British journal of anaesthesia最新文献

Clustered regularly interspaced short palindromic repeats (CRISPR)-based medical therapies are increasingly gaining regulatory approval worldwide. Consequently, patients receiving CRISPR therapy will come under the care of anaesthesiologists. An understanding of CRISPR, its technological implementations, and the characteristics of patients likely to receive this therapy will be essential to caring for this patient population. However, the role of CRISPR in anaesthesiology extends beyond simply caring for patients with prior CRISPR therapy. CRISPR has multiple direct potential applications in anaesthesia, particularly for managing chronic pain and critical illness. Additionally, given the unique skills anaesthesiologists possess, CRISPR potentially allows new roles for anaesthesiologists in the field of oncology. Consequently, CRISPR technology could enable new domains of anaesthetic practice. This review provides a primer on CRISPR for anaesthesiologists and an overview on how the technology could impact the field.

Background: The Qnox index is a novel monitor to quantify intraoperative nociception based on an electroencephalographic algorithm. We evaluated the ability of the Qnox index to discriminate noxious from non-noxious stimuli, respond to stimuli, and discriminate different levels of analgesia in patients under propofol anaesthesia with neuromuscular block.

Methods: Qnox was compared with heart rate and mean arterial pressure with five designated stimuli: tetanic stimulations without (tetanic 1) and with sufentanil (tetanic 2), skin incision, tracheal intubation, and a non-noxious period. The response around the skin incision was also evaluated at two target remifentanil concentrations.

Results: In 83 adult patients scheduled for elective surgery, Qnox performed worse than heart rate and mean arterial pressure in discriminating tetanic 2, tetanic 1, skin incision, and tracheal intubation noxious stimuli from the non-noxious period, with an area under curve of 0.52 (95% confidence interval 0.43-0.61), 0.54 (0.45-0.62), 0.67 (0.58-0.75), and 0.65 (0.57-0.73), respectively. The post-stimulus values of Qnox increased significantly after tracheal intubation and skin incision, but not after tetanic 1 or tetanic 2. Qnox values after skin incision were similar between the low- and high-remifentanil-concentration groups.

Conclusions: Qnox had a poor ability to discriminate noxious stimuli from non-noxious stimuli. Although Qnox responded to tracheal intubation and skin incision, it did not respond to tetanic stimulations and failed to discriminate different levels of analgesia. The Qnox index was not superior to heart rate or mean arterial pressure in assessing nociception during general anaesthesia.

Clinical trial registration: Chinese Clinical Trial Registry (ChiCTR2100046063).

Background: We have previously demonstrated that an extrafascial injection of 20 ml of local anaesthetic for interscalene brachial plexus block (ISB) reduces the rate of hemidiaphragmatic paralysis by 70% compared with an intrafascial injection, with similar efficacy. In this double-blind trial, we tested the hypothesis that a local anaesthetic volume of 10 ml injected extrafascially would reduce the rate of hemidiaphragmatic paralysis vs a volume of 20 ml, while providing similar analgesia.

Methods: Sixty ASA physical status 1-3 patients scheduled for elective shoulder surgery under general anaesthesia were randomised to receive ultrasound-guided extrafascial ISB using ropivacaine 0.75% 20 ml (control group) or 10 ml (low-volume group) injected lateral to the brachial plexus sheath. The primary outcome was incidence of hemidiaphragmatic paralysis (diaphragmatic excursion reduction of >75%), measured by M-mode ultrasonography, at 30 min after the procedure. Secondary outcomes included duration of analgesia and i.v. morphine consumption at 24 h after surgery.

Results: The 30-min hemidiaphragmatic paralysis rate was 80% (95% confidence interval [CI] 61-91%) in the control group and 19% (95% CI 8-40%) in the low-volume group (P<0.001). Participants in the low-volume vs control group had a shorter duration of analgesia (550 vs 873 min; P<0.01) and higher i.v. morphine consumption (20 vs 12 mg; P=0.03).

Conclusions: A low volume of local anaesthetic injected extrafascially reduced the rate of hemidiaphragmatic paralysis, but at the expense of a shorter duration of analgesia compared with standard-dose extrafascial anaesthetic injection.

Clinical trial registration: NCT04726280.

Background: Chronic neuropathic pain generally has a poor response to treatment with conventional drugs. Sympathectomy can alleviate neuropathic pain in some patients, suggesting that abnormal sympathetic-somatosensory signaling interactions might underlie some forms of neuropathic pain. The molecular mechanisms underlying sympathetic-somatosensory interactions in neuropathic pain remain obscure.

Methods: Lumbar sympathectomy was performed in spared nerve injury (SNI) mice or rats, and the up-down method was used to measure the mechanical paw withdrawal threshold. Dorsal root ganglia (DRG) injection and perfusion were used to deliver virus or drugs. Methylated RNA immunoprecipitation sequencing, RNA-sequencing, and immunoelectron microscopy were used to identify neurotransmitters.

Results: We found that sprouting tyrosine hydroxylase-positive sympathetic fibres in DRG mediated the maintenance of mechanical allodynia after SNI (day 28, P<0.001). We further found that SNI significantly increased the N⁶-methyladenosine level of CXCL16 messenger RNA (day 28, P<0.001), which was attributable to the reduced N⁶-methyladenosine demethylase fat mass and obesity-associated protein (P=0.002) and increased interaction with YTHDF1 (P=0.013) in the sympathetic ganglion. Enhanced expression of CXCL16 in the sympathetic ganglia can lead to increases release into the DRG and act synergistically with norepinephrine from sympathetic terminals to enhance DRG neuronal excitability.

Conclusions: Norepinephrine and CXCL16 co-released from sympathetic nerve terminals in the DRG synergistically contribute to maintenance of neuropathic pain in a rodent model.