ABG Flashcards
normal bicarbonate
HCO3 = 22-26
normal base deficit/excess
-2 to +2
what is the pH scale
power (logarithmic) scale that shows the inverse relationship of hydrogen ions
-low pH/acid =pH lots of H
buildup of CO2
acid
what does high CO2 indicate
acid buildup
low pH
apnea/hypoventilation
what is Co2 regulation a function of
CO2 regulation is a function of minute folume
minute volume = tidal volume (Vt) x RR (F)
Vt on ventilator settings
tidal volume
tidal volume on ventilator settings
Vt
RR on ventilator
frequency = F
F on ventilator settings
RR
CO2 over 45
acid buildup
hypoventilation/apnea
CO2 if apnea
high Co2 over 45
acidosis
CO2 if hypoventilation
high Co2 over 45.
acidic
CO2 under 35
alkalosis
high pH
CO2 if alkalosis
under 35
Vt x R
minute ventilatiob = Vt x F
tidal volume x RR
how does pH and bicarbonate move
opposite directions
22 is acidotic
26 is alkalosis
pH if too much bicarb
bicarb is alkalotic
over 26 bicarbonate
pH if too little bicarbonate
under 22
acidosis
under 22 bicarb
too little bicarbonate
bicarb and pH move in teh same direction
alkalosis
what is base excess/deficit
the amount of excess or deficit amount of base present in blood
base deficit of -4
indicator for blood transufusion
base deficit where you would consider blood transfusion
base deficit of
base deficit where death is likely
over -19
replacement formula for bicarbonate
0.1 x (-base excess) x weight in kg = bicarb needed
SaO2 at PaO2 90
100%
SaO2 at pO2 60
90%
SaO2 at pO2 30
60%
SaO2 at pO2 27
50%
what does pulse ox measure
SaO2
left shift affinity
increased
left shift mneumonic
Left = LOW
acidosis, temp, 2,3-DPG, pCO2
right shift mneumonic
Right = RAISe
alkalosis, temp, 2,3-DPG, PCO2
what 5 things change in left/right shift
LEft = LOW Right = Raise \+H temperature PCO2 2,3-DPG
CO2 & pH
Co2 is an acid so it makes ABG more acidotic
left shift
Bicarbonate & pH
bicarb is a base so makes ABG more alkalotic
right shift
CO2 follows pH
respiratory
bicarbotate follows pH
metabolic
how to tell if the ABG is compensated
the compensatory mechanism is teh opposite of the primary problem
- respiratory acidosis is compensated by bicarb
- metabolic alkalosis is compensated by CO2
compensated respiratory acidosis
compensated by bicarbonate
compensated metabolic alkalosis
compensated by CO2 (acid)
partially compensated
pH outside normal range
both resp & metabolic are outside of normal range
pH/resp/metabolic are all ouside of normal range
partially compensated
pH is normal, resp/metaboliic are ousided normal range
fully compensated
fully compensated
abnormal pH
normal CO2/bicarb
critical pH for intubation
pH under 7.2
pH under 7.2
intubate b/c critical
pCO2 over 55
intubate b/c critical
critical pCO2 to intubate
over 55
critical pO2 to intubate
under 60
pO2 under 60
intubate
acid/base if vomiting/NG/suction/dieuretics/diamox/antacid poisioning
metabolic alkalosis
causes of metabolic alkalosis
vomit/NG/suction/dieuretics/diamox/antacid overdose
considered lactic acidosis
lactate over 4
causes of m. acidosis
lactic acidosis, ketones, hyperthermia/fever, seizures, rhabdo
bicarb in m. alkalosis
over 26
bicarb in m. acidosis
under 22
acid base in antacid poisioning
m. alkalosis
acide base in sepsis
m. acidosis
acid base in rhabdo
m. acidosis
acid base in hyperthermia
m. acidosis
acid base in seizures
m. acidosis
Co2 in r. alkalosis
low CO2 under 35
acid base if hyperventilating
r. alkalosis
acid base in hypoermetabolic staes
resp alkalosis
acid base in high altitudes
r. alkalosis
acid base in ASA poisioning
r. alkalosis (CO2 less than 35) b/c it is a respiratory system stimulant
what happens in ASA poisioning
respiratory system stimulant so r. alkalosis a
hyperventilation
hyperventilation
r. alkalosis
Co2 under 35
hypoventilation
r. acidosis
CO2 over 45
Co2 in hyperventilation
under 35
alkalosis
CO2 in hypoventilation
over 45
acidosis
when is minute ventilation increased
increased to blow off CO2 (Vt x RR)
in hyperthmic states like malignant hyperthermia
limited ability to remove by hgb
every ___ in pH, expect change in bicarbonate by ___ in ___ direction
0.15 pH
10 bicarb
same direction
every ___ in pH, expect change in K by ___ in ___
0.1 pH
K shifts 0.6
oppositr direction
physiology of the pH & K relationship
*every 0.1 change in pH, K shifts 0.6 in the opposite direction
*as pH lowers, K shifts outside the cell giving a falsely elevated K level.
