9 June 25 Clinical Monitoring Pt2 Flashcards
(108 cards)
1
Q
What is the primary purpose of clinical monitoring in anesthesia?
A
To ensure patient safety and assess physiological parameters during anesthesia.
2
Q
What technique is commonly used to insert an arterial line?
A
Seldinger technique.
3
Q
What is the square wave test used to assess?
A
Damping of arterial line waveforms.
4
Q
What does systolic pressure variation (SPV) indicate?
A
Variations in systolic pressure related to respiratory cycles, specifically end-expiratory pressure.
5
Q
What is the normal range of systolic pressure variation in mechanically ventilated patients?
A
7 to 10 mmHg.
6
Q
What physiological changes occur during positive pressure ventilation?
A
Increased left ventricular preload and decreased right ventricular preload.
Remember, alveolar and extra-alveolar vessels are being compressed with positive pressure. This means that less blood is returning to the heart and blood in lung vessels is being squeezed out into the left atria/ventricle more rapidly.
7
Q
What is the significance of pulse pressure variation?
A
It assesses the maximum and minimum pressure over the entire respiratory cycle.
8
Q
What is the normal range for pulse pressure variation?
A
Less than 13%.
9
Q
What does stroke volume variation (SVV) measure?
A
Variations in stroke volume during the respiratory cycle.
10
Q
What is the normal range for stroke volume variation?
A
10 to 13%.
11
Q
What factors can affect preload during surgery?
A
- Positive pressure ventilation * Thoracic pressure changes * Lung volume changes.
12
Q
What type of monitoring can provide inaccurate information for patients who are older or in unstable rhythms?
A
Stroke volume variation monitors.
13
Q
What is the purpose of expired gas analysis in anesthesia?
A
To monitor the composition of gases during ventilation.
14
Q
What are the two types of gas sampling methods?
A
- Non-diverting (mainstream sampling) * Diverting.
15
Q
What does a high systolic pressure variation indicate?
A
Possible volume responsiveness.
16
Q
Fill in the blank: Systolic pressure variation is measured at _______.
A
End expiratory pressure.
17
Q
True or False: A decrease in right heart stroke volume can eventually decrease left heart stroke volume.
A
True.
18
Q
What is the consequence of hypervolemia on Starling’s curve?
A
It can worsen cardiac output.
19
Q
What is the relationship between thoracic pressure and venous return?
A
Increased thoracic pressure decreases venous return.
20
Q
What is the initial intervention if a patient is deemed volume responsive based on pulse pressure variation?
A
Fluid bolus.
21
Q
What is a limitation of traditional stroke volume variation monitors?
A
They require an arterial line and specific patient parameters.
22
Q
What does a decrease in systolic pressure variation below normal ranges indicate?
A
Fluid may not correct the underlying problem.
23
Q
What is the significance of monitoring expired gas analysis?
A
It assesses ventilation efficiency and gas exchange.
24
Q
What can happen if fluid is administered without addressing the underlying cause of hypotension?
A
It can lead to hypervolemia and worsen the patient’s condition.
25
Fill in the blank: The square wave test helps determine _______ in arterial line monitoring.
Damping.
26
What parameters are needed for accurate stroke volume variation readings?
* Age, Gender, Ventilation settings.
* Also, patient needs to have a normal cardiac rhythm, closed chest, and normal inta-abdominal pressure.
27
What are the two types of gas sampling?
Non diverting and diverting
## Footnote
Non diverting is also known as mainstream sampling, while diverting is referred to as side stream monitoring.
28
What is non diverting gas sampling?
Gas is not removed from the circuit
## Footnote
It is sampled within the ventilator or monitoring system.
29
What is diverting gas sampling?
Gas is removed from the circuit
## Footnote
It's monitored by another machine, separate from the main system.
30
What is a common issue when sampling respiratory gas non diverting?
High levels of water vapor
## Footnote
This occurs because exhaled gases include humidity and other substances.
31
What is the purpose of a water trap in gas sampling systems?
To collect and remove excess water vapor
## Footnote
Water vapor can damage the monitoring equipment.
32
What is Dalton's law used for in gas analysis?
To figure out partial pressure of gases
## Footnote
It helps calculate gas concentrations in different atmospheric pressures.
33
How is volume percent for oxygen calculated?
Partial pressure of oxygen divided by 760 times 100%
* Recall that when dealing with expired concentrations, we do still account for the 47mmHg water vapor pressure, but 760 is total pressure in 1 ATM
## Footnote
This gives the volume percent based on atmospheric pressure.
34
What does mass spectrometry analyze in respiratory gases?
It identifies multiple gases exhaled by the patient
## Footnote
It can calculate up to eight different gases.
35
What is the significance of an oxygen analyzer?
It measures FiO2 and expired oxygen levels
## Footnote
This helps assess patient oxygen uptake and delivery.
36
What is a low FiO2 alarm indicative of?
Possible pipeline crossover or incorrect tank contents
## Footnote
This can happen if oxygen and air lines are mixed up.
37
What can cause high FiO2 alarms?
Prolonged exposure to high FiO2 in preemies or certain chemotherapy drugs
## Footnote
High levels can lead to complications like lung damage.
