Does cricoid pressure have a detrimental impact on laryngoscopy and intubation?

Background: Cricoid pressure is used in anaesthetic practice to prevent regurgitation during anaesthetic induction; it is also used by some paramedics. However, it may have a detrimental impact upon laryngoscopy and intubation. Paramedics need to remove barriers to safe and prompt intubation of critically unwell patients. Aim: To determine if cricoid pressure has a detrimental effect on laryngoscopy and intubation. Methods: The PubMed and Cochrane Library databases were searched with a time frame filter between 1 January 2003 and 31 December 2018 and screened, leaving seven studies. Findings: Cricoid pressure is detrimental to laryngoscopy and intubation success rates for patients in the care of experienced providers in environments more optimal than those in which paramedics practise. One study produced statistically significant results; when cricoid pressure was applied, median intubation time was longer (27 seconds versus 24 seconds; p<0.001) and incidence of Cormack and Lehane grade III and intravenous views were doubled (10% versus 5%; p<0.001). Other studies were inconclusive. Conclusion: Cricoid pressure makes intubation more difficult, which may lead to higher rates of failed intubation and adverse events, especially when carried out by less proficient clinicians such as paramedics. Further pragmatic research is needed to test this hypothesis.