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
Why is this important?
This is the first systematic review of RCTs assessing different techniques for conducting awake fibreoptic intubation (AFOI), although the quality of evidence continues to be moderate-low.
Cabrini et al. reviewed 37 RCTs capturing 2,045 AFOI events.
What did they find?
There was no significant success difference among techniques for either local anaesthesia application or procedural sedation, including infusions or boluses of dexmedetomidine, propofol, opioids (fentanyl, sufentanil, remifentanil), ±midazolam, or sevoflurane.
Dexmedetomidine sedation resulted in the fewest desaturation events, and sevoflurane the fewest apnoea events.
Opioids used on their own (ie. without benzodiazepines) resulted in the highest patient recall, particularly remifentanil.
Also of interest...
When conducted by trained experts, AFOI is safe and effective regardless of technique and only very uncommonly results in intubation failure (0.59%) or severe adverse events (0.34%). No permanent morbidity or death was identified.
The take-home message:
When choosing a technique for awake fibre optic intubation, do what you do best – generally this will be what you and your institution are most experienced with.summary
Programmed intermittent epidural boluses may improve the spread of local anesthetics compared to continuous epidural infusion, improving labor analgesia and obstetric outcomes. However, there are limited data from studies using commercially available pumps capable of coadministering programmed intermittent epidural boluses or continuous epidural infusion with patient-controlled epidural analgesia. Therefore, we performed this prospective, randomized, double-blind study to compare the impact of programmed intermittent epidural boluses versus continuous epidural infusion on labor analgesia and maternal/neonatal outcomes. We hypothesized that programmed intermittent epidural boluses will result in lower patient-controlled epidural analgesia consumption compared to that with continuous epidural infusion. ⋯ Under the conditions of our study, we did not find improved outcomes with programmed intermittent epidural boluses compared to continuous epidural infusion except for less motor block with programmed intermittent epidural boluses. Future studies should assess whether smaller but clinically important differences exist and evaluate different parameters of programmed intermittent epidural boluses to optimize analgesia and outcomes with this mode of analgesia.