Variability in anaesthesia outcome: genetics, environment or both?

Anesthesiologists in their everyday practice meet patients whose individual response to stress of surgery, anaesthesia or intensive care treatment, may change predicted outcomes. Pharmacogenetics is engaged by inherited variation in drug metabolism and differences in response to drugs, especially safety and efficacy. While pharmacogenomics means wide population genomic testing for genetic variation, toxicogenomics and ecogenomics are sciences that investigate genomic changes as results of, or the effects of drugs, either environmental pollutans, respectively. Pharmacogenetic variability may influence drug disposition, drug transport, receptor structure and function, cell signaling and the myriad of downstream responses which ultimately produce a therapeutic effect, or adverse reaction. Clinicians know that different responses to drugs used in anaesthesia represent consequence of genetic background an individual patient brings, as well as environmental influences he/she has been exposed to (in immediate and distant past), psychological state, or different patient's habits. It has been recognized now that gene products interact with, and their expression and function is affected by a variety of environmental factors, such as nutrition, alcohol, smoking, environmental xenobiotics, pathogens, chronic disease, other medications and stressful life events. This interaction between gene and environment is reflected by individual differences in all aspects of health and disease, extending to responses to drugs and stress connected with anaesthesia.