Background Optimising sedation use is key to timely extubation. Whilst sedation protocols may be used to guide critical care nurses’ management of sedation, sedation management and decision-making is complex, influenced by multiple factors related to patients’ circumstances, intensive care unit design and the workforce.

Aim To explore (i) critical care nurses’ experiences managing sedation in mechanically ventilated patients and (ii) the factors that influence their sedation-related decision-making.

Design Qualitative descriptive study using semi-structured interviews. Data were analysed using Braun and Clarke’s six-step thematic analysis.

Setting and participants This study was conducted in a 26-bed level 3 accredited ICU, in a private hospital in Melbourne, Australia. The majority of patients are admitted following elective surgery. Critical care nurses, who were permanently employed as a registered nurse, worked at least 16 h per week, and cared for ventilated patients, were invited to participate.

Findings Thirteen critical care nurses participated. Initially, participants suggested their experiences managing sedation were linked to local unit policy and learning. Further exploration revealed that experiences were synonymous with descriptors of factors influencing sedation decision-making according to three themes: (i) Learning from past experiences, (ii) Situational awareness and (iii) Prioritising safety. Nurses relied on their cumulative knowledge from prior experiences to guide decision-making. Situational awareness about other emergent priorities in the unit, staffing and skill-mix were important factors in guiding sedation decision-making. Safety of patients and staff was essential, at times overriding goals to reduce sedation.

Conclusion Sedation decision making cannot be considered in isolation. Rather, sedation decision making must take into account outcomes of patient assessment, emergent priorities, unit and staffing factors and safety concerns.

Implications for clinical practice Opportunities for ongoing education are essential to promote nurses’ situational awareness of other emergent unit priorities, staffing and skill-mix, in addition to evidence-based sedation management and decision making.