Accuracy of single-pass whole-body computed tomography for detection of injuries in patients with major blunt trauma

Background:

Contrast-enhanced whole-body computed tomography (also called “pan-scanning”) is considered to be a conclusive diagnostic tool for major trauma. We sought to determine the accuracy of this method, focusing on the reliability of negative results.

Methods:

Between July 2006 and December 2008, a total of 982 patients with suspected severe injuries underwent single-pass pan-scanning at a metropolitan trauma centre. The findings of the scan were independently evaluated by two reviewers who analyzed the injuries to five body regions and compared the results to a synopsis of hospital charts, subsequent imaging and interventional procedures. We calculated the sensitivity and specificity of the pan-scan for each body region, and we assessed the residual risk of missed injuries that required surgery or critical care.

Results:

A total of 1756 injuries were detected in the 982 patients scanned. Of these, 360 patients had an Injury Severity Score greater than 15. The median length of follow-up was 39 (interquartile range 7–490) days, and 474 patients underwent a definitive reference test. The sensitivity of the initial pan-scan was 84.6% for head and neck injuries, 79.6% for facial injuries, 86.7% for thoracic injuries, 85.7% for abdominal injuries and 86.2% for pelvic injuries. Specificity was 98.9% for head and neck injuries, 99.1% for facial injuries, 98.9% for thoracic injuries, 97.5% for abdominal injuries and 99.8% for pelvic injuries. In total, 62 patients had 70 missed injuries, indicating a residual risk of 6.3% (95% confidence interval 4.9%–8.0%).

Interpretation:

We found that the positive results of trauma pan-scans are conclusive but negative results require subsequent confirmation. The pan-scan algorithms reduce, but do not eliminate, the risk of missed injuries, and they should not replace close monitoring and clinical follow-up of patients with major trauma.Severe trauma is one of the 10 leading causes of burden of disease in North America and Europe.¹ According to a report from the Canadian National Trauma Registry, 14 065 major injuries with an Injury Severity Score above 12 occurred between 2008 and 2009 in the eight provinces that contribute to the National Trauma Registry.² Of these, there were 1605 (11%) deaths, and 212 098 hospital-days resulted.Priority-oriented management requires accurate imaging during resuscitation to avoid missed injuries.^3,4 Standardized algorithms, such as Advanced Trauma Life Support (ATLS), typically comprise physical examination, focused thoracoabdominal ultrasonography and plain radiography of the chest, spine and pelvis, followed by computed tomography (CT) of the head and other selected body areas. The effectiveness of this staged diagnostic approach, however, has been called into question in recent years.^5–9Contrast-enhanced whole-body CT scanning, often referred to as “pan-scanning,” was first proposed in the late 1990s as an alternative to sequential radiologic imaging in trauma settings.¹⁰ Pan-scan algorithms have been shown to accelerate diagnostic work-up, but their effect on survival is controversial.^11–14 Opponents have voiced concerns about the overexposure of patients to radiation with the increasing and often uncritical use of CT scanning.¹⁵We designed the PATRES (Pan-Scan for Trauma Resuscitation) study to assess the accuracy of the pan-scan in detecting injuries to different body regions in patients with suspected major blunt trauma.     

Trauma services requirements in a district general hospital serving a rural area.

OBJECTIVE--To assess the demands made on a regional trauma centre by a district trauma unit. DESIGN--Two part study. (1) Prospective analysis of one month''s workload. (2) Retrospective analysis of one year''s workload by using a computer based records system. Comparison of two sets of results. SETTING--Accident unit in Gwynedd Hospital, Bangor. PATIENTS--(1) All patients who attended the accident unit in August 1988. (2) All patients who attended the accident unit in the calendar year April 1988-April 1989. MAIN OUTCOME MEASURE--Workload of a district trauma unit. RESULTS--In August 1988 there were 2325 attendances; 2302 of these were analysed. In all, 1904 attendances were for trauma; 213 patients were admitted to the trauma ward and 103 required an operation that entailed incision. Patients who attended the unit had a mean (range) injury severity score of 2-13 (0-25). Only two patients had injuries that a district general hospital would not be expected to cope with (injury severity score greater than 20). In the year April 1988-April 1989, 21,007 patients attended the unit. In all, 17,958 attendances were for orthopaedic injuries or injuries caused by an accident; 1966 patients were admitted to the unit. CONCLUSIONS--Most trauma is musculoskeletal and relatively minor according to the injury severity score. All but a few injuries can be managed in district general hospitals. In their recent report the Royal College of Surgeons has overestimated the requirements that a British district general hospital would have of a regional trauma centre.     

