Medications to reduce emergence coughing after general anaesthesia with tracheal intubation: a systematic review and network meta-analysis
The objective of this review was to determine the relative efficacies of medications in decreasing the incidence of moderate to severe coughing at emergence. 70 RCTs published between 1990 and 2018 were included in the study. The authors constructed a network geometry plot to visualise the relationships between various study medications and performed a network meta-analysis. They determined relative efficacy using surface under the cumulative ranking analysis (SUCRA), where a value closer to 100% indicates a greater likelihood of effect. They also reported on outcomes related to severe peri-extubation coughing and extubation times.
For the primary outcome (decreased incidence of moderate to severe emergence coughing), the authors ranked dexmedetomidine as the most effective (SUCRA 81.0%) followed by remifentanil (67.2%), fentanyl (66.2%), intra-cuff lignocaine (59.5%), transtracheal/topical lignocaine (59.2%) and intravenous lignocaine (52.4%). Secondary outcomes included effects on extubation times (start of emergence to extubation) and on decreasing incidence of severe emergence coughing. Remifentanil was the most effective at reducing the incidence of severe coughing. With relation to extubation times, fentanyl and tracheal/topical lignocaine were associated with reduced extubation times compared to nothing, placebo, dexmedetomidine, remifentanil, and intravenous or intracuff lignocaine.
The authors went on to perform a sensitivity analysis and removed 12 studies with high risk of bias and 4 abstracts. This then changed the result of the primary outcome, with remifentanil coming out as the most effective at decreasing the incidence of moderate to severe coughing, followed by dexmedetomidine.
Take home message
With the outbreak of SARS-CoV-2, anaesthetists are now increasingly anxious about aerosol generation and reducing cough at emergence has become an important issue. While the use of dexmedetomidine has been demonstrated to be effective, it does require 1) availability, and 2) infusions over a period of time. In my practice, I perform a lot of TIVA and have found remifentanil easy to use and very effective at reducing cough at extubation.
Reviewed by Dr Scott Ma