PEDIATRIC ANESTHESIA Flashcards
1
Q
Pediatric patients have_______Which ____Vd of _____medications
meaning required___________
• Neonates require even more, but are also_________
A
Increased total body water: • ↑Volume of distribution of water-soluble medications Larger initial dose more sensitive to effects
2
Q
Less muscle/fat →
• Slow redistribution of the drug into muscle will
A
- longer clinical drugs effect
- increase duration of clinical effect (opioids, barbiturates)
3
Q
Mean cerebral blood flow peaks
A
at 3-8 years
4
Q
Proportionally
A
↓CBF in neonates
5
Q
• Highly lipophilic drugs used for anesthetic induction
A
rapidly achieve equilibrium with brain tissue
6
Q
• Reduced cerebral perfusion means that onset time after IV induction is_________
A
slower in neonates that in early childhood
7
Q
Offset time is also delayed why?
A
because redistribution to the well perfused and deep, under perfused tissues is less
8
Q
Offset time to reach brain then
A
back to body
9
Q
Acidic drugs: (2) (BAD)
• Acidic drugs mainly bind to________
A
diazepam, barbiturates
-albumin
10
Q
- Basic drugs: __________ and _________
- Basic drugs bind to
- Mainly bound to __________= ↓premies/infants, adult levels by 6 mo
A
amide local anesthetics, alfentanil
globulins, lipoproteins, and glycoproteins
α1-acid glycoprotein (AAG) =
11
Q
MAC
A
minimum alveolar concentration
12
Q
Plasma protein binding ↓in neonates = _____and____ why?
A
more free medication –>↑pharmacological effect
↓total protein + albumin
13
Q
Significantly affects highly protein bound drugs
A
• Phenytoin, salicylate, bupivacaine, barbiturates, antibiotics, theophylline, diazepam
14
Q
Minimum Alveolar Concentration (MAC)
A
- Highest at 6 months
* Higher in children compared to adults
15
Q
Why MAC higher
A
May relate to
maturational changes in cerebral blood flow (CBF) γaminobutyric acid (GABA) class A receptor numbers
or developmental shifts in regulation of CHLORIDE transporters
16
Q
Chloride ions
A
hyperpolarizes cells
17
Q
“wash-in” aka “FA/FI” aka “induction” aka
A
GO TO SLEEP!
18
Q
Determined by 6 factors: FA/FI –> IAF/CSA
A
- Inspired concentration
- Alveolar ventilation
- Functional residual capacity (you want ideallow)
- Cardiac output
- Solubility (ideal low)
- Alveolar to venous partial-pressure gradient (ideal high)
19
Q
FA/FI means
A
Fractional alveolar to fractional inspired partial pressures
How much in alveoli from how much was given
20
Q
What’s in alveoli is whats in the
A
BRAIN
21
Q
FA/FI best if it’s
A
1
22
Q
Factors 1-3 determine
A
delivery of anesthetic to lungs
23
Q
Factors 4-6 determine
A
determine rate of removal (uptake) from lungs
24
Q
Low FRC
A
Desaturation
25
From alveoli to ______Eventually because of pressure gradient difference
blood
26
Ratio of alveolar ventilation (Va)
to FRC is the primary determinant of delivery of inhaled anesthetics to lungs
• Affects more soluble agents greatly because they are easily stolen out of the lungs
27
Greater Va/FRC =
more rapid equilibration
28
memorize slide
8
29
About ____ to get to brain
12 minutes
30
BP every
3-5 minutes
31
Normally, rate of rise in FA/FI is
| • Mostly affects more
inversely related to changes in CO
| soluble agents
32
• Less anesthesia leeched from lungs in
↓CO states
33
Opposite in pediatrics is with CO
OPPOSITE in pediatrics
• ↑CO speeds up FA/FI
• More CO distributed to vessel-rich group (VRG)
• Brain, heart, kidney, splanchnic organs, endocrine glands
***Partial pressures of anesthetics in the VRG equilibrate with those in the alveoli more rapidly in neonates than in
adults***
34
Isoflurane
Does not go to brain as quickly
35
As you go up FA/FI
more insoluble
36
Anesthetic gases are less soluble in neonates in general due to (3)
