Where do we go from here? Interim analysis to forge ahead in violence prevention.

BACKGROUND: The severity and disparity of interpersonal violent injury is staggering. Fifty-three per 100,000 African Americans (AA) die of homicide yearly, 20 per 100,000 in Latinos, whereas the rate is 3 per 100,000 in Caucasians. With the ultimate goal of reducing injury recidivism, which now stands at 35% to 50%, we have designed and implemented a hospital-based, case-managed violence prevention program uniquely applicable to trauma centers. The Wraparound Project (WP) seizes the "teachable moment" after injury to implement culturally competent case management (CM) and shepherd clients through risk reduction resources with city and community partners. The purpose of this study was to perform a detailed intermediate evaluation of this multi-modal violence prevention program. We hypothesized that this evaluation would demonstrate feasibility and early programmatic efficacy. We looked to identify areas of programmatic weakness that, if corrected, could strengthen the project and enhance its effectiveness. METHODS: We performed intermediate evaluation on the 18-month-old program. We selected the Centers for Disease Control and Prevention-recommended instrument used for unintentional injury prevention programs and applied it to the WP. The four sequential stages in this methodology are formative, process, impact, and outcome. To test feasibility of WP, we used process evaluation. To evaluate intermediate goals of risk reduction and early efficacy, we used impact evaluation. RESULTS: Four hundred thirty-five people met screening criteria. The two case managers were able to make contact and screen 73% of gun shot victims, and 57% of stab wound victims. Of those not seen, 48% were in the hospital for 6 h/wk with the client. Forty-one percent of the time, they spent 3 hours to 6 hours. Seventeen of 18 people who required >6 hours had two to three needs. Attrition rate is only 4%. The table demonstrates percent success thus far in providing risk reduction resources. CONCLUSIONS: WP case managers served high-risk clients by developing trust, credibility, and a risk reduction plan. Cultural competency has been vital. Six of seven major needs were successfully addressed at least 50% of the time. The value of reporting these results has led WP to gain credibility with municipal stakeholders, who have now agreed to fund a third CM position. Intermediate evaluation provided a framework in our effort to achieve the ultimate goal of reducing recidivism through culturally competent CM and risk factor modification.

Refining resuscitation strategies using tissue oxygen and perfusion monitoring in critical organ beds.

BACKGROUND: Muscle tissue oxygen monitoring (PmO2) holds promise as a continuous guide to resuscitation after hemorrhagic shock, but the relationship of muscle tissue oxygen to perfusion has not been described previously. On the other hand, brain tissue oxygen PbrO2 and perfusion as measured by cerebral blood flow (CBF) are already used clinically, especially as guides to vasopressor use in cerebral perfusion targeted therapy in patients with traumatic brain injury. This laboratory study was undertaken to describe the relative contributions of muscle perfusion and arterial oxygen tension (PaO2) to muscle tissue oxygen (PmO2) levels. Second, we wanted to compare the relationship between muscle oxygen and muscle blood flow (MBF) with simultaneously measured brain tissue oxygen and perfusion during the administration of a vasopressor and during experimental hemorrhagic shock. We hypothesized that muscle perfusion would be an important contributor to PmO2, thus underscoring the need for optimal fluid resuscitation after shock. We further hypothesized that PmO2 would decrease even as PbrO2 increased when vasopressor therapy was used. METHODS: Eight pigs were anesthetized, intubated, underwent splenectomies, and were instrumented to monitor PmO2, MBF, PbrO2, and CBF. Oxygen challenges were performed by increasing PaO2 from 100 to 500 mm Hg during three different experimental phases: baseline, vasopressor administration, and hemorrhage. Mean PmO2 and MBF were compared at the beginning and end of each experimental phase and correlations between PmO2, MBF, PbrO2, CBF, and traditional endpoints of resuscitation were investigated. RESULTS: During oxygen challenges in all phases, PmO2 increased (31.2 +/- 16.6 mm Hg to 56.6 +/- 34.1 mm Hg; p < 0.01), whereas MBF did not change significantly (16.4 +/- 11.3 mL/100 g/min to 15.4 +/- 11.9 mL/100 g/min). On administration of vasopressors, MBF decreased (18 +/- 8.8 mL/100 g/min to 5.3 +/- 3 mL/100 g/min; p = 0.03), but no change in PmO2 was detected. During hemorrhage, both PmO2 and MBF declined (PmO2: 40 +/- 8.8 mm Hg to 7.7 +/- 9.6 mm Hg; p = 0.002; MBF: 9.8 +/- 5.8 mL/100 g/min to 3.3 +/- 2.4 mL/100 g/min; p = 0.046). Both PmO2 and MBF showed strong relationships with measurements of resuscitation, base deficit (PmO2 and MBF: p < 0.01), and mean arterial pressure (PmO2: p < 0.01, MBF: p = 0.02). Like PmO2 and MBF, PbrO2 and CBF decreased uniformly during hemorrhage. However, on vasopressor administration, CBF and PbrO2 increased significantly, whereas MBF decreased. CONCLUSION: PmO2 and MBF can be monitored simultaneously and continuously and correlate well with measurements of resuscitation. PmO2 values reflect both local perfusion and arterial oxygen tension. The clinical application of PmO2 as a continuous endpoint of resuscitation and its relationship to muscle perfusion warrants further study in critically injured patients and these investigations may help to refine resuscitation strategies.

