Homeostasis 4: nurses as agents of control in myocardial infarction.

The role of health practitioners in attempting to reverse homeostatic imbalances essentially makes them external agents of homeostatic control-they are replacing the assessment, controlling and effector mechanisms that operate during health (homeostasis), but have failed in ill-health (homeostatic imbalances). Myocardial infarction (MI) is the homeostatic imbalance examined in this article, which aims to apply the analogy between the components of homeostatic theory and the components of the nursing process (Clancy and McVicar, 2011b) to the condition. After reading the article, nurses should be able to understand that: the components of homeostasis are associated with health, and the failure of one or more of these components results in illness; illness arises from a cellular, hence chemical, homeostatic imbalance(s); MI results from a cellular imbalance leading to a restriction in blood flow to the myocardium, and is identified by signs and symptoms (i.e. other homeostatic imbalances) related to the ischaemia; when caring for people with MI, coronary care nurses are acting as external agents of homeostatic control.