The role of environmental sensitivity in the mental health of Syrian refugee children: a multi-level analysis

Individuals with high environmental sensitivity have nervous systems that are disproportionately receptive to both the protective and imperilling aspects of the environment, suggesting their mental health is strongly context-dependent. However, there have been few consolidated attempts to examine putative markers of sensitivity, across different levels of analysis, within a single cohort of individuals with high-priority mental health needs. Here, we examine psychological (self-report), physiological (hair hormones) and genetic (polygenic scores) markers of sensitivity in a large cohort of 1591 Syrian refugee children across two waves of data. Child-caregiver dyads were recruited from informal tented settlements in Lebanon, and completed a battery of psychological instruments at baseline and follow-up (12 months apart). Univariate and multivariate Bayesian linear mixed models were used to examine a) the interrelationships between markers of sensitivity and b) the ability of sensitivity markers to predict anxiety, depression, post-traumatic stress disorder, and externalising behaviour. Self-reported sensitivity (using the Highly Sensitive Child Scale) significantly predicted a higher burden of all forms of mental illness across both waves, however, there were no significant cross-lagged pathways. Physiological and genetic markers were not stably predictive of self-reported sensitivity, and failed to similarly predict mental health outcomes. The measurement of environmental sensitivity may have significant implications for identifying and treating mental illness, especially amongst vulnerable populations, but clinical utility is currently limited to self-report assessment.

Hair hormone data from Syrian refugee children: Perspectives from a two-year longitudinal study

For numerous issues of convenience and acceptability, hair hormone data have been increasingly incorporated in the field of war trauma and forced displacement, allowing retrospective examination of several biological metrics thought to covary with refugees' mental health. As a relatively new research method, however, there remain several complexities and uncertainties surrounding the use of hair hormones, from initial hair sampling to final statistical analysis, many of which are underappreciated in the extant literature, and restrict the potential utility of hair hormones. To promote awareness, we provide a narrative overview of our experiences collecting and analyzing hair hormone data in a large cohort of Syrian refugee children (n = 1594), across two sampling waves spaced 12 months apart. We highlight both the challenges faced, and the promising results obtained thus far, and draw comparisons to other prominent studies in this field. Recommendations are provided to future researchers, with emphasis on longitudinal study designs, thorough collection and reporting of hair-related variables, and careful adherence to current laboratory guidelines and practices.

Risk and resilience in Syrian refugee children: A multisystem analysis

Refugee children are often exposed to substantial trauma, placing them at increased risk for mental illness. However, this risk can be mitigated by a capacity for resilience, conferred from multiple ecological systems (e.g., family, community), including at an individual biological level. We examined the ability of hair cortisol concentrations and polygenic scores for mental health to predict risk and resilience in a sample of Syrian refugee children (n = 1359). Children were categorized as either at-risk or resilient depending on clinical thresholds for posttraumatic stress disorder, depression, and externalizing behavior problems. Logistic regression was used to examine main and interacting effects while controlling for covariates. Elevated hair cortisol concentrations were significantly associated with reduced resilience (odds ratio (OR)=0.58, 95%CI [0.40, 0.83]) while controlling for levels of war exposure. Polygenic scores for depression, self-harm, and neuroticism were not found to have any significant main effects. However, a significant interaction emerged between hair cortisol and polygenic scores for depression (OR=0.04, 95%CI [0.003 0.47]), suggesting that children predisposed to depression were more at risk for mental health problems when hair cortisol concentrations were high. Our results suggest that biomarkers (separately and in combination) might support early identification of refugee children at risk for mental health problems.

Maternal Education Potentially Moderates the MAOA uVNTR Effects on Externalizing Behavior in Black South African Children

Interactions between the MAOA uVNTR and rearing environment are suggested to influence the developmental manifestations of childhood internalizing and externalizing behavior. However, few studies in the MAOA literature have included continental African children, or focused on non-clinical samples. We explored the main and interactive effects of the MAOA uVNTR (high and low activity alleles) in Black South African male (n = 478) and female (n = 540) children who were part of the longitudinal Birth to Twenty Plus cohort. Historical data on birth weight, gestational age at delivery, socioeconomic status, and maternal education were combined with genotypic information and analyzed using regression modeling. We found no significant main effects for the MAOA uVNTR on childhood behavior in either sex. A significant interaction (p = .04) was identified between MAOA and maternal education, suggesting that externalizing behavior in boys carrying a low activity MAOA allele varied in direct proportion to the education levels of their mothers. However, the model fit failed to reach significance, possibly due to our inclusion of only non-clinical pre-pubertal males. No significant interactions were detected for female children. Our findings lend tentative credibility to the Environmental Sensitivity metaframework, which suggests that MAOA is an important plasticity factor in childhood development.