Coronary artery surgery: are women discriminated against?

OBJECTIVE--To determine whether the sex differences in access to cardiac surgery observed in the United States exist in the United Kingdom. DESIGN--Retrospective analysis of routinely collected data. SETTING--South West Thames and North West Thames regional health authorities. SUBJECTS--8564 patients discharged from hospital with a principal diagnosis of coronary heart disease in 1987-8 in South West Thames region and 15243 discharges in North West Thames region in 1990-1. MAIN OUTCOME MEASURES--Performance of angiography or coronary artery bypass surgery. RESULTS--In all age groups and among patients with a principal diagnosis of either angina or chronic ischaemia men were significantly more likely than women to undergo revascularisation in both regions. Using multiple logistic regression to control for potential clinical and demographic confounders, the male to female odds ratio for revascularisation among all cases was 1.59 (95% confidence interval 1.25 to 2.03) in South West Thames region and 1.47 (1.32 to 1.63) in North West Thames region. CONCLUSION--There appears to be a systematic difference in the treatment received by men and women in the United Kingdom. The reasons for this are uncertain.     

Preliminary analysis of the care of injured patients in 33 British hospitals: first report of the United Kingdom major trauma outcome study.

OBJECTIVE--To measure the effectiveness of management of major trauma in the United Kingdom. DESIGN--Review of the care of all seriously injured patients seen over two years. SETTING--33 hospitals which receive patients who have sustained major trauma. SUBJECTS--14,648 injured patients admitted for more than three days, transferred or admitted into an intensive care bed, or dying from their injuries. MAIN OUTCOME MEASURE--Death or survival in hospital within three months of the injury. RESULTS--21% of seriously injured patients (1299) took longer than one hour to reach hospital. Time before arrival at hospital was not related to severity of injury. A senior house officer was in charge of initial hospital resuscitation in 57% (826/1445) of patients with an injury severity score > or = 16. More senior staff were commonly responsible for definitive operations, but only 46% (165/355) of patients judged to require early operation arrived in theatre within two hours. Mortality for 6111 patients sustaining blunt trauma and treated in the 14 busiest hospitals was significantly higher (actual 408, predicted 295.6, p < 0.001) than in a comparable North American dataset. Large differences in the 14 hospitals assessed could not be explained by variations in case load or facilities. In contrast, the outcome of the 4.1% (597) of patients with penetrating injuries was better than that of a comparable group in the United States. Analysis of the 415 penetrating injuries with complete data showed that 15 patients died (19.3 predicted; p = 0.04). CONCLUSIONS--The initial management of major trauma in the United Kingdom remains unsatisfactory. There are delays in providing experienced staff and timely operations. Mortality varies inexplicably between hospitals and, for blunt trauma, is generally higher than in the United States.     

An Observational Study of Patient Characteristics Associated with the Mode of Admission to Acute Stroke Services in North East,England

Objective

Effective provision of urgent stroke care relies upon admission to hospital by emergency ambulance and may involve pre-hospital redirection. The proportion and characteristics of patients who do not arrive by emergency ambulance and their impact on service efficiency is unclear. To assist in the planning of regional stroke services we examined the volume, characteristics and prognosis of patients according to the mode of presentation to local services.

Study design and setting

A prospective regional database of consecutive acute stroke admissions was conducted in North East, England between 01/09/10-30/09/11. Case ascertainment and transport mode were checked against hospital coding and ambulance dispatch databases.

Results

Twelve acute stroke units contributed data for a mean of 10.7 months. 2792/3131 (89%) patients received a diagnosis of stroke within 24 hours of admission: 2002 arrivals by emergency ambulance; 538 by private transport or non-emergency ambulance; 252 unknown mode. Emergency ambulance patients were older (76 vs 69 years), more likely to be from institutional care (10% vs 1%) and experiencing total anterior circulation symptoms (27% vs 6%). Thrombolysis treatment was commoner following emergency admission (11% vs 4%). However patients attending without emergency ambulance had lower inpatient mortality (2% vs 18%), a lower rate of institutionalisation (1% vs 6%) and less need for daily carers (7% vs 16%). 149/155 (96%) of highly dependent patients were admitted by emergency ambulance, but none received thrombolysis.

