ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Our trauma research center program entitled, “Trauma Primes Cells” is based on the fundamental hypothesis that prior exposure to multiple, sequential, sublethal cellular insults primes constructive or destructive pathways of cellular responses of subsequent injury. A major objective is to design therapy that will reduce the incidence of multiple organ failure. Although a number of inflammatory cascades have been incriminated in the pathogenesis of multiple organ failure (MOF), diffuse PMN-mediated tissue injury remains an attractive unifying concept. We have developed a sequential insult rodent model in which the priming event consisted of superior mesenteric arterial (SMA) clamping for 45 minutes followed by 6 hours of reperfusion. Following this priming event, activation was induced with a low dose of endotoxin (2.5 mg/kg). We believe that these studies support our hypothesis: mesenteric ischemic/reperfusion primes circulating PMNs. When these have been activated they can then be provoked by endotoxin to provoke distant organ injury. Primed PMNs are released from the postischemic mesenteric bed and enter the systemic circulation. They subsequently sequester in the pulmonary vascular bed where they are relatively harmless until they are activated by low dose endotoxin. These activated PMNs then migrate across the endothelium cell and release reactive oxygen metabolites.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Burn injury results in alterations in granulocyte and macrophage production. Since macrophages may mediate these alterations we determined the effects of macrophages obtained from animals with burn injury with and without infection on the growth of marrow granulocyte macrophage progenitor cells (GM-CFCs). The in vitro GM-CFC growth response for maximally stimulated cultures was reduced by 25% to 30% (p< 0.01) for burned and infected (B + I) animal macrophages compared with burned (B) or sham (S) animals. Macrophages stimulated with endotoxin caused a further reduction for all groups in GM-CFC growth, most notably so for B + I macrophages. Burned + infected animal macrophages or all-endotoxin macrophages cocultured with indomethacin did not suppress GM-CFC growth. Following burn injury and infection, macrophages spontaneously elaborate negative regulators of myeloid growth that is further increased by endotoxin. It is likely that PGE2, a known negative regulator of granulocyte macrophage growth, is largely responsible for this suppressive effect.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundWe previously reported that inhaled nitric oxide (NO) improved pulmonary function following smoke inhalation. This study evaluates the physiologic mechanism by which inhaled NO improves pulmonary function in an ovine model.MethodsForty-eight hours following wood smoke exposure to produce a moderate inhalation injury, 12 animals were anesthetized and mechanically ventilated (Fio2, 0.40; tidal volume, 15 mL/kg; PEEP, 5 cm H20) for 3 hours. For the first and third hours, each animal was ventilated without NO: for the second hour, all animals were ventilated with 40 ppm NO. Cardiopulmonary variables and blood gases were measured every 30 minutes. The multiple inert gas elimination technique (MIGET) was performed during the latter 30 minutes of each hour. The data were analyzed by ANOVA. Results: Pulmonary arterial hypertension and hypoxemia following smoke inhalation were significantly attenuated by inhaled NO compared with the values without NO (p< 0.05, ANOVA). Smoke inhalation resulted in a significant increase in blood flow distribution to low VA/Q areas (VA/Q < 0.10) with increased VA/Q dispersion. These changes were only partially attenuated by the use of inhaled NO. The SF6 (sulfur hexafluoride) retention ratio was also decreased by inhaled NO. Peak inspiratory pressures and pulmonary resistance values were not affected by inhaled NO.ConclusionsInhaled NO moderately improved VA/Q mismatching following smoke inhalation by causing selective pulmonary vasodilation of ventilated areas in the absence of bronchodilation. This modest effect appears to be limited by the severe inflammatory changes that occur as a consequence of smoke exposure.