Why is this important?
The numerous benefits of neuraxial anesthesia (spinal, epidural, combined spinal-epidural) versus general anesthesia for cesarean section are well established.
While maternal and emergent risks for general anesthesia are well known (ethnic groups; emergencies; maternal disease), Cobb et al. present the highest quality evidence to date showing obstetric anesthesia specialization is associated with a lower GA rate.
What did they do?
The researchers conducted a retrospective cohort study at a large metropolitan teaching hospital (Philadelphia, Pennsylvania) over a 4 year period, comparing general anesthesia versus neuraxial, and obstetric-specialized1 vs generalist anesthesiologists for 4,217 singleton CS deliveries.
And they found?
The total study GA rate was 9.0%. Two-thirds of CS anesthesia was provided by seven specialist obstetric anesthesiologists, versus one-third provided by 33 generalists.
Specialist obstetric anesthesiologists demonstrated a significantly lower GA rate, 7.3% vs 12.1% (OR-CI 0.45-0.79). This difference persisted for the urgent/emergent CS sub-group, though not for after-hours delivery.
Nonetheless several non-provider factors were more strongly associated with GA such as emergency CS (⇡ 7-fold), maternal medical indications for CS (⇡ 3-fold), and after-hours CS (⇡ OR 33%).
Thus care by a specialist obstetric anesthesiologist is associated with an almost-30% reduction in GA for CS .
"...consider selecting neuraxial techniques in preference to general anesthesia for most cesarean deliveries." - ASA obstetric anesthesia task force. 2
Between the lines...
The individual obstetric-specialized anesthesiologists in this study had an almost 10-fold greater cesarean case load than did the average generalist. Whether the outcome difference was due to technical expertise, decision making or a combination, one message here is that you get better at what you do when you intentionally do more of it.
Although the GlideScope videolaryngoscope reduces the force applied compared to direct Macintosh laryngoscopy, the longer duration of laryngoscopy with the GlideScope results in comparable total net force.
Perioperative protocols aiming to reduce unnecessary preoperative tests can successfully achieve this without negative consequences for patient care.
There is still insufficient evidence to link particular anaesthetic or analgesic interventions with tumour recurrence following cancer surgery.
Residual neuromuscular block is common at the time of extubation, occurring in up to two thirds of patients in the absence of quantitative neuromuscular monitoring.
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.
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.
Post-operative fatigue and quality of life is not improved by intraoperative anti-inflammatory interventions, namely steroid administration, tight glucose control, and light anesthesia.
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.
Evidence for cricoid pressure continues to be inadequate to make recommendations for its use or avoidance in patients at risk of pulmonary aspiration.
Hypercapnia events are common in women receiving 150 mcg intrathecal morphine for cesarean delivery, although clinical significance is uncertain.