Conclusion

Presentations of new stroke without emergency ambulance involvement were not unusual but were associated with a better outcome due to younger age, milder neurological impairment and lower levels of pre-stroke dependency. Most patients with a high level of pre-stroke dependency arrived by emergency ambulance but did not receive thrombolysis. It is important to be aware of easily identifiable demographic groups that differ in their potential to gain from different service configurations.     

Influences of practice characteristics on prescribing in fundholding and non-fundholding general practices: an observational study.

OBJECTIVE: To investigate the variation in prescribing among general practices by examining the contribution to this variation of fundholding, training status, partnership status, and the level of deprivation in the practice population and to investigate the extent to which fundholding has been responsible for any changes in prescribing. DESIGN: Analysis of prescribing data (PACT) for the years 1990-1 (before fundholding) and 1993-4 (after fundholding), Use of multiple linear regressions to investigate the variation among practices in total prescribing costs (net ingredient cost per prescribing units), and mean cost per item in each of the two years and also the change in these variables between years. SETTING: Former Mersey region. SUBJECTS: 384 practices. RESULTS: The models developed explained the variation in cost per item (43% of variation explained for 1990-1, 38% for 1993-4) and prescribing volume (34% for 1990-1, 38% for 1993-4) better than the variation in total prescribing costs (3% for 1990-1, 7% for 1993-4). The models developed to explain the change in these variables between years did not explain more than 10% of the variation. Most of the explained variation in the change in total prescribing costs was accounted for by fundholding. Of the pounds 3.71 saved by first wave fundholders compared with non-fundholders pounds 3.57 was attributable to fundholding alone. CONCLUSION: In neither year did fundholding make a major contribution to the variation in prescribing behaviour among practices, which was better explained by deprivation, training status, and partnership status, but it did seem largely responsible for differences in the rise of total prescribing costs between fundholders and non fundholders.     

Epidemiology of severe trauma among status Aboriginal Canadians: a population-based study

Background

Aboriginal Canadians are considered to be at increased risk of major trauma. However, population-based studies characterizing the distribution, determinants and outcomes of major trauma in this group are lacking. We sought to measure the impact of ethnicity, as reflected by Aboriginal status, on the incidence of severe trauma and to broadly define the epidemiologic characteristics of severe trauma among status Aboriginal Canadians in a large health region.

Methods

This population-based, observational study involves all adults (people ≥ 16 years) resident in the Calgary Health Region between Apr. 1, 1999, and Mar. 31, 2002. Stratification of the population into status Aboriginal Canadians and the reference population was performed by Alberta Health and Wellness using an alternate premium arrangement field within the personal health care number. Injury incidence was determined by identifying all injuries with severity scores of 12 or greater in the Alberta Trauma Registry, regional corporate data and the Office of the Medical Examiner.

Results

Aboriginal Canadians were at much higher risk than the reference population in the Calgary Health Region of sustaining severe trauma (257.2 v. 68.8 per 100 000; relative risk [RR] 3.7, 95% confidence interval [CI] 3.0–4.6). Aboriginal Canadians were found to be at significantly increased risk of injuries resulting from motor vehicle crashes (RR 4.8, 95% CI 3.5–6.5), assault (RR 11.1, 95% CI 6.2–18.6) and traumatic suicide (RR 3.1, 95% CI 1.4–6.1). A trend toward higher median injury severity scores was observed among Aboriginal Canadians (21 v. 18, p = 0.09). Although the case-fatality rate among Aboriginal Canadians was less than half that in the reference population (14/93 [15%] v. 531/1686 [31%], p < 0.0001), population mortality was almost 2 times greater (RR = 1.8, 95% CI 1.0–3.0, p = 0.046).

