BACKGROUND:The nature of interactions between health care professionals and families may have a significant impact on families' experience and outcomes of critical illness. The value of encouraging positive relationships with families is well documented; however, it is argued that the lack of theoretical frameworks to guide practice in this area may be a barrier to improving patient- and family-centred care. AIMS:The study on which this paper is based aimed to understand families' experiences of their interactions when a relative is admitted unexpectedly to an Australian intensive care unit and to generate a substantive theory that represents families' interactions that can be used to guide critical care nursing practice when caring for patients' families in this context. DESIGN AND METHODS:A grounded theory methodology was adopted for the study. Data were collected between 2009 and 2013 using in-depth interviews with 25 family members of 21 critically ill patients admitted to a metropolitan, tertiary-level intensive care unit (ICU) in Australia. FINDINGS:A core category of regaining control has been generated from our study. This paper focuses on Disconnectedness, which leads to increased emotional vulnerability and is also a barrier to families' regaining control. Families feel disconnected when staff emotionally and physically disengage from them, when staff interact insensitively and in a manner that offers families limited hope. CONCLUSION:Our findings offer an in-depth understanding of staff engagement with families and its impact on the families' ability to regain control. Although some themes have been previously identified in the literature in isolation, the interrelationships of the categories within a theoretical framework to represent family resilience in the context of an ICU situated in the Australian health care system are a novel finding. RELEVANCE TO CLINICAL PRACTICE:The findings can be used to support patient- and family-centred care interventions in the ICU.