Acid base disorders

Acid Base DisordersAcid Base Disorders
A Practical ApproachA Practical Approach
Ass. Lecturer critical care medicineAss. Lecturer critical care medicine
Cairo University HospitalCairo University Hospital
WALID KAMEL, MBChWALID KAMEL, MBCh

Regulation of acid-base balance:Regulation of acid-base balance:
Defense against the change in pH…
 because H+ react highly with cellular
proteins resulting in alteration in their function.
Avoiding acidemia and alkalemia by tightly
regulation H+
is essential for normal cellular
function.

What information does ABG provide about the patient?What information does ABG provide about the patient?
ABG provide an assessment of the following:
1)PaO2
: Amount of o dissolved in the blood, it give initial
information on efficiency of oxygenation.
2)PaCO2
: Adequacy of ventilation is inversely proportional to
Paco2
(when ventilation increase PaCO2
decrease
and vice verse).
3) Acid base status (pH, HCO3
, base deficit, anion gap).
4) Hb, Hct, oxygen saturation.
5) Electrolyte e.g. Na+
, K+
.

Diagnosis of acid Base disordersDiagnosis of acid Base disorders
•Arterial blood sample is common utilized clinically
but venous blood may be useful in determining acid
base status. (Except in CHF and shock).
•Blood sample should be in heparin coated syringe.
•The sample should be analyzed as soon as possible.
•Air bubble should be eliminated.
•The syringe should be capped and placed in ice.

Acid Base -Basic ConceptsAcid Base -Basic Concepts
 Hydrogen IonHydrogen Ion [H[H++
]]is tightly controlledis tightly controlled
 [H[H++
]]is determined by the balance betweenis determined by the balance between
PaCOPaCO22 and serumand serum HCOHCO33 (bicarbonate)(bicarbonate)
Henderson-Hasselbalch EquationHenderson-Hasselbalch Equation
[H[H++
] = 24 (PaCO] = 24 (PaCO22 / HCO/ HCO33
--
))

[H[H++
] pH] pH
pH = 6.1 + log ([PaCO2] / [0.03 x HCO3-])pH = 6.1 + log ([PaCO2] / [0.03 x HCO3-])
pH [H+
] pH [H+
]
7.80
7.75
16
18
7.30
7.25
50
56
7.70
7.65
20
22
7.20
7.15
63
71
7.60
7.55
25
28
7.10
7.00
79
89
7.50
7.45
32
35
6.95
6.90
100
112
7.40
7.35
40
45
6.85
6.80
141
159

Normal ValuesNormal Values
[H+] = 40 nEq/L[H+] = 40 nEq/L
pH = 7.40pH = 7.40 (7.35-7.45)(7.35-7.45)
PaCOPaCO22 = 40 mm Hg= 40 mm Hg (35-45)(35-45)
HCOHCO33 = 24 mEq/L= 24 mEq/L (22-26)(22-26)

Keep It SimpleKeep It Simple
 PaCOPaCO22 = Acid= Acid
  PaCOPaCO22 ==  pH (Acidemia)pH (Acidemia)
  PaCOPaCO22 ==  pH (Alkalemia)pH (Alkalemia)
 HCOHCO33 = Base= Base
  HCOHCO33 ==  pH (Alkalemia)pH (Alkalemia)
  HCOHCO33 ==  pH (Acidemia)pH (Acidemia)

Simple Acid-Base DisordersSimple Acid-Base Disorders
Type of Disorder pH PaCO2 [HCO3]
Metabolic Acidosis ↓ ↓ ↓
Metabolic Alkalosis ↑ ↑ ↑
Acute Respiratory Acidosis ↓ ↑ ↑
Chronic Respiratory Acidosis ↓ ↑ ↑↑
Acute Respiratory Alkalosis ↑ ↓ ↓
Chronic Respiratory Alkalosis ↑ ↓ ↓↓

