This document discusses blood gas analysis and blood gas analyzers. It explains that blood gas analysis measures how effectively the lungs are delivering oxygen and removing carbon dioxide from the blood. It also measures acid-base balance. The document then discusses the parameters measured by blood gas analyzers, including pH, pO2, pCO2, potassium, sodium, and others. It provides details on normal ranges and implications of abnormal readings for each parameter. The document explains how blood gas analyzers directly measure pH, pCO2 and pO2 using specialized electrodes. It concludes with some common problems with blood gas analyzers.

1. N O O R A F S H A N M E M O N
P R E S E N T E D B Y:

2. B LO O D G A S A N A LY S I S :
• how effectively the lungs are delivering
oxygen to the blood and how effectively they
are eliminating carbon dioxide from it.
• how well the lungs and kidneys are
interacting to maintain normal blood ph (acid
base balance).

3. B LO O D G A S A N A LY Z E R :
Blood gas an alyzer measu res th e followin g
p arameters:
• p H ( ac id d eg ree)
• PO 2 ( p artial p ressu re of oxygen in b lood )
• PCO 2 ( p artial p ressu re of carb on d ioxid e in b lood )
• c k ( p otassiu m con c entration )
• Na ( sod iu m con c entration )
• Glucose
• Total b iliru b in

4. 1 ) p H :
• It stan d s for th e p erc entage of hyd rogen .
• Th e amou nt of hyd rogen p resent in you r b od y.
• Too mu c h hyd rogen = p H sh ifts an d b ecomes
“ac id iotic ”.
• N ot en ou g h hyd rogen = b od y b ecomes “alkalotic ” .
• It reflec ts on th e overall ac id b ase b alan c e of th e
b od y.
• N ormal b od y pH range: 7.35-7.45
•Perfect body pH is 7.40.
• if p H d rops p atient b ecomes ac id ized ; th e p atient
d evelops ac id osis. ( wh en th e p H falls it falls to
ac id ic ) .

5. 2 ) p C O 2 :
•p CO 2 is th e resp irator y ac id .
• n ormal p CO 2 ran ge = 3 5 - 4 5
•Th e in c rease in amou nt of resp irator y ac id in th e
b od y, th e p CO 2 is in c reasin g .
•A n d th e p atient may d evelop resp irator y ac id osis.
•If p CO 2 d rops n ormal th an lower th e p atient may
d evelop resp irator y alkalosis.
3 ) H C O 3 :
• it is a metab olic b ase. ( it ’s an alkalin e)
• th e in c rease in amou nt of metab olic b ase in th e b od y
than the normal range ; the patient may develop
metab olic alkalosis.
• n ormal HCO 3 ran ge = 2 2 - 2 6

6. 4 ) p O 2 :
• n ormal p O 2 ra n g e s : 8 5 – 1 0 0 .
• it sh ou ld b e ab ou t 5 * F iO 2 ( a d m i n i s t ra te d t o t h e
p a t i e n t ) .
•Oxygen in air is 2 1 % , so p O 2 sh ou ld b e arou n d 1 0 0 .
• h owever wh en th e p atient is on th e ventilator with
1 0 0 % of F iO 2 an d p O 2 is also 1 0 0 % th e p atient is n ot
oxygen atin g well.
•Th e A BG is to b e correc ted .
•Hy p oxemia is an ab n ormally low level of oxygen ( O 2 )
in th e b lood .
•Hyp erox ia an exc ess su p p ly of oxygen ( O 2 ) or h ig h er
th an n ormal p artial p ressu re of oxygen .

7. R E A D I N G T H E A B G :
if:
p H = 7 .3 6 ( d eviates toward s ac id osis)
p CO 2 = 5 7 ( exc eed s th e n ormal ran ge to resp irator y
acidosis )
HCO 3 =3 1 ( exc eed s th e n ormal ran ge to alkalosis )
• Th e b od y h as maintain ed th e b od y p H by th e p roc ess of
“comp en sation ”.
• metab olic or resp irator y , on e will comp en sate th e
oth er to b rin g th e p H to n ormal. Th is p roc ess is kn own
as “fu ll comp en sation .”
• If the body could not maintain pH by compensating the
con d ition is called “p artial comp en sation ”.

8. E L E C T R O D E S O F A B G :
1 ) P h e l e c t r o d e :
•H+ ion sen sitive u ses th e referen c e elec trod e with th e
kn own p H .
• calibration solution pH ranges = 6.3 – 7.4
2 ) p C O 2 e l e c t r o d e :
• CO 2 re a c t s w i t h s o l u t i o n t o p ro d u c e H + .
•Hig h CO 2 = h ig h H+ = h ig h PCO 3
3 ) P O 2 e l e c t r o d e :
• O 2 d iffu ses ac ross memb ran e p rod u c in g an elec trical
c u rrent measu red as PO 2 .
•Direct measurement by specialized electrodes =
pH, pCO2, pO2
•Indirect measurement= HCO 3 & O2 sat.

9. C O M M O N P R O B L E M S W I T H
B LO O D G A S / p H A N A LY Z E R S
I N C LU D E :
• O u t of d ate b u ffer solu tion s.
• N o calib ration gas.
• Poor flu sh in g .
• N ot takin g th e time to p rop erly warm u p th e
an alyzer.
• B ad elec trod es.