic field, the difference in concentrations creates a _______.
This is seen in what O2 analyzer?
pressure differential
Paramagnetic O2 analyzer.
What are the advantages of a paramagnetic O2 analyzer? (4)
- There are no replaceable parts.
- It is self calibrating.
- Fast response time
- Permits continuous breath by breath monitoring of FiO2.
In a Paramagnetic O2 Analyzer
Increasing oxygen tension creates an increased ___________.
A pressure wave is generated and sensed,
Then converted to an electrical signal proportional to PO2 and displayed as ________.
magnetic tension;
Volume %
Adequate FiO2 does not equal Adequate SaO2 (T/F)
True.
Pulse Oximetry measures:
Measures pulse rate and oxygen saturation of hemoglobin (SpO2)
** not the same as SpO2
SpO2 (%) is related to oxygen tension (mmHg); specifically the:
Hemoglobin Dissociation Curve
Pulse Oximetry is affected by (2):
hypothermia and hypoperfusion
Pulse oximetry is noninvasive, easy to use, and risk-free (T/F)
F - ALMOST risk free.
Pulse oximetry works on what pulsation?
Arterial pulsation ONLY.
Pulse Oximetry Premises
- The color of the blood is a function of _________.
- The change in color results from the optical properties of Hb and its interaction with O2.
- The ratio of oxyhemoglobin (HbO2) to hemoglobin (Hb) can be determined by absorption ______________.
O2 saturation;
spectrophotometry
Under what assumption does the pulse oximeter work on? and why is this assumption incorrect?
That Hemoglobin is either bound to O2 or it is not bound to O2.
** it is incorrect because there are other species of Hgb but the pulse ox cannot detect them.