L. Oppenheimer

Epidemiology of trauma deaths

The records of all 437 persons who died from trauma in San Francisco in 1977 were examined. Sixty-five percent of the sample (285 younger than 50 years, and 119 were between ages 21 and 30. Gunshot wounds (140 or 32 percent) and falls (122 or 28 percent) were the most common causes of injury. Fifty-three percent of the sample were dead at the scene of injury before transport could be accomplished, 7.5 percent died in the emergency room, and 39.5 percent died in the hospital. Fifty-five percent of the 359 patients who died within the first 2 days died from brain injury, while 78 percent of the 55 late deaths were due to sepsis and multiple organ failure. In 10 cases (2 percent), death was due to delayed transport or to errors in diagnosis and treatment and was deemed preventable. The key areas in which advances are necessary in order to reduce the number of trauma deaths are prevention of trauma, more rapid and skilled transport of injured victims, better early management of primary brain injuries, and more effective treatment of the late complications of sepsis and multiple organ failure.

Vascular properties of canine lungs perfused with Eurocollins solution and prostacyclin.

Although Eurocollins solution (ECS) is commonly used for lung preservation, its vascular effects and their time course and response to pharmacological interventions are not well understood. The effect of 4 degrees C ECS on the pulmonary circulation was assessed in excised canine left lower lobes. The roles of static oxygen inflation and prostacyclin infusion during ECS perfusion were also examined. The lobes were divided into five groups: time control (A), ECS with oxygen (B), ECS without oxygen (C), ECS with glycine buffer (D), and ECS with prostacyclin (E); group D was the control for E. Eurocollins solution had no effect on gas exchange but had a marked effect on the pulmonary circulation. Vascular conductance decreased from 22.6 to 18.9 mL/min/cm H2O and from 21.3 to 14.1 mL/min/cm H2O with average vascular closure increasing by 1.2 and 2.1 cm H2O in groups B and C, respectively. The decreased vascular conductance and increased vascular closure was associated with a reduction in vascular compliance from 1.63 to 1.25 mL/cm H2O. When prostacyclin was added to ECS, the reduction in vascular closure was much less and was associated with a decrease in vascular closure and no loss of vascular compliance. Eurocollins solution increases pressure cost for perfusion by causing both vascular obstruction and increased tone, especially when oxygen is not provided. This is significantly overcome by addition of prostacyclin infusion during ECS perfusion.

Development and validation of a predictive model for all-cause hospital readmissions in Winnipeg, Canada

Objective A number of predictive models have been developed to identify patients at risk of hospital readmission. Most of these have focused on readmission within 30 days of discharge. We used population-based health administrative data to develop a predictive model for hospital readmission within 12 months of discharge in Winnipeg, Canada. Methods This was a retrospective cohort study with derivation and validation data sets. Multivariable logistic regression analyses were performed and factors significantly associated with readmission were selected to construct a risk scoring tool. Results Several variables were identified that predicted readmission (i.e. older age, male, at least one hospital admission in the previous two years, an emergent (index) hospital admission, Charlson comorbidity score >0 and length of stay). Discrimination power was acceptable (C statistic =0.701). At a median risk score threshold, the sensitivity, specificity, positive and negative predictive values were 45.5%, 79%, 68.8% and 58.6%. Conclusions This predictive model demonstrated that hospital readmission within 12 months of discharge can be reasonably well predicted based on administrative data. It will help health care providers target interventions to prevent unnecessary hospital readmissions.

Geographical variation analysis of all-cause hospital readmission cases in Winnipeg, Canada

BackgroundHospital readmission is costly and potentially avoidable. The concept of virtual wards as a new model of care is intended to reduce hospital readmissions by providing short-term transitional care to high-risk and complex patients in the community. In order to provide information regarding the development of virtual wards in the Winnipeg Health Region, Canada, this study used spatial statistics to identify geographic variations of hospital readmissions in 25 neighborhood clusters.MethodsThe data were obtained from the Population Health Research Data Repository housed at the Manitoba Centre for Health Policy. We used a Bayesian Disease Mapping approach which applied Markov chain Monte Carlo (MCMC) for cluster detection.ResultsBetween 2005/06 and 2008/09, 123,842 patients were hospitalized in all Winnipeg hospitals. Of these, 41,551 (33%) were readmitted to hospital in the year following discharge. Most of these readmitted patients (89.4%) had 1–2 readmissions, while 11.6% of readmitted patients had more than 2 readmissions after initial discharge. The smoothed age- and sex- adjusted relative risk rates of hospital readmission in 25 Winnipeg neighborhood clusters ranged between 0.73 and 1.27. We found that there were spatial cluster variations of hospital readmission across the Winnipeg Health Region. Seven neighborhood clusters are more likely to be significant potential clusters for hospital readmissions (p < .05), while six neighborhood clusters are less likely to be significant potential clusters.ConclusionsThis study provides the foundation and implementation guide for the Winnipeg Regional Health Authority virtual ward program. The findings will also help to improve long-term condition management in community settings and will help program planners to assure the efficient use of healthcare resources.

Measurement of extra- vascular lung water during abdominal aortic surgery

Cross-clamping of the abdominal aorta can be associated with significant changes in haemodynamic variables. However, intraoperative changes in extravascular lung water (EVLW) have not been studied. Nine patients undergoing elective surgery, either aortic aneurysm repair or aorto-bifemoral grafting, were monitored invasively with arterial lines, pulmonary artery catheters and Edwards lung water catheters inserted in either the brachial or axillary artery. Determinations of EVLW were made prior to and five minutes after application of the aortic cross-clamp and at 30-minute intervals during the course of the operation. Baseline EVLW was found to be 7− 9ml·kg− 1. There were no significant changes in haemodynamic variables and no changes in EVLW with cross-clamping of the aorta. The EVLW did not change during the course of surgery. The EVLW did not increase in the absence of sustained elevation of pulmonary capillary wedge pressure. One patient developed an axillary artery thrombosis which required thrombectomy at the site of lung water catheter insertion. Two other patients lost their distal pulses without overt ischaemic changes. It was felt that such relatively high incidence of complications precluded further use of the lung water catheter in the axillary or brachial artery.RésuméD’aucuns ont rapporté des perturbations hémodynamiques lors du clampage de l’aorte abdominale sans mesurer cependant la quantite de liquide interstitiel pulmonaire (EVLW). Neuf patients subissant une résection élective d’anévrysme aortique ou un pontage aorto-bifémoral ont été choisis pour cette étude. On lew installait d’abord un cathéter intra-artériel et un de type Swan-Ganz puis ensuite un cathéter d’Edwards pour mesure de l’EVLW par l’artére humerale ou axillaire. On mesurait alors l’EVLW juste avant et cinq minutes après le clampage aortique et aux 30 minutes par la suite, jusqu’à la fin de l’intervention. Les valeurs de départ de l’EVLW allait de 7 à 9 ml·kg.−1 Nous n’avons pas note de changement significatif des variables hemodynamiques non plus que de l’EVLW lors du clampage aortique et cette dernière variable est demeurée stable pendant l’intervention, tout comme la pression capillaire pulmonaire. On a par ailleurs noté une disparition des pouls en aval du site d’insertion du cathéter à EVLW sans manifestation ischémique cependant, mais un autre patient a du subir une thrombectomie axillaire. Ce taux de complication disqualifie done les artères humérales et axillaires comme voie d’entrée pour le cathéter à EVLW.