News briefs

Lidocaine infusions help relieve pain in unresponsive chronic migraine

Infusions of the local anesthetic lidocaine may provide some pain relief to people with chronic migraine that does not respond to other treatments, according to a study published in Regional Anesthesia & Pain Medicine. The researchers, from Thomas Jefferson University in the US, analysed the hospital records of 609 patients who were admitted with refractory chronic migraine and treated with infusions of lidocaine to assess the short and medium term benefits of this approach. Patients included in the analysis had experienced at least eight debilitating headache days per month for at least 6 months and failed to respond to or had contraindications to the seven classes of medicine for migraine. Patients received lidocaine infusions over several days along with other aggressive drug treatments for migraine, such as ketorolac, magnesium, dihydroergotamine, methylprednisolone and neuroleptics. Most patients (87.8%) experienced rapid pain relief. At the time of admission, the median rating given by patients was 7.0 and this decreased to 1.0 by the time of hospital discharge. Patients attending follow‐up appointments around one month after discharge also reported that the number of headache days that they experienced had fallen. The 266 patients who attended these appointments, which took place between 25 and 65days after discharge, said that the number of headache days in the past month had fallen from a mean of 26.8 to 22.5. Some patients experienced nausea and vomiting during the treatment but all adverse events experienced were mild. This was an observational study, and as such, could not establish cause.

https://rapm.bmj.com/content/47/7/408

During general anaesthesia, 1 in 10 may be “conscious” following intubation

An international study led by the University of Sydney has found that around one in 10 participants under general anaesthesia responded to commands after intubation but before surgery started. Nearly half of those who responded to commands also responded to confirm they had pain. The research, published in the British Journal of Anaesthetics, investigated “connected consciousness” of 338 patients aged from 18 to 40years under general anaesthesia. One surprising finding was the risk of being responsive under general anaesthetic after intubation was three times higher in females. Fortunately, no one remembered the commands, although one person (0.3% of participants) reported they were able to clearly recall the experience of surgery after the procedure ended. The study found that maintaining a continued level of anaesthesia before intubation decreased the risk of “connected consciousness” in patients. Provision of continuous anaesthesia during that time is standard practice in Australia. Professor Robert Sanders, an anaesthetist from the University of Sydney and co‐author of the paper said: “The goal is not to discourage people from surgeries under general anaesthetic – it is very important to note that patients did not remember responding to the commands”. He also observed that it was “also reassuring to see that if anaesthetic drugs are administered continuously in the time period between induction of anaesthesia and intubation, the risk of connected consciousness was greatly reduced. This research also highlights the need to better understand how different people respond to the anaesthesia medication. There is an urgent need for further research on the biological differences, particularly sex, that may influence sensitivity to anaesthetic medication.”

https://www.bjanaesthesia.org/article/S0007‐0912(22)00192‐1/fulltext