when correct imbalance by raising pH, K shifts intracellulary so life threatening low K
every change in ___ ETCO2, expect pH to change by ___ in the ___ direction
10 mm hg ETCO2
0.08
opposite direction
every change in ___ CO2, K shifts ___ in teh ___ direction
10 CO2
K 0/5
same direction
pH & K relationship
VERSUS
CO2 & K
every change in 0.1 pH, the K shifts 0.6 in the opposite direction
every change in 10 CO2, K shifts 0.5 in the same direction
ABG to intubate
7.2 pH
CO2 over 55
PaO2 <60
*intubate even if only 1 is off
Pediatric Assessment Triangle
appearance
work of breathing
circulation
ETT size for pediatrics
16 + age in years
divided by
4
16 + age/4ll
ETT size for pediatrics
emergency airway for pediatricsl
needle cric if under 8l
difficult airway predictors0+
LEMON, HEAVEN
look, evaluate w/ 3-3-2, Mallampati, obstruction, neck mobility
3-3-2
difficult aiwary predictor
3 fingers in mouth
3 fingers between jaw and hyoid
2 fingers between hyoid and thyroid
Mallampati 2
tonsillar pillars hidden by tongue
Mallampati 3
only base of uvula is seen
LEMON
look evaluate w/3-3-2 mallampati obstruction neck mobility
HEAVEN
predictors in difficult emergent airways Hypoxemia under 93% extreme of size (under 8 or obese) anatomic challenges vomit/blood/fluid exsanguination/anemia neck monility
“E” in HEAVEN
exsanguination/anemia can accelerate decompensation during RSI
ramping
ear to sternal notch
problem of the supine position during intubation
ramp instead (ear to sternal notch) decrease functional reserve capacity/tidal volume/preload
posterior pressure on cricoid cartiliage believed to occlude the esophagus
Sellick maneuver
External Laryngeal Manipulation
provider brings cords into view the the assistant holds pressure.
Macintosh v MIller blade
Macintosh = lifts epiglottis via vallecula
Miller - direct displacement of the epiglottis
preferred intubation blade for pediatrics
Miller (direct displacement of the epiglottis)
bougie size adult versus kids
adult = 15 Fr kids = 10Fr
problem of supraglittic devices
blind insertion
little protection agaisnt aspiration
air inflation into ETT
25mm is standard
CXR confirmation of ETT placement
distal tip 2-4 cm above carina
level of T3-T4
confirm by visualizing Murphy’s eye where the clavicle meets
waveform of the ETCO2
half square
expiration - expiratory plateau- ETCO2- inhalation- baseline
where is ETCO2 measured on the ETCO2 waveform?
right side of square
what can you do when you are preparing & pretreating a pt for RSI intubation
3-5 min of passive oxygen via NC 10-15L
pretreatment for RSI
LOAD
position for RSI
ear to sternal notch = ramping
pad behind shoulder for pediatrics
reason for RSI pretreatment
LOAD
b/c manipulation of the hypopharynx, larynx, and trachea may cause a reflex sympathet9c response leading to catecholamine mediated increase in BP/HR/ICP
RSI preteatment options
LOAD Lidocaine Opiates Atropine Defssciculating
lidocaine as RSI pretreatment
blunts the cough reflex preventiong ICP increase
opiates as RSI pretreatment
blunts the pain response
atropine as RSI pretreatment
prevents reflexive bradycardia in infants under 1yo
defasciculating rx as RSI pretreatemnt
1/10 dose of Roc or VEc prior to administering Succ
Fentanyl as RSI analgesic
dose, onset, duration, complication
1mcg/kg
onset 3-5 min
duration 30-60 min
low risk of chest wall rigidity
RSI for awake sedation
Etomidate
dose for Etomidate
0.3mg/kg
onset/duration for Etomidate
15-45sec onset
lasts 3-12 min
caution w/Etomidate
no analgesic
short duration (3-12 min)
use cautiously if hemodyanmically unstable
vomit when awake
NOT: if adrenal suppression, shock/Addisions/CODP/asthma
RSI not to use if adrenal suppression
ETomidate
RSI not to use if in shock
Etomidate = don’t use if adrenal suippression/shock/COPD/asthma/Addisions, or if hymedynamically unstable