Trauma-specific intensive care units can be cost effective and contribute to reduced hospital length of stay

Our hypothesis was that clinical outcomes are improved and cost and hospital length of stay (LOS) reduced as a result of the opening of a closed trauma intensive care unit (ICU). We conducted a cross-sectional study in a university-affiliated Level I trauma center. Our study population comprised trauma patients admitted to the ICU between June 1, 1996 and July 1, 1998 for at least 24 hours and with an Injury Severity Score (ISS) >16 (excluding those with severe brain injury). The main outcome measures were changes in LOS and number of ventilator days, prevalence of complications, changes in patient charges, and hospital costs. Two hundred four patients were included [trauma ICU (TICU) 60, surgical ICU 144]. The two groups were not statistically different in age, ISS, mechanism of injury, infection rate, and mortality; however, the TICU patients had a lower number of ventilator hours (83.1 vs 100.0; P = 0.007), lower ICU LOS (9.4 vs 12.1 days; P = 0.06), and lower total hospital LOS (15.6 vs 22.3 days; P = 0.01). Although this was not of statistical significance TICU patients had lower hospital charges ($125,383 vs $152,994; P = 0.06) and lower cost per case ($42,306 vs $47,548; P = 0.35) for a net savings of $314,520 during the first 6 months of operation of the TICU. This study suggests that improved clinical outcomes and decreases in cost and LOS are directly related to the opening of a closed trauma ICU.

Recurrent trauma in elderly patients

HYPOTHESIS

Older patients (those aged > or = 70 years) who have experienced trauma have an increased risk of recurrent trauma. Demographic, medical, and functional factors are potential contributors to the risk of subsequent trauma among injured elderly patients.

DESIGN

Retrospective follow-up study.

PARTICIPANTS

Study participants were derived from the Longitudinal Study of Aging, an extension of the 1984 National Health Interview Survey focusing on persons who were aged 70 years and older in 1984. A cohort of elderly patients participating in the Longitudinal Study of Aging and hospitalized for injury in 1985 (n = 100) was identified using Medicare hospital discharge data. An uninjured cohort (n = 401) was also identified from the Longitudinal Study of Aging and matched for age (1 year) and sex.

MAIN OUTCOME MEASURES

Risk of admission for trauma among the injured cohort compared with the uninjured cohort and associations between demographic, medical, and functional characteristics and trauma recurrence.

RESULTS

Following adjustment for potential confounding factors, the injured cohort was 3.25 times more likely (95% confidence interval, 1.99-5.31) to be hospitalized for injury during the follow-up period compared with the uninjured cohort. Among the injured cohort, those at greatest risk of subsequent trauma included women and those with chronic medical conditions or functional impairments, the latter being the only factor independently associated with recurrence.

CONCLUSIONS

Elderly patients who have experienced trauma are at increased risk of subsequent injury. Interventions to reduce the likelihood of trauma recurrence should focus on those with chronic illnesses and functional impairments.

Long-term survival in the elderly after trauma

BACKGROUND

In the elderly, trauma has been associated with increased, long-term, all-cause mortality. Functional limitations secondary to injury may be responsible for the reduced survival rate. The objective of this study was to test this hypothesis using data from the Longitudinal Study of Aging (LSOA).

METHODS

The LSOA is an extension of the 1984 National Health Interview Survey, which focused on 7,527 persons who were 70 years and older in 1984. Using data from the LSOA, a cohort of elderly patients hospitalized for injury in 1985 (N = 102) was identified from Medicare hospital discharge data. An uninjured cohort (N = 408) was also identified using the LSOA and matched by age (within 1 year) and sex. Deaths in both cohorts were identified using the National Death Index. Hazard ratios (HRs) for mortality within 6 years subsequent to injury, adjusted for demographic, health status, and functional characteristics, were calculated.

RESULTS

The injured cohort had a significantly reduced rate of survival compared with the uninjured cohort (HR = 1.5; 95% confidence interval [CI] 1.1-2.2), and this relationship persisted after adjusting for demographic and health characteristics (HR = 1.4; 95% CI 1.0-2.0). After additional adjustment for measures of functional decline, the association diminished (HR = 1.2; 95% CI 0.8-1.7). Functional decline remained a strong, independent factor for the risk of mortality.

CONCLUSION

Trauma in the elderly has both an acute and long-term influence on mortality; the latter seems to be mediated through a decline in function resulting from the injury. This study suggests that strategies to return the elderly patient to preinjury functional status are of paramount importance. Future research should explore the impact of these interventions on long-term survival.

