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Biomedical subjects

R V Maier

Publications and source records attributed to R V Maier.

At least 37 records · Page 2Linked to original sources
PubMed2000

Harborview assessment for risk of mortality: an improved measure of injury severity on the basis of ICD-9-CM.

BACKGROUND: There have been several attempts to develop a scoring system that can accurately reflect the severity of a trauma patient's injuries, particularly with respect to the effect of the injury on survival. Current methodologies require unreliable physiologic data for the assignment of a survival probability and fail to account for the potential synergism of different injury combinations. The purpose of this study was to develop a scoring system to better estimate probability of mortality on the basis of information that is readily available from the hospital discharge sheet and does not rely on physiologic data. METHODS: Records from the trauma registry from an urban Level I trauma center were analyzed using logistic regression. Included in the regression were Internation Classification of Diseases-9th Rev (ICD-9CM) codes for anatomic injury, mechanism, intent, and preexisting medical conditions, as well as age. Two-way interaction terms for several combinations of injuries were also included in the regression model. The resulting Harborview Assessment for Risk of Mortality (HARM) score was then applied to an independent test data set and compared with Trauma and Injury Severity Score (TRISS) probability of survival and ICD-9-CM Injury Severity Score (ICISS) for ability to predict mortality using the area under the receiver operator characteristic curve. RESULTS: The HARM score was based on analysis of 16,042 records (design set). When applied to an independent validation set of 15,957 records, the area under the receiver operator characteristic curve (AUC) for HARM was 0.9592. This represented significantly better discrimination than both TRISS probability of survival (AUC = 0.9473, p = 0.005) and ICISS (AUC = 0.9402, p = 0.001). HARM also had a better calibration (Hosmer-Lemeshow statistic [HL] = 19.74) than TRISS (HL = 55.71) and ICISS (HL = 709.19). Physiologic data were incomplete for 6,124 records (38%) of the validation set; TRISS could not be calculated at all for these records. CONCLUSION: The HARM score is an effective tool for predicting probability of in-hospital mortality for trauma patients. It outperforms both the TRISS and ICD9-CM Injury Severity Score (ICISS) methodologies with respect to both discrimination and calibration, using information that is readily available from hospital discharge coding, and without requiring emergency department physiologic data.

Adolescent↗
PubMed2000

Interactions of calcium/calmodulin-dependent protein kinases (CaMK) and extracellular-regulated kinase (ERK) in monocyte adherence and TNFalpha production.

The circulating monocyte possesses a markedly different functional phenotype relative to the macrophage (Mphi). The adhesive interactions encountered by the monocyte, en route to the inflammatory focus, generate signals that culminate in the expression of a pro-inflammatory Mphi phenotype, marked by enhanced cytokine production. Previously, we demonstrated that calcium and calmodulin are essential for maximal Mphi activation and, in particular, TNFalpha production. These effects are likely to be mediated through signal transduction kinases that require the calcium/calmodulin complex. Here, we investigated the effect of adherence on calcium/calmodulin-dependent protein kinase (CaMK) II and IV activation of the extracellular-signal regulated kinase (ERK) 1/2 cascade and on lipopolysaccharide (LPS)-induced TNFalpha production by human monocytes. Adherence activated ERK 1/2 and led to an 8-fold potentiation in LPS-induced TNFalpha production over similarly stimulated non-adherent cells. Inhibition of CaMK II prior to adherence prevented ERK 1/2 activation and attenuated by up to 40%, the TNFalpha response to subsequent LPS stimulation. CaMK II inhibition after adherence, however, failed to modify cytokine release. Inhibition of CaMK IV, both after adherence and in non-adherent monocytes, significantly inhibited LPS-induced ERK 1/2 activation and abrogated TNFalpha production by up to 75%. These data suggest that the function of CaMK II in TNFalpha production by adherent monocytes occurs during adhesion, is mediated in part by activation of ERK 1/2, and appears to "prime" the monocyte for enhanced cytokine production. CaMK IV, through activation of ERK 1/2, appears to have a direct role in the LPS signal transduction for TNFalpha production.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2000

Adherence regulates macrophage signal transduction and primes tumor necrosis factor production.

