Article Notes
This large study of 428,204 New York caesarean section records (2006-2013), including 34,356 general anaesthetics (8%), investigated the association between mode of anaesthesia and post-partum depression (PPD). Other studies have shown an association between caesarean section (emergency > elective) and PPD. (Sun 2021, Xu 2017, and others), though this is the first to look specifically at general anaesthesia as a PPD risk factor.
Guglielminotti and Li found that general anaesthesia increased the odds of severe PPD by 54% (aOR 1.54, 1.21-1.95), and suicidal ideation by a massive 91% (aOR 1.91, 1.12-3.25), though not a significant increase in anxiety or PTSD.
The researchers discuss many potential causative factors, particularly known associations between GA CS & poor pain control, and subsequent pain & PPD – while also acknowledging the obvious potential for confounders. Of note patients receiving GA were older, more often non-Caucasian, had more co-morbidities, neonatal complexity, and lower socio-economic levels – also all independently associated with PPD risk.
In order to quantify the potential confounding contribution of emergency vs elective status, the researchers employed the novel E value:
To assess the impact of emergent cesarean delivery on our results, we calculated the E value associated with the aOR for the risk of PPD and suicidality. This relatively new metric takes into consideration 2 associations: (1) that between the confounder (emergent cesarean delivery) and the outcome (PPD); and (2) the association between the confounder (emergent cesarean delivery) and the exposure (general anesthesia).
An E value of 1.7 for the unmeasured confounder emergent cesarean delivery indicates that to explain away the association between general anesthesia and depression, either: (1) emergent cesarean delivery increases the risk of depression by at least 70%; or (2) emergent cesarean delivery is at least 70% more prevalent among general anesthesia than among neuraxial anesthesia. Either association is clinically plausible.
Keep it in perspective...
We already know that general anaesthesia for CS is suboptimal: it compromises both maternal experience and safety, but it should (hopefully) only ever be a chosen mode of anaesthesia when there is a true contraindication to regional anaesthesia – even at the modestly-high 8% GA rate among this New York cohort.
Looking at it from the other end, bear in mind that the modestly-faster time-to-incision for GA over regional is also of questionable neonatal benefit.
The take-home:
Just another reason to avoid GA CS when possible – but you already knew that, right?
"...general anesthesia is a potentially modifiable risk factor for PPD. This finding provides further supporting evidence favoring neuraxial over general anesthesia in cesarean delivery whenever possible."
Daniel Jolley
Unfortunate wording in the conclusion here, implying causation where in fact there is no evidence of such. Delivery mode does not have a significant effect – it is rather significantly associated with PPD.
The mode of delivery has a significant effect on the occurrence of mild postpartum depression.
It's unfortunate that the authors and editors were not more careful with their wording in a very emotionally-charged and controversial area.
Daniel Jolley
This airway study is a neat little randomised-but-not-blinded study of the effect of head rotation on the oropharyngeal leak pressure of both the i-gel and LMA Supreme 2nd generation supraglottic airways.
The researchers investigated the leak pressure (OPLP) of the i-gel and LMA Supreme in paralysed patients with the head: 1. neutral, 2. rotated 30°, and 3. rotated 60°. They found that rotation of the head through 30° and 60° progressively increased OPLP by a clinically-significantly amount (0° vs 60° 5.5 cmH2O (3.3-7.8) & 6.5 cmH2O (5.1-8.0) respectively).
Before you get too excited...
The result however may not be reliably applicable to all populations, notably the study subjects were overwhelmingly small (x̄ ~160cm & 60kg) Japanese women (71%), receiving a TIVA muscle-relaxant anaesthetic (propofol, remifentanil, rocuronium). How well this improvement-with-rotation holds up among, for example, spontaneously ventilating large Caucasian males, is unclear.
Bottom-line
When using an i-gel or LMA Supreme 2nd generation supraglottic airway, careful head rotation to 60° may increased oropharyngeal leak pressure and so assist with ventilation troubleshooting. However head and neck rotation of anaesthetised, paralysed patients should be performed gently and cautiously – you are after all, not a chiropractor!
Daniel Jolley