Reduction of vancomycin-resistant enterococcal infections by limitation of broad-spectrum cephalosporin use in a trauma and burn intensive care unit

Both vancomycin and third-generation cephalosporin use are believed to contribute to a rise in vancomycin-resistant enterococci (VRE) infections. In 1998, the largest number of VRE infections in our hospital occurred in the trauma/burn intensive care unit (TBICU), accounting for nearly 20% of hospital infections. In an attempt to control the VRE infection rate, antibiotic protocols for prophylaxis, empiric, and definitive therapy were initiated during the final quarter of 1998 to minimize cephalosporin use by the introduction of piperacillin/tazobactam. Therefore, we undertook a study of the VRE infection rate for the TBICU in relation to vancomycin, piperacillin/tazobactam, piperacillin, third-generation cephalosporin, and total cephalosporin use before and after efforts to limit cephalosporins. These data were compared to those in the medical and surgical intensive care units. During 1998, seven VRE infections occurred in the TBICU. Following initiation of antibiotic protocols, one case of VRE infection occurred in the subsequent month and no cases in the 17 months since. The decrease in the VRE infection rate corresponded with a significant increase in the use of piperacillin/tazobactam and a reduction in third-generation and total cephalosporin use. In contrast, cephalosporin use in the medical and surgical intensive care units remains significantly higher than in the TBICU, and neither unit has had a reduction in their VRE infection rates.

The April 8, 1998 tornado: assessment of the trauma system response and the resulting injuries

BACKGROUND

On April 8, 1998, an F5 tornado touched down in two counties of Alabama producing a wide path of destruction. The presence of a regional trauma system in this area presents an opportunity to evaluate the effectiveness of the system in responding to the victims of this natural disaster.

METHODS

Emergency room logs and the regional trauma system database were searched for all patients treated for injuries sustained from the tornado, and medical records were reviewed for demographic information, mode of transportation to hospital, injuries, treatment, and outcome. Fatalities were identified by means of the coroner's office.

RESULTS

A total of 224 patients were evaluated at nine area hospitals, of whom 63 (28%) required admission. There were 32 deaths: 30 persons were dead at the scene, and 2 patients subsequently died at Level I trauma centers. Among patients with nonfatal injuries, 39% were managed at Level I facilities, 46% at Level III facilities, and 15% at nontrauma facilities. Forty patients (55%) seen at Level I facilities required admission compared with 15 patients (17%) at Level III facilities and 8 patients (29%) at nontrauma facilities; Level I facilities also had the highest Injury Severity Score. Of patients requiring admission, 83% were transported by emergency medical services; these patients also had the highest Injury Severity Score.

CONCLUSION

The regional trauma system facilitated appropriate and efficient triage to system hospitals, routing the most severely injured patients to the Level I centers without overwhelming them with the more numerous, less severely injured patients.

Contribution of Escherichia coli alpha-hemolysin to bacterial virulence and to intraperitoneal alterations in peritonitis

Alpha-hemolysin (Hly) is a common exotoxin produced by Escherichia coli that enhances virulence in a number of clinical infections. The addition of hemolysin production to laboratory bacterial strains is known to increase the lethality of E. coli peritonitis. However, the mechanisms involved have not been determined and the contribution of hemolysin to the alterations in the host intraperitoneal environment and the leukocyte response is not known. Utilizing a rat peritonitis model, we show that wild-type hemolytic E. coli strains have a significant competitive advantage over nonhemolytic strains within the peritoneum. To examine the specific contribution of Hly to E. coli-induced virulence and alterations within the peritoneum, a mixed peritonitis model of E. coli, Bacteroides fragilis, and sterile fecal adjuvant was used. Three transformed E. coli strains were utilized: one strongly secretes active hemolysin (WAF 270), a second secretes active hemolysin but a reduced amount (WAF 260), and the third does not produce hemolysin (WAF 108). After an equal inoculum of each of the three strains, WAF 270 produced a markedly increased lethality and an increased recovery of both E. coli and B. fragilis from the host relative to the other strains. Changes in the intraperitoneal pH, degree of erythrocyte lysis, and recruitment and viability of leukocytes within the peritoneum following the induction of peritonitis differed significantly between the strongly hemolytic and nonhemolytic strains. Induction of peritonitis with WAF 270 caused a pronounced decrease in intraperitoneal pH, lysis of most of the intraperitoneal erythrocytes, and a marked decrease in recoverable viable leukocytes compared to WAF 108. Thus, hemolysin production by E. coli within the peritoneum may alter not only the host's ability to control the hemolytic strain itself but also other organisms.

Endovascular therapy of traumatic injuries of the extracranial cerebral arteries

The field of neuroendovascular therapy is rapidly growing. New technology and operators' expertise are developing at a pace that will make this discipline progressively more available and successful. For patients who have traumatic injuries of the extracranial arteries, endovascular therapy offers a new dimension to the treatment of these injuries and the prevention of stroke. Because many of these patients are likely to be critically ill, it is important to keep in mind the principles of their management before, during, and after the procedure, thus assuring the best chance for a successful outcome. Furthermore, some of the issues related to their neurointensive care will serve as guides for the need for endovascular therapy, as well as its timing.

