Monitoring regional blockade.

This review attempts to draw on the published literature to address three practical clinical questions. First, what means of testing the degree of regional blockade pre-operatively are available, and can eventual success or failure be determined soon after injection? Second, is it possible to predict if a block inserted after the induction of general anaesthesia will be effective when the patient wakes? Third, what features, and what duration, should cause concern when a block does not resolve as expected after surgery? Although the relevant literature is limited, we recommend testing of multiple sensory modalities before surgery commences; temperature and thermographic changes may offer additional early warning of success or failure. There are a number of existing methods of assessing nociception under general anaesthesia, but none has yet been applied to gauge the onset of a regional block. Finally, criteria for further investigation and neurological referral when block symptoms persist postoperatively are presented.

Seeing the forest and trees: whole-body and whole-brain imaging for circadian biology.

Recent advances in methods for making mammalian organs translucent have made possible whole-body fluorescent imaging with single-cell resolution. Because organ-clearing methods can be used to image the heterogeneous nature of cell populations, they are powerful tools to investigate the hierarchical organization of the cellular circadian clock, and how the clock synchronizes a variety of physiological activities. In particular, methods compatible with genetically encoded fluorescent reporters have the potential to detect circadian activity in different brain regions and the circadian-phase distribution across the whole body. In this review, we summarize the current methods and strategy for making organs translucent (removal of lipids, decolourization of haemoglobin and adjusting the refractive index of the specimen). We then discuss possible applications to circadian biology. For example, the coupling of circadian rhythms among different brain regions, brain activity in sleep-wake cycles and the role of migrating cells such as immune cells and cancer cells in chronopharmacology.

Remimazolam sedation for awake tracheal intubation.

We present a case of a 55-year-old woman presenting for an elective minor procedure. Following a previous anaesthetic, a 'can't intubate, can't oxygenate' incident had been documented. She had since undergone awake tracheal intubation for procedures requiring general anaesthesia. We were able to safely facilitate awake tracheal intubation using remimazolam for sedation. Remimazolam is a novel ultra-short acting benzodiazepine with similar pharmacodynamic effects to its parent compound midazolam, having minimal cardiovascular or respiratory effects and offering excellent anxiolysis and amnesia. It has a significantly shorter duration of action than midazolam, making it a valuable sedative agent for awake tracheal intubation. The patient remained stable throughout the procedure, with minimal effects on the respiratory and cardiovascular systems. The quality of sedation was reported as highly satisfactory by both the patient and the team.