EXPECTED CHANGES IN ACID-BASE DISORDERSEXPECTED CHANGES IN ACID-BASE DISORDERS
Primary DisorderPrimary Disorder ExpectedExpected
ChangesChanges
Metabolic acidosisMetabolic acidosis PCO2 = 1.5 × HCO3 + (8 ± 2)PCO2 = 1.5 × HCO3 + (8 ± 2)
Metabolic alkalosisMetabolic alkalosis PCO2 = 0.7 × HCO3 + (21 ± 2)PCO2 = 0.7 × HCO3 + (21 ± 2)
Acute respiratory acidosisAcute respiratory acidosis delta pH = 0.008 ×delta pH = 0.008 ×
(PCO2 - 40)(PCO2 - 40)
Chronic respiratory acidosisChronic respiratory acidosis delta pH = 0.003 ×delta pH = 0.003 ×
(PCO2 - 40)(PCO2 - 40)
Acute respiratory alkalosisAcute respiratory alkalosis delta pH = 0.008 × (40 - PCO2)delta pH = 0.008 × (40 - PCO2)
Chronic respiratory alkalosisChronic respiratory alkalosis delta pH = 0.003 × (40 -delta pH = 0.003 × (40 -
PCO2)PCO2)

Acid-Base AnalysisAcid-Base Analysis
What do You Need?What do You Need?
 Arterial Blood gases (pH, COArterial Blood gases (pH, CO22))
 Serum chemistry (Na, K, Cl, HCOSerum chemistry (Na, K, Cl, HCO33))

 A 39 year old woman was admitted with a history ofA 39 year old woman was admitted with a history of
generalized weakness, dyspnea, continuous nauseageneralized weakness, dyspnea, continuous nausea
and diarrhea. Bowel motions were frequent andand diarrhea. Bowel motions were frequent and
watery.watery.
 ABG: pH 7.29, PaCO2 25.6, PaO2 98ABG: pH 7.29, PaCO2 25.6, PaO2 98
 NaNa++
=125, K=125, K++
=2.8, Cl=2.8, Cl--
=101, HCO=101, HCO33=14=14
Study CaseStudy Case
MetabolicMetabolic Acidosis

Simple Vs. MixedSimple Vs. Mixed
Compensation ConceptCompensation Concept
[H[H++
] = 24 (PaCO] = 24 (PaCO22 / HCO/ HCO33
--
))
 Is compensation appropriate?Is compensation appropriate?
 Must know “rules of thumb” of compensationMust know “rules of thumb” of compensation

Respiratory CompensationRespiratory Compensation
 Compensate for metabolicCompensate for metabolic
disordersdisorders
 Prompt responsePrompt response
 Metabolic acidosisMetabolic acidosis
 Hyperventilation - ↓ PaCOHyperventilation - ↓ PaCO22
 Metabolic alkalosisMetabolic alkalosis
 Hypoventilation - ↑ PaCOHypoventilation - ↑ PaCO22

Respiratory CompensationRespiratory Compensation
 Metabolic AcidosisMetabolic Acidosis
PaCO2 = [1.5 x HCOPaCO2 = [1.5 x HCO33 + 8] ± 2+ 8] ± 2
 Metabolic AlkalosisMetabolic Alkalosis
∆∆PaCO2 = 0.9 ∆ HCOPaCO2 = 0.9 ∆ HCO33

Metabolic CompensationMetabolic Compensation
 Compensation for respiratory disordersCompensation for respiratory disorders
 Slow responseSlow response
 Starts in 6-12 hoursStarts in 6-12 hours
 Steady state in few daysSteady state in few days
 Respiratory acidosisRespiratory acidosis
 Stimulates HCOStimulates HCO33 reabsorption --reabsorption --↑ HCO↑ HCO33
 Respiratory alkalosisRespiratory alkalosis
 Inhibits HCOInhibits HCO33 reabsorption --reabsorption -- ↓ HCO↓ HCO33

Metabolic CompensationMetabolic Compensation
 Chronic Respiratory AcidosisChronic Respiratory Acidosis
∆∆ HCOHCO33= 0.35 ∆ PaCO= 0.35 ∆ PaCO22
 Chronic Respiratory AlkalosisChronic Respiratory Alkalosis
∆∆ HCOHCO33= 0.5 ∆ PaCO= 0.5 ∆ PaCO22