Prognostic factors in patients with inferior vena cava injuries

Inferior vena cava (IVC) injuries are potentially devastating insults that continue to be associated with high mortality despite advances in prehospital and in-hospital critical care. Between 1987 and 1996, 37 patients (32 males and 5 females; average age, 30 years) were identified from the trauma registry as having sustained IVC trauma. Overall mortality was 51 per cent (n = 19), with 13 intraoperative deaths and five patients dying within the first 48 hours. Blunt IVC injuries (n = 8) had a higher associated mortality than penetrating wounds (63% versus 48%). Of the 29 patients with penetrating IVC trauma, the wounding agent influenced mortality (shotgun-100% versus gunshot-43% versus stab-0%). Anatomical location of injury was also predictive of death [suprahepatic (n = 3)-100% versus retrohepatic (n = 9)-78% versus suprarenal (n = 6)-33% versus juxtarenal (n = 2)-50% versus infrarenal (n = 15)-33%]. A direct relationship existed between outcome and the number of associated injuries: nonsurvivors averaged four and survivors averaged three. Eighty per cent of patients sustaining four or more associated injuries died, by contrast to a 33 per cent mortality in those suffering less than four injuries. Physiological factors were also predictive of outcome. Patients in shock (systolic blood pressure < 80) on arrival had a higher mortality than those who were hemodynamically stable (76% versus 30%). Preoperative lactate levels were of prognostic value for death (> or = 4.0-59% versus < 4.0-0%), as was base deficit (< 4-22%, > or = 4, and < 10-36%, > or = 10-73%). Interestingly, neither time from injury to hospital arrival (47.4 minutes versus 33.0 minutes) nor time in the emergency department before surgery (45.6 minutes versus 42.6 minutes) differed between survivors and fatalities. Mortality remained high in the 34 patients who had operative control of their IVC injuries [lateral repair (n = 27)-44% versus ligation (n = 6)-66% versus Gortex graft (n = 1)-0%]. As wounding agent, anatomical location, associated injuries, and physiological status seem to most directly impact mortality, future efforts must focus both on establishing prevention programs directed at reducing the incidence of this injury, as well as on advancing the management of those who do survive to hospitalization, if we are to improve on the outcome of these devastating injuries.

Diagnosis of blunt rupture of the right hemidiaphragm by technetium scan

Traumatic rupture of the diaphragm, particularly of the right hemidiaphragm, may be occult and can be difficult to diagnose if laparotomy is not required for concomitant injury. Missed or delayed diagnosis of such injuries can produce life-threatening complications, such as intestinal herniation, ischemia, and necrosis. We present a case of traumatic rupture of the right hemidiaphragm that demonstrates the typically occult nature of this injury. The majority of right-sided injuries are diagnosed during laparotomy performed for other injuries. In those patients not requiring laparotomy, the diagnosis is usually delayed because this injury seldom produces clinical or radiographic findings that are either sensitive or specific. In this case, intraperitoneal injection of technetium sulfur colloid was used to establish the diagnosis of right diaphragm rupture, and an uncomplicated repair was undertaken.

Combined blunt cardiac and pericardial rupture: review of the literature and report of a new diagnostic algorithm

The spectrum of blunt cardiac injury varies from the asymptomatic cardiac concussion to the immediately fatal cardiac rupture. Although the majority of victims sustaining blunt cardiac rupture die before receiving medical attention, some survive to evaluation. The diagnosis of cardiac rupture, if established, typically results from the signs and symptoms of pericardial tamponade. However, some patients may have remarkably few signs and symptoms suggestive of cardiac injury and represent a significant diagnostic challenge. We provide two cases of cardiac rupture in which the diagnosis was delayed by the presence of an associated pericardial tear with decompression into the mediastinum and pleural space. In neither of the cases did existing institutional algorithms for blunt cardiac injury assist in establishing the diagnosis before the acute demise of the patient. The presence of a coexisting pericardial injury in these patients with blunt cardiac rupture obscured the diagnosis, leading to the deaths of these patients. A discussion of these two cases and review of the literature is provided with recommendations for diagnostic algorithms in patients sustaining blunt thoracic trauma with possible cardiac and pericardial injury.

