Performance of advanced resuscitation skills by pediatric housestaff

OBJECTIVE: To describe pediatric housestaff resuscitation experience and their ability to perform key resuscitation skills. DESIGN: Cohort study of 63 pediatric residents in a university-based training program. PARTICIPANTS AND METHODS: Investigators observed, scored, and timed resident performance on 4 key resuscitation skills. Cognitive ability was tested with 4 written scenarios. Housestaff provided self-reports of the number of months since their last American Heart Association Pediatric Advanced Life Support course, number of mock and actual codes attended, number of times skills were performed, and self-confidence with respect to resuscitation. RESULTS: A total of 45 pediatric residents (71%) participated. Median cognitive score was 5 (range, 1-5). Of all residents, 44 (97%) successfully bag mask-ventilated the mannequin; 24 (53%) and 36 (80%) used the correct bag and mask size, respectively. Thirty-nine residents (87%) placed a tube in the mannequin trachea, 12 (27%) checked that suction was working prior to intubation, and 30 (67%) chose the correct endotracheal tube size. Forty residents (89%) discharged the defibrillator, and 25 (56%) and 32 (71%) correctly chose asynchronous mode and infant paddles, respectively. Thirty-eight residents (84%) inserted an intraosseous line; 35 (78%) had correct placement. Median times for successful skill completion were 83 seconds for bag mask ventilation, 136 seconds for intubation, 149 seconds for defibrillation, and 68 seconds for intraosseous line placement. CONCLUSION: Pediatric housestaff previously trained in pediatric advanced life support were generally able to reach the end point of 4 key resuscitation skills but less frequently performed the specific subcomponents of each skill. This poor performance and the prolonged time to skill completion suggest the need for greater attention to detail during training.     

Off flavours in large waterbodies: physics, chemistry and biology in synchrony.

The Laurentian Great Lakes of North America are a drinking water source for millions of Canadian and US consumers. These waterbodies have undergone extensive change over the past century as a result of widespread degradation and remediation. Many of the Lakes are prone to taste and odour (T&O), and although these outbreaks have been poorly monitored, evidence suggests that they are increasing in frequency. Tracing and controlling T&O in such large systems presents a challenging task, due to their physical size and complexity. This paper presents an overview of recent investigative and management approaches to T&O in Lake Ontario and its outflow, the St. Lawrence River. We have identified three distinct patterns of T&O in these source-waters, caused by geosmin and 2-methylisoborneol and differing in their planktonic and benthic sources, and temporal and spatial dynamics. Each pattern has required a different approach by scientists and management, in partnership with the water industry. We have shown these T&O outbreaks are caused and moderated by physical, chemical and biological mechanisms over a spectrum of spatial and temporal scales. Canadian municipalities affected by these outbreaks have been key to the investigation of the links between T&O and ecosystem processes with the aim to develop more proactive water treatment and long-term management.     

Analytical approaches to characterising fish tainting potential of oil sands process waters.

A three-stage study has been carried out with rainbow trout (Oncorhyncus mykiss) to develop analytical approaches which can provide a fingerprint for tainting by oil sands chemicals from process-affected waters and natural sources. The objective was to find a simpler alternative to sensory evaluation. In the first stage, a set of seven test compounds was added to fish tissue which was analysed by headspace and solvent (dichloromethane, DCM) extraction followed by gas chromatography-mass spectrometry (GC-MS). In the second stage, fingerlings (5-20 g) were exposed for 96 hours to the test compound mixture at 1.0 and 0.5 times the estimated tainting threshold concentrations. In the final stage, fingerlings were exposed for 96 hours to an oil sands process water at 5, 10, 20 and 50% concentrations in clean water. None of the test compounds was identified in DCM extracts of tissue from exposed fish. Two long-chain aldehydes, hexadecanal and 9-octadecenal, were tentatively identified in these extracts by matching of mass spectra with library spectra.     

Advances in ventricular synchronous demand cardiac pacemakers

New ventricular synchronous demand (VVT) pacemaker functions have been developed that provide improved performance in electromagnetic interference (EMI) environments and improved sensing of ventricular premature contractions. All previous ventricular synchronous pacemakers had an inherent design conflict between choosing the optimal (relatively long) input refractory interval needed for limiting the maximum pulse delivery rate and choosing the optimal (relatively short) input refractory interval (sensing dead time) following either a sensed or paced cardiac contraction. The necessary compromise resulted in a device that in the presence of EMI, stimulated at a rate (approximately 150 ppm) which was dangerously fast for certain patients, yet was insensitive to early poststimulation (400 to 500 msec) premature ventricular contractions, resulting in a risk of T-wave stimulation. Partly because of these deficiencies, the VVT function has not been widely employed by the medical profession: instead, the ventricular inhibited (VVI) pacemaker has evolved as the treatment of choice for the cardiac patient with intermittent heart block, even though total inhibition by certain EMI radiators is a potentially serious problem. New VVT structures have been developed that allow control separation of the maximum EMI discharge rate and the sensing refractory interval by employing independent input and output refractory intervals. New low-power digital devices provide building blocks applicable to the developed architectures.     

