Article Notes
- Perineural dexamethasone is probably safe, though conclusive safety evidence is still lacking.
- Systemic effects from IV dex is unlikely to explain the profound block prolongation.
- Prolongation is not enough on its own.
- Need to prevent aortocaval compression.
- Early securing of the airway.
- Rapid perimortem Caesarean delivery.
- Likelihood of a non-cardiac/pregnancy cause.
A growing collection of landmark papers relevant to intensive care and critical care medicine.
These papers are practice changing and hold current, ongoing significance beyond their historical importance.
This is a dynamic and changing document that will be updated, pruned and added to as appropriate. Many of these papers have free full-text provided by the publisher because of their significance.
A cautionary summary of the benefits and potential risks of perineural dexamethasone.
"...there have been no reports of neurotoxicity or complications of any kind attributed to perineural dexamethasone in the nearly 700 patients who have received it in published studies of peripheral nerve blocks ... We must acknowledge that complications in regional anesthesia are rare, and 700 patients are woefully inadequate to declare dexamethasone safe for routine perineural use." (Noss 2014)
Noss concludes that:
This is the first published recommendation for perimortem cesarean sections in maternal cardiac arrest – from Katz, Dotters and Droegemueller (1986).
It was this recommendation that lead to the ‘4 minute rule’ for deciding to commence a CS in a resuscitation scenario, with the aim of delivering the baby within 5 minutes.
A very practical review of the evidence, indications and rationale for the perimortem cesarean section. Richard Parry describes the specific steps required to perform a PMCS, along with discussion of the pros and cons of different approaches. The importance of multidisciplinary training is emphasised.
Chazot et al. describe a 25 yo undergoing a Nissen fundoplication, receiving TCI propofol/remifentanil (targets of 2.3 ug/mL & 4 ng/mL respectively) along with rocuronium. The deep neuromuscular block was reversed with sugammadex 4 mg/kg and the patient awoke within 80 seconds (clinically and BIS > 90) despite TCI targets continuing. No awareness was noted.
A review of all published perimortem cesarean section case reports by Vern Katz, following up his article in 1986 first recommending this procedure.
While this does not offer proof of benefit (huge survival selection bias), of the 38 cases reported, 34 neonates survived (includes multiple gestations), and of the 20 cases with reversible causes, 13 mothers were discharged from hospital.
Katz writes:
In 12 of 18 reports that documented hemodynamic status, cesarean delivery preceded return of maternal pulse and blood pressure, often in a dramatic fashion. Eight other cases noted improvement in maternal status. Importantly, in no case was there deterioration of the maternal condition with the cesarean delivery.
McDonnell highlights the differences in managing the collapsed parturient, namely:
The two cases presented include arrest due to ruptured uterus and arrest possibly due to iatrogenic magnesium overdose. Both resulted in favorable, though not perfect, outcomes for mother and baby.
The need for delivery suite ‘perimortem cesarean section packs’ is also discussed, as well as the use of regular simulation training.