Bioefficacy of mosquito mat vaporizers and associated metabolic detoxication mechanisms in Aedes aegypti (Linnaeus) in Selangor, Malaysia: A statewide assessment

@#This study aims to examine the efficacy of mosquito mat vaporizers on Aedes aegypti and their associated metabolic detoxication mechanisms. For this purpose, Aedes aegypti (Linnaeus) was collected from nine districts in Selangor, Malaysia and tested with mosquito vaporizing mat bioassays. The same populations were also subjected to biochemical assays to investigate activities of detoxifying enzymes, namely non-specific esterase (EST), glutathione-S-transferase (GST) and mixed function oxidase (MFO). The efficacy of Ae. aegypti on the active ingredients tested in decreasing order were d- allethrin > dimefluthrin > prallethrin with PBO > prallethrin. The results further indicated significant enhancement mean levels of EST, GST and MFO in pyrethroid-resistant populations. The mortality rate of Ae. aegypti in response to pyrethroid active ingredients was associated with MFO activity, suggesting it is an important detoxification enzyme for the populations tested. In view of the presence of resistance against household insecticide products, pyrethroid efficacy on Ae. aegypti populations needs to be monitored closely to ensure the implementation of an effective vector control program in Malaysia.

Unexpected anesthetic leakage from a damaged O-ring on the Selectatec back bar: A case report

The Selectatec mounting system was devised to provide easy and quick on-site fitting of various vaporizers for the anesthetic machine. However, a quick changing system for the vaporizer can also damage the O-ring due to friction between the vaporizer and the Selectatec back bar. We herein report a case of an unexpected anesthetic gas leakage from a damaged O-ring on the Selectatec back bar, which resulted from exchanging the vaporizers between two operations. In cases using the Datex Ohmeda machine, it is not easy to detect leakages from the vaporizers because of the location of the check valve near to the fresh gas outlet. This complicates the use of the positive pressure leakage test to detect a low pressure system leakage on the Selectatec back bar. We recommend the preanesthetic negative pressure or low-flow leakage test to detect a low pressure leakage when exchanging vaporizers on the Selectatec system.

Effects on the Output Concentrations of Sevoflurane with Different Lengths and Pipe Sizes / 医学研究杂志

Objective To discuss the effects on the output concentrations with different lengths and pipe sizes of variable bypass va -porizer.Methods The output concentrations of different lengths and pipe sizes of variable bypass vaporizer were detected .Results Compared with concentrations controlled ,the output concentrations with different lengths and pipe sizes were lower (P<0.05).Conclusion The effect of length and pipe size can affect the accuracy of output concentration of sevoflurane ,the data in our research can also help in the design of variable bypass vaporizer .

Optimización de inyector de temperatura prograada en el análisis de residuos de plaguicidas mediante el método simplex / Optimiztion of tthe programmed temperatre vaporiser in analysis of pessticide residues by the simplex method / Otimização o vapporizador de temperatura prgramada na análise de resíduos de pesticidas pelo método simplex

Este estudio muestra los resultados obtenidos en la aplicación del método simplex para optimizar el inyector de temperatura programada en cromatografía de gases en dos modos de operación: inyección sin división en frío (inyección de 4 µL) e inyección con venteo de solvente (inyección de 20 µL). Para el primer modo de operación se optimizaron 5 variables en 12 experimentos; para el modo de venteo de solvente se optimizaron 7 variables en 19 experimentos. Con el fin de evaluar el proceso de optimización se empleó como referencia la inyección de 1 µL en modo sin división en caliente con pulso de presión. Esta evaluación mostró que el modo de inyección sin división en frío presentaba respuestas cromatográficas hasta 5 veces más altas que el método en caliente. Finalmente, para la inyección con venteo de solvente se determinó que para los compuestos con puntos de ebullición más altos se presentaban resultados equivalentes a la inyección sin división en frío.

This study shows the results of the simplex method implementation for optimization of a programmed temperature vaporizer in two modes: cold splitless (injection 4 µL) and solvent vent (20 µL injection). Five variables in 12 experiments were optimized in the first mode of operation and seven variables were optimized in 19 experiments in the solvent vent mode. To evaluate the optimization process, the injection of 1 µL in hot pulsed splitless mode was used as reference. The chromatographic responses obtained in cold splitless mode (4 µL) were up to 5 times higher than in hot splitless method. Finally, in the solvent vent mode, compounds with higher boiling points showed similar results to those obtained with cold splitless mode.

