Misc. Monitoring Flashcards
(55 cards)
1
Q
Febrile temperature
A
> 38 C
2
Q
Hypothermia
A
<36 C
3
Q
Room temp
A
23 C
4
Q
Recommended operating room temperature and why
A
68 to 75 F (20 to 24 C)
To inhibit bacteria growth)
5
Q
Who may require warmer temperatures to prevent hypothermia?
A
Infants, children and burn patients
6
Q
Temperature monitoring sites
A
- Blood (from a pulmonary artery catheter)
- Esophageal
- Rectal (less reliable if rectum is not clear)
- Nasal
- Bladder (less reliable if urine output is low)
- Skin/axillary
7
Q
The best estimate of body temperature
A
Blood
8
Q
The most consistently reliable measurement of body temperature
A
Esophageal
9
Q
Etiologies of intraoperative temperature loss
A
- IV fluids (1 unit of blood or 1L of crystalloids can dec temp by 0.25 C)
- Vasodilation
- Blood products (except platelets)
- Volatile agents
10
Q
Cardiac adverse effects of hypothermia
A
- Platelet dysfunction and bleeding
- Decreased stroke volumes
- Bradycardia and/or arrhythmias
- Increased blood viscosity
11
Q
Neuro adverse effects of hypothermia
A
- Increased cerebral vascular resistance and decreased cerebral blood flow
- for every 1 C drop in temperature, cerebral blood flow decreases 5-7%
12
Q
Renal adverse effects of hypothermia
A
- Decreased GFR and impaired tubular function
13
Q
Respiratory adverse effects of hypothermia
A
- Respiratory depression
2. L shift of HbO2 dissociation curve
14
Q
Metabolic adverse effects of hypothermia
A
- Decreased drug metabolism and delayed emergence from anesthesia
- Decreased wound healing
- Shivering
15
Q
Shivering is more likely with:
A
- Lower intraoperative temperature
- longer surgeries
- higher concentrations of volatile agents
16
Q
Why is shivering concerning?
A
It increases O2 consumption 5 fold, which is concerning for patients with CAD
17
Q
Treatments for shivering
A
- Warm the patient
2. Demerol (25mg IV)
18
Q
Types of heat loss in OR in order from most to least
A
- Radiation (60%)
- Evaporation (20%)
- Convection (15%)
- Conduction (5%)
19
Q
Purpose of esophageal stethoscope
A
- Measure temperature
2. Listen to heart and lung sounds
20
Q
Purpose of precordial stethoscope
A
- Valuable in transport
- Constant heart/lung sounds
- Popular in pediatrics
21
Q
BIS reading for sedation
A
65-85
22
Q
BIS reading for general anesthesia
A
40-65
23
Q
BIS reading for too deep anesthesia
A
<40
24
Q
Ketamine (increases/decreases) BIS number
A
Increases
25
Common situations for the BIS monitor
1. Paralyzed patients
2. Patients undergoing TIVA who are paralyzed
3. Sick patients that require less anesthesia
26
When can you not monitor vital signs for awareness?
1. When B blockers are given
| 2. When patients cannot mount a normal sympathetic response
27
Indicator of adequate cardiac output and renal perfusion
Urine output
28
Common goal for urine output
>0.5 -1 ml/kg/hr
29
Ultrasound of cardiac structures, with the probe resting in the esophagus posterior to the heart
Transesophageal Echocardiography (TEE)
30
What can the TEE estimate?
1. Ejection fraction
2. Cardiac output
3. Patency of heart valves (stenosis vs regurg)
4. Pulmonary artery pressure
5. The BEST monitor for diagnosing venous air embolism (VAE)
31
Purpose of evoked potentials
To monitor nerves that are close to the surgical site
32
Method of evoked potentials
1. The nerve is electrically stimulated, which produces a waveform
2. Ischemic or damaged nerves produce abnormal waves
33
Amplitude of evoked potentials
Height of the wave
34
Latency of evoked potentials
Time from the onset of the wave to the peak of the response
35
Effects of nerve damage and ischemia on evoked potentials
Decreased amplitude and increased latency
36
True/false: anesthetics increase amplitude and latency
False. Anesthetics DECREASE amplitude and increase latency
37
How can an anesthetist intervene if the evoked potential amplitude decreases and/or latency increases intraoperatively?
By increasing the patient's blood pressure
38
Effects of propofol and volatile agents on evoked potentials
Decrease amplitude and increase latency
39
Volatile agents and nitrous oxide have the greatest effects on __evoked potentials
SSEPs
40
Effects of versed on evoked potentials
Decrease amplitude
| No effect on latency
41
Effects of ketamine and etomidate on evoked potentials
Increases latency
| Increases amplitude
42
Effects of nitrous oxide on evoked potentials
Decreases amplitude
| No change on latency
43
Effects of opioids on evoked potentials
Minimal effect on evoked potentials
44
Types of evoked potentials
1. Somatosensory evoked potentials (SSEPs)
2. Motor evoked potentials (MEPs)
3. Brainstem auditory evoked potentials (BAEPs)
4. Visual evoked potentials (VEPs)
45
What is purpose of SSEPs?
To monitor the integrity of sensory nerves (dorsal nerve roots)
46
True/false: muscle relaxants do not affect the sensory pathways for SSEPs
True
47
Method of motor evoked potentials
Similar to SSEPs, but through the motor nerves instead
| Anterior and lateral pathways of the spinal cord
48
True/false. SSEPs are more sensitive to volatile agents than MEPs
False, MEPs are more sensitive to volatile agents
49
True/false. Muscle relaxants should not be administered when MEPs are used
True
50
What does BAEPs measure?
The integrity of the vestibulocochlear nerve (VIII) and the brainstem
51
Which potentials are least affected by anesthetics?
BAEPs
52
Which potentials are most affected by anesthetics?
VEPs
53
What do VEPs measure?
The integrity of the optic nerve, can be used for pituitary tumor resection
54
Anesthetic management with evoked potentials
1. <0.5 MAC volatile agent or use propofol drip or narcotic drip
2. Keep anesthetic level as constant as possible
3. Avoid muscle relaxants if MEPs are being used
55
When does propofol have less of an effect on evoked potentials?
Infusions have less of an effect than boluses