Strategic failure in social interaction: Evidence for expectancy disconfirmation processes.

Two experiments were conducted to test the idea that individuals may fail strategically in order to lower the expectations that others hold for their performances. In a pilot study, participants reported that, when lacking confidence, they would be particularly uncomfortable and anxious with high expectations and would attempt to lower them strategically. In Experiment 1, socially anxious and nonanxious participants were led to believe that an interviewer's high or low expectations were due to a prodigious amount of effort or to very little effort. Socially anxious individuals tended to fail strategically when confronted with high as opposed to low expectations presumably based on a prodigious amount of previous effort. In Experiment 2, individuals high or low in social anxiety were led to believe that an interviewer held either high or low expectations for them. High-anxiety participants, led to believe their initial performance would affect high expections, showed much poorer initial performance relative to all other groups. These findings show that individuals who are particularly doubtful about their ability to perform up to par will sometimes fail strategically at the outset of social interaction as a means to create lower and safer standards. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kawaihiko and the third-quartile day [traffic management]

The Kawaihiko network, linking the New Zealand universities to the Internet, pioneered traffic measurement as a tool for network management and cost recovery. Its history and its use of the real-time traffic flow measurement architecture to measure its traffic are described. The Kawaihiko members wanted a “measured bandwidth” metric which would be a good indicator of the bandwidth required to carry each site's traffic. Kawaihiko developed such a metric-the third-quartile day-based on a daily usage profile or third-quartile profile. The 3QP and 3QD are described in detail, and illustrated with typical plots from several of the Kawaihiko sites. The Kawaihiko members found 3QD to be an effective bandwidth measure, and 3QP a useful traffic management tool     

Spatial-spectral volume holographic systems: resolution dependence on effective thickness

The resolution dependence of spatial-spectral volume holographic imaging systems on angular and spectral bandwidth of nonuniform gratings is investigated. Modeling techniques include a combination of the approximate coupled-wave analysis and the transfer-matrix method for holograms recorded in absorptive media. The effective thickness of the holograms is used as an estimator of the resolution of the imaging systems. The methodology, which assists in the design and optimization of volume holographic simulation results based on our approach, are confirmed with experiments and show proof of consistency and usefulness of the proposed models.     

Differentiation-specific enhancer activity in transduced keratinocytes: a model for epidermal gene therapy

Active sequences from the laminin alpha1 and alpha2 chain carboxyl-terminal globular domains (G domain) have been identified by screening overlapping synthetic peptides in a number of biological assays (Nomizu et al. [1995] J. Biol. Chem. 270:20583-20590; Nomizu et al. [1996] FEBS Lett. 396:37-42). We have tested the activity of these peptides in submandibular gland explants of embryonic day 13 mice to determine the functional sites involved in organ development. The laminin alpha1 chain peptide, RKRLQVQLSIRT (residues 2719-2730 and designated AG-73), significantly inhibited epithelial branching morphogenesis. In contrast, other cell adhesive laminin alpha1 chain peptides including the AASIKVAVSADR and NRWHSIYITRFG failed to inhibit the branching. MG-73, a homologue of AG-73 from the laminin alpha2 chain, did not inhibit the branching. The alpha2 chain peptide had no effect, which may be due to the low levels of this laminin chain in day 13 mice. Laminin alpha2 chain-specific monoclonal antibodies strongly reacted with the basement membranes of developed acini but only weakly stained embryonic day 13 submandibular epithelium. The expression of E-cadherin and alpha6 integrin, as detected by immunofluorescence, were unchanged in both AG-73 and control scramble peptide-treated epithelial cells of the explants. In contrast, immunostaining of nidogen/entactin showed that explants treated with AG-73 for 3 days had a discontinuous basement membrane. Explants treated for 3 days with control peptide showed a normal basement membrane. These results suggest that the region containing the AG-73 sequence of the laminin alpha1 chain is crucial for development of submandibular gland at early embryonic stages. The discontinuous basement membrane in AG-73-treated explants may indicate an important role for this region in basement membrane assembly.