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Introduction BTS guidelines recommend local anaesthetic (LA) should be used when performing arterial blood gas (ABG) procedures, outside of emergency situations, as it reduces pain for patients (O’Driscoll BR et al, Thorax. 2017 Jun;72).While CPET is elective, it requires the ABG be taken at maximal exertion. Using LA increases the time taken to perform an ABG, so it cannot be administered at the end of CPET. Alternatives to ABGs that do not require LA include arterialised ear-lobe samples. However, these tend to underestimate PaO2 readings and are not recommended for use in CPET with patients with chronic lung disease (Radtke T et al, Eur Respir Rev. 2019 Dec 18;28(154)). Many LA agents have a duration of over one hour, which is longer than a standardised ramp CPET (Taylor A BJA Educ. 2020 Feb;20(2):34–41)Methods We devised a protocol to administer 1–2 ml of 1% lidocaine subcutaneously over the radial artery prior to CPET initiation. This provides anaesthetic cover for the required ABG at the end of the test, giving pain relief as recommended by guidelines.Data on administration of lidocaine was recorded and collected March to July 2024, including adverse events and success of ABG sampling. If more than one test had to be aborted due to adverse events from local anaesthetic, or a significant increase in ABG failure rate, the protocol would be abandoned.Differences in ABG success were analysed using fischer’s exact test.Results 152 patients underwent CPET within the period. 91 patients had LA administered to protocol with no adverse events. 61 did not have, or declined LA. Those who had LA administered reported less pain from the ABG sampling. 87% ABGs were successful in those receiving LA, and 72% in those that had no LA (p 0.0343).Conclusions Administration of local anaesthetic prior to CPET is a safe and effective method for reducing pain from required ABGs. It may also reduce the failure rate of obtaining ABG samples (p 0.0343). We therefore propose this is a safe and effective method of reducing pain from ABGs required as part of a CPET testing protocol.