Notes: We reviewed the maintenance records of lee vaporizers which had been in clinical use for up to 4 years. Tec 4s and Enfluratec 3s were found to be extremely reliable, but Fluotec 3s suffered progressively from mechanical and calibration problems. Their most recurrent fault was sticking valves caused probably by thymol crystallising on the valve faces. This fault did not occur with Fluotec 4s, which are designed to prevent liquid agent reaching the valve surfaces. We found, in a study of the effects of thymol accumulation, that only occasional draining of a Fluotec vaporizer is required to keep thymol concentration below the level at which its output is reduced. We conclude that, if regular field calibration checks are carried out as a safety measure, the service interval for Tee vaporizers could be extended beyond Ohmeda's present recommendation of one year.

Notes: The performance of the Travenol infusor when used to administer an intravenous infusion of analgesic after surgery has been investigated. Mean flow was very similar to the manufacturer's quoted figure of 2 ml/hour, but there was a large interindividual variation. Results from a laboratory study suggest that this was due to variation in the manufacture of the infusor.

Notes: The use of the new Medishield anasthetic gas scavenging system with ventilators in the Siemens-Elema Servo 900 series was investigated. It was discovered that this combination of equipment creates the hazard that a disconnexion in the patient breathing system may not be detected by the ventilator alarm. This happens because the suction generated by the scavenging system draws a considerable flow of room air through the expiratory system of the ventilator when a disconnexion occurs. Possible solutions to the problem were investigated, and it was discovered that the problem can be overcome by applying a small amount of positive end-expiratory pressure to counteract the suction from the scavenging system.

Notes: Objectives: The Oral Health of Older Adults with Dementia was instigated in the late 1990s to quantify and compare coronal and root caries incidence and increments in community-living older Australians with and without dementia.Methods: A longitudinal design was used to conduct dental inspections at baseline and one-year, for two groups of randomly selected community-living older adults - one group of 116 people with dementia and a comparison group of 116 people without dementia.Results: At one-year there were 103 dementia and 113(112 dentate) non-dementia participants. Coronal and root surface caries incidence was higher for dementia participants (p〈0.05). Dementia participants had higher coronal and root caries adjusted caries increments (ADJCI) (p〈0.01). Both coronal and root ADJCI were evident in half of dementia participants, compared with one-quarter of non-dementia participants. Dementia participants with higher coronal ADJCI were those who had visited the dentist since baseline, who were taking neuroleptics with high anticholinergic adverse effects, and whose carer had high carer burden score (p〈0.01). Dementia participants with higher root ADJCI were those needing assistance with oral hygiene care and whose carers had difficulties with oral hygiene care (p〈0.05). Baseline characteristics predictive in linear regression for: (1) coronal caries increments among all participants were - dementia participants, those with cognitive testing scores indicative of moderate-severe dementia, those with private health insurance; (2) root caries increments among all participants were - dementia participants, and those who had 1 decayed/filled root surface at baseline. Among dementia participants, being male was the baseline characteristic predictive in logistic regression for coronal caries increments, and having 1 decayed coronal surface was the baseline characteristic predictive for root caries increments.Conclusions: Coronal and root caries incidence and increments were significantly higher in the community-living older adults with dementia over the one-year follow-up period. Dementia participants had high levels of coronal and root caries increments; characteristics related to high caries increments included sex (males), dementia severity (moderate-severe), high carer burden, oral hygiene care difficulties, use of neuroleptic medication (with high anticholinergic adverse effects) and previous experience of caries.