Article Notes
- 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?
- Complicating large volume resuscitation in an awake patient.
- Accentuating hypotension due to sympathectic block.
- Having an unsecured airway in the event of intraoperative crisis.
- Creating neuraxial uncertainty when coagulopathy occurs.
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Notably, a further 5 (4%) required GA conversion before delivery due to inadequate block. ↩
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The researchers administered the remaining 90 mcg fentanyl IV, along with droperidol 1.25 mg and acetaminophen/paracetamol 15mg/kg after baby delivery. An NSAID (diclofenac 50mg) was only provided when breakthrough pain was requested. ↩
Why is this important?
Post-operative fatigue (POF) is common and has significant effects on post-operative recovery and quality of life.
Past studies have linked post-operative fatigue to the pro-inflammatory effects of surgery and anesthesia. Other studies have suggested anti-inflammatory benefits of steroids, tight glucose control and avoiding deep anesthesia.
What did they do?
Abdelmalak and team randomized 381 patients using a 3-factorial design for the three interventions. 306 patients were analysed for POF outcome.
Surgical interventions covered a wide range of major non-cardiac procedures, with mean surgical length just under 5 hours and 75% of patients being ASA 3 or 4.
And they found?
No difference for any of the interventions for either fatigue or quality of life.
Hang on...
While it may be that post-operative inflammation is not the causative factor for POF, more likely the study interventions had insufficient impact on inflammation to change fatigue outcomes.
For minor and moderate surgery of shorter duration in lower-acuity patients (ASA 1 & 2) who have experienced significant POF previously, these simple interventions may still be beneficial.
Daniel Jolley
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.
They note...
Be smart
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.
Daniel Jolley
What did they do?
Markley et al. conducted a single-center retrospective cohort study of 23 years of data from a tertiary North American academic hospital. The investigators identified 129 patients meeting criteria, requiring elective Cesarean delivery (CD/CS) for suspected morbidly adherent placenta (MAP): placenta accreta, increta or percreta.
Why the fuss?
Historically there has been concern that neuraxial anaesthesia may add additional complexity when managing a major haemorrhage associated with MAP CS, by:
And they found...
The majority of patients with morbidly adherent placentas can be safely managed with neuraxial anesthesia alone. GA conversion was also safe for those requiring it.
Of the 129 patients, 5% were electively given a GA. Of the 122 (95%) who received neuraxial anesthesia (NA), only 15 (12%) were converted to GA after delivery.1 There were three difficult intubations (AFOI, VL and bougie each) among the 22 GAs. NA was predominately combined-spinal epidural or epidural.
Of the 72 patients requiring hysterectomy, 21% (15) needed NA-GA conversion.
The only independent predictors for GA conversion were history of ≥3 previous CS and long surgical duration.
The big question
Although retrospective, this data again reassures that neuraxial anesthesia can be a safe and appropriate choice for cesarean delivery with placenta accreta, increta or percreta. The big question will be whether you are happy managing an emergent NA-GA conversion and intubation in the 1-in-8 requiring it (or 1-in-5 with hysterectomy) or plan for an elective GA pre-surgery.
Daniel Jolley
What did they do?
Tamura and team randomised 176 elective CS patients to spinal anaesthesia with or without morphine, in addition to placebo or ultrasound-guided quadratus lumborum block (QLB).
And they found
Only intrathecal morphine significantly improved analgesia, not QLB whether performed with or without spinal morphine. Thus QLB probably does not improve analgesia further beyond current best practices.
Not so fast...
While this modest-sized RCT concluded that QLB did not improve pain after caesarean section, the conclusion is i) somewhat inconsistent with earlier studies that did show benefit, and ii) the adjuvant analgesic regime1 used may not be applicable to practice outside Japan.
Daniel Jolley