Haematology Flashcards
What is an acid
Acidic solutions have more hydrogen ions in them. Acids can give away an H+ or can dissociate to release H+ in solution leading to an increase in the acidity of a solution (a decrease in pH).
What is acidaemia
Acidaemia refers to the acid state of the blood or a pH of < 7.4
What is acidosis
Acidosis is process causing an acidaemia
What is alkalaemia
Alkalaemia refers to the alkaline state of the blood or a pH of > 7.4
What is alkalosis
Alkalosis is process causing an alkalaemia
What is a base
Bases can accept and bond H+, in effect ‘buffering’ or reducing the acidity of a solution such as blood plasma.
What is a base excess or deficit
An increase or decrease in the amount of base compared with the amount of acids present
What is Hb and what does it signify in the blood
Amount of haemoglobin (and therefore the oxygen-carrying capacity) in blood
What is HCO3-
Concentration of hydrogen bicarbonate in blood. With pH and CO2, used to determine source of acid-base imbalance.
What is lactate/lactic acid
When aerobic metabolism decreases or ceases due to inadequate O2 supply, glycolysis results in the production of lactate (instead of pyruvate) which then leads to intracellular, then systemic lactic acidosis if tissue hypoxia persists.
What is FiO2
Fraction of inspired oxygen. This refers to the percentage of inspired O2 expressed as a decimal, e.g., FiO2 1.0 = 100% O2
What is PaO2
Arterial oxygen tension. This is the partial pressure in mmHg of oxygen dissolved in each 100 mL of plasma in arterial blood. It should always be interpreted in conjunction with the patient’s fraction of inspired oxygen.
What is SaO2
Calculated haemoglobin saturation of arterial oxygen.
What is PaCO2
Carbon dioxide partial pressure in mmHg (tension) of CO2 dissolved in plasma. This measurement reflects the adequacy of alveolar ventilation.
What does the pH of body fluids indicate
The pH provides an indication of the effectiveness of buffer systems, the respiratory system and the renal system in maintaining normal acid base balance.
What is the bicarbonate buffering system
Carbon dioxide + water form carbonic acid, which can dissociate to form acid (H+) and bicarbonate
