1. Blood gas analysis evaluates respiratory gas exchange, acid-base status, electrolytes, glucose, and osmolality. Significant pH deviations can cause intracellular metabolic issues.
2. The human body tightly regulates pH between 7.35-7.45 through buffer systems, respiration, and the kidneys. The main buffer system involves bicarbonate and carbonic acid, while respiration controls carbon dioxide levels and the kidneys regulate acid excretion.
3. Analyzing arterial blood gases provides information about respiratory and metabolic acid-base disorders. The anion gap and bicarbonate levels indicate the degree and cause of acidosis or alkalosis. Diagnosis involves considering pH, carbon dioxide, and b
The normal pH of the blood is maintained the narrow range of 7.35-7..pdfRubanjews
The normal pH of the blood is maintained the narrow range of 7.35-7.45 that is slightly alkaline.
Any change in the normal value can cause marked alterations in the chemical reactions of the
cell.
The body has developed three mechanisms of defence to regulate or maintenance of blood pH or
acid-base balance.
1. Blood buffers
2. Respiratory mechanism.
3. Renal mechanism.
1. Blood buffers : Buffers are present both in the plasma and in the RBC\'s. The buffer cannot
remove H+ ion from the body, it temporarily acts as a shock absorbent to reduce the free H+
ions.
The blood consists of 3 buffer systems.
A. Bicarbonate buffer system : Sodium bicarbonate and carbonic acid (NaHCO3 - H2CO3) is the
most predominant buffer system of the extracellular fluid and plasma. At blood pH 7.4, the ratio
of carbonic acid is 20:1. Thus the bicarbonate concentration is much higher than carbonic acid in
the blood. This is referred to as alkali reserve and is responsible for the active buffering of h+
ions, generated by the body. The plasma bicarbonate [HCO3-] concentration is around 22-26
mmol/l. Carbonic acid is the solution of CO2 in water.
B. Phosphate buffer system: Sodium dihydrogen phosphate and disodium hydrogen phosphate
(NaH2PO4 - Na2HPO4) constitute the phosphate buffer. It is of less importance in plasma due to
its low concentration with a pk of 6.8, close to blood pH 7.4, the phosphate buffer would have
been more effective, had it been present in high concentration. It is estimated that the ratio of
base to acid fort phosphate buffer is 4, compared to 20 for bicarbonate buffer.
C. Protein buffer system : The plasma proteins and hemoglobin together constitute the protein
buffer system of blood. The buffering capacity of proteins is dependent on the Pk of ionizable
groups of amino acids. The imidazole group of histidine (Pk = 6.7) is the most effective
contributor of protein buffers. The plasma proteins account for about 2% of the total buffering
capacity of the plasma.Hemoglobin of RBC is also an important buffer. It mainly buffers the
fixed acid, besides being involved in the transport of gases (O2 and CO2).
2. Respiratory mechanism : Lungs are actually the most effective organs for rapid pH adjustment
or maintaining acid-base balance. About one-half of the H+ ions drained by the cells to the
extracellular fluids combine with HCO3- to form H2CO3, which disassociates into H2O and
CO2. The CO2 thus formed is subsequently eliminated by the lungs. So the elimination of one
molecule of CO2 means the removal of one H+ ion.
The rate of respiration is controlled by a respiratory center, located in the medulla of the brain,
highly sensitive to changes in the pH of blood. Any decrease in blood pH causes hyperventilation
to blow off CO2, there by reducing the H2CO3 concentration, simultaneously the H+ ions are
eliminated as H2O.
An increase in blood P (P - partial pressure) CO2 increases pulmonary ventilation. Pulmonary
ventilation is also increased with slight incr.
The normal ranges for arterial blood gas values
Approach to arterial blood gas interpretation
Arterial blood gas abnormalities in special circumstances
The normal pH of the blood is maintained the narrow range of 7.35-7..pdfRubanjews
The normal pH of the blood is maintained the narrow range of 7.35-7.45 that is slightly alkaline.
Any change in the normal value can cause marked alterations in the chemical reactions of the
cell.
The body has developed three mechanisms of defence to regulate or maintenance of blood pH or
acid-base balance.
1. Blood buffers
2. Respiratory mechanism.
3. Renal mechanism.
1. Blood buffers : Buffers are present both in the plasma and in the RBC\'s. The buffer cannot
remove H+ ion from the body, it temporarily acts as a shock absorbent to reduce the free H+
ions.
The blood consists of 3 buffer systems.