38
What are pulmonary inspiratory pressures monitored for?
To assess airway pressure during ventilation
## Footnote
It helps evaluate patient effort and overall respiratory function.
39
What does an inspiratory pressure monitor measure?
Inspiratory pressure **and** negative pressure during spontaneous breaths
## Footnote
It can also display PEEP levels.
40
What type of alarm does an airway pressure monitor not have?
It does not have an alarm system unless set manually
## Footnote
Continuous monitoring is essential, as it does not record data automatically.
41
What are the two types of oxygen analyzers mentioned?
Fuel cell analyzers and paramagnetic analyzers
## Footnote
Fuel cell analyzers have a short lifespan, while paramagnetic analyzers provide continuous updates.
42
Fill in the blank: The distance for gas sampling should ideally be ______ from the elbow.
close
## Footnote
Sampling too far can lead to less accurate respiratory gas monitoring.
43
True or False: Nasal cannulas provide highly accurate end-tidal CO2 readings.
False
## Footnote
They can only provide a rough estimate due to gas escaping into the atmosphere.
44
What should be monitored to ensure proper oxygen delivery in a patient?
FiO2, flow meter settings, and wall pressure systems
## Footnote
Monitoring these parameters helps identify any issues in oxygen delivery.
45
What is the function of electronic pressure gauges in ventilators?
They record and display airway pressure data.
46
What does a low peak inspiratory pressure indicate?
It indicates hypoventilation or under ventilation.
47
What should be checked if a low minimum inspiratory pressure alarm goes off?
Check for disconnection, extubation, apnea, or misplacement of the OG tube.
48
What is the typical calibration range for high pressure alarms in ventilators?
50 to 80 centimeters of water.
49
What might cause a sustained pressure reading in a ventilator?
An obstruction or occlusion in the circuit.
50
What is the recommended approach for troubleshooting ventilation issues?
Start from one end of the system and check components sequentially.
51
What types of nerve stimulators are commonly used in anesthesia?
Electrical is the most common. Magnetic stimiulators are typically only used in research.
* Electrical stimulators help us to monitor ulnar nerve, facial nerve, and posterior tibial nerve stimulators.
52
What is the principle of muscle fiber response to stimulation?
Muscle fibers respond in an all-or-nothing manner.
53
What is the significance of train of four monitoring?
It assesses the degree of neuromuscular blockade.
54
What does a zero train of four response indicate?
A very deep neuromuscular blockade.
55
What does post-tetanic stimulation indicate about recovery?
It suggests that recovery is occurring.
56
What is a phase one block with succinylcholine characterized by?
No fade and no post-tetanic facilitation.
* Recall that there is a difference between facilitation and fasiculations.
57
What is the role of cholinesterase activity in the context of succinylcholine?
Normal plasma cholinesterase activity is necessary for proper recovery.
58
What happens if succinylcholine is overdosed?
It can result in a phase two block presentation.
59
Fill in the blank: A high pressure alarm on a ventilator is activated when the pressure exceeds _______.
a preset limit.
60
True or False: The diaphragm is the first muscle to recover from neuromuscular blockade.
False
61
What are the typical signs of a deep neuromuscular blockade?
No train of four responses and possibly post-tetanic stimulation.
62
What is the purpose of using neuromuscular blocking drugs during surgery?
To facilitate intubation and control muscle movement.
* Preventing patient harm is primary, making the surgeon happy is secondary.
63
What should be monitored to determine readiness for extubation?
The return of inspiratory effort and muscle strength.
64
What is an important consideration when using succinylcholine on patients with abnormal pseudocholinesterase?
They may require prolonged ventilation post-surgery.
65
Which muscle group typically requires more drug for paralysis compared to peripheral muscles?
The diaphragm.
## Footnote
It can actually require up to 50% more paralytic....crazy
66
What is the recommended practice regarding neuromuscular blockade depth during surgery?
Aim for a deep block during surgery and allow recovery by the end.
67
What is succinylcholine commonly used for?
Succinylcholine is used as a neuromuscular blocker in anesthesia for emergent intubation. Usually in traumas or full-stomachs that need RSI.
68
What happens during a phase two presentation of succinylcholine?
The effects resemble those of a non-depolarizing neuromuscular blocker.
69
What are some alternatives to succinylcholine mentioned?
* Rocuronium
* Vecuronium
* Atracurium
* Cisatracurium
70
How many channels does a traditional EEG use?
16 channels.
71
What do the odd and even numbers on EEG represent?
Odd numbers are in the left hemisphere; even numbers are in the right hemisphere.
72
What EEG waveforms are associated with alert and attentive states?
Beta waves (greater than 13 hertz).
73
What EEG waveforms are seen in unconscious patients under general anesthesia?
Delta waves, less than 4Hz.
74
What is the purpose of processed EEG in the operating room?
To monitor the depth of anesthesia and assess brain activity via algorhythmic trends.
75
What is the typical range for a Bispectral Index (BIS) for general anesthesia?
40 to 60.
76
What does a BIS reading above 80 indicate?
The patient is likely awake or lightly sedated.
