Dr S Parthasarathy MD DA DNB MD Acu Dip Diab DCA Dip Software statistics Ph d physio Mahatma gandhi medical college and research institute puducherry India ID: 908885
Download Presentation The PPT/PDF document "ANION GAP" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
![2-++H3O+Proton donorAlso Al3+ is an acidic anion[Al(H2O)6]3+ [Al(OH)(H](https://thumbs.docslides.com/104175/2-h3o-proton-donoralso-al3-is-an-acidic-anion-al-h2o-6-3.jpg)
Slide1
ANION GAP
Dr. S. Parthasarathy
MD
., DA., DNB, MD (
Acu
), Dip.
Diab
. DCA, Dip. Software
statistics Ph d (
physio
)
Mahatma
gandhi
medical college and research institute,
puducherry
, India
Slide2What
is Normal ??
In
serum
,
number
of anions =
number
of cations
(Na + K+ Ca2 + Mg2 + Protein) -
( Cl + HCO3+
Protein +HPO4 +SO4)
Some
are
measurable
but
others
are not
So
comes
the gap
Slide3Why unmeasured cations
??
total unmeasured anions exceed the
total unmeasured
cations
, there is an anion gap.
Slide4Unmeasured
anions = anion gap
Gamble
gram
Slide5To calculate
Anion gap = (Na
+
+ K
+
) – ( HCO3
-
+
Cl-)
(140 + 5) – ( 25 + 104 )
145 – 129 = 16
meq Unmeasured anions sulphates and a number of serum proteins.
Slide6Methodology of estimation
values were based on sodium concentration
determined by
flame photometry
, chloride concentration by a
colorimetric method
(usually mercuric-nitrate
thiocyanate
),and total CO2 content by acidification of the specimen followed by colorimetric titration
Slide7Anion gaps are important in acidosis
Anion gap can be classified as either high, normal or, in rare cases, low
High means what ??
([Na
+
] + [K
+
]) − ([
Cl
−
] + [HCO
3−]) a loss in HCO3− without raise in
Cl
−
Slide8Increased anion gap acidosis
DKA.
Lactic acidosis
Alcohol intoxication
Salicylate
poisoning
Azotemia
In all these, acidosis sets to deplete HCO3 but !!
Slide9Values
Normally 16
Increased means around 22
45 are reported only one case of 90 is reported
Low means usually around 4
Slide10CUTE DIMPLES- pneumonic
Cyanide ,
uremia
Toluene
Ethylene glycol
DKA
INH,
Methanol
Propylene Ethylene glycolSalicylate
Slide11Increased anion gap
Anion gap = (Na
+
+ K
+
) – ( HCO3
-
+
Cl-)
There is no increase in
Cl
-Gap widens Usually above 22
meq
Slide12Diagnosis and severity of acidosis
∆ AG is inversely proportional to ∆ HCO3
anion gap
HCO3 decrease anion gap increase
But latter this may not be there
Slide13Normal anion gap metabolic acidosis
NAGMA
Slide14Causes
Administration of chlorides
Carbonic
anhydrase
inhibitors
Pancreatic fistula
Ureterocolic
fistula
Renal tubular acidosis
Slide15HCO3 decreases but
Cl
increases
i.e. the retention or excess of hydrochloric acid
Anion gap = (Na
+
+ K
+
) – ( HCO3
-
+
Cl-)
Slide16FUSEDCARS - pneumonic - Causes
Administration of chlorides
Carbonic
anhydrase
inhibitors
Pancreatic fistula
Ureterocolic
fistula
Renal tubular acidosis
Slide17Examples
Ammonium chloride ingestion
Diuretic
NH4 → NH3 + H
+
ion
But chloride remains
Renal tubular acidosis –
reabsorbtion
of bicarbonate or excretion of hydrogen ions
Anions of metabolic acids like phosphates sulfates get excreted , Chloride increases
Hence anion gap is normal
Slide18RTA
loss of bicarbonate, along with its counterbalancing
cation
sodium, produces volume contraction, thereby stimulating the renal tubule to retain sodium chloride.
The consequences of these events are the replacement of sodium bicarbonate by sodium chloride.
Slide19Examples
Nacl
administration (150 + 150)
↓
NaHCO3 excreted
↓
retention of Hydrogen ions and chloride ions
NAGMA
Slide20Gaps in anion gap
Decreased anion gap
Decreased unmeasured anions
Why ?? Range ! 1%
Hypoalbuminemia
Albumin decreased 4 to 3 gm ↓ anion gap 2.75
meq
Lab errors
Slide21Gaps in anion gap
Abnormal
cations
Paraproteinemias
Lithium or bromine poisoning
Water excess
All electrolyte decreased by 10 % (127 + 3) - ( 24 + 92 )
130 - 116 = 14
Slide22Gaps in anion gap
Serum chloride concentration was raised by approximately 3
mEq
/L for every 1-mEq/L increase in the concentration of bromide
lithium is a
cation
, it can lower the serum anion gap when present in sufficient concentration
Hypercalcemia
as a result of primary
hyperparathyroidism, the serum anion gap was reduced by approximately 2.4
mEq
/L
Slide23Anion gap – summary
Serum
cations
= anions
Anion gap = (Na
+
+ K
+
) – ( HCO3- + Cl
-
)
Unmeasured anions HCO3 decrease is acidosis but sometimes Chloride increases to maintain anion gap in acidosis There are some gaps
Slide24Thank you all