Deranged Physiology » Core Topics in Intensive Care

Arterial Blood Gas Interpretation

 

The Measurement of pH
1.0.1 Basic foundations of acid-base chemistry for the intensivist
1.0.2 The Arrhenius definition of acids and bases
1.0.3 The Brønsted-Lowry definition of acids and bases
1.0.4 Lewis' definition, and the modern concept of acids and bases
1.0.5 The hydrogen ion as a convenient narrative device
1.0.6 The Sorensen definition of pH as hydrogen ion concentration
1.0.7 The modern concept of pH
1.1.0 The gold standard of pH measurement
1.1.2 History of the glass electrode
1.1.3 Measurement of pH in a modern ABG analyser
1.1.4 Neutrality and the influence of temperature and pressure on pH
1.1.5 Alpha-stat and pH-stat models of blood gas interpretation
The Measurement of the Partial Pressures of Dissolved Gases
2.0.1 Fundamental gas laws relevant to critical care medicine
2.0.2 Partial pressure and the solubility of gases in biological systems
2.0.3 The alveolar gas equation
2.0.4 Measurement of dissolved pO2 by electrolysis of dissolved oxygen
2.0.5 Principles of pO2 measurement with the Clark electrode
2.0.6 Principles of measuring pCO2 with the Severinghaus electrode
Absorption Spectroscopy of Haemoglobin Species
3.0.1 Absorption spectroscopy of haemoglobin species
3.0.2 Concentration of total haemoglobin in the ABG sample
3.0.3 Haematocrit: erythrocyte volume as fraction of total volume
3.0.4 Methaemoglobin measurement by the blood gas analyser
3.0.5 Biological properties of methaemoglobin
3.0.6 Causes and mechanisms of methaemoglobinaemia
3.0.7 Spectrophotometry of carboxyhaemoglobin
Assessment of Gas Transport and Gas Exchange
4.0.1 Measurement of oxygen saturation by the blood gas analyser
4.0.2 Fraction of oxygenated haemoglobin
4.0.3 The oxygen - carrying capacity of whole blood
4.0.4 The oxyhaemoglobin dissociation curve
4.0.5 Factors which influence the affinity of haemoglobin for oxygen
4.0.6 The p50 value of a blood gas sample
4.0.7 The idealised p50 value for a standard set of conditions
4.0.8 Oxygen tension - based indices of oxygenation
4.0.9 The shunt equation and content - based indices of oxygenation
Measurement of Electrolyte and Metabolyte Concentration
5.0.1 The ion-sensitive electrode chain in the blood gas analyser
5.0.2 Ion-selective electrode membranes
5.0.3 The potassium-sensitive electrode in the blood gas analyser
5.0.4 The sodium-sensitive electrode in the blood gas analyser
5.0.5 The calcium-sensitive electrode in the blood gas analyser
5.0.6 Factors influencing the concentration of ionised calcium
5.0.7 Correction of ionised calcium for pH
5.0.8 The chloride-sensitive electrode in the blood gas analyser
5.1.0 Principles of amperometric measurement
5.1.1 Amperometric measurement of glucose
5.1.2 Amperometric measurement of lactate
Assessment of Acid-Base Disturbance and Buffering
6.0.1 The actual bicarbonate value
6.0.2 The standard bicarbonate value
6.0.3 The actual base excess
6.0.4 Standard base excess
6.0.5 Assessment of compensation: Boston and Copenhagen methods
6.0.7 Stewart's approach to analysis of acid-base disorders
Practical Interpretation of Blood Gas Data
7.0.1 The officical diagnostic sequence for blood gas interpretation
7.0.2 A systematic approach to the interpretation of blood gas data
7.0.3 Summary of equations used for blood gas interpretation
7.0.4 The anion gap; its merits and demerits
7.0.5 Delta gap and delta ratio
Central Venous and Mixed Venous Blood Gases
8.0.1 The relationship of venous oxygenation and cellular metabolism
8.0.2 Practical use of central and mixed venous blood gases
Case Studies in Respiratory Acidosis
93.01 Catastrophe in the sleep lab
93.03 Post-Operative Respiratory Failure
93.08 Difficult intubation with prolonged poor quality manual ventilation
Case Studies in High Anion Gap Metabolic Acidosis
94.02 Poisoning by an Unknown Substance
94.07 Ischaemic gut
Case Studies in Mixed Metabolic Acidosis
95.05 Septic shock resuscitated with normal saline
Exotic Blood Gas Scenarios
99.04 "That can't possibly be human arterial blood"