Biological efficacy and stability of diluted ticarcillin-clavulanic acid in the topical treatment of Pseudomonas aeruginosa infections

Topical compounded Timentin(®) diluted with an inactive vehicle has been reported to be effective in the treatment of otitis externa caused by Pseudomonas aeruginosa. The aims of this study were to determine the biological efficacy of Timentin(®) (ticarcillin and clavulanic acid) when diluted in the carrier vehicle Methopt(®) against P. aeruginosa and to determine the efficacy and stability of Timentin(®) aqueous stock concentrate solution. Timentin(®) stock concentrate was tested against four P. aeruginosa isolates on days 0, 7, 14, 21 and 28; then after 2, 3, 4, 5, 6, 9 and 12 months of storage at 4 or -20°C. The diluted Timentin(®)-Methopt(®) solutions were tested against all isolates after 0, 2, 4, 6, 8, 10, 12, 14, 17, 21, 24 and 28 days of storage at 24 or 4°C. Minimal inhibitory concentration (MIC) levels for all strains were determined using the broth microdilution method. The MIC of the stock solution remained relatively constant and acceptable throughout the study when stored at -20°C and was also acceptable for shorter time periods (6-9 months) when stored at 4°C. The MIC for the diluted Timentin(®)-Methopt(®) solution remained relatively constant and acceptable throughout the study for all four bacterial strains, with no difference between the solutions stored at 4 or 24°C. The results of this study indicate that storage of the Timentin(®) stock solution at -20°C does not compromise efficacy for at least 12 months and that Timentin(®) diluted in Methopt(®) was stable for 28 days when stored at either 4 or 24°C.Fiona L. Bateman, Susan M. Moss, Darren J. Trott, and Michael A. Shipston

How reliable is parental/carer assessment of infant health status?

Problems often arise in cases of lethal inflicted injury in infants and children in determining the chronology of events. However, on occasion it may be assumed that a parent's statement that the child appeared normal at a particular time is correct. It is then inferred that the lethal injury occurred after this time. In a study of infants from Queensland, Australia a significant number of cases occurred where a parent/carer did not actually recognise that an infant was deceased or in extremis despite handling of the infants, some of whom had established rigor mortis. Assessment of their infant's health status was quite flawed, presumably due to inattention, fatigue, or confirmatory bias (seeing what is expected). This could also apply to infants with head injuries who may manifest quite non-specific signs such as lethargy, somnolence or alteration in conscious state, manifestations that could easily be confused with normal drowsiness or sleep. Thus, the evaluation of parent/carer statements must be tempered by the knowledge that their opinions may not always (for completely understandable reasons) be reliable, and should not be uncritically accepted as a basis for deciding the time course for a lethal process

An evaluation of pathologists’ application of the diagnostic criteria from the San Diego definition of SIDS and unclassified sudden infant death

Despite being widely used, few studies have assessed the utility of the San Diego definition of sudden infant death syndrome (SIDS). The purpose of this study was to evaluate pathologists' application of the San Diego definition in all cases of sudden unexpected death in infancy (SUDI) that occurred in Queensland, Australia, between 2010 and 2014. Key coronial documents of 228 cases of SUDI were reviewed independently by three reviewers and classified according to the San Diego definition. Clear guidance regarding the evidentiary threshold for classification and interpretation of the San Diego definition was provided. All reviewers classified cases identically in 202 cases (88.6%). Consensus was achieved on the classification of the remaining 26 deaths following case discussion. After review, 79 cases were classified as SIDS, a one third reduction compared with the original classification, mainly due to a high probability of accidental asphyxia. The number of cases classified as undetermined (USID) almost doubled (75/228, 32.9%), and there was more than a fivefold increase in cases classified as asphyxia (43/228, 18.9%). Natural conditions decreased by approximately one third (21/228, 9.2%). This study demonstrates that with clear guidelines for interpretation, the San Diego definition can be applied reliably, with discrepancies resolved through a process of peer review