Interpretation

Severe trauma disproportionately affects Aboriginal Canadians.In Canada, injury is the leading cause of death among people under the age of 45 and the leading cause of potential years of life lost.¹ Although difficult to quantify, the cost of injury was estimated to be at least $12.7 billion in 1998.² Trauma has been known, even in industrialized countries, to disproportionately affect the most marginalized members of society.³ Aboriginal Canadians are considered to be particularly at risk, and data showing alarming patterns of trauma mortality in this group are beginning to emerge. Unfortunately, the number of studies looking at injury risk among Aboriginal Canadians is small,⁴ and little attention has been paid to quantifying the risk of nonfatal injury. Better understanding of the nature of trauma risk and outcome among Aboriginal Canadians could lead to more effective prevention and treatment strategies.In this study, we used a population-based design in an attempt to quantify the impact of injury, both fatal and nonfatal, on the Aboriginal community in a large, heterogeneous Canadian region with over 1 million urban and rural inhabitants. We sought to measure the impact of ethnicity (defined by registered status within the definition of the Indian Act⁵) on the incidence of severe trauma and to broadly define the epidemiologic characteristics of severe trauma among status Aboriginal Canadians.     

The influence of residential distance on time to treatment in ST-elevation myocardial infarction patients

AimsTo evaluate the relation between residential distance and total ischaemic time in patients with acute ST-elevation myocardial infarction (STEMI).MethodsSTEMI patients were transported to the Isala Hospital Zwolle with the intention to perform primary percutaneous coronary intervention PCI (pPCI) from 2004 until 2010 (n = 4149). Of these, 1424 patients (34 %) were referred via a non-PCI ‘spoke'' centre (‘spoke’ patients) and 2725 patients (66 %) were referred via field triage in the ambulance (ambulance patients).ResultsA longer residential distance increased median total ischaemic time in ‘spoke’ patients (0–30 km: 228 min, >30-60 km: 235 min, >60-90 km: 264 min, p < 0.001), however not in ambulance patients (0–30 km: 179 min, >30-60 km: 175 min, >60-90 km: 186 min, p = 0.225). After multivariable linear regression analysis, in ‘spoke’ patients residential distance of >30-60 km compared with 0–30 km was not independently associated with ischaemic time; however, a residential distance of >60-90 km (exp (B) = 1.11, 95 % CI 1.01-1.12) compared with 0–30 km was independently related with ischaemic time. In ambulance patients, residential distance of >30-60 and >60-90 km compared with 0–30 km was not independently associated with ischaemic time.ConclusionA longer distance from the patient’s residence to a PCI centre was associated with a small but significant increase in time to treatment in ‘spoke’ patients, however not in ambulance patients. Therefore, referral via field triage in the ambulance did not lead to a significant increase in time to treatment, especially at long distances (up to 90 km).     

Elevation of neutrophil-derived factors in patients after multiple trauma

Trauma represents one of the leading causes of death worldwide. Traumatic injuries elicit a dynamic inflammatory response with systemic release of inflammatory cytokines. Disbalance of this response can lead to systemic inflammatory response syndrome or compensatory anti-inflammatory response syndrome. As neutrophils play a major role in innate immune defence and are crucial in the injury-induced immunological response, we aimed to investigate systemic neutrophil-derived immunomodulators in trauma patients. Therefore, serum levels of neutrophil elastase (NE), myeloperoxidase (MPO) and citrullinated histone H3 (CitH3) were quantified in patients with injury severity scores above 15. Additionally, leukocyte, platelet, fibrinogen and CRP levels were assessed. Lastly, we analysed the association of neutrophil-derived factors with clinical severity scoring systems. Although the release of MPO, NE and CitH3 was not predictive of mortality, we found a remarkable increase in MPO and NE in trauma patients as compared with healthy controls. We also found significantly increased levels of MPO and NE on Days 1 and 5 after initial trauma in critically injured patients. Taken together, our data suggest a role for neutrophil activation in trauma. Targeting exacerbated neutrophil activation might represent a new therapeutic option for critically injured patients.     

Improving the care of patients with major trauma in the accident and emergency department.

