Final answer:
Cardiopulmonary bypass in LAST should be considered after standard resuscitation efforts have failed and the patient experiences cardiovascular collapse.
Step-by-step explanation:
In the context of Local Anesthetic Systemic Toxicity (LAST), cardiopulmonary bypass should ideally be a consideration after resuscitation efforts with standard treatment (such as advanced cardiac life support protocols) have failed and the patient is experiencing cardiovascular collapse. This approach is in line with LAST guidelines which emphasize initial treatment with lipid emulsion therapy and other resuscitation measures before proceeding to more invasive procedures such as cardiopulmonary bypass. LAST is a critical condition where prompt and appropriate management is essential for patient survival.