Mental illness as an independent risk factor for unintentional injury and injury recidivism.

BACKGROUND: Twelve percent of Americans are diagnosed and treated for mental illness annually. The relationship between mental illness and intentional injuries such as assault and suicide has previously been described. However, unintentional injury among mentally ill adults has not been characterized. The purpose of this study was to identify relationships between mental illness diagnosis and unintentional injury. We hypothesized that diagnosed mental illness is an independent risk factor for unintentional injury and it increases the risk of recidivism. METHODS: In this retrospective cohort study, trauma registry data, medical records, and outpatient mental health care data from the San Francisco Department of Public Health Billing Information System (BIS) were used to identify patients admitted with unintentional injury at a Level I urban trauma center in 2003 and 2004. Data collected included mechanism of injury, patient outcome and disposition, mental health diagnoses, substance abuse history, presence of homelessness, number of repeat injury events, and outpatient mental health treatment history. The incidence of unintentional injury requiring admission to a trauma center and the risk of intentional injury recidivism in subjects with a mental illness diagnosis were compared with those in subjects without a mental illness diagnosis. The risk of recidivism in those who had received publicly funded outpatient treatment before their injury was also evaluated. RESULTS: Of the 1,709 patients admitted for unintentional injury, 20% had a diagnosis of mental illness. Individuals with mental illness had twice the rate of unintentional injury requiring admission (2.2-2.4 people in 1,000 vs. 1.0-1.1 in 1,000) and 4.5 times the odds of injury recidivism (odds ratio [OR] = 4.5, 95% confidence interval [CI] 3.3-6.1) as those who did not have a mental illness diagnosis. Mental illness was a more robust predictor of injury recidivism than substance abuse (OR = 3.2, 95% CI 2.3-4.3) or homelessness (OR = 2.3, 95% CI 1.5-3.4). Compared with the nonmentally ill group, subjects with mental illness had a longer hospital stay and were less likely to be discharged home. Also, their injuries were more likely the result of falling or being hit by cars, and less likely the result of motor vehicle collisions than subjects without mental illness. CONCLUSIONS: Mental illness is an independent risk factor for unintentional injury and injury recidivism. Individuals with mental illness also have a different pattern of injury and hospitalization. They tended to suffer from different mechanisms of injury, stayed in the hospital longer, and were more likely to be discharged to a skilled nursing facility. Recognition of mental illness as a risk factor for injury may prompt re-examination of resource allocation for mental health and injury prevention and highlights the mentally ill as a prime target population for unintentional injury prevention efforts.

Continuous muscle tissue oxygenation in critically injured patients: a prospective observational study.

BACKGROUND: Despite normalization of vital signs, critically injured patients may remain in a state of occult underresuscitation that sets the stage for sepsis, organ failure, and death. A continuous, sensitive, and accurate measure of resuscitation after injury remains elusive. METHODS: In this pilot study, we evaluated the ability of two continuous measures of peripheral tissue oxygenation in their ability to detect hypoperfusion: the Licox polarographic tissue oxygen monitor (PmO2) and the InSpectra near-infrared spectrometer (StO2). We hypothesized that deltoid muscle tissue oxygenation measurements could detect patients in "occult shock" who are at increased risk for post-injury complications. The study was designed to (1) define values for PmO2 and StO2 in patients who by all standard measures appeared to be clinically resuscitated; (2) evaluate the relationship between PmO2, StO2 and other physiologic variables including mean arterial pressure (MAP), lactate and base deficit (BD); and (3) examine the relationship between early low tissue oxygen values and the subsequent development of infections and organ dysfunction. Licox probes were inserted into the deltoid muscle of critically injured patients after initial surgical and radiologic interventions, and transcutaneous StO2 monitors were applied over the same muscle bed. PmO2, StO2, and standard physiologic data were collected continuously using a multimodal bioinformatics system. RESULTS: Twenty-eight critically injured patients were enrolled in this study at admission to the intensive care unit (ICU). For patients who appeared to be well resuscitated (defined as MAP > or = 70 mm Hg, heart rate [HR] < or = 110 bpm, BD > or = -2, and partial pressure of arterial oxygen (PaO2) = 80 and 150 mm Hg), the mean PmO2 was 34 +/- 11 mm Hg and StO2 was 63 +/- 27%. There was a strong relationship between PmO2 and BD (p < 0.001) but no significant relationship between StO2 and BD. The relationship between PmO2 and StO2 was weak but statistically significant. Early low values of both PmO2 and StO2 identified patients at risk for infectious complications or multiple organ failure (MOF). In patients who were well resuscitated by standard continuous parameters (HR and MAP), low PmO2 during the first 24 hours after admission (PmO2 < or = 25 for at least 2 hours) was strongly associated with the development of infectious complications (Odds Ratio = 16.5, 95% CI 1.49 to 183, p = 0.02). CONCLUSIONS: PmO2 is a responsive, reliable and continuous monitor of changes in base deficit. Initial low values for either PmO2 or StO2 were associated with post-injury complications. PmO2 monitoring may be useful in identifying patients in the state of occult underresuscitation who remain at risk for developing infection and MOF.

