Abstract
OBJECTIVES: to develop a middle-range theory for the risk for shock in people with acute myocardial infarction. METHODS: theoretical-causal validity of the nursing diagnosis "Risk for shock" in people with acute myocardial infarction, based on a middle-range theory. The study followed six stages: definition of the approach for theory construction; definition of conceptual models; definition of main concepts; development of pictorial diagram; construction of propositions; establishment of causal relationships and evidence for practice. RESULTS: three essential attributes were identified, 23 clinical antecedents related to the risk for shock, eight theoretical propositions were formulated, and causal relationships were established between the identified stimuli and the essential attributes. CONCLUSIONS: the theory developed established relationships between theory and practice based on the establishment of propositions and causal relationships that allow nurses' diagnostic reasoning.