Este estudo mostra os resultados obtidos na aplicação do método simplex para otimizar a temperatura do injetor em dois modos: sem divisão de fluxo a frio (injeção 4 µL) e com remoção do solvente (20 µL injeção). Para o primeiro modo de operação foram otimizadas cinco variáveis em 12 experimentos, enquanto que para o modo com remoção do solvente sete variáveis foram otimizadas em 19 experimentos. Para avaliar o processo de otimização foi utilizado como referência uma injeção de 1 µL no modo sem divisão de fluxo a quente e com pulso de pressão. Os resultados indicam que o modo de injeção sem divisão de fluxo a frio apresentou respostas cromatográficas com intensidades de até cinco vezes maiores que o método aquecido. Finalmente, respostas equivalentes foram obtidas somente para alguns compostos, com pontos de ebulição altos, quando injetados no modo com remoção do solvente e comparados com o modo sem divisão de fluxo a frio.

Interruption in the supply of breathing gas during general anesthesia due to malposition of the vaporizer: A case report / 대한마취과학회지

We report a case of interruption in the supply of breathing gas during general anesthesia caused by malposition of the Drager Vapor 2000(R) vaporizer, which was accidentally tilted and lifted off the Selectatec manifold of the anesthesia machine. Because the patient was an 1-month-old infant, we couldn't check if he had experienced awareness with recall. We emphasize the importance of checking the anesthetic vaporizer after mounting it on the back bar of the anesthesia machine.

Awareness during general anesthesia due to the unlock position of the vaporizer : A report on two cases / 대한마취과학회지

Awareness with recall after general anesthesia is a relatively infrequent occurrence and this awareness is often associated with significant adverse psychological sequelae, including posttraumatic stress disorder. The occurrence of awareness is often the consequence of the light anesthetic techniques with using minor anesthetic agents. Because the locking lever of the Penlon Sigma Delta Anesthetic vaporizer (sevoflurane) was at the unlock position, disconnection happened between the anesthetic machine and the vaporizer (the Selectatec(R) vaporizing system). In our two cases, the inhalation agents were not supplied and awareness with recall was identified after surgery. We recommend to check the concentration of the inhalation agents by monitoring the concentration of using endtidal inhalation agents and to measure the hypnotic level of anesthesia via the bispectral index (BIS) and the auditory evoked potential (AEP).

Awareness during General Anesthesia due to Vaporizer Malfunction: A case report / 대한마취과학회지

We report a case of awakening during general anesthesia due to a vaporizer malfunction. The sevoflurane vaporizer had a hole through which approximately 20% of fresh gas escaped. The gas in the common gas outlet contained only 60% of the sevoflurane stated on the vaporizer setting. Moreover, the gas monitor module was out of order, and the heart rate and blood pressure were stable. As a result, we were unaware of the low sevoflurane concentration. The leakage through the hole could not be detected with the commonly used low-pressure system leak checking method. The implication of this case is that unexpected awakening can occur in patients with stable vital signs with an inhalation anesthesia. Therefore, more attention is needed to detect the level of patient awareness.

An Unexpected Vapor Leakage from Unlocked Vaporizer (Penlon Sigma Delta Anesthetic Vaporizer): A case report / 대한마취과학회지

We present a case of an anesthetic gas leak through the valve of the Selectatec back bar during a surgical procedure. The Selectatec Vaporizing System is a quick-change system consisting of anesthetic vaporizers of the 'Tec models' of the Ohmeda machine that are seated on a compatibility manifold block located on the back bar of the anesthetic machine. In order to prevent a leak and a failure of vapor delivery, the "Tec models series" can only be turned 'on' when the locking lever is turned to the 'lock' position. However in this case, the control knob was rotated despite the back bar locking mechanism not being engaged, and a gas leak developed through the unlocked valves in Selectatec back bar. The Penlon Sigma Delta Anesthetic Vaporizer (sevoflurane) in a Datex-Ohmeda Aestiva/5 anesthesia machine can be turned 'on' when the locking lever is maintained at the 'unlock' position.