A. Bicarbonate buffer system : Sodium bicarbonate and carbonic acid (NaHCO3 - H2CO3) is the
most predominant buffer system of the extracellular fluid and plasma. At blood pH 7.4, the ratio
of carbonic acid is 20:1. Thus the bicarbonate concentration is much higher than carbonic acid in
the blood. This is referred to as alkali reserve and is responsible for the active buffering of h+
ions, generated by the body. The plasma bicarbonate [HCO3-] concentration is around 22-26
mmol/l. Carbonic acid is the solution of CO2 in water.
B. Phosphate buffer system: Sodium dihydrogen phosphate and disodium hydrogen phosphate
(NaH2PO4 - Na2HPO4) constitute the phosphate buffer. It is of less importance in plasma due to
its low concentration with a pk of 6.8, close to blood pH 7.4, the phosphate buffer would have
been more effective, had it been present in high concentration. It is estimated that the ratio of
base to acid fort phosphate buffer is 4, compared to 20 for bicarbonate buffer.
C. Protein buffer system : The plasma proteins and hemoglobin together constitute the protein
buffer system of blood. The buffering capacity of proteins is dependent on the Pk of ionizable
groups of amino acids. The imidazole group of histidine (Pk = 6.7) is the most effective
contributor of protein buffers. The plasma proteins account for about 2% of the total buffering
capacity of the plasma.Hemoglobin of RBC is also an important buffer. It mainly buffers the
fixed acid, besides being involved in the transport of gases (O2 and CO2).
2. Respiratory mechanism : Lungs are actually the most effective organs for rapid pH adjustment
or maintaining acid-base balance. About one-half of the H+ ions drained by the cells to the
extracellular fluids combine with HCO3- to form H2CO3, which disassociates into H2O and
CO2. The CO2 thus formed is subsequently eliminated by the lungs. So the elimination of one
molecule of CO2 means the removal of one H+ ion.
The rate of respiration is controlled by a respiratory center, located in the medulla of the brain,
highly sensitive to changes in the pH of blood. Any decrease in blood pH causes hyperventilation
to blow off CO2, there by reducing the H2CO3 concentration, simultaneously the H+ ions are
eliminated as H2O.
An increase in blood P (P - partial pressure) CO2 increases pulmonary ventilation. Pulmonary
ventilation is also increased with slight incr.
The normal ranges for arterial blood gas values
Approach to arterial blood gas interpretation
Arterial blood gas abnormalities in special circumstances
4. Renal Block-Acid Base Balance-for Medical students.pptxRajendra Dev Bhatt
Acid–Base balance (also known as pH HOMEOSTASIS ) : one of the essential functions of the body, it is concerned with the precise regulation of free (unbound) hydrogen ion concentration in body fluids.
essential details on maintenance of extracellular fluid pH, Especially Blood for normal physiological function of the body and condition associated wit acid base imbalance
Concepts of acid base balance and its disorders are very important for practice of medicine.It is for the benefit of medical and students of allied fields.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
4. Renal Block-Acid Base Balance-for Medical students.pptxRajendra Dev Bhatt
Acid–Base balance (also known as pH HOMEOSTASIS ) : one of the essential functions of the body, it is concerned with the precise regulation of free (unbound) hydrogen ion concentration in body fluids.
essential details on maintenance of extracellular fluid pH, Especially Blood for normal physiological function of the body and condition associated wit acid base imbalance
Concepts of acid base balance and its disorders are very important for practice of medicine.It is for the benefit of medical and students of allied fields.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
2. 1 ABG analysis
Evaluation and monitoring of respiratory gas
exchange, acid– base status, basic electrolyte
concentrations (serum [K+], [Na+], [Ca2+]),
plasma glucose, and osmolality
3 Important agents affected pH
changes
Local anaesthetic agents.
Vasopressors.
Inotropes.
Neuromuscular- blocking agents
2 Any significant pH deviation
Intracellular metabolic derangement and
reduced protein synthesis and transport
activity, with significant physiological and
clinical sequelae
4
Prompt diagnosis and
management underlying aetiology
Care should be taken to distinguish respiratory
and metabolic disorders, and acute from
chronic conditions with any physiological
compensation that may have occurred
Blood gas analysis and acid – base disorders
4. Maintenance of acid–base balance in the human body
The normal pH range in the human body
is narrow (7.35– 7.45)
H2CO3 is the largest source of hydrogen ions
(H+) in the human body and is a volatile (or
respiratory) acid, dissociates into either H+
ions and bicarbonate ions (HCO3−) or CO2 and
water, with the respiratory acid (CO2)
subsequently being excreted by the lungs
pH homeostasis is maintained, acids
produced by the body must either be
buffered (neutralized) or excreted
The buffer system.
The respiratory system.
The renal system
5. The buffer system
•This is responsible for over 50% of the buffering capacity of the body and is the main
component of ECF buffering (80%).
