Lactate
Description
Amount of lactate in blood measured in first 10 minutes after admission to hospital. Lactate is measured in mmol/litre units by arterial blood gas (ABG) test. Lactate is a by-prouct of anaerobic cell metabolism. Lactate variable is used as a marker for determining the Hypoperfusion state.
Excluded BN Elements
In the RLH dataset, we identified a sub-group of patients with abnormally raised lactate levels due to physical exertion and no evidence of bleeding. These factors can be included in the BN to decrease the uncertainty between lactate and hypoperfusion
The relation between lactate levels and the underlying state of hypoperfusion has uncertainty since infusion of Ringer's lacate, sepsis, impaired hepatic function, diabetic patients with ketoacidosis and excessive alcohol use can increase the lactate levels regardless of the presence of haemorrhagic hypoerfsuion.
Relations exist between some markers of hypoperfusion. For example, pH is not independent of lactate levels when state of the hypoperfusion is known. However, these interdependencies were not considered for the modelling of this measurement idiom because there is no need to predict unmeasured values.