Case Study - 1Case Study - 1
 A 39 year old woman was admitted with a history of generalizedA 39 year old woman was admitted with a history of generalized
weakness, dyspnea, continuous nausea and diarrhea. Bowelweakness, dyspnea, continuous nausea and diarrhea. Bowel
motions were frequent and watery.motions were frequent and watery.
 NaNa++
=125, K=125, K++
=2.8, Cl=2.8, Cl--
=101, HCO=101, HCO33=12=12
PaCO2 = [1.5 x HCO3 + 8] ± 2PaCO2 = [1.5 x HCO3 + 8] ± 2
PaCo2=[1.5X12]+8 ± 2PaCo2=[1.5X12]+8 ± 2
PaCO2 =PaCO2 = 2525 ± 2± 2
Simple (compensated) metabolic acidosis

Metabolic AcidosisMetabolic Acidosis
Anion GapAnion Gap
 Metabolic acidosis is groupedMetabolic acidosis is grouped
according to the anion gapaccording to the anion gap
 Anion Gap (AG)Anion Gap (AG)
 The difference between measured cationsThe difference between measured cations
and measured anions in the serumand measured anions in the serum
AG= NaAG= Na++
- [Cl- [Cl--
+ HCO+ HCO33
--
]]
 Normal (9 - 12 mEq/LNormal (9 - 12 mEq/L))

Wide Anion Gap AcidosisWide Anion Gap Acidosis
 MethanolMethanol
 UremiaUremia
 Diabetic Ketoacidosis, KetoacidosisDiabetic Ketoacidosis, Ketoacidosis
 ParaldehydeParaldehyde
 Iron, Isoniazid (INH)Iron, Isoniazid (INH)
 Lactic AcidosisLactic Acidosis
 Ethanol, Ethylene glycolEthanol, Ethylene glycol
 SalicylatesSalicylates

Non (normal) Anion GapNon (normal) Anion Gap
AcidosisAcidosis
 HyperalimentationHyperalimentation
 Acetazolamide, amphotericinAcetazolamide, amphotericin
 RTA –Renal Tubular AcidosisRTA –Renal Tubular Acidosis
 DiarrheaDiarrhea
 Ureteral DiversionsUreteral Diversions
 Pancreatic fistulaPancreatic fistula
 Saline resuscitationSaline resuscitation

Non anion gap metabolic acidosis:
Metabolic acidosis associated with normal AG is
typically characterized by hyperchloremia.
Calculation of AG in urine:
Urine AG = ( Na+
+ K+
) – CL-
In a patient with a hyperchloraemic metabolic
acidosis:
•A negative UAG  GIT loss of bicarbonate (eg
diarrhoea)
•A positive UAG  impaired renal distal acidification
(ie renal tubular acidosis).

BASE EXCESSBASE EXCESS
 It is an estimate of the amount of strong acid orIt is an estimate of the amount of strong acid or
base needed to correct the met. component of anbase needed to correct the met. component of an
acid base disorder (restore plasma pH to 7.40at aacid base disorder (restore plasma pH to 7.40at a
PacoPaco22 40 mmHg)40 mmHg) represent only the metabolic
component of acid base disorders.
 Its +ve value indicate metabolic alkalosis, wIts +ve value indicate metabolic alkalosis, while
–ve value indicate metabolic acidosis.

Study Case - 1Study Case - 1
 A 39 year old woman was admitted with a history ofA 39 year old woman was admitted with a history of
generalized weakness, dyspnea, continuous nauseageneralized weakness, dyspnea, continuous nausea
and diarrhea. Bowel motions were frequent andand diarrhea. Bowel motions were frequent and
watery.watery.
 NaNa++
=125, K=125, K++
=2.8, Cl=2.8, Cl--
=101, HCO=101, HCO33=14=14
AG = Na – (Cl+HCO3)
AG = 125 – (101+14) = 10
Normal anion gap metabolic acidosis

Metabolic AlkalosisMetabolic Alkalosis
 Characterized byCharacterized by
 PrimaryPrimary ↑↑ in HCO3 concentrationin HCO3 concentration
 CompensatoryCompensatory ↑↑ in PaCO2in PaCO2
 Classified according to urinary chlorideClassified according to urinary chloride
 Chloride responsiveChloride responsive
 Chloride resistantChloride resistant

