Mass casualty modelling: a spatial tool to support triage decision making

Background

During a mass casualty incident, evacuation of patients to the appropriate health care facility is critical to survival. Despite this, no existing system provides the evidence required to make informed evacuation decisions from the scene of the incident. To mitigate this absence and enable more informed decision making, a web based spatial decision support system (SDSS) was developed. This system supports decision making by providing data regarding hospital proximity, capacity, and treatment specializations to decision makers at the scene of the incident.

Methods

This web-based SDSS utilizes pre-calculated driving times to estimate the actual driving time to each hospital within the inclusive trauma system of the large metropolitan region within which it is situated. In calculating and displaying its results, the model incorporates both road network and hospital data (e.g. capacity, treatment specialties, etc.), and produces results in a matter of seconds, as is required in a MCI situation. In addition, its application interface allows the user to map the incident location and assists in the execution of triage decisions.

Results

Upon running the model, driving time from the MCI location to the surrounding hospitals is quickly displayed alongside information regarding hospital capacity and capability, thereby assisting the user in the decision-making process.

Conclusions

The use of SDSS in the prioritization of MCI evacuation decision making is potentially valuable in cases of mass casualty. The key to this model is the utilization of pre-calculated driving times from each hospital in the region to each point on the road network. The incorporation of real-time traffic and hospital capacity data would further improve this model.     

Does luminal gastrin stimulate gastric acid secretion?

The effects of pentagastrin on acid secretion, short circuit current, electrical conductance and potential difference were determined in isolated bullfrog fundic mucosa. Biologically active luminal pentagastrin had no effect on gastric mucosa, even at a concentration 100 times higher than that necessary for stimulation of the mucosa from the serosal side. It is concluded that luminal gastrin does not appear to have a physiologic role in gastric secretory processes.     

Animal model for the study of internal anal sphincter activity

This paper describes a simple and reliable model for studying the internal anal sphincter (IAS) in the rat. The activity of the sphincter was recorded by a two-balloon system. The compliance of the balloon allowed measurements of pressure changes lower than 0.1 cm H2O. The anatomical and physiological characteristics of the rat IAS were found to be in many aspects similar to those found in the human. The rectoanal reflex in the rat consists of relaxation followed by contraction. The threshold for this response is 0.4-0.6 ml of air. The response of the IAS to prolonged rectal distension showed adaptation in 50% of the animals. Intraarterial application of drugs produced rapid, dose-dependent and reproducible effects on the IAS. The results described in this work show that the rat is a useful and convenient model for studying anal function. It may be used to investigate both the physiology and pharmacology of the IAS activity.     

Fluoroscopically controlled removal of a blunt esophageal foreign body using a Foley catheter in children

The removal of foreign bodies from the esophagus with a Foley catheter is a simple, safe, and highly successful procedure. This technique should be used initially when managing a blunt foreign body in the esophagus; it reduces the risk, time, and expense involved in endoscopic removal.Offprint requests to: P. Mogle     

Pneumococcal pneumonia and septic shock in the newborn infant

Pneumococcal sepsis and pneumonia in the neonate are rarely reported. They appear either as an early-onset respiratory distress with a high mortality rate or as a delayed infection. The authors describe 3 term neonates with an early respiratory distress syndrome and recall the main points of this severe foeto-maternal infection. Neonatal pneumococcal sepsis is strikingly similar to early-onset group B streptococcal infection. The isolation of the germ in the mother's vaginal flora is hazardous. Such cases suggest that early respiratory support and intensive circulatory resuscitation lead only to a slight decrease in the mortality rate, and thus preventive antibiotherapy is a necessity.     

A protocol for determining differences in consistency and depth of palliative care service provision across community sites

Numerous accounts document the difficulty in obtaining accurate data regarding the extent and composition of palliative care services. Compounding the problem is the lack of standardisation regarding categorisation and reporting across jurisdictions. In this study, we gathered both quantitative and spatial – or geographical – data to develop a composite picture that captures the extent, composition and depth of palliative care in the Canadian province of British Columbia (BC). The province is intensely urban in the southwest and is rural or remote in most of the remainder. For this study, we conducted a detailed telephone survey of all palliative care home care teams and facilities hosting designated beds in BC. We used geographic information systems to geocode locations of all hospice and hospital facilities. In‐home care data was obtained individually from each of five BC regional health authorities. In addition, we purchased accurate road travel time data to determine service areas around palliative facilities and to determine populations outside of a 1‐hour travel time to a facility. With this data, we were able to calculate three critical metrics: (i) the population served within 1 hour of palliative care facilities – and more critically those not served; (ii) a matrix that determines access to in‐home palliative care measured by both diversity of professionals as well as population served per palliative team member; and (iii) a ranking of palliative care services across the province based on physical accessibility as well as the extent of in‐home care. In combination, these metrics provide the basis for identifying areas of vulnerability with respect to not meeting potential palliative care need. In addition, the ranking provides a basis for rural/urban comparisons. Finally, the protocol introduced can be used in other areas and provides a means of comparing palliative care service provision amongst multiple jurisdictions.     