While monocyte/macrophage (Mphi) adherence to a matrix is necessary for differentiation and prolonged survival, the effect of adherence on the signaling mechanisms responsible for Mphi activation is unknown. Lipopolysaccharide (LPS) activates Mphi by signaling through members of the mitogen activated protein kinase (MAPK) family thereby inducing transcription of proinflammatory cytokines, such as TNF-alpha. Since adherence has been shown to affect different activities of various myeloid phagocytes, we investigated whether adherence affects intracellular signaling and modulates activation of the Mphi proinflammatory phenotype. We assessed the effect of adherence on activation of rabbit alveolar Mphi by measuring LPS-induced TNF-alpha mRNA and TNF-alpha secreted product in adherent versus nonadherent cells, in vitro. The effect of adherence on LPS-induced activation of MAPK was assessed by western analysis using a dual phosphospecific antibody against p38MAPK, p42,44ERK, and p54SAPK. LPS is known to induce activation of NF-kappaB and AP-1. Modulation of these two transcription factors by LPS under adherent versus nonadherent conditions was evaluated by gel-shift analyses. The results were that adherent cells treated with LPS, 10 ng/mL or 1 microg/ml, elicited a 26- and 132-fold increase, respectively, in TNF-alpha production. Nonadherent cells did not elicit significant TNF-alpha in response to LPS. Adherence alone induced significant ERK and AP-1 activation, but did not stimulate a significant TNF-alpha response and no further activation of ERK and AP-1 was observed with LPS stimulation. Adherence alone did not activate p38MAPK or NF-kappaB, but primed Mphi for an augmented response to LPS in activation of p38, NF-kappaB and in production of TNF-alpha. We conclude that adherence primes Mphi for activation and regulates MAPK signal transduction pathways.

Animals↗
PubMed2000

Effect of an older sibling and birth interval on the risk of childhood injury.

OBJECTIVE: Certain family structures have been identified as putting children at high risk for injury. To further define children at highest risk, we set out to explore the effect of an older sibling and birth interval on the risk of injury related hospital admission or death. METHODS: Data were analyzed using a case-control design. Cases and controls were identified by linking longitudinal birth data from Washington state (1989-96) to death certificate records and hospital discharge data obtained from the Washington State Comprehensive Hospital Abstract Reporting System and frequency matched in a 1:2 ratio on year of birth. Cases consisted of singleton children 6 years of age or younger who were hospitalized or died as a result of injury during the years 1989-96. Multivariate logistic regression was used to identify and adjust for confounding variables. RESULTS: There were 3145 cases and 8371 controls. The adjusted odds ratio for injury in children with an older sibling was 1.50 (95% confidence interval 1.37 to 1.65). The effect was greatest in children under 2 years of age, and in those with a birth interval of less than two years. As the number of older siblings increased, so did the risk of injury, with the highest risk in children with three or more older siblings. CONCLUSION: These data suggest that the presence of an older sibling is associated with an increased risk of injury. The risk is highest in those with very short birth intervals. Potential mechanisms for this increased risk may relate to inadequate parental supervision. Pediatricians and other care providers need to be alert to these identifiable risk factors and then direct preventive strategies, such as home visits and educational programs, toward these families.

Birth Certificates↗
PubMed1999

Alcohol (ethanol) inhibits IL-8 and TNF: role of the p38 pathway.