* ↑water content
* ↓protein/lipid concentration
* Reduces time for equilibration
37
For older people, VA induction with mask if CO is lower than normal
they go to sleep faster
| less anesthesia leeched from lungs
38
The opposite in pediatric, proportion of blood that gets to the brain is
WAY MORE THAN ADULT
| SLEEP FASTER
39
Solubility for gas (VA) is
NOT GOOD
| IT IS SLOW
40
* Wash-out follows
| * Exact opposite of
exponential decay
| wash-in curves
41
* Washout similar in
| * More rapid in
children and adults
| neonates and infants
42
Cardiovascular
• Both directly and indirectly depressed
43
Affect Directly CV by
* Ca2+ channel blockade, altering conduction system, dilating peripheral vasculature
* ↓ Ca2+ flux
44
AFFect Indirectly CV by
* Affecting balance of ANS and neurohumoral, renal, or reflex responses
* All inhalational anesthetics modestly depress systolic BP in children
45
Down syndrome patients have increased risk of
bradycardia during induction
46
Sevoflurane can cause
bradycardia during induction
| Junctional rhythm
47
HR normally unaffected by desflurane unless inspired concentration↑ suddenly
• Attenuated by________ administration
opioid administration
48
VOLATILE ANESTHETICS: Isoflurane:
| LPC
☺ Less myocardial depression than Halothane
☺ Preservation of heart rate
☺ CMRO2 reduction rate (brain requiring less O2)
49
It is a PULMONARY IRRITANT
DESFLURANE (NOT USE IN KIDS OR WITH MASK)
50
Desflurane (2) major (IC) think DIC
☺ Increased incidence of coughing, laryngospasm,
secretions
☺ Concern of hypertension and tachycardia from
sympathetic activation
51
CONTRAINDICATED FOR ASTHMA
DESFLURANE
52
VOLATILE ANESTHETICS: SEVOFLURANE (LCM)
Sevoflurane
☺ Less pungent than Isoflurane
☺ Concern of compound A (nephrotoxicity) (for rats
☺ Most suitable for induction
53
Sevo usually run at
2L/min
54
ONLY FDA approved for INHALATIONAL Induction
SEVOFLURANE
55
Underlying pulmonary conditions
Do not use desflurane
56
Remember: About MAC and neonates and premies
MAC for potent volatile anesthetics
is increased in neonates, but may be lower for
sicker neonates and premies
57
*** MATH**must know Induction drugs:
Methohexital dose is ? Rectal dose is? when can you use it ?
Long acting vs short acting
Advantage of methohexital (1)
Methohexital 1-2 mg/kg IV ☺20-30 mg/kg per rectum(can be used when propofol not available)
• Short acting barbiturate
• Minimal CV effects
58
Side effects and Contraindications for METHOHEXITAL
BAEH
Contraindication to Methohexital?
```
☺ Side effects:
burning
hiccup
apnea
extrapyramidal syndrome
☺ Contraindication: temporal lobe epilepsy
```
59
Propofol
Causes CHLORIDE SHIFT
Made from
GABA agonist
• Made from 1% propofol, soybean oil, egg yolk
phosphatide (ovolecithin), glycerol,**** EDTA (BURNS!),
NaOH (buffer)
60
Propofol dose until (6 years of age)
☺ 3 mg/kg i.v. (until 6 years of age)
61
Propofol pain on injection use what?
☺ Pain on injection - 0.2 mg/kg Lidocaine i.v
62
Ketamine dose ______IV, PR orally
1mg/kg IV
| ☺6-10 mg/kg PR, orally
63
Ketamine works on _____receptor
• N-methyl-D-aspartate (NMDA) receptor
64
• Duration of KETAMINE if single IV bolus =
5-8 minutes
65
Advantages of Ketamine
• No upper airway obstruction but can still cause
| hypoventilation (high doses)
66
****Contraindications of KETAMINE (COIS)
Increased ICP
Open globe injury
Seizure hx (cerebral excitation)
Can’t be used for EEG
67
Ketamine leads to (salivation )
☺ Increased SALIVATION (laryngospasm!) → antisialagogue
68
KETAMINE will do what to IOP
Increase
69
Etomidate dose pediatric
0.2 - 0.3 mg/kg IV
70
ETOMIDATE has_______
propylene glycol ; so it burns on injection
71
ETOMIDATE children needs?
ADvantages?
Disadvantage?
