British journal of anaesthesia
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Women make up an increasing proportion of the physician workforce in anaesthesia, but they are consistently under-represented in leadership and governance. ⋯ Whilst certain trends suggest improvements in the workplace, barriers to promotion of women in key leadership and research positions continue within anaesthesiology internationally.
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Review Meta Analysis
Intravenous lidocaine to prevent postoperative airway complications in adults: a systematic review and meta-analysis.
Cough: why care?
Although often minor, common post-operative complications have by definition a broad impact on the perioperative experience. Some common complications, such as coughing on extubation, can also have significant surgical consequences such as for neurosurgical or ophthalmic procedures.
Both coughing on extubation (reported incidence 15-94%) and post-operative sore throat (21-72%) are very common among surgical patients.
What did they do?
Yang and team performed a high-quality meta-analysis of RCTs investigating the effect of intravenous lidocaine/lignocaine on coughing at extubation. Many of these trials also looked at further secondary effects, such as post-operative sore throat. They included 16 trials, totalling 1,516 subjects. Although the trials demonstrated significant heterogeneity, subgroup analyses still confirmed the study's findings.
And they found...
There was significant reduction in cough RR 0.64 (0.48-0.86 & NNT=5), and post-operative sore throat RR 0.46 (0.32-0.67), though no difference in laryngospasm, adverse events or time to extubation with modern volatile agents.
Analysing various lidocaine timings (pre-operative vs intra-operative) and dose ranges (low <1.5mg/kg or high >1.5 mg/kg) yielded no evidence of clear advantage. Nonetheless the findings are consistent with previous reviews, such as from Clivio et al. (2019) showing lidocaine 1.5 mg/kg reduced cough (RR: 0.44; 0.33–0.58), and that the effect is probably dose responsive.
Ok, but how does lidocaine work?
The mechanism of action reducing cough is not understood, although several possibilities have been proposed, including...
"...the suppression of airway sensory C fibres, the reduction of neural discharge of peripheral nerve fibres, and the selective depression of pain transmission in the spinal cord."
Bottom-line
Peri-operative intravenous lignocaine effectively reduces coughing on extubation and reduces post-operative sore throat, without any increase in adverse events.
summary -
Atelectasis during general anaesthesia increases with age up to 50 years and BMI up to 30 kg/m2, but appears curiously limited beyond this.
pearl