Hemolytically active (acylated) alpha-hemolysin elicits interleukin-1beta (IL-1beta) but augments the lethality of Escherichia coli by an IL-1- and tumor necrosis factor-independent mechanism

Many pathogenic Escherichia coli produce the toxin alpha-hemolysin (Hly), and lipopolysaccharide (LPS), interleukin-1 (IL-1), and tumor necrosis factor (TNF) have all been recognized as important effector molecules during infections by gram-negative organisms. Despite the characterization of many in vitro effects of hemolysin, no direct relationship has been established between hemolysin, LPS, proinflammatory cytokine production, and E. coli-induced mortality. Previously, we have shown in vivo that hemolysin elicits a distinct IL-1alpha spike by 4 h into a lethal hemolytic E. coli infection. Using three transformed E. coli strains, WAF108, WAF270, and WAH540 (which produce no Hly [Hlynull], acylated Hly [Hlyactive], or nonacylated Hly [Hlyinactive], respectively), we sought to determine the specific roles of hemolysin acylation, LPS, IL-1, and TNF in mediating the lethality of E. coli infection in mice. WAF270 was 100% lethal in BALB/c, C3H/HeJ, and C57BL/6 mice; in mice pretreated with antibody to the type 1 IL-1 receptor; in type 1 IL-1 receptor-deficient mice; and in dual (type 1 IL-1 receptor-type 1 TNF receptor)-deficient mice at doses which were nonlethal (0%) with both WAF108 and WAH540. At lethal doses, WAF270 killed by 6 +/- 2.3 h while WAF108 and WAH540 killed at 36 +/- 9.4 and 36 +/- 13.8 h, respectively. These differences in mortality were not due to IL-1 or TNF release, and the enhanced expression of LPS, which corresponded to Hly expression, was not likely the primary factor causing mortality. We demonstrate that bacterial fatty acid acylation of hemolysin is required in order for it to elicit IL-1 release by monocytes and to confer its virulence on E. coli.

Determining anatomic injury with computed tomography in selected torso gunshot wounds

BACKGROUND

Changes in the management of torso gunshot wounds (TGSWs) have evolved in recent years as a result of differences between military and civilian injuries and increasing interest in avoiding nontherapeutic invasive procedures. The objective of this study was to establish the utility and accuracy of computed tomography (CT) in the evaluation of selected patients with TGSWs.

METHODS

Retrospective review for a 6-year period of patients who sustained TGSWs and underwent CT solely for the purpose of trajectory determination. Patients had complete physical examinations and plain radiographic evaluations by a dedicated group of in-house trauma surgeons. When trajectory was indeterminate after evaluation, CT was performed. In some cases, CT was used when trajectory was determined to be intracavitary but organ injury was believed to be unlikely or amenable to nonoperative management.

RESULTS

Fifty TGSW patients underwent 52 computed tomographic scans. Abdominal/pelvic CT was performed in 37 patients, and thoracic CT was performed in 15 patients. All patients were stable and none sustained complications attributable to CT or delay in therapy. Twenty of 37 abdominal/pelvic computed tomographic scans excluded transabdominal or pelvic trajectory. Seventeen of 37 scans proved transabdominal or pelvic trajectory; nine laparotomies were performed, and eight patients were observed. Nine of 15 thoracic computed tomographic scans excluded transmediastinal trajectory. Six of 15 scans suggested vascular proximity and prompted further workup, which was positive in two cases.

CONCLUSION

CT of selected TGSW patients is safe and may reduce the incidence of invasive diagnostic procedures. A prospective evaluation of CT for TGSW patients is warranted.

Emerging evidence of selection of fluconazole-tolerant fungi in surgical intensive care units

OBJECTIVE

To determine whether increased use of fluconazole has coincided with a shift in the relative proportion of fluconazole-tolerant species isolated from critically ill surgical patients in 2 university hospitals.

DESIGN

Microbiological data and fluconazole administration frequencies were reviewed among patients treated in the surgical intensive care units (SICUs) from January 1, 1990, through December 31, 1995.

SETTING

The SICUs of the University of Virginia Medical Center, Charlottesville, and the Hospital of the University of Pennsylvania, Philadelphia.

MAIN OUTCOME MEASURES

The number and species types of all fungal isolates and the number of patients treated with fluconazole for each of the 6 years were determined.

RESULTS

A sharp increase in the use of fluconazole among critically ill surgical patients has occurred at both medical centers from 1990-1995. The culture results of most patients treated with fluconazole were negative for fungi (73% and 63% at the University of Virginia Medical Center and the Hospital of the University of Pennsylvania, respectively); there was a greater tendency to use fluconazole at the University of Virginia Medical Center compared with the Hospital of the University of Pennsylvania (2.2% vs 1.8% of patients admitted to the SICU received it, respectively; P = .007). There was a significant increase in the proportion of Candida glabrata isolated at the University of Virginia Medical Center (P < .01) from 1990-1995, but a similar change was not detectable at the Hospital of the University of Pennsylvania.

CONCLUSIONS

These data justify concern that the increased use of fluconazole in SICUs may be promoting a shift in the fungal flora that cause nosocomial infections toward species that are more difficult to treat. Prospective studies about the use of fluconazole for prophylaxis and empirical therapy among SICU patients are warranted before its widespread use in these settings continues.

