Article Notes
The flaw with many closed loop TIVA-BIS studies, such as this one, is that they unquestionably assume reliability of BIS and are not powered for important morbidity or mortality outcomes.
This study while professing to show 'superiority' of a closed-loop system, really just shows that when given a monitor target the algorithm can more accurately and rapidly adjust the TIVA to maintain this. This may well be a good outcome, but does not necessarily equate to 'good' or safe anesthesia.
It's important to note that BIS has been validated essentially as an awareness alarm, not (yet) as a guide to appropriate depth of anesthesia.
This is a very significant and large study, and should give us pause to ponder the consequences of invasive airway management and surgery requiring muscle relaxation. It is also important to note that qualitative neuromuscular monitoring (as opposed to quantitative) appears to offer no risk reduction, consistent with other research in this area.
Nonetheless, the retrospective nature of this study means these relationships should not necessarily be viewed as causal. This is not a study of an intervention per se, but the association between certain perioperative characteristics that may be unavoidable (e.g. using muscle relaxants).
An important paper for any concerned anaesthetist or anesthesiologist to read in full.
This is a great review to start with, providing a good overview of many of the myths regarding the use of neuromuscular blocking drugs that are still widely believed and practised by the global anaesthesia community.
All five of Fink & Hollman's 'myths' still hold today after reviewing the latest research in these areas.
Make sure to read the editorial in the same issue from Schneider, Restrict relaxants, be aware, and know the limitations of your depth of anaesthesia monitor, and a related study from back in 2003 from Messner, The bispectral index declines during neuromuscular block in fully awake persons.
This is a most fascinating study, both academically, clinically and psychologically. The full Method deserves to be read, along with the participant's description of their experience in the Results.
...fasciculations attributable to suxamethonium were painful, and the ensuing paralysis was experienced as a feeling of profound heaviness, ‘as if someone had pulled the plug and drained the fluid out’.