G. Patrick Kealey

Blunt splenic injury in adults: Multi-institutional study of the Eastern Association for the Surgery of Trauma

BACKGROUND Nonoperative management of blunt injury to the spleen in adults has been applied with increasing frequency. However, the criteria for nonoperative management are controversial. The purpose of this multi-institutional study was to determine which factors predict successful observation of blunt splenic injury in adults. METHODS A total of 1,488 adults (>15 years of age) with blunt splenic injury from 27 trauma centers in 1997 were studied through the Multi-institutional Trials Committee of the Eastern Association for the Surgery of Trauma. Statistical analysis was performed with analysis of variance and extended chi2 test. Data are expressed as mean +/- SD; a value of p < 0.05 was considered significant. RESULTS A total of 38.5 % of patients went directly to the operating room (group I); 61.5% of patients were admitted with planned nonoperative management. Of the patients admitted with planned observation, 10.8% failed and required laparotomy; 82.1% of patients with an Injury Severity Score (ISS) < 15 and 46.6% of patients with ISS > 15 were successfully observed. Frequency of immediate operation correlated with American Association for the Surgery of Trauma (AAST) grades of splenic injury: I (23.9%), II (22.4%), III (38.1%), IV (73.7%), and V (94.9%) (p < 0.05). Of patients initially managed nonoperatively, the failure rate increased significantly by AAST grade of splenic injury: I (4.8%), II (9.5%), III (19.6%), IV (33.3%), and V (75.0%) (p < 0.05). A total of 60.9% of the patients failed nonoperative management within 24 hours of admission; 8% failed 9 days or later after injury. Laparotomy was ultimately performed in 19.9% of patients with small hemoperitoneum, 49.4% of patients with moderate hemoperitoneum, and 72.6% of patients with large hemoperitoneum. CONCLUSION In this multicenter study, 38.5% of adults with blunt splenic injury went directly to laparotomy. Ultimately, 54.8% of patients were successfully managed nonoperatively; the failure rate of planned observation was 10.8%, with 60.9% of failures occurring in the first 24 hours. Successful nonoperative management was associated with higher blood pressure and hematocrit, and less severe injury based on ISS, Glasgow Coma Scale, grade of splenic injury, and quantity of hemoperitoneum.

Contribution of age and gender to outcome of blunt splenic injury in adults: Multicenter study of the eastern association for the surgery of trauma

BACKGROUND The purpose of this study was to examine the contribution of age and gender to outcome after treatment of blunt splenic injury in adults. METHODS Through the Multi-Institutional Trials Committee of the Eastern Association for the Surgery of Trauma (EAST), 1488 adult patients from 27 trauma centers who suffered blunt splenic injury in 1997 were examined retrospectively. RESULTS Fifteen percent of patients were 55 years of age or older. A similar proportion of patients > or = 55 went directly to the operating room compared with patients < 55 (41% vs. 38%) but the mortality for patients > or = 55 was significantly greater than patients < 55 (43% vs. 23%). Patients > or = 55 failed nonoperative management (NOM) more frequently than patients < 55 (19% vs. 10%) and had increased mortality for both successful NOM (8% vs. 4%, p < 0.05) and failed NOM (29% vs. 12%, p = 0.054). There were no differences in immediate operative treatment, successful NOM, and failed NOM between men and women. However, women > or = 55 failed NOM more frequently than women < 55 (20% vs. 7%) and this was associated with increased mortality (36% vs. 5%) (both p < 0.05). CONCLUSION Patients > or = 55 had a greater mortality for all forms of treatment of their blunt splenic injury and failed NOM more frequently than patients < 55. Women > or = 55 had significantly greater mortality and failure of NOM than women < 55.

Predicting survival in an elderly burn patient population

The purpose of this study was to analyze the outcome of elderly burn victims and to determine an instrument to predict survival in this population. Charts of three hundred and eight burn patients > or =60 yr of age who were admitted to a university-based hospital between the years of 1977-1996 were retrospectively analyzed. The mean age of the population was 71.5+/-8.6, with a male predominance (1.8 to 1, P < 0.001). The majority of the burns were secondary to flame injuries (210, 68.6%). The median body surface area (BSAB) was 13.0% with an in-hospital mortality rate of 30.2%. We demonstrated improved survival in patients aged 60-74 yr as compared to 1965-1971 national burn survival data. A similar trend could not be shown in the very old (> 75 yr of age). Only age and BSAB were related to death by multiple stepwise forward linear regression. The Baux score, which adds age and BSAB, was predictive of outcome in 87.0% of our population. In conclusion, this study reinforces the high mortality associated with burn injuries in the elderly and the superior ability of the Baux score (age + percent burn) in predicting outcome in this population.

Prospective analysis of nosocomial infection rates, antibiotic use, and patterns of resistance in a burn population.

Despite significant advances in burn care, infection remains a major cause of morbidity and mortality in burn patients. We sought to determine accurate infection rates, risk factors for infection, and the percentage of infections caused by resistant organisms. In addition, we attempted to identify interventions to decrease the use of antimicrobial drugs. Data were collected prospectively from 157 burn patients admitted to the University of Iowa Carver College of Medicine burn treatment center from October 2001 to October 2002. A research assistant reviewed the medical record for each patient identified by burn surgeons as being infected to determine whether these episodes met the infection control criteria for nosocomial infections. The infection control assessment agreed with the surgeon′s assessment for 16.7% of the pneumonias, 70.0% of the burn wound infections, 57.1% of the urinary tract infections, and 70.0% of the bloodstream infections. By multiple logistic regression analysis, body surface area burned, comorbidities, and use of invasive devices were significantly related to acquisition of nosocomial infections as identified by both the burn surgeons and the infection control criteria. Staphylococcus aureus and Pseudomonas were the most common resistant organisms identified. In our population, surgeons could decrease antimicrobial use by using explicit criteria for identifying patients with hospital-acquired infections, limiting perioperative prophylaxis to patients at highest risk of infection, and decreasing the incidence of nosocomial infection with reduced use of devices and strict adherence to aseptic technique.

Carbon monoxide toxicity.

Inhalation injury consists of a multitude of insults, the first of which is the toxic gases inhaled during the combustion of organic and inorganic substances. Significant morbidity and mortality in patients with burn injury occur due to the varying effects of these gases. This section of the compendium initially addresses two classically described inhaled gases: carbon monoxide and cyanide, followed by a discussion of a gas associated with illicit drug use: metamphetamine. Understanding the varying effects of the toxic gases at the scene of injury may facilitate the development of specific treatment regimens for inhalation injury.

Expression of Thrombomodulin and Consequences of Thrombomodulin Deficiency during Healing of Cutaneous Wounds

Thrombomodulin is a cell surface anticoagulant that is expressed by endothelial cells and epidermal keratinocytes. Using immunohistochemistry, we examined thrombomodulin expression during healing of partial-thickness wounds in human skin and full-thickness wounds in mouse skin. We also examined thrombomodulin expression and wound healing in heterozygous thrombomodulin-deficient mice, compound heterozygous mice that have <1% of normal thrombomodulin anticoagulant activity, and chimeric mice derived from homozygous thrombomodulin-deficient embryonic stem cells. In both human and murine wounds, thrombomodulin was absent in keratinocytes at the leading edge of the neoepidermis, but it was expressed strongly by stratifying keratinocytes within the neoepidermis. No differences in rate or extent of reepithelialization were observed between wild-type and thrombomodulin-deficient mice. In chimeric mice, both thrombomodulin-positive and thrombomodulin-negative keratinocytes were detected within the neoepidermis. Compared with wild-type mice, heterozygous and compound heterozygous thrombomodulin-deficient mice exhibited foci of increased collagen deposition in the wound matrix. These findings demonstrate that expression of thrombomodulin in keratinocytes is regulated during cutaneous wound healing. Severe deficiency of thrombomodulin anticoagulant activity does not appear to alter reepithelialization but may influence collagen production by fibroblasts in the wound matrix.