Management of hepatic artery injury: case report

The trauma surgeon encounters hepatic arterial injury only rarely. The majority of these injuries appear to be due to penetrating trauma, with few cases of hepatic artery injury secondary to blunt trauma reported in the literature. In the setting of blunt trauma, hepatic artery injury is generally accompanied by other severe injuries, and mortality remains high. We present two patients who sustained an avulsion of the left hepatic artery complicating severe blunt trauma to the abdomen and pelvis. Surgical management included ligation of the involved vessel. Both patients required management in the intensive care unit, one eventually succumbing to multisystem organ failure. The cases highlight management principles in these injuries, and treatment options are discussed.

Coagulopathy in severe closed head injury: is empiric therapy warranted?

Closed head injuries account for a significant portion of the morbidity and mortality following blunt trauma. Severe closed head injuries can be complicated by the development of a coagulopathy that may worsen blood loss and delay invasive neurosurgical procedures. Awaiting the results of coagulation studies prior to initiating treatment of such a coagulopathy introduces an inherent delay that may allow worsening of the coagulation disturbance and negatively influence outcome. This study was undertaken to see if a subgroup of patients with severe closed head injuries had a high probability of developing a coagulopathy and would warrant empiric treatment with fresh frozen plasma. The records of adult patients admitted to our trauma center with a Glasgow coma score (GCS) of < or = 8 and an extracranial abbreviated injury score of < or = 2 during a 9-month period were reviewed. Patients with penetrating trauma or whose altered level of consciousness was due to sedation or shock were excluded. The presence of coagulation abnormalities was determined according to prothrombin time and partial thromboplastin time obtained on admission. The time to invasive neurosurgical procedures for both coagulopathic and noncoagulopathic patients was determined as well as the mean number of hospital days, intensive care unit days, and the mortality for each group. Eighty-one per cent of the patients with a GCS < or = 6 were coagulopathic on admission, and all patients with a GCS of 3 or 4 were coagulopathic. In contrast, no patient with a score of 7 or 8 was coagulopathic. The coagulopathic patients tended to have a higher mortality than the noncoagulopathic patients (53 versus 22%) as well as longer intensive care unit and hospital stays. The mean time to neurosurgical intervention for the coagulopathic group was 226.0 +/- 190.9 minutes versus 84.8 +/- 38.4 minutes for the noncoagulopathic patients. We conclude that patients with closed head injuries who present with a GCS of 6 or less are candidates for empiric treatment for coagulopathy. Such treatment will negate the delay of awaiting coagulation studies. Whether or not such therapy shortens the interval between admission and neurosurgical procedures or alters outcome will require prospective study.

In vivo cytokine response to Escherichia coli alpha-hemolysin determined with genetically engineered hemolytic and nonhemolytic E. coli variants

Alpha-hemolysin is an Escherichia coli exotoxin that enhances bacterial virulence, has profound effects on leukocytes in vitro, and induces the release of interleukin-1 (IL-1) but not tumor necrosis factor (TNF) from human monocytes in vitro. The purpose of this study was to examine alpha-hemolysin's influence on virulence and TNF and IL-1 production in vivo. Two genetically engineered, isogeneic strains of E. coli were used; one variant produces alpha-hemolysin, and the other does not. Male BALB/c mice were injected with either of the two variants and serum TNF and IL-1 were assayed. These results were compared with those obtained from the injection of either of two serotypes of lipopolysaccharide (LPS). The nonhemolytic E. coli strain produced no mortality and no significant elevation of serum TNF or IL-1 levels. In contrast, equal inocula of the hemolytic E. coli strain produced significant mortality and elevation of serum IL-1 levels. No significant elevation of TNF levels was detected in this group despite high-level mortality. A pattern of induction of mortality and elevation of serum IL-1 levels without elevation of serum TNF levels is distinct from the pattern typical of LPS. In these experiments, both serotypes of LPS caused elevations of TNF and IL-1 levels whether or not mortality was induced. Thus, alpha-hemolysin produces a cytokine response in vivo that is similar to that previously demonstrated in vitro by Bhakdi et al. (S. Bhakdi, M. Muhly, S. Korom, and G. Schmidt, J. Clin. Invest. 85:1746-1753, 1990) and appears to induce mortality independently of serum TNF.

