Acid-Base

Question 1

common causes of metabolic acidosis

Answer 1

results from loss of bicarbonate or the gaining of acid
Loss of bicarbonate - hyperchloramia and normal anion gap, can happen from loss in intestinal tract from diarrhoea, or renal losses. Renal loss of bicarbonate can be an appropriate response to a respiratory alkalosis (metabolic compensation), but if it occurs as a primary process this is called Renal Tubular Acidosis (RTA),

Question 2

common causes of metabolic alkalosis

Answer 2

blah blah

Question 3

common causes of respiratory acidosis

Answer 3

Can be a result of decreased alveolar minute ventilation, increased CO2 production or increases in inhaled CO2.

Question 4

Define pH

Answer 4

pH = pH, also referred to as acidity, historically denotes “potential of hydrogen”. It is a scale used to specify the acidity or basicity of an aqueous solution. Acidic solutions are measured to have lower pH values than basic or alkaline solutions. There is an inverse relationship between pH and [H+] in the body, the higher the H+, the lower the pH. The acidity of a solution refers to the chemical activity of its constituent H+ ions
* hydrogen ions are present at onemillionth the concentration of other electrolytes. What, then, accounts for the emphasis on hydrogen ions in biology and medicine? The answer lies in the fact that hydrogen ions are highly reactive. The proteins of the body have many dissociable groups. These may gain or lose protons as [Hþ] changes, resulting in alterations in charge and molecular configuration that may adversely affect protein structure and function. The [Hþ] of body fluids must be kept constant so that detrimental changes in enzyme function and cellular structure do not occur. The range of [Hþ] compatible with life is 16 to 160 nEq/L.*

Question 5

RESPIRATORY ALKALOSIS

Answer 5

result of increased alveolar minute ventilation generated by increased respiratory rate

Question 6

Explain how the body regulates acid base balance and how it compensates for pathological disturbances

Question 7

Correctly interpret simple acid base disturbances using the traditional approach to acid base assessment

Answer 7

The traditional approach to acid-base evaluation focuses on the relationship between pH, HCO3 , and PCO2 as described by the Henderson-Hasselbalch equation. In this approach, pH is shown to be a function of HCO3 concentration and PCO2. The PCO2 is viewed as the respiratory component and is determined by alveolar ventilation, whereas the HCO3 concentration is considered the metabolic (or nonrespiratory) component and is regulated by the kidneys. This approach may lead to the impression that PCO2 and HCO3 are independent variables. In reality, only PCO2 is independent. When a primary increase in PCO2 occurs, proteins (notably hemoglobin) buffer the hydrogen ions that are produced by dissociation of H2CO3, and the HCO3 concentration increases secondarily. Furthermore, an understanding of the effects of changes in other electrolytes (e.g., Naþ, Kþ, Cl) and plasma proteins on acid-base balance is not facilitated by the traditional approach

Question 8

Process to evaluate acid base

Answer 8

1)Confirm the sample collection and handling was appropriate
2)Evaluate pH (Normal, acidaemia, alkalaemia)
3)PCO2 (inc? Acidotic. Dec? alkalotic)
4)Evaluate metabolic component (SBE or HCO3)
5)Define the primary process (which process is the same direction as the pH)
6)Evaluate if compensation is as expected
7)Determine the overall acid-base analysis
8) Is a primary metabolic acidosis present? If so, calculate the anion gap (can be helpful to determine the cause but is prone to error and does not provide a definitive dx)