Like propofol, children need higher bolus
• Cardiac stable, less apnea than propofol, quickly redistributes
• Burns on injection (propylene glycol)
72
Diazepam pediatric dose
☺ 0.1-0.3 mg/kg orally
73
***Diazepam half life
***80 hours
74
****Diazepam contraindicated
***infants less than 6 months
75
Only FDA benzo approved in neonates
Midazolam
76
Midazolam dose
| IV, intranasal, IM, oral , rectal
```
☺ 0.1mg/kg IV (
☺ 0.2 mg/kg intranasal (2 nose)
☺ 0.1-0.15 mg/kg IM
☺ 0.5mg/kg orally
☺ 0.5-1mg/kg rectal (large dose)
```
77
Side effects of each route
| Most common is
```
Oral - slow onset (most common)
IM – pain
Rectal - uncomfortable, defecation, burn
Nasal -irritating
Sublingual -bad taste
```
78
Roles on
Role when awake separation of child from
parent before induction is planned.
2. Its success may be judged by the peacefulness of
the separation.
3. Large volume of literature indicates lack of
clearly ideal technique
79
```
Versed PO:
• Bioavailability =
• Peak serum levels after______
• Peak sedation by about_______
• 85% peaceful separation
• Mix with
```
up to 12 mg max.
30%
about 45 minutes
30 minutes
Grape concentrate or acetaminophen
(Tylenol) syrup or elixir or Motrin Suspension (10
mg/kg of the 2% suspension)
80
Possible concern with versed
Nasal dose
animal studies reveal neurotoxicity after topical application.
0.2mg/kg, peak 10 minutes, higher doses may delay intubation
81
Methohexital (Brevital) rectal dose is _______as ____% solution in __________
• 85%__________________
induction of GA (very peaceful separation)
*****Sleep duration:****
****Rectal 25 to 30 mg/kg as 10% solution in warm
tap water
sleeping within 10 minutes = rectal
about 45 to 90 minutes
82
```
Ketamine PO:_________
• May slightly prolong time to discharge after a
short case
• IM:__________ sedation;
• 2 mg/kg did not delay recovery
• 10 mg/kg:_______________
```
6 to 10 mg/kg
3 to 4 mg/kg
as effective as Midazolam 1 mg/kg but
some delay in recovery may be expected
83
Ketamine• = __________IM induction of general
| anesthesia
6 to 10 mg/kg
84
Midazolam + Ketamine:
| DOSE
• PO 0.4 mg/kg + 4 mg/kg respectively
| 100% successful separation
85
Ketamine + Propofol in the same syringe
KETAFOL (50mg of ketamine in 50 mg of propofol)
86
Consider medication
| Fentanyl Lollipo consideration
Glycopyrollate (ENT, airway surgery )
| Can increase volume of gastric contents
87
EMLA cream:
Eutectic mixture of Lidocaine and Prilocaine.
88
MORPHINE
Water soluble? or lipid soluble?
Who does if affect more and why?
rectal administation =______-->______
```
Morphine 0.05-0.2 mg/kg
☺Water soluble = slow CNS
☺Neonates affected more → immature BBB
☺Rectal administration = delayed absorption → resp.
arrest
```
89
```
MEPERIDINE dose
only indicated for_________
_____Route not recommended
______Vd= _______Resp depression
Long infusion leads to _________---> _______-->
```
Meperidine 1-2 mg/kg
☺Only indicated for anti-shivering, NOT analgesia
☺Rectal route not recommended
☺Larger Vd = less respiratory depression
☺ Long infusions → normeperidine → seizures
90
Fentanyl dose
Lipid or water soluble?
CV response?
Synergistic with what medication>?
-->1 mcg/kg
☺Lipid soluble, small molecules → efficient BBB
penetration and redistribution
☺Stable cardiovascular response
☺Synergistic with midazolam
☺Fast administration → chest wall + glottic rigidity
☺Can ↑vagal tone → bradycardia
91
Fentanyl too fast you can get
CHEST WALL and GLOTTIC RIGIDITY
92
Alfentanyl and Sufentanyl:
☺ More rapid clearance than adults
***** Can cause parasympathetic response -->
bradycardia, hypotension******
93
Volume of distribution make succinylcholine
HIGHER DOSES in pediatric
| More water
94
Succinylcholine dose _______
Laryngospasm breaking dose__________IV IM
GIVE WITH IT__________ or prior
Potential side effects:
```
☺ 1-2 mg/kg IV; 4.0 mg/kg IM
☺Laryngospasm breaking dose = 0.1mg/kg IV,
4mg/kg IM
☺ Consider Atropine 10-15 mcg/kg given prior SUX
☺ Potential side effects:
Rhabdomyolysis
Hyperkalemia
Masseter spasm
MH
```
95
Know ROC
0.1
96
```
Benzylisoquinoline: Atra and cisa
Atra dose?
Metabolism?
Intubation condition in _____minuts
Lasts ______mins
```
* Atracurium 0.5 mg/kg IV
* Hofmann elimination, ester hydrolysis
* Intubation conditions in 2-3 minutes
* Lasts 30 minutes
97
Cisatracurium
Dose
Daughter of __________
Same ______except____
```
0.15 mg/kg IV
• Daughter of atracurium
• Same elimination except NO ester hydrolysis
• Same duration
• Onset ↑with ↑ dose
```
98
Atracurium may give some
Airway issues
99
Potentiation of NMB with anesthesia gases in descending order:
DO NOT NEED TO MEMORIZE,
• isoflurane, desflurane, sevoflurane > nitrous oxide
• Per Barash: des > sevo > iso > N2O
100
Hoffman ALKALOSIS
Favor elimination
101
Hoffman acidosis
Less elimination
102
Aminosteroids
• Vecuronium
| Rocuronium
103
```
Vecuronium dose is _______
CV effects
Intubating conditions in ______
Metabolized ______, excreted _______
Who is sensitive?
```
```
0.1 mg/kg
No adverse CV effects
• Intubating conditions in 3-5 min
• Metabolized by liver and excreted via bile
• Infants significantly sensitive
```
104
Rocuronium dose?
compared to vec is ________? intubating conditions?
with HR?
0.6-1.2 mg/kg, 1.8mg/kg IM
• Faster acting than vecuronium, 0.5-1.5 min for intubating conditions depending on dose
• Transient ↑HR seen with higher doses
105
Reversal agents: Peds at high risk of
| • Monitor
resp. failure w/residual NMB
| - TOF at adductor pollicis
106
Clinical signs of NMB antagonism in infants:
Flex hips/arms, lift legs, return of abdominal muscle tone, inspiratory force of -25 cm H2O or greater (more negative)
107
• Hypothermia
potentiates NMB (makes muscle slower)
108
Potentiated by NMB
| • Potentiated by magnesium
antibiotics: aminoglycoside derivatives (gentamicin, tobramycin, and neomycin) = greatest effect
Magnesium and HYPOCALCEMIA
109
Rule of 6
twitch and cc of neogstimine
4/4 twitch 6-4= 2 cc
1/4 twitch 6-1= 5 cc
*****CAN'T GO OVEr 5
110
```
Anticholinesterases
• Neostigmine dose________
• Require ___________than adults
• Doses >_________
• Co-administer with_________
```
0.020-0.025 mg/kg
0.1mg/kg can cause paradoxical weakness from ↑Ach at NMJ
smaller dose
glycopyrrolate 0.005-0.01 mg/kg
111
```
Sugammadex dose is
Class
Roc vs Vec encapsulates better
Safe in peds?
Worry about?
```
Sugammadex 2 mg/kg (moderate block; reversed in 1.2 min)
• Cyclic oligosaccharide
• Encapsulates rocuronium best, vecuronium less
• Studies have concluded safe to use for peds
• Worry about allergic/anaphylactic reactions
MAY GET BRADYCARDIA
112
FASTING Clear liquids -
☺ If infants are breast fed -
☺ For older patients =
☺ Be aware of
2-3 h before the procedure
4 h before the procedure
the adults rule
dehydration
113
```
Inhalational induction:
After induction -->
Use suggestions in older child -->
What protects against anesthetic OD-->
In a case of difficult airway --> _________
```
Younger than 12 months
☺ After the induction, place the intravenous catheter
☺ Use suggestions in older child (pilot’s mask)
☺Spontaneous ventilation protects against anesthetic
overdose
☺ In a case of difficult airway - Fiberoptic intubation
114
What agents used for RECTAL INDUCTION
```
☺ Methohexital (KeMidMethoThi)
☺ Thiopental
☺ Ketamine
☺ Midazolam
☺ Technique no more intimidating than rectal
temperature measurement
☺ Usual time of onset ~ 10-15 min
```
115
Usual time of onset of RECTAL INDUCTION
10-15 min
116
IM induction
Most common used is ______
Disadvantage is _______
ADvantage ______
☺ Most common used Ketamine
☺ Disadvantage painful needle insertion
☺ Advantage: reliability
117
```
IV induction
The most ______ and _______Technique
Disadvantage is __________
if patient is older _______
If you insert the IV line"
3 things you should do?
```
☺ The most reliable and rapid technique
☺ Disadvantage - starting intravenous line
☺ If patient is older ask the patient
☺ If you insert IV line:
I. Do not allow the patient to see it
II. Use EMLA cream
III. If use local - ask the patient if there is any sensation on puncture
118
Patient with a FULL STOMACH
RSI with ________using _______
Tell the patient that will feel ________
Be aware of ________which leads to _______
What should you administer before Succinylcholine and why ?