Acute ethanol (EtOH) intoxication has been identified as a risk factor for infectious complications in trauma and burn victims. However, the mechanism of this immune dysfunction has yet to be elucidated. The monocyte/macrophage production of cytokines, in particular IL-8 and TNF-alpha, is critical in the regulation of the acute inflammatory response to infectious challenge. IL-8 is a potent chemoattractant and activator of neutrophils. TNF-alpha, a proinflammatory cytokine, initiates expression of endothelial cell surface adhesion molecules and neutrophil migration. p38, a member of the mitogen-activated protein kinases, plays an important role in mediating intracellular signal transduction in endotoxin-induced inflammatory responses. We examined the effects of LPS and ethanol on p38 activation and the corresponding IL-8 and TNF-alpha production in human mononuclear cells. LPS-induced IL-8 and TNF-alpha production was inhibited in a similar pattern by pretreatment with either EtOH or SB202190 (1 microM), a specific inhibitor of p38 kinase. Western blot analysis, using a dual phospho-specific p38 mitogen-activated protein kinase Ab, demonstrated that EtOH pretreatment inhibited LPS-induced p38 activation. These results demonstrate that alcohol suppresses the normal host immune inflammatory response to LPS. This dysregulation appears to be mediated in part via inhibition of p38 activation. Inhibition of IL-8 and TNF-alpha production by acute EtOH intoxication may inhibit inflammatory focused neutrophil migration and activation and may be a mechanism explaining the increased risk of trauma- and burn-related infections.

Adult↗
PubMed1999

Hypertonic saline induces prostacyclin production via extracellular signal-regulated kinase (ERK) activation.

BACKGROUND: Hypertonic saline (HTS) resuscitation exerts protective effects in reperfusion injury including a decrease in pulmonary vascular resistance and an increase in microvascular perfusion and cerebral blood flow; however, the mediators of these effects are unknown. Prostacyclin (PGI2) is a paracrine mediator with two main effects, vasodilation and inhibition of platelet aggregation. We hypothesized that HTS may induce PGI2 production by endothelial cells. METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with varying concentrations of NaCl. After 12 h of incubation, the supernatant was assayed for 6-keto-prostaglandin F1, a stable metabolite of PGI2, by ELISA. Phospho-specific ERK-1 and ERK-2 mitogen-activated protein kinase (MAPK) antibody, which recognizes only activated ERK, was used to determine ERK activation status by Western blotting. RESULTS: Addition of 20-100 mM NaCl or endotoxin [lipopolysaccharide (LPS)] induced PGI2 production by HUVECs. HTS and LPS induced ERK-1 and ERK-2 activation. PGI2 production was inhibited when the HUVECs were pretreated with PD 98059, a specific inhibitor of ERK phosphorylation. CONCLUSION: These data suggest that HTS induces PGI2 production in HUVECs. In addition, HTS and LPS induce activation of ERK which is required for PGI2 production. HTS resuscitation may improve microvascular circulation and decrease reperfusion injury via induction of PGI2 production by endothelial cells.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

Does the face protect the brain? A case-control study of traumatic brain injury and facial fractures.

BACKGROUND: The relationship between facial fractures and traumatic brain injury is controversial. Some studies show an increased risk of brain injury with the presence of facial fractures while others claim that facial fractures protect against brain injury. OBJECTIVE: To examine the association between facial fractures and traumatic brain injuries. DESIGN: Case-control study. SETTING: Subjects were recruited from the emergency departments of 7 hospitals in the Seattle, Wash, area. PATIENTS: Three thousand eight hundred forty-nine injured bicyclists and 5 scene deaths were identified from March 1, 1992, to August 31, 1994, with complete data available on 3388 bicyclists. INTERVENTIONS: None. RESULTS: The study group was composed of 1602 cases with injuries to the head, face, or brain and 1540 control subjects. There were 203 bicyclists with traumatic brain injuries, of whom 62 had an identifiable intracranial injury and 141 suffered a concussion. A total of 81 patients sustained facial fractures. The odds ratio for the risk of intracranial injury associated with facial fractures after adjustment for significant confounders was 9.9 (95% confidence interval, 5.1-19.3). The effect was less strong but still present when all traumatic brain injuries including concussions were considered (odds ratio, 2; 95% confidence interval, 1.1-3.7). No association was found for concussion only. CONCLUSIONS: This study demonstrates no evidence that facial fractures help prevent traumatic brain injury. Data indicate that facial fractures are markers for increased risk of brain injury.