Endermologie: Humoral repercussions and estrogen interaction

Endermologie is a motorized rhythmic folding–unfolding and suction technique of the panniculus adiposus. Our study shows that one 40-min Endermologie session produces no noticeable changes in biological parameters, except for plasma estradiol levels, which vary significantly, first by decreasing during the session, then by increasing afterward. Such an Endermologie/estrogen interaction can be compared to the clinical effects observed in some patients undergoing regular Endermologie treatment: return of menses in amenorrheal patients and a trophic effect on skin and subcutaneous connective tissue comparable to that observed during postmenopausal hormone replacement therapy. Understanding such an interaction with the estrogen metabolism requires additional studies and opens many paths for research on therapeutic applications before and after menopause beyond refinement of the body contour and improvement of the appearance of the panniculus adiposus.     

Early maturation of evoked otoacoustic emissions and medial olivocochlear reflex in preterm neonates

The present study was designed to investigate the early maturation of the brainstem regulation of the cochlear function in preterm neonates. Evoked otoacoustic emissions (EOAE) and their regulation via the medial olivocochlear efferent (MOC) reflex were investigated in a large population of preterm neonates and compared with full-term neonates and young babies from birth to 4 y and school-aged children. In 28-wk preterm neonates, EOAE were seen in the mid-frequency range. These responses extended both to the low (down to 1025 Hz) and high (up to 6152 Hz) frequency ranges at 38 wk of gestational age and remained stable up to 4 mo. At this stage, the amplitude of EOAE overlapped adult values. EOAE amplitudes then decreased to reach adult values at 3 y of age. Maturation of MOC efferents innervating the outer hair cells was investigated by studying the suppressive effect of contralateral sound on the EOAE amplitudes (MOC reflex). The first MOC responses were recorded in preterm neonates of 32-33 wk of gestational age, reaching adult-like values at 37 wk of gestational age. The maximum effect of MOC efferent activation occurred between 2000 and 4000 Hz. These results suggest that, in humans, MOC efferents mature in utero. Thus, testing the MOC reflex may have a clinical relevance to detect an abnormal development of the auditory pathways, particularly of a brainstem circuitry not explored through conventional testing.     

Reactions of nitric oxide, peroxynitrite, and carbonate radicals with nitroxides and their corresponding oxoammonium cations

Cyclic nitroxides effectively protect biological systems against radical-induced damage. However, the mechanism of the reactions of nitroxides with nitrogen-derived reactive species and carbonate radicals is far from being elucidated. In the present study, the reactions of several representative piperidine- and pyrrolidine-based nitroxides with *NO, peroxynitrite, and CO3*- were investigated, and the results are as follows: (i) There is no evidence for any direct reaction between the nitroxides and the *NO. In the presence of oxygen, the nitroxides are readily oxidized by *NO2, which is formed as an intermediate during autoxidation of *NO. (ii) *NO reacts with the oxoammonium cations to form nitrite and the corresponding nitroxides with k1 = (9.8 +/- 0.2) x 10(3) and (3.7 +/- 0.1) x 10(5) M(-1) s(-1) for the oxoammonium cations derived from 2,2,6,6-tetramethylpiperidine-1-oxyl (TPO) and 3-carbamoyl-proxyl (3-CP), respectively. (iii) CO3*- oxidizes all nitroxides tested to their oxoammonium cations with similar rate constants of (4.0 +/- 0.5) x 10(8) M(-1) s(-1), which are about 3-4 times higher than those determined for H-abstraction from the corresponding hydroxylamines TPO-H and 4-OH-TPO-H. (iv) Peroxynitrite ion does not react directly with the nitroxides but rather with their oxoammonium cations with k(10) = (6.0 +/- 0.9) x 10(6) and (2.7 +/- 0.9) x 10(6) M(-1) s(-1) for TPO+ and 3-CP+, respectively. These results provide a better insight into the complex mechanism of the reaction of peroxynitrite with nitroxides, which has been a controversial subject. The small effect of relatively low concentrations of nitroxides on the decomposition rate of peroxynitrite is attributed to their ability to scavenge efficiently *NO2 radicals, which are formed during the decomposition of peroxynitrite in the absence and in the presence of CO2. The oxoammonium cations, thus formed, are readily reduced back to the nitroxides by ONOO-, while forming *NO and O2. Hence, nitroxides act as true catalysts in diverting peroxynitrite decomposition from forming nitrating species to producing nitrosating ones.