The potential for dexamethasone and other glucocorticoids to prolong peripheral nerve blocks was first noted almost 20 years ago.
While the effect has been observed with several different blocks (upper & lower extremity, and even TAP blocks), the clinical significance varies and several questions still remain:
Is the effect exclusive to perineural dexamethasone? Several studies have observed similar effects for both IV and perineural dexamethasone (though less profound than other papers).
Is the effect safe? This is perhaps the most concerning, as there are suggestions that the effect may represent an enhancement of the well-known neurotoxicity of local anaesthetic agents.
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.summary
Is the conventional assumption that left-lateral tilt and uterine displacement avoids aortocaval compression during Caesarean section actually valid?
50 years of assumed orthodoxy is challenged by studies showing that:
- True aortal compression is relatively uncommon (Higuchi 2015, Lee 2012).
- Caval compression is probably near-universal, but also usually not improved by a mere 15 degree tilt. (An impractical 30 degrees is more likely required for meaningful impact!) (Palmer 2015).
- Caval compression probably has limited haemodynamic or fetal consequences in the fit, well, term parturient (Higuchi 2015; Lee 2012).
- Judicious use of vasopressor infusions may obviate the need for traditional uterine displacement (Lee 2017; Farber 2017).
Time to change practice then?
Not quite yet...summary