Research Output Accuracies of Private Hospital Vaporizers / 대한마취과학회지

BACKGROUND: Vaporizers convert liquid anesthetics into measured amount of vapor that are added to the fresh gas mixture to produce known concentrations of anesthetics. As with anesthesia machines, mordern precision vaporizers require regular checks with respect to technical safety by experts. Some private hospitals in Korea do not have had a anesthesiologist belong exclusively to hospital. Therefore it is difficult to perform a regular checks of anesthesia machine especially vaporizers. We had a question about the accuracy of vaporizer output which used in the private hospitals. METHODS: We investigated outputs of 47 vaporizers which used in 23 private hospitals and 5 general hospitals around Kangdong Gu and Kangnam Gu in Seoul, Korea. Anesthetic agent monitor(Biochem anesthetic agent monitor 8100, Waukesha, Wisc, USA) was used and its analysis value was 0.1 vo1%. 50 vo1% O2 and 50 vol% N2O were used as a carrier gas. The flow rates of the carrier gas were 4 1/min. Dial settings were 0.5, 1, 1.5, 2, 3 vo1%. RESULTS: The result was that vaporizers which had the inaccuracy ranges of concentration less than +/-0.5 vo1% was 76.6% of 47 vaporizers, +/-1 vo1% was 93.6%. And above +/-1 vol% was 6.4% of all. CONCLUSIONS: This research concludes that great care needed when the anesthesiologist strange to the vaporizers in the private hospitals operates the vaporizers.

Evaluation of an electronic vaporizer: the Gambro-Engstrom Eas 9010 / 中华麻醉学杂志

Objective To evaluate the accuracy of performance of Engstrom Eas 9010 vaporizerMethods Using Datex Capnomac AS/3 monitored the output of Gambro-Engstrom Eas 9010 anesthetic agent vaporizer under various situations l Determing the output of vaporizer at different gas flow rates of 0 5,1 0,2 0,4 0,6 0 and 8 0 L?min -1 2 The effects resulting from up stream oxygen flushing 3 The effects due to additional nitrous oxide as carrier gas 4 Effects of different airway pressure at the same flow rate Results 1 The output of the vaporizer was highly correlated with the dial setting at various gas flow rate except dial setting was more than 8% and gas flow rate less than 0 5L?min -1 2 Upstream oxygen flush could not decrease the concentration remarkably 3 The output of the vaporizer was not affected by additional carrier gas 4 The effect on vaporizer output was not remarkable under different airway pressure at the same flow rate Conclusions The anesthetic vaporizer principle used in the Gambro-Engstrom Eas 9010 apparatus is innovative Electronically controlled vapor quanta injection is used with safety feed back Its accuracy can't be influenced by temperature,pressure and carrier gas indicating to be safely applied to the low or even minimal flow anesthesia

Development of WMZ-03 anaesthesia workstation with chest intergrated with apparatus / 医疗卫生装备

This paper introduces a type of anaesthesia workstation which is composed of two vertical medical chests, i.e. the upper and lower parts. Taken out of the chest, the two parts are butted against and locked to make the workstation ready for operation. After operation is finished, the two parts are uncoupled and put into the chests, and then the workstation can be stored and transported with the chests closed.

Overdose with Malfunctional Halothane Vaporizer / 대한마취과학회지

A Vaporizer should deliver a constant concentration of anesthetics under the varying conditions of gas flow, liquid volume, and ambient temperature. We had encountered 3 patients with arrhythmia and ST change on EKG monitoring and cardiovascular collapse which occurred immediately after turning on the halothane vaporizer (Drager Halothan Vapor 19.1 No. 24302). Sudden cardiovascular collapse during the induction of anesthesia in an otherwise healthy patient was suggestive of anesthetic overdose. Thus we checked this vaporizer with the Capnomac Datex and Drager Iris. The inspiratory concentration of the vaporizer was found to be much higher than that of the dial setting. Vaporizers are sensitive, accurate, and scientific instruments which are directly involved in critical life support. All vaporizers should be treated and tested with great care for performance after shipment, any major service repair, or equipment modification.