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Acute brain injury followed by hemorrhagic shock (HEM) causes prohibitive mortality in trauma patients because these combined events lead to low cerebral blood flow (CBF) and cerebral oxygen delivery (co2del). Proper treatment therefore requires rapid correction of cerebral perfusion deficits. Previous studies have shown that hypertonic crystalloid resuscitation significantly improves CBF and co2del in a model of brain injury and HEM when compared to lactated Ringer's (LR) solution. The mechanism or mechanisms for this advantage, however, are not well understood. We hypothesized that hypertonic fluid resuscitation would reduce pial arteriolar tone after brain injury and HEM resulting in an increase in CBF when compared to LR resuscitation. We measured cerebral and systemic variables in a porcine model of focal cryogenic brain injury and hemorrhagic shock over a 5-hour period. Swine were randomized to receive either hypertonic sodium lactate (HSL) or LR fluid resuscitation. The HSL resuscitation produced a significant and sustained elevation in cerebral perfusion pressure and pial arteriole diameter (p< 0.05), and a sustained elevation in CBF after brain injury and HEM when compared with LR. These data suggest that hypertonic fluid resuscitation following brain injury and HEM improves CBF, at least in part, by causing vasodilation of cerebral resistance vessels.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The use of cytokines and other naturally occurring substances as biopharmaceuticals for modulating the host response to trauma and infection offers new therapeutic possibilities. Cytokine pretreatment protects animals in a variety of experimental models, including splenectomized mice following pneumococcal aerosol challenge. Since splenectomy appears to affect alveolar macrophage function, we postulated that pretreatment with interleukin 1 (IL-1) and granulocyte colony stimulating factor (G-CSF) improved survival in mice following aerosol challenge of live pneumococci by activating alveolar macrophages. Alveolar macrophage bactericidal and phagocytic function was slightly, but consistently, depressed following splenectomy. Interleukin-1 and G-CSF pretreatment had pronounced effects on macrophage phagocytic and bactericidal activity, and these effects were quite different depending upon whether the mice were eusplenic or asplenic. Splenectomy augmented the effects of IL-1 on alveolar macrophage bactericidal function compared with eusplenic mice (p< 0.001), while more pronounced effects on macrophage function following G-CSF treatment were seen in mice with intact spleens (p< 0.001). The use of cytokines and other substances to modify the host response to infection has great potential. Individuals with deficits such as splenectomy will have a different net response to therapy. It is important that we be able to predict these responses accurately in most patients in order to use these substances more effectively.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Recent articles in the literature on adults have recommended prophylaxis for pulmonary embolism (PE) in selected trauma patients; however, to date no information is available regarding pediatric patients. We decided to investigate whether the incidence of PE in pediatric trauma patients is as high as that reported in adults, and identify those children who might be at high risk and benefit from prophylactic treatment. Utilizing the data from the National Pediatric Trauma Registry (NPTR), records were reviewed of all pediatric trauma patients (age < 19 years) admitted to the participating institutions between December 1987 and February 1993. Patients with documented PE were identified as well as those having associated risk factors as identified in adult trauma patients (deep venous thrombosis, extremity injury, spinal cord injury, and head injury). A total of 28,692 pediatric trauma patients were reviewed from the NPTR. The mean age was 9 years and the mean Injury Severity Score for the group was 11. Two thousand one children (7%) had serious head injuries (Glasgow Coma Scale score <8), over 5700 (20%) had an isolated extremity injury, 290 had an identified spinal cord injury (108 with associated paralysis), and deep venous thrombosis was identified in 6 patients. Pulmonary embolism occurred in only two of the children in this series. Both patients with PE had spinal cord injuries with associated paraplegia, significant pulmonary injury, and high ISSs (25 and 27). The overall incidence of PE in the group was 0.000069%, and for those children with paralysis from spinal cord injury 1.85%. Although the literature suggests that PE is a common occurrence in adult trauma victims, it appears to be extremely rare in pediatric trauma patients. From these data, the prophylaxis for PE recommended for adult patients appears unwarranted in injured children. Older teenagers with paraplegia should be treated expectantly for PE, and prophylaxis should be considered if confounding associated injuries are present.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