Use _________dose ________
Use Succinylcholine dose _________
☺ RSI with ODL using cricoid pressure
☺ Tell the patient that will feel “touching on the neck”
☺ Be aware of Increased VO2 (desaturation)
☺ 0.02 mg/kg of Atropine administer before SUX to
avoid bradycardia (usually after 2nd dose)
☺ Use Rocuronium 1.2 mg/kg
☺ Use Succinylcholine 1-2 mg/kg if really need
short duration (difficult airway)
119
Premature infant -
Full-term infant -
3-12 month old child -
1 year and older child -
100 ml/kg
90 ml/kg
80 ml/kg
70 ml/kg
120
MABL
EBV (Starting Hct - TARGET hct)/ Starting Hct
121
```
Packed Red Blood Cells:
☺ Child usually tolerates Hct_______ ~
☺ If the child is
-
-
-
☺ No one formula permits a definitive decision
☺ Replace________blood with _____Of L
☺ Be aware of blood disorders (sickle cell disease)
```
```
20 in mature children
Premature,
- Cyanotic congenital disease
- Decreased O2 carrying capacity
Hct ~ 30
```
1ml blood with 3 ml of LR
122
What is a late sign of decreased O2 carrying capacity
☺ Lactic acidosis
123
Bleeding and FFP rule of thumb
☺ A patient should be never given FFP to replace bleeding that is surgical in nature
124
Blood transfusion : If transfused faster than________ severe______May occur
1.0 ml/kg/min ionized hypocalcemia may occur
125
BLood transfusion Ionized hypocalcemia can occur in neonates frequently why?
because of decreased ability to mobilize Ca++ and metabolize citrate
126
Monitoring the Pediatric Patients:
```
☺ Must be consistent with the severity of the
underlying medical condition
☺ Minimal monitoring:
I. ASA monitors
II. ***Precordial stethoscope***
III. Anesthetic agent analyzer
```
127
Special Monitoring the Pediatric
Patients:
☺ Intraarterial catheter - most common _______
☺ Pulmonary artery catheters are indicated or not? why?
☺ In a case of severe multisystem organ failure
What might be helpful ?
☺_____________atheters are valuable in ICU patients
☺ In a case of rapid fluid replacement ______________might be very useful
☺__________________________
or umbilical vein may be life-saving
☺ Intraarterial catheter - most common radial
☺ Pulmonary artery catheters are rarely indicated
because equalization of the pressure right/left heart
☺ In a case of severe multisystem organ failure
insertion of PAC might be particularly useful
☺ Multilumen catheters are valuable in ICU patients
☺ In a case of rapid fluid replacement peripheral
venous catheter might be very useful
☺ Short-term cannulation of femoral/brachiocephalic
or umbilical vein may be life-saving
128
How do nonrebreathing circuits work?
• Expiration →exhaled gas pushed down expiatory
limb and collects in reservoir bag and opens
expiratory valve (“pop-off, APL”)
• All NRB are convenient, light weight, and easily
scavenged
129
Recommended circuit in children is the
Use of _______is recommended in children < ___-kg
3 reasons?
☺Use of Mapleson D system is recommended in
children < 10 kg
• More sensitive to changes in gas flow
• More sensitive to humidification
• Actual delivered volume is greater than other systems
130
```
Mapleson D is
________ circuit
__________
FGF tubing directed within the _______limb
FGF enters _________
Adds more ____+______
```
* Bain circuit
* “coaxial” Mapleson D circuit
* FGF tubing directed within the inspiratory limb
* FGF enters circuit near mask
* Adds more heat + humidity
131
```
Anesthesia Circuits: Non-Rebreathing
Speeds-up rate of _____________
•_______And __________ are less
(small circuit volume)
• No ____________r = rebreathing highly dependent
on ________
• Minimum FGF ___________
```
```
All lack unidirectional valves
• Minimal work of breathing
Speeds-up rate of inhalational induction
• Compression and compliance volumes are less
(small circuit volume)
• No CO2 scrubber = rebreathing highly dependent
on FGF
• Minimum FGF 5L/min (or 2-3 x MV)
```
132
Sugammadex only work for
ROCURONIUM > VECURONIUM
NOT for atracurium or cisatracurium
133
Gases have
MUSCULAR RELAXANT PROPERTIES
134
REDUCE doses of volatiles anesthetics because they also have muscular relaxant properties
KNOW SLIDE 38
