The State of UK Dental Anaesthesia: Results From The NAP5 Activity Survey. A national survey by the 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland.

The National Health Service anaesthesia annual activity (2013) was recently reported by the Fifth National Audit Program of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland. Within a large dataset were 620 dental cases. Here, we describe this data subset. The estimated annual dental caseload was 111,600:60% were children (< 16 y), 38.5% adults (16 - 65y) and 1.5% the elderly (> 65y). Almost all were elective day procedures (97%) and ASA 1 or 2 patients (95%).The most senior anaesthetist present was a Consultant in 82% and a non-career grade doctor in 14%.Virtually all (98%) cases were conducted during GA. Propofol was used to induce anaesthesia in almost all adults compared with 60% of children. Propofol maintenance was used in 5% of both children and adults. Almost all adults received an opioid (including remifentanil) compared with only 40% of children. Thirty one per cent of children had a GA for a dental procedure without either opioid or LA supplementation. Approximately 50% of adults and 16% of children received a tracheal tube: 20% of children needed only anaesthesia by face mask. These data show that anaesthetists almost always use general anaesthesia for dental procedures and this exposes difficulties in training of anaesthetists in sedation techniques. Dentists, however, are well known to use sedation when operating alone and our report provides encouragement for a comprehensive survey of dental sedation and anaesthesia practice in both NHS and non-NHS hospitals and clinics in the UK.

Effect of pain and audiovisual stimulation on the depression of acute hypoxic ventilatory response by low-dose halothane in humans.

BACKGROUND: The effects of different low-dose volatile agents in blunting the acute hypoxic ventilatory response (AHVR) are variable. Arousal (due to audiovisual stimulation) may prevent isoflurane-induced blunting of AHVR. The purpose of this study was to assess whether this was also the case for halothane. The authors also assessed the effects of pain on the interaction of halothane and AHVR. METHODS: Step decreases in end-tidal partial pressure of oxygen using dynamic end-tidal forcing were performed from normoxia to hypoxia (50 mmHg) in 10 healthy volunteers, with end-tidal partial pressure of carbon dioxide held 1-2 mmHg above normal, in six protocols: (1) control conditions (darkened, quiet room, eyes closed) without halothane and (2) with 0.1 minimum alveolar concentration (MAC) halothane; (3) audiovisual stimulation (bright room, loud television) without halothane and (4) with 0.1 MAC halothane; (5) pain (electrical stimulation of skin over the tibia to produce a visual analog pain score of 5-6 out of 10) without halothane and (6) with 0.1 MAC halothane. The Bispectral Index of the electroencephalogram was also monitored. RESULTS: Halothane did not affect normoxic minute ventilation in any arousal state but significantly reduced the magnitude of AHVR by 50% regardless of the background arousal state (P < 0.001). Bispectral Index values were reduced by halothane only in the absence of arousal (P < 0.003). Both pain and audiovisual stimulation modestly increased normoxic minute ventilation (P < 0.002) and AHVR (P < 0.003). CONCLUSIONS: Audiovisual stimulation does not prevent the blunting of AHVR by low-dose halothane. This result with halothane differs from previous results with isoflurane. Therefore, different anesthetics interact in different ways with arousal states. This finding raises the possibility that different anesthetics might differentially affect the hypoxic chemoreflex loop or that they might act in the brain at sites separate from the chemoreflex loop, differently to influence the wakefulness drive to ventilation.