Effects of 23.4% sodium chloride solution in reducing intracranial pressure in patients with traumatic brain injury: a preliminary study.

OBJECTIVE: Mannitol is the standard of care for patients with increased intracranial pressure (ICP), but multiple administrations of mannitol risk renal toxicity and fluid accumulation in the brain parenchyma with consequent worsening of cerebral edema. This preliminary study assessed the safety and efficacy of small-volume injections of 23.4% sodium chloride solution for the treatment of intracranial hypertension in patients with traumatic brain injury who became tolerant to mannitol. METHODS: We retrospectively reviewed the charts of 13 adult patients with traumatic brain injury who received mannitol and 23.4% sodium chloride independently for the treatment of intracranial hypertension at San Francisco General Hospital between January and October 2003. Charts were reviewed to determine ICP, cerebral perfusion pressure, mean arterial pressure, serum sodium values, and serum osmolarity before and after treatment with 23.4% sodium chloride and mannitol. Complications were noted. RESULTS: The mean reductions in ICP after treatment were significant for both mannitol (P < 0.001) and hypertonic saline (P < 0.001); there were no significant differences between reductions in ICP when comparing the two agents (P = 0.174). The ICP reduction observed for hypertonic saline was durable, and its mean duration of effect (96 min) was significantly longer than that of mannitol treatment (59 min) (P = 0.016). No complications were associated with treatment with hypertonic saline. CONCLUSION: This study suggests that 23.4% hypertonic saline is a safe and effective treatment for elevated ICP in patients after traumatic brain injury. These results warrant a rigorous evaluation of its efficacy as compared to mannitol in a prospective randomized controlled trial.

Acute respiratory distress syndrome criteria in trauma patients: why the definitions do not work.

BACKGROUND: The international consensus definitions for acute respiratory distress syndrome (ARDS) have formed the basis for recruitment into randomized, controlled trials and, more recently, standardized the protocols for ventilatory treatment of acute lung injury. Although possibly appropriate for sepsis-induced ARDS, these criteria may not be appropriate for posttraumatic ARDS if the disease patterns are widely divergent. This study tests the hypothesis that standard ARDS criteria applied to the trauma population will capture widely disparate forms of acute lung injury and are too nonspecific to identify a population at risk for prolonged respiratory failure and associated complications. METHODS: Patients with and Injury Severity Score > or = 16 ventilated for > 12 hours were prospectively enrolled. Clinical data, including elements of cardiovascular, renal, hepatic, hematologic, neurologic, and pulmonary function, were collected daily. Two hundred fifty-four patients were enrolled over a 36-month period, of whom 70 met the consensus definitions of ARDS. Patients from whom support was withdrawn within 48 hours were excluded. The remaining 61 patients were stratified into two groups on the basis of intubation (n = 12) days. RESULTS: There was considerable disparity in severity and clinical course. A mild, limited form of ARDS was characterized by earlier onset (group 1, 2 days; group 2, 4 days; p = 0.002), fewer intubation days (7 days vs. 28 days; p < 0.001), and less severe derangements in lung mechanics. A significant difference between the two groups was also seen in systemic inflammatory response syndrome score, incidence of sepsis, and incidence of multiple organ failure. CONCLUSION: The criteria for ARDS, when applied to the trauma population, capture a widely disparate group and has poor specificity for identifying patients at risk. Recruitment of trauma patients for ARDS studies or preemptive ventilatory management based solely on these criteria may be ill-advised.