OBJECTIVE--To determine whether improvement in the care of victims of major trauma could be made by using the revised trauma score as a triage tool to help junior accident and emergency doctors rapidly identify seriously injured patients and thereby call a senior accident and emergency specialist to supervise their resuscitation. DESIGN--Comparison of results of audit of management of all seriously injured patients before and after these measures were introduced. SETTING--Accident and emergency department in an urban hospital. PATIENTS--All seriously injured patients (injury severity score greater than 15) admitted to the department six months before and one year after introduction of the measures. RESULTS--Management errors were reduced from 58% (21/36) to 30% (16/54) (p less than 0.01). Correct treatment rather than improvement in diagnosis or investigation accounted for almost all the improvement. CONCLUSIONS--The management of seriously injured patients in the accident and emergency department can be improved by introducing two simple measures: using the revised trauma score as a triage tool to help junior doctors in the accident and emergency department rapidly identify seriously injured patients, and calling a senior accident and emergency specialist to supervise the resuscitation of all seriously injured patients. IMPLICATIONS--Care of patients in accident and emergency departments can be improved considerably at no additional expense by introducing two simple measures.     

The interleukin-6 G(-174)C polymorphism and the ex vivo interleukin-6 response to endotoxin in severely injured blunt trauma patients

The aim of this study was to evaluate whether the -174 G/C promoter polymorphism of the interleukin-6 (IL-6) gene is associated with the ex vivo, whole blood IL-6 response to endotoxin with the development of severe sepsis in severely injured, blunt trauma patients. Patients with a severe trauma and an injury severity score of 16 were included in the study. The IL-6 -174 G/C promoter polymorphism was determined by real-time polymerase chain reaction (PCR) assay using specific fluorescence-labelled hybridisation probes. Whole blood of the patients was stimulated with endotoxin and the IL-6 concentrations were measured by ELISA. There was no association between the IL-6 -174 genotypes and the ex vivo, stimulated IL-6 response: 25% of the patients developed severe sepsis later in the clinical course. These patients had higher IL-6 concentrations following whole blood stimulation on day 1 (p = 0.046) after the trauma than patients with uncomplicated post-traumatic recovery. The difference was even more significant on day 2 after the trauma (p = 0.02). High IL-6 responses in a whole blood stimulation assay with endotoxin on days 1 and 2 after a trauma are associated with severe post-traumatic sepsis. Genotyping for the IL-6 -174 G/C polymorphism does not allow early identification of trauma patients with a high, ex vivo IL-6 synthesis capacity.     

CT-measured regional specific volume change reflects regional ventilation in supine sheep.

Computer tomography (CT) imaging techniques permit the noninvasive measurement of regional lung function. Regional specific volume change (sVol), determined from the change in lung density over a tidal breath, should correlate with regional ventilation and regional lung expansion measured with other techniques. sVol was validated against xenon (Xe)-CT-specific ventilation (sV) in four anesthetized, intubated, mechanically ventilated sheep. Xe-CT used expiratory gated axial scanning during the washin and washout of 55% Xe. sVol was measured from the tidal changes in tissue density (H, houndsfield units) of lung regions using the relationship sVol = [1,000(Hi - He)]/[He(1,000 + Hi)], where He and Hi are expiratory and inspiratory regional density. Distinct anatomical markings were used to define corresponding lung regions of interest between inspiratory, expiratory, and Xe-CT images, with an average region of interest size of 1.6 +/- 0.7 ml. In addition, sVol was compared with regional volume changes measured directly from the positions of implanted metal markers in an additional animal. A linear relationship between sVol and sV was demonstrated over a wide range of regional sV found in the normal supine lung, with an overall correlation coefficient (R(2)) of 0.66. There was a tight correlation (R(2) = 0.97) between marker-measured volume changes and sVol. Regional sVol, which involves significantly reduced exposure to radiation and Xe gas compared with the Xe-CT method, represents a safe and efficient surrogate for measuring regional ventilation in experimental studies and patients.     

Use of automated external defibrillator by first responders in out of hospital cardiac arrest: prospective controlled trial

