Fasting prior to cardiac catheterisation: a single-centre observational study.

Aim: Previous generation contrast agents were associated with high rates of nausea, vomiting and risk of aspiration leading to recommendations to fast prior to the procedure. However, modern contrast agents are well tolerated with a low risk of aspiration. Our current guidelines recommend fasting four to six hours before elective and semi-urgent cardiac catheterisation despite a lack of evidence to support this. We sought to determine the duration and effects of fasting at our centre.

Methods: A single-centre prospective observational study in patients undergoing elective cardiac catheterisation over a six-month period between 7 August 2017 to 7 February 2018 at Auckland City Hospital, New Zealand.

Results: One thousand and thirty patients with a mean age of 66±12 years underwent catheterisation. Sixty-seven percent were male, 26% had diabetes, 72% had hypertension and 23% had stage 3 or worse chronic kidney disease. The mean duration of fasting was 11.6±4.9 hours with 80% fasting longer than recommended. One hundred and eight (48%) patients with documented chronic kidney disease did not receive recommended pre-hydration. The most common symptoms related to fasting were hunger (47 %), nausea (3.9%) and vomiting (0.8%). Hypertension (4.1%) and hyperglycaemia (0.8%) occurred due to missed medication. There were no reports of aspiration.

Conclusion: Most patients were fasted for significantly longer than recommended and pre-hydration was underutilised in patients at high risk of contrast-induced nephropathy. There were no episodes of aspiration with modern contrast agents. Further studies are required to evaluate the need for fasting prior to non-emergency cardiac catheterisation.