•When excess H+ ions are added to the systemequilibrium shifts to the leftformation of
H2CO3 by the reaction of H+ ions with HCO3−.
•When H+ ions are removed from the reaction [or excess base added, e.g. hydroxide ions
(OH−)] equilibrium shifts to the right dissociation of H2CO3 to release H+ ions.
Bicarbonate– carbonic acid buffer
•At the Ph of the human body, the predominant buffer pair is dihydrogen phosphate (H2PO4−)
as the weak acid, and hydrogen phosphate (HPO42– ) as the weak base
•The pKa of H2PO4− is 7.21, making the phosphate buffer system an ideal buffer in the human
body
Phosphate buffer
6. The buffer system
Protein buffers
Protein buffers in blood include both
haemoglobin and plasma proteins
The plasma protein buffering system is the most
abundant intracellular and ECF buffering pair but
is responsible for only 15% of the body’s
buffering capacity
Haemoglobin and
oxyhaemoglobin
CO2 from the cells enters erythrocytes and
combines with water to form H2CO3 by the
action of carbonic anhydrase.
Oxyhaemoglobin gives up its bound O2 to the
cells, producing reduced haemoglobin
(negatively charged).
7. The buffer system
RBC
H2CO3 dissociates into H+ and HCO3−. The HCO3− ions
diffuse into plasma in exchange for chloride (Cl−) ions (the
chloride shift) to retain electroneutrality, and reduced
haemoglobin attracts H+ ions (binding them more readily
than oxyhaemoglobin).
This results in the formation of protonated haemoglobin
(H- Hb), which is a weaker acid than H2CO3
Bohr effect
When blood reaches the pulmonary capillaries, the
presence of a high O2 concentration favours O2 binding
and promotes the loss of H+ ions from H- Hb.
Reduced haemoglobin is converted to oxyhaemoglobin,
and H+ ions are released and buffered by the bicarbonate–
carbonic acid system to form CO2 and water.
Aqueous CO2 follows a concentration gradient into blood,
across the alveolar membrane, and into the alveolar space
where it is eliminated during ventilation
8. The respiratory system
The addition of H+ ions to blood activates the bicarbonate– carbonic acid buffer
system, increasing H2CO3 concentration.
This subsequently dissociates into CO2 and water, and excess CO2 then diffuses
passively into the alveoli of the lungs and is eliminated.
Ventilation plays a major role in pH
homeostasis by eliminating or
conserving CO2.
•Stimulated by free H+ ions, CO2 in plasma, and CO2 in the cerebrospinal fluid,
respectively↑respiratory rate and tidal volume, leading to greater minute
ventilation and increased CO2 elimination
Peripheral chemoreceptors in the
carotid and aortic bodies and
central chemoreceptors in the
medulla oblongata
If the HCO3− concentration is increased (metabolic alkalosis), the CO2 concentration
increases to buffer the excess HCO3− (respiratory compensation).
High HCO3− concentration therefore inhibits central and peripheral chemoreceptors,
resulting in reduced minute ventilation (rate . tidal volume) and reduced CO2
elimination
By controlling CO2 concentration of
blood, the respiratory system is
capable of compensating for pH
changes due to metabolic
derangement.
9. The renal system
Kidneys actively regulate acid– base balance through several mechanisms:
1. Reabsorption of HCO3 − for use in the bicarbonate– carbonic acid buffer system.
2. Excretion of fixed acids [e.g. ammonium (NH4+) and titratable acids] which also results in HCO3
− production
Particularly low urinary pH (high urine acidity) is a good indicator of renal compensation for
systemic acidosis; however, as all mechanisms are via active transportation, compensation is
slow, taking days, rather than minutes.
In response to a low pH, H+ ions are secreted into the urine either in exchange for Na+ ions via the Na+– H+ antiporter or by
using the H+– ATPase active transport systems.
Excess H+ secretion by H+– ATPase pumps in distal convoluted tubular cells, in response to an acid load, leads to greater NH3
diffusion into the tubules and its combination with H+ to form NH4+, and hence greater excretion of free H+ ions. HCO3− is
simultaneously produced in the proximal tubules by the metabolism of α- ketoglutarate and is then transferred to the
systemic circulation
10. Arterial blood gas analysis
Base excess and HCO3−
concentration will inform the
clinician of the degree of acidosis/
alkalosis (with or without Ph
change)
Conversely, ‘base deficit’ defines
the amount of strong base that
must be added to restore normal
pH to blood, assuming the blood
sample is fully oxygenated, at a
temperature of 37°C, and PaCO2
is maintained at 40 mmHg
Basis interpreting acid– base
balance interdependence
between pH, HCO3−
concentration, and PaCO2
‘standard bicarbonate’ and ‘buffer
base followed by the concept of
‘base excess’ (the concentration of
H+ ions required to return the pH of
blood to 7.4)
11. The H+ ions produced by these acids are buffered by
HCO3−, reducing the concentration of the measured
anions that, in turn, increases the proportion of
these unmeasured anions, and the gap increases.