Objective To test the hypothesis that the use of an automated external defibrillator by police and fire fighters results in higher discharge rates for out of hospital cardiac arrest.Design Controlled clinical trial with initial random allocation of automated external defibrillators to first responders in four of the eight participating regions; each region switched from control to experimental, and vice versa, every four months.Setting Amsterdam and surroundings, the Netherlands.Participants Patients with witnessed out of hospital cardiac arrests, identified by the emergency medical system between January 2000 and January 2002.Main outcomes measures Survival to hospital discharge; return of spontaneous circulation; admission to hospital.Results 243 patients (65% in ventricular fibrillation) were included in the experimental area and 226 patients (67% in ventricular fibrillation) in the control area. The median time interval between collapse and first shock was 668 seconds in the experimental area and 769 seconds in the control area (P < 0.001). 44 (18%) patients in the experimental area versus 33 (15%) patients in the control area were discharged (odds ratio 1.3 (95% confidence interval 0.8 to 2.2), P = 0.33), 139 (57%) experimental versus 108 (48%) control patients had return of spontaneous circulation (1.5 (1.0 to 2.2), P = 0.05), and 103 (42%) experimental versus 74 (33%) control patients were admitted (1.5 (1.1 to 1.6), P = 0.02). The median delay from receipt of call to dispatch of the ambulance was 120 seconds, and the delay to dispatch of the first responder was 180 seconds.Conclusions Use of automated external defibrillators by first responders did not significantly increase survival to discharge from hospital, although it did improve return of spontaneous circulation and admission to hospital. Improved dispatch procedures should increase the success of programmes of first responders using external defibrillators.     

Effects of trace element supplementation on the inflammatory response in a rabbit model of major trauma

Patients with a severe trauma exhibit a strong oxidative stress, an intense inflammatory response, and long-lasting hypermetabolism, all of which are proportional to the severity of injury. In this study, we investigated the impact of trace element (TE) supplementation on the inflammatory response in an animal model of major trauma. New Zealand White rabbits were randomly assigned as a control group (n=5) and an experimental group (n=70) that, after receiving a major trauma, was subdivided into Trauma-Control (n=35) and Trauma-TE (n=35) groups. Systemic inflammatory response syndrome (SIRS) was observed in 40 out of 70 rabbits with a trauma, with a higher incidence in the Trauma-Control group (88.6%; 31/35) than the Trauma-TE group (28.6%; 10/35) (p<0.01). The mortality rate was significantly different between the Trauma-Control and the Trauma-TE groups; (34% vs. 8%; p<0.01).There were significant post-trauma alterations in the levels of (1) serum and spleen zinc (Zn), copper (Cu), selenium (Se), and manganese (Mn), (2) serum AST and ALT, (3) serum interleukin-6/10, and (4) nuclear factor kappa binding (NF-κB) activity and the expression. TE supplementation: (1) improved blood urea nitrogen (BUN), and creatinine (Cr) levels, (2) stabilized IL-6/10 production, (3) decreased NF-κB p⁶⁵ production. Appropriate TE supplementation can improve the TE status, mitigate SIRS, and reduce the mortality due to multiple organ dysfunction syndromes (MODS)/multiple organ failure (MOF) after major trauma.     

Bacterial meningitis after craniocerebral trauma in the community

Craniocerebral trauma is one of major risk factors for development of meningitis. We reviewed 30 cases of bacterial meningitis occurring in community after craniocerebral trauma. Alcohol abuse was significant risk factor occurring in trauma patients with meningitis present in 50% in our cohort (p=0.0001). The most common pathogen in posttraumatic meningitis was Str. pneumoniae (90% vs. 33.8%, p=0.0001). However mortality was very low, only 5% probably because of early diagnosis and treatment of patients at risk for bacterial meningitis but neurologic sequellea were significantly more common (p=0.00001) in patients after craniocerebral trauma.     

The effects of major and minor trauma on lymphocyte kinetics in mice.

The effects of major and minor trauma on the circulating white blood cell populations of C57BL mice were followed. The results showed that not only major trauma (nephrectomy) but minor injury and stress (e.g. injection, bleeding) triggered a highly significant fall (50-70%) in the number of lymphocytes circulating in the blood. The fall was a gradual one, with the maximal drop 2 h after the operation or handling procedure. Major trauma resulted in a fall in both B and T lymphocytes. Minor trauma produced a fall in B lymphocytes only. A 3-4 fold increase in circulating polymorph numbers also accompanied major trauma, but no increase was observed after minor trauma. The blood picture returned to normal generally within 24 h of both minor and major trauma. Repetition of the trauma stimulus after recovery led to a renewed trauma response. Bilateral adrenalectomy abolished the lymphocyte response to major and minor trauma and decreased the polymorph response to major trauma by more than 50%, indicating that stress hormones played a role in these changes. Studies with 51chromium-labelled lymphocytes, transferred into traumatized and adrenalectomized animals, suggested that decreased entry of lymphocytes into the blood (rather than increased exit from the blood into the tissues, or cell death) was the most likely mechanism of the lymphopenia following trauma.     

