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Waveform capnography: an alternative to physician gestalt in determining optimal intubating conditions after administration of paralytic agents
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  • Published on:
    Peripheral nerve stimulation use in the Emergency Department
    • Leo T Urquhart, Anaesthetics Core Trainee NHS Dumfries and Galloway
    • Other Contributors:
      • Vincent Perkins, Consultant Anaesthetist

    We would like to comment of the use of waveform capnography (WC) as an adjunct to help determine adequate paralysis during rapid sequence induction (RSI). The article used recognition of apnoea by loss of WC as an early indicator of muscle paralysis and evidence was presented that this method improved first pass success rates and reduced time to intubation for RSI in an emergency setting.

    Although apnoea can be a useful indicator for the presence of paralysis we would suggest that use of a peripheral nerve stimulator is a more accurate tool for determining when muscle relaxants have produced an adequate effect. The use of this simple and relatively inexpensive machine is standard practice for anaesthetists in determining the level of paralysis. It is also viewed as a standard for provision of anaesthesia outside of the operating theatre environment (Association of Anaesthetists of Great Britain and Ireland: Recommendations for standards of monitoring during anaesthesia and recovery, 2015, Page 8). We suggest from clinical experience that apnoea alone does not always reflect adequate muscle relaxation to allow for optimal intubating conditions. Reactive vocal cords may be present despite apparent correct dosing and timing of muscle relaxants. In addition, apnoea and loss of WC could possibly be a reflection of respiratory depression due to administration of the anaesthetic induction agent, opiods or a deteriorating clinical condition.

    We recognise that some Em...

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    Conflict of Interest:
    None declared.