Types and risk factors of ambulance accidents: A scoping review.

BACKGROUND: A scoping review was conducted to map out the common research focusses on ambulance accidents, their key findings and some of the major knowledge gaps in this area. MATERIALS AND METHODS: Relevant, peer-reviewed, Englishlanguage articles on land ambulance accidents were independently searched by the authors using the MEDLINE and CINAHL databases. Anecdotal reports, testimonies and stories in trade or popular magazines and other grey literature were excluded. Articles that do not directly address ambulance accidents were also excluded. Additional articles were identified from the reference lists of the selected articles and from Google search engine. RESULTS: From an initial yield of 879 articles, 19 articles were included. Most of these articles were published from 2001 - 2005 (5 articles, 26.3%) and 2006 - 2010 (5 articles, 26.3%). Eighteen articles (78.3%) are original articles (18 articles, 78.3%) and another one article is a review article. Most of these articles focused on (1) the types of collisions and (2) the risk factors of ambulance accidents. Nine risk factors were identified to have contributed to ambulance accidents: (1) driving in urban areas (2) driving on dry road (3) the use of lights & sirens (4) the failure to use restraints (5) driving for emergency use (6) back seating (7) at road intersection (8) driver's previous records of accidents and (9) interfacility transfer. The two most common risk factors studied were (1) the use of lights & sirens and (2) driving at intersection. CONCLUSIONS: Most of the above risk factors can be mapped into three categories of risk factors: task-related factors, vehicle-related factors and environment-related factors. The category of risk factors least studied is the category of driver-related factors.

Rapid determination of sildenafil and its analogues in dietary supplements using gas chromatography-triple quadrupole mass spectrometry.

Application of gas chromatography-triple quadrupole mass spectrometry for identification, confirmation and quantification of 6 phosphodiesterase-5 (PDE-5) inhibitors (sildenafil, dimethylsildenafil, homosildenafil, thiosildenafil, thiodimethylsildenafil and thiohomosildenafil) in dietary supplements was investigated. The MS was operated in multiple reaction monitoring mode, for better sensitivity and selectivity. In this manner, the method is adequate to reduce background noise with less interference from co-eluting compounds in the samples. Two different ionisation techniques, electron ionisation (EI) and chemical ionisation (CI), were studied and compared. The chromatographic separation was performed on a short 10 m non-polar capillary column without any derivatisation step. This permitted fast analysis for all analogues with retention time less than 11 min, for both techniques. Use of backflushing can aid method retention time reduction and improves column maintenance. Evaluation of method validation included limit of detection (LOD), lower limit of quantitation (LLOQ), linearity, precision and recovery were performed for both EI and CI techniques. The LOD obtained varied from 0.03 to 1.50 µg/g and the LLOQ ranged from 0.10 to 5.00 µg/g. Good calibration linearity was obtained for all analogues for both techniques, with correlation coefficients (r(2)) higher than 0.99. Mean recoveries of all analogues using CI show higher values (83.4-108.8%) than that of EI (61.9-91.1%). The intra- and inter-assay precisions were evaluated for all analogues at spiked concentration of 10 µg/g and the relative standard deviation was less than 15% for both methods. These methods were then successfully applied to dietary supplement samples without prior derivatisation, confirming that the samples were adulterated with sildenafil and/or its analogues.

Isolation and identification of hydroxythiohomosildenafil in herbal dietary supplements sold as sexual performance enhancement products.

An unknown compound is detected and isolated from two herbal dietary supplements bought on the internet. The structure of the unknown compound is elucidated using ESI-MS/MS, NMR, UV and IR. The compound, named hydroxythiohomosildenafil, is identified as an analogue of sildenafil in which the oxygen atom is substituted with a sulfur atom in the pyrazolopyrimidine moiety, and a hydroxyethyl group instead of a methyl group is attached to the piperazinyl nitrogen. It is the first report of this compound being detected in herbal dietary supplements. The UV, IR and completely assigned NMR data of hydroxythiohomosildenafil is recorded.