Implications for practice and research

• The results of this study suggest that percutaneous coronary intervention (PCI) can be safely conducted without preprocedural fasting.

• Revision is needed of current fasting protocols.

• The findings of Hamid and colleagues must be confirmed by further randomised trials.

Context

PCI is currently performed in hospitals around the world. This procedure is generally conducted with light sedation and local anaesthesia. Patients are routinely kept nil-per-os/nil-by-mouth (NPO/NBM) for 6–8 h prior to PCI to minimise the risks of vomiting and bronchial aspiration. Conversely, there is a large body of evidence showing that shortening of the fasting time with either clear liquids or carbohydrate-rich beverages is not only safe but is also associated with many beneficial effects for patients.1

Findings

No patients required emergency intraprocedural endotracheal intubation, and no patients developed either intraprocedural or postprocedural aspiration pneumonia. Hospital mortality was 0.2%, none of which were due to PCI complications. Almost 80% of patients were discharged on the same day as receiving treatment.

Commentary

Preoperative or preprocedural overnight fasting is based on dogma rather than scientific evidence.1 ,2 Hamid and colleagues should be congratulated for their excellent study. In almost 2000 cases of PCI performed in patients without fasting, no cases of bronchial aspiration or aspiration pneumonia were reported. These data are relevant and suggest that NPO need not be mandatory for PCI. These data are also particularly important because as far as we know there are no guidelines for preprocedural fasting in emergency or elective sedation for invasive cardiac interventions.

Preoperative fasting was introduced just after World War II, based on a retrospective study of parturients.2 Despite the abundance of evidence to the contrary, 6–8 h of preoperative fasting is still considered essential by many surgeons and anaesthesiologists worldwide to prevent bronchial aspiration of gastric contents. Unfortunately, patients frequently fast for 12 h or more because of operating room delays and operating schedule changes. However, this practice is considered obsolete by modern guidelines from various international societies of anaesthesiologists, who recommend 6–8 h fasting for consumption of solids but allow clear liquids or carbohydrate-rich beverages to be consumed up to 2 h before anaesthesia.3

Prolonged preoperative fasting increases insulin resistance and gluconeogenesis. Insulin resistance as a result of many hours of fasting may exacerbate the metabolic response after trauma.1 ,4 In one study, the abbreviation of fasting with carbohydrate-rich beverages reduced the length of stay in patients undergoing coronary artery bypass.5 In addition, it has been shown that perioperative discomfort including malaise, thirst, hunger and weakness can be reduced by shortening preoperative fasting.6

Interestingly, patients admitted with acute myocardial infarction to undergo emergency PCI are not fasted beforehand. We agree with the authors’ judgement that prolonged fasting leads to dehydration and the use of intravenous contrast may increase the risk of acute renal failure. The findings of this study highlight the necessity for revision on the fasting protocol for PCI.