Chloride ResponsiveChloride Responsive
Urine ClUrine Cl--
>20 mEq/L>20 mEq/L
 Volume Contraction:Volume Contraction:
 Nasogastric suctioningNasogastric suctioning
 VomitingVomiting
 DiureticsDiuretics
 Post HypercapniaPost Hypercapnia
 HypokalemiaHypokalemia
 HypomagnesemiaHypomagnesemia
 PenicillinPenicillin

Chloride UnresponsiveChloride Unresponsive
 Mineralcorticoid excessMineralcorticoid excess
 Exogenous steroidsExogenous steroids
 Alkali IngestionAlkali Ingestion
 LicoriceLicorice
 Too much wineToo much wine
 Tobacco chewersTobacco chewers
 Bartter’s SyndromeBartter’s Syndrome
Urine Cl- < 20 mEq/LUrine Cl- < 20 mEq/L

 A 78 year old lady presented with at a 1 weekA 78 year old lady presented with at a 1 week
history of abdominal pain and vomiting.history of abdominal pain and vomiting.
 ABG: pH 7.49, PaCO2 52, PaO2 78ABG: pH 7.49, PaCO2 52, PaO2 78
 Na 137, K 2.2, CL 91, HCO3 38Na 137, K 2.2, CL 91, HCO3 38
 Urine CI 43Urine CI 43 mEq/LmEq/L
Metabolic Alkalosis
Vomiting and hypokalemia

SolvingSolving
Acid Base DisordersAcid Base Disorders

Rule 1Rule 1
Validate the ABGValidate the ABG
[H[H++
] = 24 (PaCO] = 24 (PaCO22 / HCO/ HCO33
--
))
80 - [H80 - [H++
]] ~ the last two digits of the pH~ the last two digits of the pH
 [H[H++
] of 24: pH of (80-24=56) ~ 7.] of 24: pH of (80-24=56) ~ 7.5656
 [H[H++
] of 53: pH of (80-53=27) ~ 7.] of 53: pH of (80-53=27) ~ 7.2727

Another method
Determine if numbers fit:Determine if numbers fit:
H+ =H+ =
3
2
HCO
PCO24×
H+ = (7.8-PH)×100.H+ = (7.8-PH)×100.
The Rt side of the equation should beThe Rt side of the equation should be
within 10% of the Lt Side. If not so anotherwithin 10% of the Lt Side. If not so another
ABG or chemistry panel for HCO3 should beABG or chemistry panel for HCO3 should be
done.done.

Rule 2Rule 2
 What is the pH?What is the pH?
 > 7.40 → 1° disorder is alkalosis> 7.40 → 1° disorder is alkalosis
 < 7.40 → 1° disorder is acidosis< 7.40 → 1° disorder is acidosis
 Does theDoes the PaCOPaCO22 explains the pH?explains the pH?
 YesYes → 1° disorder is respiratory→ 1° disorder is respiratory
 No → 1° disorder is metabolicNo → 1° disorder is metabolic

Rule 3Rule 3
 Does theDoes the PaCOPaCO22 explains the pH?explains the pH?
 YesYes → 1° disorder is respiratory→ 1° disorder is respiratory
 No → 1° disorder is metabolicNo → 1° disorder is metabolic

Rule 4Rule 4
Apply compensation rulesApply compensation rules
 If calculated compensation:If calculated compensation:
 Within the expected range → simpleWithin the expected range → simple
acid/base disorderacid/base disorder
 Less or more than expected → 2°Less or more than expected → 2°
acid/base disorderacid/base disorder

There is no over correction orThere is no over correction or
compensation in acid base balance →compensation in acid base balance →
if the compensatory response is moreif the compensatory response is more
or less than expected → it is mixedor less than expected → it is mixed
acid base disorderacid base disorder

 A 39 year old woman was admitted with a historyA 39 year old woman was admitted with a history
of generalized weakness, dyspnea, continuousof generalized weakness, dyspnea, continuous
nausea and diarrhea. Bowel motions were frequentnausea and diarrhea. Bowel motions were frequent
and watery.and watery.
 NaNa++
=125, K=125, K++
=2.8, Cl=2.8, Cl--
=101, HCO=101, HCO33=12=12
PaCO2 = [1.5 x HCO3 + 8] ± 2PaCO2 = [1.5 x HCO3 + 8] ± 2
PaCO2 = 25 ± 2PaCO2 = 25 ± 2
Simple (compensated) metabolic acidosis