Adolescent↗
PubMed1999

Priming interleukin 8 production: role of platelet-activating factor and p38.

HYPOTHESIS: Platelet-activating factor (PAF) activates p38, an important intracellular signal transduction kinase, and primes human mononuclear cells for the production of interleukin 8 (IL-8), a potent chemoattractant and activator of neutrophils. METHODS: Human mononuclear cells were isolated from healthy adults by Ficoll-paque density-gradient centrifugation. Interleukin-8 in the supernatant was measured by enzyme-linked immunosorbent assay. Dual phospho-specific p38 antibody was used to detect activated p38 by Western blotting. RESULTS: Lipopolysaccharide (LPS) and PAF activated p38. There was a shorter latency to peak p38 activation with PAF vs LPS stimulation, 5 vs 30 minutes. Platelet-activating factor-induced p38 activation was calcium dependent because it was inhibited by ethyleneglycoltetracetic acid. Lipopolysaccharide, 0.01 to 1.00 ng/mL, induced significant IL-8 production. Although PAF did not induce significant IL-8 production, it potentiated LPS-induced IL-8 production. Production of IL-8, in response to LPS alone or in combination with PAF, was inhibited by SB202190, a specific p38 inhibitor. CONCLUSIONS: Although LPS and PAF activated p38, only LPS induced IL-8 production; PAF acted as a priming agent. It seems that p38 activation is necessary but not sufficient for IL-8 production by human mononuclear cells. Identifying and evaluating the activation state of inflammatory signal transduction pathways might lead to methods for controlling and preventing neutrophil-induced tissue injury without interfering with the normal host immune response.

Adult↗
PubMed1999

Reasons why trauma surgeons fail to screen for alcohol problems.

BACKGROUND: Alcohol screening and intervention have been recommended as routine components of trauma care but are rarely performed. HYPOTHESIS: An association exists between current screening and counseling practices and the trauma surgeon's knowledge, attitude, and perceived role and responsibility toward alcohol problems. PARTICIPANTS: Random-sample survey (n = 241) of members of the American Association for the Surgery of Trauma. MAIN OUTCOME MEASURES: Reported screening and counseling practices. RESULTS: Fifty-four percent of respondents screened 25% or fewer patients, while only 29% screened most patients. The most common reason for not screening was "lack of time." Most (76%) were not familiar with the most common clinically used screening questionnaires, and 83% reported no training in alcohol screening. Screening was more likely if attending physicians perceived a major responsibility for screening (P<.001). Nonscreeners were twice as likely to state screening was "not what I was trained to do" and more frequently believed screening offends patients (P =.001). Independent predictors of screening were perceived major role responsibility (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.38-4.01) and confidence in screening ability (OR, 1.96; 95% CI, 1.05-3.67) and counseling ability (OR, 2.27; 95% CI, 1.34-3.85). Eighty-eight percent of respondents would be willing to devote time to training if shown that counseling is effective. CONCLUSIONS: Lack of screening and counseling appears to be due to cognitive factors, not lack of motivation. Skills on how to screen and counsel for alcohol abuse should be taught to trauma surgeons, because a strong correlation exists between screening and confidence in skills. There is a need for education regarding results of effective intervention trials in medical settings.

Alcohol-Related Disorders↗
PubMed1999

Ten-year trend in survival and resource utilization at a level I trauma center.