CD4+ T cells mediate preexposure-induced increases in murine intraabdominal abscess formation

We have previously shown that an increased number of Escherichia coli/Bacteroides fragilis intraabdominal abscesses are produced in mice after preexposure to small numbers of live E. coli or B. fragilis. Splenic lymphocyte subset changes and the importance of different elements of the immune response in this system were studied. Preexposure to bacteria induced a significant increase in the percentage of splenic T cells without altering the CD4/CD8 ratio. The passive transfer of either 10(7) mixed splenic lymphocytes, 5 x 10(6) mixed T cells, or 2.5 x 10(6) CD4+ T cells from preexposed animals to naive siblings 24 hr prior to abscess induction resulted in increased abscess formation. Transfer of serum, B cells, < 10(7) lymphocytes, CD8+ T cells, or any cell type from naive animals did not change abscess number. The bacterial composition of abscesses changed only in animals receiving either serum or B cells from donors preexposed to B. fragilis, where an increased number of B. fragilis per abscess was found. The CD4+ T cell response can be altered by transient infections and is critical to subsequent abscess formation, and a concurrent humoral response may play a role in determining an abscess' ultimate bacterial composition.

The role of Candida albicans in the pathogenesis of experimental fungal/bacterial peritonitis and abscess formation

The recovery of Candida albicans along with bacteria from the abdomen in the setting of peritonitis is becoming increasingly common. It is not known whether the interactions between the fungal and bacterial elements of these infections are synergistic, competitive, or neutral. To study this question, we have examined the effects of both the addition of C. albicans to a solely bacterial infection caused by Escherichia coli and Bacteroides fragilis, and the deletion of various components of this system using directed antimicrobial therapy. In a mixed infection, both C. albicans and bacteria contributed to mortality, since only the combination of cefoxitin and amphotericin B improved survival (from 50% to 90%). The addition of C. albicans to the bacterial inoculum increased the recovery of abscesses, but only to the number seen with fungal infection alone, implying two fairly independent processes. Although the number of bacteria recovered from abscesses at 10 days postinfection was unchanged with the addition of fungi, the deletion of the bacterial component of mixed infections led to the overgrowth of C. albicans. We conclude that this model of mixed C. albicans/E. coli/B. fragilis peritonitis is best characterized as two nonsynergistic, parallel infections with incomplete competition, allowing the survival of all three organisms to eventual abscess formation.

Anterior lung herniation: another aspect of the seatbelt syndrome

Shoulder harnesses can be a source of thoracic injury in motor vehicle crashes. Sternal and rib fractures are most commonly reported. We present a case of a traumatic anterior lung herniation secondary to shoulder harness trauma in a motor vehicle crash victim with multiple injuries. A brief review of lung hernias is provided as well as a brief discussion of the thoracic manifestations of the seatbelt syndrome.

Effectiveness of fluconazole in murine Candida albicans and bacterial C. albicans peritonitis and abscess formation

The role of fluconazole in the treatment of many forms of focal mycoses remains unclear. We studied the effectiveness of three different oral doses of fluconazole in three murine models of Candida albicans peritonitis leading to intra-abdominal abscess formation. During monomicrobial Candida infection, fluconazole decreased mortality and the number of C. albicans cultured per abscess; prolonged treatment also eliminated Escherichia coli translocation. In mixed C. albicans/E. coli/Bacteroides fragilis infection, prolonged treatment with higher doses of fluconazole decreased mortality, the number of abscesses formed, and the number C. albicans per abscess. In animals with a similar polymicrobial infection but with concurrent cefoxitin treatment, fluconazole decreased mortality and the number of C. albicans per abscess; in addition, prolonged treatment reduced the number of abscesses. Amphotericin B gave similar results in all three models. These data indicate that the clinical use of fluconazole in peritonitis should be investigated.

Development of Candida albicans and C. albicans/Escherichia coli/Bacteroides fragilis intraperitoneal abscess models with demonstration of fungus-induced bacterial translocation

The development of models of both Candida albicans and mixed C. albicans/Escherichia coli/Bacillus fragilis peritonitis in immunologically normal mice are described, each with significant mortality and intra-abdominal abscess formation. C. albicans inoculated alone induced bacterial translocation into abscesses, and the addition of bacteria reduced the number of, but did not eliminate. C. albicans in abscesses. There was no synergy seen between fungi and bacteria in terms of either morbidity or mortality.

Enhanced virulence of Escherichia coli bearing a site-targeted mutation in the major structural subunit of type 1 fimbriae

Type 1 fimbriae promote enterobacterial adherence to a variety of mammalian cells and are thought to play an important role in the establishment of various extraintestinal infections. Whether or not this adhesin has a role in the pathogenesis of peritoneal Escherichia coli infections, such as those initiated by bowel leakage during intraabdominal surgery, is unclear. By using two genetically engineered E. coli strains, each bearing an antibiotic resistance element inserted at a different site within the type 1 fimbria operon, we examined the role of type 1 fimbriation in intraperitoneal infection in rats. A permanently nonfimbriated insertion mutant was compared with an analogously constructed normally fimbriated one. After intraperitoneal inoculation of adult rats, the permanently nonfimbriated mutant produced mortality more rapidly and resulted in a greater number of culturable organisms from both the peritoneum and the blood. Moreover, the differences between these two insertion mutants were dramatically enhanced by preinoculation growth conditions favoring fimbrial expression. After growth under these conditions, 10(3) CFU of the fimbriation-proficient strain inoculated intraperitoneally caused no mortality; in sharp contrast, the permanently nonfimbriated insertion mutant resulted in death in 60% of the animals inoculated. Notwithstanding evidence that type 1 fimbriae mediate enterobacterial adherence to mammalian oropharyngeal and bladder mucosae, the results presented here demonstrate that type 1 fimbrial expression can lead to diminution of the number of E. coli organisms within the peritoneum.

Anti-tumor necrosis factor antibody reduces mortality in the presence of antibiotic-induced tumor necrosis factor release

The systemic tumor necrosis factor (TNF) response has been extensively studied during infection. In addition, antibiotics that cause cell-wall lysis have been associated with endotoxinemia and, therefore, could trigger TNF release. We studied the effects of pretreatment with cefoxitin and/or anti-TNF antibody on mortality and early (90 minutes) and delayed (6 hours) serum TNF levels in a murine model of mixed Escherichia coli/Bacteroides fragilis peritonitis. At low and intermediate inocula levels, cefoxitin, but not anti-TNF antibody, prevented death, and low serum TNF levels were noted in all groups. At the highest inoculum level, mortality was uniform in control, cefoxitin, and anti-TNF antibody groups, and a significant elevation in serum TNF levels was seen only at the 6-hour point in animals receiving cefoxitin. The addition of anti-TNF antibody to cefoxitin at this inoculum level abrogated the 6-hour rise in serum TNF levels and reduced mortality to 40%. These results emphasize that the cytokine response in disease is dependent on both the nature of the insult and other forms of therapeutic interventions.

Peritonitis into the 1990s: changing pathogens and changing strategies in the critically ill

To study the effect of severe illness on the nature of peritonitis and intra-abdominal abscesses, the microbiology and clinical course of patients operated on over a 1-year period with culture-proven intra-abdominal infections whose preoperative Acute Physiology and Chronic Health Evaluation (APACHE) II scores were greater than or equal to 15 (predicted mortality at least 50%) were examined. Twenty-nine patients were enrolled, and overall mortality was 52 per cent, with increasing mortality correlating with higher APACHE II scores. The organism most commonly isolated from the peritoneum was Candida albicans, followed by Enterococcus species, Enterobacter species, and Staphylococcus epidermidis. An increase in the mean of the APACHE II scores on Days 3 and 7 compared to the preoperative score was associated with a 91 per cent mortality, while a decrease was associated with only a 22 per cent mortality. The authors conclude that the microbiology of intra-abdominal infections is inherently different in severely ill patients and that longitudinal clinical scoring may be more useful than a single scoring in predicting outcome. These data suggest that trials to investigate the broadening of standard perioperative antimicrobial coverage in the ill and use of longitudinal clinical scoring to direct aggressive reintervention may be warranted.

Comparative studies on succinate and terminal oxidase activity in microbial and mammalian electron-transport systems

A comparative study was undertaken to examine the succinate and terminal oxidase activities of the electron-transport systems of Azotobacter vinelandii and mammalian mitochondria. For succinate oxidation, both systems exhibited similar relative specificities for the electron acceptors phenazine methosulfate, O2, methylene blue, K3Fe(CN)6, nitrotetrazolium blue, 2,6-dichlorophenolindophenol (DCIP), and cytochrome c. They differed in that DCIP and cytochrome c were less active in the Azotobacter electron-transport system (R3 fraction) than in the bovine mitochondrial system. Comparative studies with known inhibitors of mammalian mitochondrial electron-transport demonstrated that the succinoxidase activity of the Azotobacter R3 fraction was, at least, 2000 times less sensitive to antimycin A, 700 times less sensitive to thenoyl-trifluoroacetone, and 30 times less sensitive to 2-n-heptyl-4-hydroxy-quinoline-N-oxide. Both systems were equally sensitive to KCN, p-chloromercuribenzoic acid, and chlorpromazine.The ability of the two systems to use tetramethyl-p-phenylenediamine (TMPD) and its derivatives as electron donors, for terminal oxidation, was also similar. Studies on steady state reduction revealed that in the Azotobacter R3 fraction, the cytochromes (a2, a1, b1, c4 + c5) and flavoprotein components were reduced substantially by succinate as well as by TMPD in the presence of ascorbate. Ultrastructure analyses of the Azotobacter R3 electron-transport fraction revealed the vesicular membranous components identified as oxidosomes according to the terminology used by DeLey and contained spherical headpiece units of 80 Å in diameter which appeared to be morphologically identical with the tripartite units or the elementary particles described by Green and associates, viz., Kopaczyk et al., and by Fernandez-Moran et al.