The predominant unmeasured extracellular cations
are K+, Ca2+, and magnesium (Mg2+), so the AG can
be affected by increases or decreases in unmeasured
cations or anions
Unmeasured anions and cations contributing to the AG
Anion Gap
Formula AG
12. A normal AG is <11 mEq/ L, and a high
gap usually indicates metabolic
acidosis.
Using the AG can help to differentiate
between HCO3− loss and consumption
(e.g. a renal from a non- renal cause of
metabolic acidosis).
An AG acidosis is also present,
regardless of the pH or [HCO3−], when
the AG is >20 mEq/ L
Causes of alterations in the plasma AG
13. Normal AG acidosis results from a net increase in [Cl−],
secondaryto a loss of HCO3−. This is known as
hyperchloraemic metabolic acidosis and is most
commonly associated with:
•GI HCO3− loss (diarrhoea, ileus, pancreatic fistula, villous adenoma).
•Renal HCO3− loss (AKI, proximal and distal renal tubular acidosis,
carbonic anhydrase inhibitors).
•Isotonic (0.9%) saline infusion.
Hypercarbia causes significant physiological changes.
•At low levels, there is generalized cardiovascular, respiratory, and
autonomic stimulation
•An alveolar PACO2 of >100 mmHg is incompatible with life when a
patient is breathing room air, due to associated severe hypoxaemia that
will result from the high partial pressure of CO2 in the alveolus
Physiological effects of hypercarbia by system
15. Is the pH normal?
•If the pH is <7.35, then
acidaemia is present; if
it is >7.45, alkalaemia
predominates. If it is
normal, there is either
no disturbance or a
compensated or mixed
state exists
Algorithm for initial acid– base interpretation
Normal ABG values
16. •If PaCO2 is altered, the primary disturbance is respiratory.
•If [HCO3−] is altered, the primary disturbance is metabolic.
•If both are abnormal, then the directional change should be compared, which will help to
identify the specific disorder.
•If both PaCO2 and pH change in a direction opposite from each other, the primary
abnormality is respiratory.
•If both PaCO2 and [HCO3−] change in the same direction(either increasing or
decreasing), the primary disorder is metabolic.
•If PaCO2 and [HCO3−] change in the opposite direction, then the primary disorder is
mixed.
•If the trend of change in PaCO2 and [HCO3−] is the same, the one with the greatest
percentage difference from normal is the dominant disorder (as compensation is not
perfect).
Is the primary disturbance respiratory or metabolic?
18. If the primary disturbance is respiratory, is it acute or chronic?
If PaCO2 is high, it is important to
gauge its chronicity by examining the
ratio between the change in [H+] and
PaCO2 from their reference values
∆H++ ∆PaCO2
Note: >0.8, acute; 0.3– 0.8, acute on
chronic; <0.3, chronic)
19. • Respiratory compensation for metabolic disorders can be marked. This can be investigated using
the Winter’s formula to calculate the expected PaCO2:
• If the actual PaCO2 is the same as the expected PaCO2, then there is adequate respiratory
compensation.
• If the actual PaCO2 is less than the expected PaCO2, then there is concomitant respiratory alkalosis.
• If the actual PaCO2 is more than the expected PaCO2, then there is concomitant respiratory
acidosis.
• In general, respiratory compensation results in a 1.2 mmHg change in PaCO2 for every 1.0 mEq/ L
change in plasma [HCO3−], down to a minimum of 10– 15 mmHg and a maximum PaCO2 of 60
mmHg
If the primary disturbance is metabolic, also calculate the expected PaCO2.
20. If the AG is normal and the cause is
unknown, then calculate the urine
AG (UAG).
This will help to
differentiate renal
tubulopathies from
other causes of non-
elevated AG acidosis.
If UAG is positive:
renal tubular
acidosis or early
acute renal failure
is the likely
diagnosis.
If UAG is negative:
most likely a GI
cause of metabolic
acidosis.
If it is >11 mEq/ L, then the
metabolic acidosis is due
to one of the disorders
noted in E Table 16.4. If it
is normal, then any
metabolic acidosis is likely
to be GI or renal in origin.
If the primary disturbance is
metabolic acidosis, calculate the
AG.
21. THANK YOU
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget
dolor. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus
mus.