Randomized Controlled Trial Comparative Study
Zdravkovic, Rice and Brull take an objective look at the current evidence for cricoid pressure (CP) and professional guidelines for its use, reiterating the persistent uncertainty and general low-quality of evidence supporting use or avoidance.
- Sellick's original 1961 description is based upon significantly flawed audit data.
- There is much contradictory primary science research showing some effect of CP.
- NAP4 found pulmonary aspiration responsible for more deaths than intubation or ventilation failures, and the US ASA Closed Claims database shows it to be the third most common pulmonary event leading to claims. Thus recommendations and guidelines for the use of cricoid pressure carry very real medicolegal implications even in the absence of quality clinical evidence.
- Microaspiration in elective surgery is common (20%) but does not appear to be modified by CP.
- CP has a variable effect on the ease of intubation.
- There is no agreement on CP application technique nor even on scenarios where it should or should not be used.
- CP guidelines are variable, based on low-quality evidence and largely dependent on expert opinion.
- CP use is largely up to individual judgement, with a pragmatic approach best adopted for its application or release.
- Perhaps the greatest impact can be gained from ultrasound evaluation of gastric volume to identify those most at risk of aspiration?
Bedside risk stratification for pulmonary aspiration is probably the single greatest modifiable factor in anesthesia practice to reduce aspiration, almost certainly of greater importance than the ongoing cricoid pressure debate – which may never be conclusively resolved.summary
Identifying operations and individuals with an increased risk of chronic postsurgical pain (CPSP) has led to significant interest in interventions with the potential to achieve primary prevention of this condition. Pharmacological prevention remains controversial with a Cochrane review identifying perioperative ketamine administration as the only intervention with possible benefit although, with only small, heterogeneous studies, the authors called for a large randomised controlled trial (RCT) to confirm the validity of this result. In response to these data, a group of researchers from Australia and Hong Kong designed the ROCKet trial - Reduction Of Chronic Post-surgical Pain with Ketamine, endorsed by the Australian and New Zealand College of Anaesthetists (ANZCA) Clinical Trials Network (CTN).