Our data suggest that dexmedetomidine, even if used for deep sedation, does not have deleterious effects on local perfusion or tissue metabolism in denervated musculocutaneous flaps.

Therapeutic, II.

2b. Laryngoscope, 127:1821-1825, 2017.

Keypoints• Postoperative circulatory impairment of free microvascular flaps leads to failure of the reconstructions and major re-operations.• In the head and neck region vitality of the reconstructed site is often difficult to observe especially in flaps placed in the posterior oral cavity or hypopharynx.• The ideal follow-up method should be easy to use, reliable, harmless to the flap and it should rapidly alert the personnel to circulatory problems.

Aim of this study was to evaluate the reliability of a continuous real-time tissue oxygen monitoring method (Licox®) for postoperative follow-up of free microvascular flaps after ablative head and neck tumour surgery. We also wanted to establish and test accurate alarm levels for this monitoring method. One hundred eighteen head and neck cancer patients, operated in Tampere University Hospital, Finland, were analysed. Tissue oxygen (P ti O 2 ) levels were continuously monitored with the Licox® system. Receiver operating characteristic analysis was performed considering following alarming signals: a clear change in the trend of the curve leading to a decline more than 50% in 1 h or a decline below 10 mmHg in the P ti O 2 level. Licox® recognized all the patients who needed re-operation with sensitivity of 100% and specificity of 88%. The overall success rate was 99.2% (117 of 118) and flap salvage rate 88% (seven of eight), respectively. The Licox® tissue oxygen pressure monitoring system is a reliable method for detecting early postoperative circulation problems in free microvascular flaps. The suggested alarm signals are a clear change in the trend of the curve leading a decline more than 50% in an hour or a decline below 10 mmHg.