OBJECTIVE: To determine the impact of increasing trauma center experience over time on survival and resource utilization. METHODS: The authors studied a retrospective cohort at a single level I trauma center over a 10-year period, from 1986 to 1995. Patients included all hospital admissions and emergency department deaths. The main outcome measures were the case-fatality rate adjusted for injury severity, hospital length of stay, and costs. RESULTS: A total of 25,979 patients were admitted or died. The number of patients per year increased, from 2063 in 1986 to 3313 in 1995. The proportion of patients transferred from another institution increased from 16.2% to 34.4%. Although mean length of stay declined by 28.4%, from 9.5 to 6.8 days, costs increased by 16.7%, from $14,174 to $16,547. The use of specific radiologic investigations increased; the frequency of operative procedures either remained unchanged (craniotomy, fracture fixation) or decreased (celiotomy). After adjusting for injury severity and demographic factors, the mortality rate decreased over 10 years. The improvement in survival was confined to patients with an injury severity score > or =16. CONCLUSION: Over a 10-year period, the case-fatality rate declined in patients with severe injuries. Overall acute care costs increased, partially because of the increased use of radiologic investigations. Even in otherwise established trauma centers, increasing cumulative experience results in improved survival rates in the most severely injured patients. These data suggest that experience contributes to a decrease in mortality rate after severe trauma and that developing trauma systems should consider this factor and limit the number of designated centers to maximize cumulative experience at individual centers.

Adult↗
PubMed1999

Defining excess resource utilization and identifying associated factors for trauma victims.

BACKGROUND: Trauma system evaluation addresses aspects of the process, structure, and outcomes of trauma care. This approach may not identify all opportunities for trauma system improvement. Hospital length of stay (LOS) represents a meaningful measure of resource utilization and may help focus efforts to improve care. The purpose of this study is to estimate expected hospital LOS after trauma and determine the consequences of excessive LOS. METHODS: Patients admitted during a 2-year period (January 1, 1993 to December 31, 1994) were retrospectively reviewed, and expected LOS was estimated. Excess LOS was defined as an observed LOS > or =100% of expected. Injuries, complications, and American College of Surgeons' Committee on Trauma audit filters were compared between the groups. RESULTS: Observed LOS exceeded expected by 100% or more for 568 of 5,226 patients (10.9%), and most survived (98.3%). Complications predicted excess LOS, whereas audit filters did not. Median costs for these 568 patients were $30,315 and totaled 30% of the expenditures for the entire cohort of 5,226 patients. CONCLUSION: Prolonged LOS represents an adverse outcome. Estimation of LOS and evaluation of outliers represents an important method for the evaluation of care within established trauma systems and centers.

Adult↗
PubMed1999

Stapled versus sutured gastrointestinal anastomoses in the trauma patient.

BACKGROUND: Construction of gastrointestinal anastomoses by using stapling devices has become a familiar procedure. Most studies have shown no significant differences in complication rates between stapled and sutured anastomoses performed during elective surgery. To date, no study has evaluated the incidence of complications of stapled anastomoses in the trauma patient. The purpose of our study was to determine whether the incidence of postoperative complications differs between stapled and sutured anastomoses after the emergent repair of traumatic bowel injuries. METHODS: A retrospective analysis of the medical and institutional trauma registry records of patients identified to have undergone a gastrointestinal anastomosis in a regional Level I trauma center over a 4-year period. RESULTS: A total of 84 patients with 118 gastrointestinal anastomoses were identified. A surgical stapling device was used to create 58 separate anastomoses, whereas a hand-sutured method was used in 60 anastomoses. A complication was defined as an anastomotic leak verified at reoperation. The ratio of blunt versus penetrating injuries, mean abdominal Abbreviated Injury Scale score, and Injury Severity Score were similar in the two groups. Stapling and suturing techniques were evenly distributed between small and large bowel repairs. Mean intensive care unit length of stay was comparable in both cohorts. However, inpatient length of stay was longer in patients with solely a stapled anastomosis compared with sutured anastomoses. Four of the 58 stapled anastomoses and none of the 60 hand-sewn anastomoses resulted in a clinically significant leak requiring reoperation (relative risk = undefined; 95% confidence interval, 1.14-infinity; p = 0.037). Each anastomotic leak occurred in a separate individual. The only death occurred in the stapled cohort secondary to peritonitis and subsequent sepsis. CONCLUSION: Anastomotic leaks seem to be associated with stapled bowel repairs compared with sutured anastomoses in the traumatically injured patient.

Adult↗
PubMed1999

Complications of surgical feeding jejunostomy in trauma patients.

