EEG bispectral index sensor guidance improves accuracy and safety of procedural sedation

To re-audit compliance with an amended sedation protocol following the latest national guidelines. To confirm the improved safety achieved through EEG guidance for drug administration during procedural sedation.

Following the revision of the departmental protocol, 14 standards were set. Sedation data and outcomes in 150 consecutive patients undergoing fluoroscopic and combined endoscopic procedures were evaluated against these. Combination sedo-analgesia was titrated by the interventional radiology nurses guided by bispectral index sensor (BIS) measurements to achieve readings between 80 and 85. Doses were stratified by patient age and ASA status. Nasal oxygen was given and standard monitoring including pulse oximetry and capnography were used alongside to assess for complications, notably hypoxaemia of ≤ 94%.

85% were non-vascular procedures, the bulk made up of oesophageal stent insertion, gastrostomy, oesophageal dilatation of radiation strictures and biliary procedures. Mean procedure time was 32.9 minutes (10-170). Mean doses of midazolam and fentanyl were 3.99mg (±1.9) and 92.3μg (±35.4), respectively. 84% of patients were classified as having received light or moderate sedation (BIS 70-89). Three standards for patient sedation were missed, but no patient required sedation reversal or airway management, and none developed hypoxaemia.

BIS guidance of sedation administration allows real-time assessment of the patient's response to sedo-analgesia administered and allows prediction about the safety of further drug administration. It identifies patients waking up, allowing this to be anticipated and reduces interruptions of the procedure. It offers clear clinical advantages to interval assessment of patients' response to clinical stimuli and reduces under-as well as oversedation.