The Epidemiology of Cytomegalovirus Infection Among Patients with Burns

To determine the epidemiology of cytomegalovirus (CMV) infections among patients with burns, we prospectively studied 120 burn patients admitted to the University of Iowa Burn Center over a two-and-one-half year period. At the time of their admission, 44% of the patients had serologic evidence of prior CMV infection. Among 44 seropositive patients, 23 (52%) had four-fold or greater rises in CMV antibody titers. These patients had more severe burns (mean body surface area burn [BSAB] 26.8%) than those who did not exhibit titer rises (mean BSAB 16.2%, p = .04). Among 43 seronegative patients observed for at least 65 days after discharge from the center, eight (18.6%) seroconverted. Patients who seroconverted had longer hospital stays (p = .03), trends toward more severe burns (p = .08) and a younger age (p = .15) than patients who remained seronegative. Despite frequent serologic evidence of CMV infection, CMV did not contribute, either directly or indirectly, to the morbidity or mortality of burns in these patients.

The Effect of Burn Center and Burn Center Volume on the Mortality of Burned Adults-An Analysis of the Data in the National Burn Repository

Regional variations of care, and improved outcomes with larger volumes, have been well described in the medical and surgical literature for a variety of conditions including heart surgery, vascular surgery, and orthopedic surgery. Burn care has not been recently subjected to such an analysis. The National Burn Repository (NBR) contains de-identified patient and burn center data to allow this analysis. The NBR was queried for adult burn patients admitted for an acute thermal burn injury. A multivariable regression analysis to identify risk of death was performed incorporating patient characteristics, de-identified burn center, and burn center volume. Patient characteristics such as age, size of burn, mechanism of burn, inhalation injury, race, and sex determine mortality. There is also a statistically significant difference in death rates when individual, de-identified centers are compared. This difference in care persists even when accounting for burn center volume. Analysis of registries like the NBR, insurance claims databases, and statewide hospital discharge databases may help identify opportunities to improve burn care. According to this analysis of data available in the NBR, burn mortality depends not only on patient characteristics but also where the patient is treated. Mortality does not linearly improve with burn center volume and plateaus with increasing burn center size. The optimal burn center size is a complicated and contentious question. Future discussions about burn center size and density should incorporate not only mortality but also the region’s ability to absorb surges in volume, and the optimal “staffing” ratios for the multidisciplinary aspects of burn care.

The evolution of resource utilization in regional burn centers.

Regional burn centers provide unique multidisciplinary care that has been associated with dramatically improved outcomes for burn victims. Patients with complex skin and soft tissue injuries are increasingly admitted to these centers for definitive care. This study was designed to assess current trends in burn center resource utilization. Members of the Multicenter Trials Group of American Burn Association were invited to participate in this retrospective review of all patients admitted to their respective regional burn centers during a 10-year period. Collected data included admission diagnosis, demographics, length of stay (LOS), hospital charges, and mortality. Five regional academic burn centers participated. They collectively admitted 18,246 patients during the study period, of whom 15,219 (83.4%) had a primary burn diagnosis and 3027 (16.6%) were patients with nonburn diagnoses. During this period, annual admissions for the five centers increased by 34.7%, ranging from 19 to 83% for individual centers. Simultaneously, mean burn size decreased from 12.3 to 8.8% TBSA. From 1998 to 2006, admissions for nonburn diagnoses increased by 244.9%, whereas burn admissions increased by 31.1%. Although mean LOS was reduced by >25%, total charges for all patients increased by 37.7% after adjustment for inflation. Nonburn patients had significantly higher mean age, longer LOS, greater mortality, and higher daily charges. This review of admissions to five academic burn centers reveals that these centers are treating more patients with smaller burns and an increasing number of complex nonburn conditions. Nonburn patients represent an older and more debilitated population that consumes disproportionately more resources than burn patients. These data show a dramatic shift in burn center resource utilization and the concurrent evolution of regional burn centers into centers for the care of complex wounds.

Fournier’s gangrene with an unusual urologic etiology

Fourniers gangrene is a necrotizing infection affecting the male genitalia and perineum, caused by synergistic aerobic and anaerobic organisms. We report on a previously undescribed upper urinary tract etiology for this life-threatening infection.