To determine the frequency of inadequate decompression and its complications, the medical records of 108 pediatric burn patients requiring escharotomies or fasciotomies were reviewed. Of 108 patients, 100 (93%) had escharotomies or fasciotomies performed at an outlying facility before transfer. Of these 100 patients, 44 (117 limbs) were inadequately decompressed and required further decompression after admission to our facility. Initial mean compartment pressures were 50.3 ± 1.3 mm Hg, which were reduced to 16.3 ± 0.5 mm Hg after decompression. Pulses were present in 74% of limbs requiring decompression. Twenty limbs required decompression despite noncircumferential burns. Complications of inadequate or delayed decompression included foot drop in 20 patients (35 limbs) and muscle necrosis in 13 patients (23 limbs). Four patients (seven limbs) required amputations because of progressive muscle necrosis and infection. Complications of the procedure itself were limited to bleeding in three patients. In conclusion, compartment pressures should be followed in patients with significant burns since pressures may increase over time and pulses are not predictive of ischemia. Failure to decompress extremities with elevated pressures leads to significant but preventable complications.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Study of the distribution, characteristics, costs and effects involving 125 assaults, 22 attempted suicides (plus 5 completed out-of-hospital suicides), and 49 injuries of questionable intent was carried out among local area patients treated in a hospital serving 22 communities (150,000 population) in northern Vermont. Patients referred from the service areas of other hospitals were specifically excluded in order to provide a picture of injuries from violence in the community, rather than of injuries treated at the hospital. The percentages hospitalized were assault, 5%; attempted suicide, 50%; and unknown intent, 6%. Most assault injuries were to the head or upper extremity administered by fist; suicide attempts most often were by medication or a sharp instrument to arms, while injuries of unknown intent usually resulted from smashing a hand against a building structure. Alcohol use was noted for 26%, 38%, and 23% of patients aged 15 years or older in the three respective categories. Average hospital charges (excluding physicians' bills) for the three respective injury events were $420, $2639, and $388. Only 2% of hospital bills were paid by patients or their families, 25% were paid by commercial insurance, 19% by government sources, and 54% remained unpaid. One eighth of physicians' bills for hospital and followup care were paid by patients or their families, and about 60% were still unpaid a year after billing. Among assault patients who could be contacted for followup and who had been employed or in school previously, 27% had no disability for work or school and the remainder averaged 18 days of complete plus partial disability.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

ObjectiveTo develop a statistically valid method for trauma reimbursement and quality assurance (QA) length-of-stay filters. This is needed because diagnosis related group (DRG)-based trauma payment systems assume a random sampling of injury severities from a normally distributed population and thus result in economic disincentives to level I trauma centers.Methods142 trauma patients with MVC blunt multisystem injuries (MSI) (ISS ≥ 16) were studied concurrently during their hospital course.SettingLevel I regional trauma center.Outcome MeasuresOutcome measures were (dependent variables) length of stay (LOS) and state-approved hospital charges (COST).ResultsMean acute care COST was $74,310, but the distribution of COST was log normal, rather than Gaussian normal as assumed by DRGs. The LOS for MSI was more than twice the average for all trauma (22 vs. 9 days), reflecting skewed severities of level I patients and was related to COST (r2= 0.802;p< 0.0001). The ISS alone was a weak determinant of COST or LOS (r2= 0.05;p< 0.0001). The best single determinant of COST and LOS was survival (r2= 0.15;p< 0.0001): as it increased, it increased LOS. The most costly injuries (allp< 0.0001) involved the lower extremity (LE) or hip joint (HIP), whereas sepsis and pulmonary and surgical complications constituted the most costly complications (allp< 0.0001). Regression models that accounted for the log-normal distribution of the dependent variable and based on binary variables for survival, LE and HIP injuries, and the complications of sepsis, ARDS, pulmonary failure, MOFS, plus ISS, explained nearly two thirds of the variability in COST (r2= 0.621;p< 0.0001) or LOS (r2= 0.687;p< 0.0001) and the residuals were normally distributed.ConclusionsThese models provide a valid method of reimbursement for MSI trauma for level I trauma centers, since the data imply that good care associated with survival from specific complications of MSI are the major determinants of COST, rather than the specific type of injury or the resultant ISS. Moreover, using survival and ISS plus the disease-related complications as determinants of LOS, this method can be applied to any U.S. region since local factors can be used to adjust hospital COST as a highly correlated function of LOS. This method also permits identification of LOS outliers for QA, taking into account the influence of injury complications.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID