Background Nurses are often the first responders to in-hospital cardiac arrest in postoperative cardiac surgical patients. Poor clarity about role expectations and responsibilities can hinder nurses' performance during cardiac advanced life support (CALS) procedures.

Aim To seek expert consensus on nurses' roles and responsibilities in CALS for patients in postoperative cardiac surgical patients.

Study design A two-round modified eDelphi survey. Delphi items were informed by guideline literature, an audit of resuscitation records and expert interviews. Panellists, drawn from a single site of a large tertiary health service in metropolitan Melbourne, included nurses, doctors and surgeons familiar with the management of cardiac arrest in post-operative cardiac surgical patients.

Results The two rounds of the modified eDelphi generated 55 responses. A consensus of >80% agreement was reached for 24 of the 41 statements in Round 2. All items related to nurses' roles and responsibilities during nurses pre- and post-arrest phases reached consensus. In contrast, only 29% (n = 4/14) of items related to peri-arrest, and 36% of those related to nurse scope of practise in CALS arrest (n = 4/11) reached consensus.

Conclusion The study's aim was only partially achieved. Findings indicate high agreement about nurses' roles and responsibilities before and immediately after a cardiac arrest, but limited clarity about nurses' roles when implementing the CALS protocol, such as resternotomy and internal cardiac massage. There is an urgent need to address uncertainty about nurses' roles and scope of practice in CALS, which is essential to the recognition of nurses' contribution to the cardiac specialty workforce.

Relevance to clinical practise Uncertainty about nurses ‘roles and responsibilities when implementing the CALS protocol may hinder their performance to their full scope of practice, leading to poor patient outcomes.