OBJECTIVE: To determine the complication rate of feeding jejunostomy (FJ) performed as an adjunct to trauma celiotomy. METHODS: Retrospective analysis of 222 patients from January of 1988 to May of 1998. RESULTS: Thirty-seven total FJ-related complications occurred in 22 patients (10%). Major FJ-related complications occurred in nine patients (4%): two small bowel perforations, two small bowel volvuli with infarction, two intraperitoneal leaks, and three small bowel necroses. Patients suffering major FJ-related complications were similar to those without complications, except for the FJ type. Patients with major FJ-related complications were more likely to have had a Witzel tube jejunostomy than a needle catheter jejunostomy (p = 0.03). Three deaths were related to major FJ complications, for a FJ-related mortality rate of 1.4%. CONCLUSIONS: FJ has a major complication rate of 4% in severely injured patients. Major complications occur more frequently with larger, Witzel-type tubes. Needle catheter jejunostomy appears to be a safer method of surgical jejunal access in trauma patients.

Abbreviated Injury Scale↗
PubMed1998

Open pelvic fracture and fecal diversion.

BACKGROUND: Mandatory fecal diversion has been advocated as an appropriate measure to prevent infection in the clinical setting of an open pelvic fracture. However, the efficacy of this practice has not been verified by prospective investigation and has received only inconsistent support from retrospective analyses. OBJECTIVE: To determine whether fecal diversion is associated with a substantially lower incidence of abdominopelvic infectious complications in patients with open pelvic fractures. DESIGN: Case-control study. SETTING: University-based tertiary care, level I trauma center. METHODS: The current study reviews our experience with 60 cases admitted from 1987 to 1993 to Harborview Medical Center, a regional level I trauma center. Data collected on each patient included age, sex, Injury Severity Score, Glasgow Coma Scale, initial heart rate and systolic blood pressure, location and severity of wound, fracture pattern, pelvic stability, time to open reduction internal fixation or external fixation, mortality, use of fecal diversion, and incidence and location of infection. Review of the literature produced an additional 186 patients amenable to analysis. RESULTS: Fecal diversion was performed in 19 patients, 5 (26%) of whom experienced subsequent abdominopelvic infectious morbidity. Of the remaining 41 patients, 7 patients (17%) experienced infectious complications. The 2 groups (diversion vs no diversion) were comparable with regard to relevant demographic and clinical characteristics of injury severity. Combining the present series with those reported by others gave a composite series of 246 patients. For the composite series, diversion was performed in 70% of patients. Infection developed in 27% of patients who underwent diversion vs 29% in patients who did not. In the present series, only mechanical instability was determined by stepwise logistic regression to be significantly associated with pelvic infection. This association was not altered by diversion status. CONCLUSIONS: Diversion of the fecal stream to protect open pelvic fractures is not associated with a lower incidence of abdominopelvic infectious complications. Diversion may offer protection to a select group of patients with extensive soft tissue injury or posterior wounds. Mechanical instability was independently associated with infection.

Abdominal Abscess↗
PubMed1998

Incidence of infectious complications associated with the use of histamine2-receptor antagonists in critically ill trauma patients.

OBJECTIVE: To determine the impact of histamine2 (H2)-receptor antagonist use on the occurrence of infectious complications in severely injured patients. SUMMARY BACKGROUND DATA: Some previous studies suggest an increased risk of nosocomial pneumonia associated with the use of H2-receptor blockade in critically ill patients, but other investigations suggest an immune-enhancing effect of H2-receptor antagonists. The purpose of this study was to determine whether H2-receptor antagonist use affects the overall incidence of infectious complications. METHODS: Patients enrolled in a randomized trial comparing ranitidine with sucralfate for gastritis prophylaxis were examined for all infectious complications during their hospitalization. Data on the occurrence of pneumonia were prospectively collected, and other infectious complications were retrospectively obtained from the medical record. The relative risk of infectious complications associated with ranitidine use and total infectious complications were analyzed. RESULTS: Of 98 patients included, the charts of 96 were available for review. Sucralfate was given to 47, and 49 received ranitidine. Demographic factors were similar between the groups. Ranitidine use was associated with a 1.5-fold increased risk of developing any infectious complication (37 of 47 vs. 26 of 47; 95% confidence interval, 1.04 to 2.28). Infectious complications totaled 128 in the ranitidine-treated group and 50 in the sucralfate-treated group (p = 0.0014). These differences remained after excluding catheter-related infections (p = 0.0042) and secondary bacteremia (p = 0.0046). CONCLUSIONS: Ranitidine use in severely injured patients is associated with a statistically significant increase in overall infectious complications when compared with sucralfate. These results indicate that ranitidine should be avoided where possible in the prophylaxis of stress gastritis.

Adult↗
PubMed1998

Trauma mortality patterns in three nations at different economic levels: implications for global trauma system development.

BACKGROUND: Whereas organized trauma care systems have decreased trauma mortality in the United States, trauma system design has not been well addressed in developing nations. We sought to determine areas in greatest need of improvement in the trauma systems of developing nations. METHODS: We compared outcome of all seriously injured (Injury Severity Score > or = 9 or dead), nontransferred, adults managed over 1 year in three cities in nations at different economic levels: (1) Kumasi, Ghana: low income, gross national product (GNP) per capita of $310, no emergency medical service (EMS); (2) Monterrey, Mexico: middle income, GNP $3,900, basic EMS; and (3) Seattle, Washington: high income, GNP $25,000, advanced EMS. Each city had one main trauma hospital, from which hospital data were obtained. Annual budgets (in US$) per bed for these hospitals were as follows: Kumasi, $4,100; Monterrey, $68,000; and Seattle, $606,000. Data on prehospital deaths were obtained from vital statistics registries in Monterrey and Seattle, and by an epidemiologic survey in Kumasi. RESULTS: Mean age (34 years) and injury mechanisms (79% blunt) were similar in all locations. Mortality declined with increased economic level: Kumasi (63% of all seriously injured persons died), Monterrey (55%), and Seattle (35%). This decline was primarily due to decreases in prehospital deaths. In Kumasi, 51% of all seriously injured persons died in the field; in Monterrey, 40%; and in Seattle, 21%. Mean prehospital time declined progressively: Kumasi (102 +/- 126 minutes) > Monterrey (73 +/- 38 minutes) > Seattle (31 +/- 10 minutes). Percent of trauma patients dying in the emergency room was higher for Monterrey (11%) than for either Kumasi (3%) or Seattle (6%). CONCLUSIONS: The majority of deaths occur in the prehospital setting, indicating the importance of injury prevention in nations at all economic levels. Additional efforts for trauma care improvement in both low-income and middle-income developing nations should focus on prehospital and emergency room care. Improved emergency room care is especially important in middle-income nations which have already established a basic EMS.

Cross-Cultural Comparison↗
PubMed1998

Imprecision in lower "inflection point" estimation from static pressure-volume curves in patients at risk for acute respiratory distress syndrome.

BACKGROUND: Static pressure-volume (PV) curves have been promoted as a tool for selecting positive end-expiratory pressure (PEEP) by identifying a lower "inflection point" (Pflex) from these curves. Their visual interpretation is subjective and difficult, however, particularly with subtle changes in the slope of the curves. This study was designed to examine the physician-to-physician variability in estimating the lower Pflex from these curves. METHODS: Static PV curves for eight patients were obtained within 24 hours of admission. Five intensivists and one respiratory therapist independently estimated the lower Pflex from these curves. RESULTS: Pflex estimates for individual patients were highly variable, ranging from 5 to 9 cm H2O. This variability was not attributable to a single discordant estimate, nor was a single physician responsible for consistently high or low estimates. CONCLUSION: Static PV curve interpretation with current methods imprecisely estimates the lower inflection point and is of limited usefulness in PEEP selection.

Humans↗