 A 78 year old lady presented with at least aA 78 year old lady presented with at least a
week history of abdominal pain and vomiting.week history of abdominal pain and vomiting.
 Na 137, K 2.2, CL 91, HCO3 38Na 137, K 2.2, CL 91, HCO3 38
 Urine CI 43Urine CI 43 mEq/LmEq/L
Metabolic Alkalosis
∆∆PaCO2 = 0.9 ∆ HCO3 : 0.9 X 14 = 17PaCO2 = 0.9 ∆ HCO3 : 0.9 X 14 = 17
PaCO2 = 53PaCO2 = 53
Simple

Mixed Acid-Base DisordersMixed Acid-Base Disorders
 pH may be within normal (7.35-7.45)pH may be within normal (7.35-7.45)
 Cannot over-compensateCannot over-compensate
 Simultaneous co-existence ofSimultaneous co-existence of
disordersdisorders
 2 respiratory + 2 metabolic2 respiratory + 2 metabolic
 Acute on top of chronicAcute on top of chronic
 The pH determines which is primary:The pH determines which is primary:
 pH < 7.40 – primary disorder is AcidosispH < 7.40 – primary disorder is Acidosis
 pH > 7.40 – primary disorder is AlkalosispH > 7.40 – primary disorder is Alkalosis

 A 21 year old MS is brought to the ER at ~3A 21 year old MS is brought to the ER at ~3
am, stuporous and tachypneic. History isam, stuporous and tachypneic. History is
remarkable for failing the respiratory moduleremarkable for failing the respiratory module
in 2in 2ndnd
year. An ABG and electrolytes haveyear. An ABG and electrolytes have
been drawn by the ER nurse.been drawn by the ER nurse.
 ABG: pH=7.38, PaCOABG: pH=7.38, PaCO22=18=18
 NaNa++
=140, K=140, K++
=3.8, Cl=3.8, Cl--
=106, HCO=106, HCO33=12=12

 A 21 year old MS is brought to the ER at ~3 am, stuporous and tachypneic.A 21 year old MS is brought to the ER at ~3 am, stuporous and tachypneic.
History is remarkable for failing the respiratory module in 2History is remarkable for failing the respiratory module in 2ndnd
year. An ABG andyear. An ABG and
electrolytes have been drawn by the ER nurse.electrolytes have been drawn by the ER nurse.
 NaNa++
=143, K=143, K++
=3.8, Cl=3.8, Cl--
=106, HCO=106, HCO33=12=12
AG = 143-106-12 = 25
Wide AG Metabolic acidosis
PaCO2 = 1.5 X 12 +8 = 26 ±2
Wide AG metabolic acidosis and Respiratory Alkalosis
Aspirin
Overdose

Primary Respiratory DisordersPrimary Respiratory Disorders
Acute vs. ChronicAcute vs. Chronic
 ACUTEACUTE
 Δ PCO2 = 10 → Δ pH=0.08 (~0.1)Δ PCO2 = 10 → Δ pH=0.08 (~0.1)
 CHRONICCHRONIC
 Δ PCO2 = 10 → Δ pH=0.03Δ PCO2 = 10 → Δ pH=0.03

 A 55 year old woman presented to the ERA 55 year old woman presented to the ER
with dyspnea and wheezes. She is heavywith dyspnea and wheezes. She is heavy
smoker. An ABG and electrolytes have beensmoker. An ABG and electrolytes have been
drawn by the ER nurse.drawn by the ER nurse.
 NaNa++
=144, K=144, K++
=4.2, Cl=4.2, Cl--
=104, HCO=104, HCO33=32=32

 A 55 year old woman presented to the ER with dyspnea andA 55 year old woman presented to the ER with dyspnea and
wheezes. She is heavy smoker. An ABG and electrolytes havewheezes. She is heavy smoker. An ABG and electrolytes have
been drawn by the ER nurse.been drawn by the ER nurse.
 NaNa++
=144, K=144, K++
=4.2, Cl=4.2, Cl--
=104, HCO=104, HCO33=32=32
Chronic Respiratory Acidosis

Approach To ALL Acid/BaseApproach To ALL Acid/Base
ProblemsProblems
 Don’t get overwhelmed by all the numbersDon’t get overwhelmed by all the numbers
at once!at once!
 Use a methodical system to dissect theUse a methodical system to dissect the
numbers.numbers.
 Don’t jump ahead when doing calculations.Don’t jump ahead when doing calculations.

