Preoxygenation is the administration of oxygen to a patient prior to intubation to extend 'the safe apnoea time'. The primary mechanism is 'denitrogenation' of the lungs, however maximal preoxygenation is achieved when the alveolar, arterial, tissue, and venous compartments are all filled with oxygen.
Metformin use is associated with lactic acidosis, but it remains controversial as a disease entity
Metabolic alkalosis is a a primary acid-base disorder that causes the plasma bicarbonate to rise to an abnormally high level. the severity of a metabolic alkalosis is determined by the difference between the actual [HCO3] and the expected [HCO3]
Evaluation of causes of metabolic alkalosis requires a systematic approach involving history, examination and some specific investigations.
a metabolic acidosis is an abnormal primary process or condition leading to an increase in fixed acids in the blood -> resulting in a fall in arterial plasma bicarbonate
Post-intubation care: key steps in patient care following intubation
A metabolic acidosis is a process which, if uncorrected, would lead to an acidaemia. It is usually associated with a low bicarbonate concentration (or total CO2), but an acidosis may be masked by a co-existing metabolic alkalosis.
increased lactate production (including enhanced pyruvate production, reduced pyruvate conversion to CO2 & water or glucose, or preferential conversion of pyruvate to lactate)
Ketoacidosis is a high anion gap metabolic acidosis due to an excessive blood concentration of ketone bodies (keto-anions).
Delta Ratio = the increase in Anion Gap / the decrease in HCO3-. if one molecule of metabolic acid (HA) is added to the ECF and dissociates, the one H+ released will react with one molecule of HCO3- to produce CO2 and H2O (buffering).
Paralytics for Intubation of the Critically Ill. should suxamethonium or rocuronium be used for rapid sequence intubation? is a neuromuscular blocker even necessary for intubation of the critically ill? (facilitated or sedation only intubation)
Base excess is dose of acid or alkali to return in vitro blood to normal pH (7.40) under standard conditions ( at 37C at a PCO2 of 40 mm Hg). Standard base excess is dose of acid or alkali to return the ECF to normal pH (7.40) under standard conditions ( at 37C at a PCO2 of 40 mm Hg)