77
What does a BIS reading below 40 suggest?
The patient is likely too deep in anesthesia.
78
What is the suppression ratio in EEG monitoring?
The period of time that the EEG is flat.
## Footnote
....this should be zero unless your patient is braindead. Please do not overdose them.
79
What are evoked potentials used for?
To assess the integrity of sensory and motor pathways.
80
What are the types of evoked potentials mentioned?
* Sensory
* Motor
* Auditory
* Visual
81
What can affect the latency and amplitude of evoked potentials?
Anesthetics, especially nitrous oxide.
* No nitrous should be used when trending evoked potentials and gases should be kept below 0.5 MAC
82
What is the recommended anesthetic approach when using evoked potentials?
Use half a MAC of volatile anesthetic and avoid nitrous oxide.
83
What is the main concern with using paralytics during motor evoked potentials?
They prevent motor responses from being observed.
84
What does temperature regulation in the body primarily involve?
The hypothalamus.
85
What types of fibers transmit cold sensations?
A-delta fibers.
86
What types of fibers transmit warm sensations?
C fibers.
87
What factors can influence body temperature during anesthesia?
* Metabolism
* Thyroid function
* Drugs, especially anesthetics
88
Fill in the blank: The range of BIS that indicates a patient is likely awake is _______.
above 80.
89
Fill in the blank: The suppression ratio in EEG monitoring should always be _______.
zero.
90
True or False: A BIS reading of 30 is considered adequate for general anesthesia.
False.
91
What regulates body temperature?
Hypothalamus
## Footnote
The hypothalamus is the primary structure responsible for maintaining body temperature.
92
What type of fibers transmit cold sensations?
Alpha Delta fibers
## Footnote
Alpha Delta fibers are responsible for transmitting cold sensations to the brain.
93
What type of fibers transmit warm sensations?
C fibers
## Footnote
C fibers transmit warm sensations to the brain.
94
What is the typical temperature in an OR?
The temperature in the operating room is typically around 70F/21C but can get as low as 65F/18C or even 60 degrees Fahrenheit, which is quite cold.
95
What is the primary method of heat loss in surgical patients?
Radiation
## Footnote
Radiation accounts for about 40% of heat loss in surgical patients.
96
How does body surface area affect heat loss?
Higher body surface area increases radiation heat loss
## Footnote
Obese patients lose more heat due to a larger body surface area.
97
What is the impact of cold IV fluids on temperature?
Increases heat loss
## Footnote
Cold IV fluids can significantly contribute to heat loss during surgery.
98
What happens to a patient's temperature during general anesthesia in the first 30min? how about hours 1-2 and 3-4?
Initial rapid loss of 0.5 to 1.5 degrees Fahrenheit (slide says clecius but it is basically the same at these temperatures so who cares really?)
## Footnote
Patients typically experience a rapid drop in temperature soon after induction.
99
What physiological changes occur due to anesthetic drugs?
Vasodilation
## Footnote
Anesthetic drugs cause vasodilation, leading to increased heat loss from the core to the periphery.
100
What can happen to a patient's temperature after two hours of surgery?
Drop close to three degrees Celsius lower
## Footnote
Continuous heat loss can lead to a significant drop in temperature after two hours.
101
What is a common method to maintain temperature during surgery?
Use of thermal bear hugger gowns
## Footnote
Thermal bear hugger gowns are employed preoperatively to maintain patient temperature.
102
What is the gold standard for core temperature monitoring?
Pulmonary artery catheter
## Footnote
The pulmonary artery catheter is considered the gold standard for accurately measuring core temperature...we don't really do this often though and tend to rely on small nasopharyngeal or esophageal probes instead.
103
What alternative temperature monitoring method approximates hypothalamic temperature?
* Tympanic membrane temperature measurements can approximate **hypothalamic ** temperature at the risk of perforation.
* Nasopharyngeal reflects **brain** temperature but is prone to error and **epistaxis**
* Esophagus is safe, easily accessible, and accurate. Should be placed in the distal esoophagus (lower 1/3-1/4) and, if necessary, can be used as a cardiopulmonary monitoring device.
104
What are some complications of hypothermia in surgical patients?
* Increased cardiac mortality
* Increased BP, HR, and catecholamine levels
* Increased O2 demand (from shivering)
* Increased wound infection
* Coagulopathy issues
* Increased blood loss
* Increased need for transfusions
## Footnote
Hypothermia can lead to various complications, including increased cardiac risks and wound healing issues.
105
What is a recommended practice when giving blood during surgery?
Warm the blood
## Footnote
Blood should be warmed before administration to prevent hypothermia.
106
What is the effect of hypothermia on neuromuscular blocking drugs?
Increases duration of action
## Footnote
Hypothermia can prolong the effects of neuromuscular blocking agents.
107
True or False: Hypothermia improves outcomes after cardiac arrest.
True
## Footnote
Hypothermia can have protective effects following cardiac arrest, improving survival rates.
108
What are some benefits of mild hypothermia?
* Protective against cerebral ischemia
* Harder to trigger malignant hyperthermia
* Reduces metabolism
## Footnote
Mild hypothermia can have beneficial effects in specific medical situations.