METHODICAL SYSTEMMETHODICAL SYSTEM
 Get all your numbers in front you first…Get all your numbers in front you first…
 Look at pH first: Acidotic or alkalotic?Look at pH first: Acidotic or alkalotic?
 Metabolic or Respiratory?Metabolic or Respiratory?
 Go straight to Bicarb!Go straight to Bicarb!
 Correlate bicarb with PCO2 and it should beCorrelate bicarb with PCO2 and it should be
obviousobvious
 Calculate anion gap no matter what theCalculate anion gap no matter what the
disturbance is!disturbance is!

SYSTEM…continuedSYSTEM…continued
 After you come up with “primary disturbance”,After you come up with “primary disturbance”,
your next question should ALWAYS BE =your next question should ALWAYS BE =
 ““Is there compensation?”Is there compensation?”
 For metabolic acidosis… do last two digits of pHFor metabolic acidosis… do last two digits of pH
equal PCO2 or notequal PCO2 or not
 For resp acidosis… is it acute or chronic, and isFor resp acidosis… is it acute or chronic, and is
the HCO3 up appropriately?the HCO3 up appropriately?
 For resp alkalosis… is it acute or chronic, and isFor resp alkalosis… is it acute or chronic, and is
the HCO3 down appropriately?the HCO3 down appropriately?

CompensationCompensation
The Two Given Rules of Compensation:The Two Given Rules of Compensation:
1.1. METABOLIC = BICARB (HCO3)METABOLIC = BICARB (HCO3)
……So if you dealing with figuring out yourSo if you dealing with figuring out your
disturbance and it is metabolic (up or downdisturbance and it is metabolic (up or down
HCO3), then the compensation will beHCO3), then the compensation will be
RESPIRATORY (is the PCO2 appropriatelyRESPIRATORY (is the PCO2 appropriately
up or down)up or down)

Compensation…continuedCompensation…continued
2.2. RESPIRATORY = PCO2RESPIRATORY = PCO2
……So if you are dealing with respiratorySo if you are dealing with respiratory
alkalosis or acidosis, you want to know ifalkalosis or acidosis, you want to know if
the METABOLIC (HCO3) compensationthe METABOLIC (HCO3) compensation
is appropriate or notis appropriate or not

SYSTEM…continuedSYSTEM…continued
 If the compensation is INAPPROPRIATE, thenIf the compensation is INAPPROPRIATE, then
you automatically have a SECONDyou automatically have a SECOND
superimposed acid/base disordersuperimposed acid/base disorder

Case 1Case 1
 A 75-year-old man presents to the ED after aA 75-year-old man presents to the ED after a
witnessed out of hospital VF cardiac arrest.witnessed out of hospital VF cardiac arrest.
 Arrived after 10 minutes, CPR had not beenArrived after 10 minutes, CPR had not been
attempted.attempted.
 The paramedics had successfully restoredThe paramedics had successfully restored
spontaneous circulation after 6 shocks.spontaneous circulation after 6 shocks.
 On arrival the man is comatose with a GCS of 3On arrival the man is comatose with a GCS of 3
and his lungs are being ventilated with 50%and his lungs are being ventilated with 50%
oxygen via ET tube.oxygen via ET tube.
 He has HR of 120/min and a blood pressure ofHe has HR of 120/min and a blood pressure of
150/95 mmHg.150/95 mmHg.