common SE w/Etomidate
common to vomit when awake
properties of KEtamine
hypnotic
analgesic
Amnesic
benefit of Ketamine
has unique ability to preserve laryngeal reflex/help w/airway preotection
best RSI for asthma/airway issues
Ketamine b/c preserves laryngeal reflexes/airway protection
Ketamine dose for RSI
1-2mg/kg
onset and duration of Ketamine
onse = 40 -60 sec duration = 10-20min
best RSI for asthatics w/reactive airway complications
Ketamine is a potent bronchodilator
SE of ketamine
may hallucinate
may cause laryngospasms
reversal agent for Versed
Flumazenil 02mg
SE of Flumazenil
BP
good RSI choice if shock
Ketamine
what is propofol
hypnotic w/ no analgesic properties
“milk of amnesia”
dose of Propofol
1-2mg/kg
25-50mcg/kg/min maintence
onset/duration of propofol
onset 15-45 sec
duration 5-10 minutes
RSI decreases MAP/CPP
PRopofol
what cannot Propofol do
milk of amnesia - hyponotic BUT NO PAIN RX
who should not have Propofol
decreases CPP & MAP so not for HEad INjury or if hemodynamically unstable
contraindicatiosn for Propofol
Head injury & hemodynamically unstable
*b/c decreases MAP/CPP
RSI rx & their complications
Fentnanyl - chest wall rigidity, hypotension
ETomidate - adrenal suppression
Ketamine preserves laryngeal function so airway protect
Propofol = decreases CPP/MAP so not for head injury or hemodyunamically unstable
RSI induction
fentanyl, etomidate, ketamine, propofol
what will you see someone on Succ do
fasciculation = muscle twitch
SE of SUCC - 2
high K
malignant hyperthermia
what is linked to malignant hyperthermia
Succ
drug class of Succ
depolarizing neuromuccular agent
burns contraindicate dfor Succ
over 24hrs
contrainidcation for SUcc
burns over 24hr rhabdo, high K hx of Malignant hyperthermia crush or eye injuries any nervous system injury like G-B or MG
pathophysiology of Malignant Hyperthermia
defect in skeletal muscle sarcoplasmic retiulum
*r/t problem w/Ca removal from the cell
treat Malignant Hyperthermia
Dantrolene
NEVER CaChannel blockers (b/c MH is a problem w/sustained Ca removal from teh cell)
Rx not to give someone with Maligant Hyperthermia
Ca ChB (b/c probelm with calcium removal from the muscle_
s/s of Malignant Hyperthermia
sustINED TETANIC MUSCLE CONTRACTION masseter spasm trismus (lockjaw) rapid incrase in temp up to 110F HTN/high RR mixed acidosis increased ETCO2
acid base in Malignant Hyperthermia
mixed acidosis
increased ETCO2
tachycardia
lockjaw
trismus
when do you give Dantrolene
for Malignant Hyperthermia s/p gases or Succ
cause of Malignant Hyperthermia
induction gasses or Succ
dose of Succ
2.5mg/kg
Sugammadex
reverses Roc
reverses Roc
Sugammadex
drug class of Roc
Non-Depolarizing Neuromuscular BLocking
onset/duration of Roc
0.6 - 1.2 mg/kg
onset and duration of Roc
onset under 2 min
lduration 30-60 moin
important Rx to give if induce w/vec or roc
NO pain management
how to dose RSI if pt is hemodynamically unstable/shock and low CO
1/2 induction. less rx is needed due to depleted catecholamine stores
double paralytic b/c low CO slowws the onset
RSI dose of induction agent if pt is shock/hemodynamically unstable w/ low CO
1/2 induction.
less rx is needed due to depleted catacholamine stores
RSI dose of paralytic if pt is shock/hemodynamically unstable w/low CO
double paralytic b/c low CO slows the onset
SALAD technique
suction assisted laryngoscopy airway decontamination
clear airway w/ suction, plae suction in the esophagus wile the intunation tube is passed.
post intubation management
Fentanyl, KEtamine, Versed drip
failed airway algorithm
3 attemps of laryngoscopy unsuccessful
can’t intubate, ventilatie, oxygenate = CRIC
what do you palpate for when you cric
feel for ht ecricothyroid membrane
what type of cri to use
surgical cric over 8yo
needle crif if under 8