Atmospheric teleconnection patterns associated with wheat stripe rust disease in North China

 Previous work has shown that long-term (>40 years) time series of wheat stripe rust disease from North China contain a signal related to the Southern Oscillation Index (SOI). However, no cause-and-effect relationships or direct links between SOI and disease have been established. Because mid-latitude teleconnection patterns form important links between global atmospheric variations and regional weather anomalies, such as the Southern Oscillation, studies of such patterns could result in a better physical and biological interpretation for the SOI-disease association observed previously. We used cross-spectral analyses to determine if and on which time scales severity of stripe rust in five regions of North China between 1952 and 1990 was associated with fluctuations in four Northern Hemisphere teleconnection patterns. These included the Pacific/North American, the Western Atlantic, the Western Pacific, and the Eurasian patterns. The analysis showed consistent and significant (P≤0.10) coherence relationships between the Western Atlantic (WA) pattern and stripe rust severity at a periodicity of 3.00 years. The phase relationships showed that, at the 3.00-year periodicity, the WA series and the disease series were out of phase by about half a period in all five regions. This phase difference indicated that peaks in the WA series, which are associated with below-normal winter temperatures over much of China, coincided with troughs in the disease series (i.e. low disease severity), presumably because of the negative effect of low winter temperatures on survival of the stripe rust pathogen. The analysis further showed that the WA series and the SOI series were highly significantly (P≤0.01) coherent at a periodicity of 4.33 years, which could explain the association between SOI and stripe rust severity reported previously. Received: 12 February 1997 / Accepted: 18 May 1998     

Nitrogen Cycles: Past, Present, and Future

This paper contrasts the natural and anthropogenic controls on the conversion of unreactive N₂ to more reactive forms of nitrogen (Nr). A variety of data sets are used to construct global N budgets for 1860 and the early 1990s and to make projections for the global N budget in 2050. Regional N budgets for Asia, North America, and other major regions for the early 1990s, as well as the marine N budget, are presented to Highlight the dominant fluxes of nitrogen in each region. Important findings are that human activities increasingly dominate the N budget at the global and at most regional scales, the terrestrial and open ocean N budgets are essentially disconnected, and the fixed forms of N are accumulating in most environmental reservoirs. The largest uncertainties in our understanding of the N budget at most scales are the rates of natural biological nitrogen fixation, the amount of Nr storage in most environmental reservoirs, and the production rates of N₂ by denitrification.     

Etiology of shock in blunt trauma.

Patients who have suffered blunt trauma and present in shock of uncertain cause represent a problem frequently encountered by emergency physicians. A retrospective review of the charts of 879 patients who had suffered blunt trauma and presented to a regional trauma unit over a 44-month period revealed that 154 of the patients had presented to either a hospital or the trauma unit in shock. The most common causes of shock when a single source of hemorrhage was identified were, in order of decreasing frequency, intraperitoneal hemorrhage, pelvic or other musculoskeletal fractures, thoracic hemorrhage, severe head injury and spinal cord injury. Severe head injuries accounted for only 8% of the single-source cases and contributed to shock in only seven of the remaining cases.     

Current concepts in trauma: 2. The Sunnybrook Medical Centre trauma program: the first 11 years.

Sunnybrook Medical Centre is a tertiary care teaching hospital situated in metropolitan Toronto. Its trauma unit, opened in June 1976, serves the inhabitants of metropolitan Toronto and the surrounding area (approximately 5 million). More than 3200 patients were admitted to the unit between 1976 and 1987. The criteria for admission were age at least 14 years and an Injury Severity Score (ISS) of 16 or greater, two or more significant injuries at anatomically discrete sites when the score on the Abbreviated Injury Scale was 3 or greater, or grade IV shock (systolic blood pressure of 80 mm Hg or less). The number of patients admitted annually to the unit increased over the study period. The survival rate also increased, from 76% in 1976 to 88% in 1987, although the average age and ISS of the patients remained unchanged. Less than 2% of the patients required long-term rehabilitative or chronic care. The patient profile is similar to that seen in other trauma centres in North America. The success of this program is largely the result of expeditious stabilization and transfer from referring hospitals coupled with early definitive surgical intervention.