ABG Analysis reveals:ABG Analysis reveals:
 FFiiOO22 0.50.5
 pHpH 7.107.10
 PaCOPaCO22 45 mmHg45 mmHg
 PaOPaO22 56 mmHg56 mmHg
 HCOHCO33
--
14 mmol/l14 mmol/l
 BEBE - 10 mmol/l- 10 mmol/l

Case 2Case 2
 A 65-year-old man with severe COPDA 65-year-old man with severe COPD
has just collapsed in the respiratoryhas just collapsed in the respiratory
high-care unit.high-care unit.
 On initial assessment he is found to beOn initial assessment he is found to be
apnoeic but has an easily palpableapnoeic but has an easily palpable
carotid pulse at 90/min.carotid pulse at 90/min.
 A nurse is ventilating his lungs withA nurse is ventilating his lungs with
an Ambu bag and supplementary O2an Ambu bag and supplementary O2

 FFiiOO22 0.85 (estimated)0.85 (estimated)
 pHpH 7.207.20
 PaCO2PaCO2 151 mmHg151 mmHg
 PaO2PaO2 147 mmHg147 mmHg
 HCO3-HCO3- 36 mmol/l36 mmol/l
 BEBE + 12 mmol/l+ 12 mmol/l

Case 3Case 3
 A 75-year-old lady is admitted to the EDA 75-year-old lady is admitted to the ED
following a VF cardiac arrest, which wasfollowing a VF cardiac arrest, which was
witnessed by the paramedics.witnessed by the paramedics.
 A spontaneous circulation was restoredA spontaneous circulation was restored
after 4 shocks, but the patient remainedafter 4 shocks, but the patient remained
comatose and apnoeic.comatose and apnoeic.
 The paramedics intubated her trachea,The paramedics intubated her trachea,
and on arrival in hospital her lungs areand on arrival in hospital her lungs are
being ventilated with an automaticbeing ventilated with an automatic
ventilator using a tidal volume of 900 mlventilator using a tidal volume of 900 ml
and a rate of 18 breaths/min.and a rate of 18 breaths/min.

 FFiiOO22 1.01.0
 pHpH 7.607.60
 PaCOPaCO22 20 mmHg20 mmHg
 HCOHCO33
--
20 mmol/l20 mmol/l

Case 4Case 4
 An 18-year-old male insulin dependentAn 18-year-old male insulin dependent
diabetic is admitted to the ED.diabetic is admitted to the ED.
 He has been vomiting for 48 hours andHe has been vomiting for 48 hours and
because he was unable to eat, he omittedbecause he was unable to eat, he omitted
his insulin.his insulin.
 He has HR of 130/min and his bloodHe has HR of 130/min and his blood
pressure is 90/65 mmHg.pressure is 90/65 mmHg.
 He is breathing spontaneously with deepHe is breathing spontaneously with deep
breaths at a rate of 35/min. His GCS is 12breaths at a rate of 35/min. His GCS is 12
(E3, M5, V4(E3, M5, V4).).

 FFiiOO22 0.40.4
 pHpH 6.796.79
 PaCOPaCO22 11.3 mmHg11.3 mmHg
 PaOPaO22 129.2 mmHg129.2 mmHg
 HCOHCO33
--
4.7 mmol/l4.7 mmol/l
 BEBE - 29.2 mmol/l- 29.2 mmol/l

Case 5Case 5
His vital signs are:His vital signs are:
 Heart rateHeart rate 120/min – sinus120/min – sinus
tachycardia – warm peripheriestachycardia – warm peripheries
 Blood pressureBlood pressure 70/40 mmHg70/40 mmHg
 Respiratory rateRespiratory rate 35 breaths/min35 breaths/min
 SpOSpO22 on oxygenon oxygen 92%92%
 Urine outputUrine output 50 ml in the last 6 hours50 ml in the last 6 hours
 GCSGCS 13 (E3, M6, V4)13 (E3, M6, V4)

 FFiiOO22 0.4 (approx)0.4 (approx)
 pHpH 7.127.12
 PaCOPaCO22 36 mmHg)36 mmHg)
 HCOHCO33
--
12 mmol/l12 mmol/l

Acid base disorders

Recomendados

Recomendados

Mais conteúdo relacionado

Mais procurados

Mais procurados (20)

Semelhante a Acid base disorders

Semelhante a Acid base disorders (20)

Mais de Amir Mahmoud

Mais de Amir Mahmoud (20)

Último

Último (20)

Acid base disorders

Notas do Editor