The role of avoidance in modulating single prolonged stress effects on emotional memory in male and female rats.

The incidence of post traumatic stress disorder (PTSD) is greater in women than men, but mechanisms via which this difference manifests remain under explored. The single prolonged stress (SPS) rodent model of traumatic stress has been used to identify mechanisms through which traumatic stress leads to deficits in retaining extinction (a core PTSD symptom), but has been mostly utilized in male model systems. Recent studies have observed that SPS leads to changes in persistent fear memory in female rats, though these results are variable. This variability could be driven by changes in behavioral strategy in females during extinction, but this possibility has not been sufficiently explored. To address this, we examined the impact of SPS on freezing and avoidance (a core PTSD symptom) during extinction in male and female rats. In male rats, SPS enhanced acquisition of conditioned freezing, but did not enhance freezing during extinction training or testing. SPS also decreased avoidance during extinction training, but not extinction testing. In female rats, SPS had no impact on conditioned freezing. Avoidance was not observed in control rats, but emerged in SPS/female rats during extinction testing. Furthermore, avoidance was negatively correlated with freezing in female rats (high avoidance associated with lower freezing), but this relationship was disrupted with SPS. The results suggest that introducing avoidance during extinction negates SPS effects on extinction retention in male and female rats, control/female rats engage in avoidance to regulate fear expression, and this relationship is disrupted with SPS.

Does Bronchoscopic Evaluation of Inhalation Injury Severity Predict Outcome?

Although fiber-optic bronchoscopy is essential in the diagnosis of smoke inhalation injury (INH), controversy still exists over whether or not the visualized severity of the mucosal injury predicts clinically meaningful outcomes. The purpose of this study was to assess whether the grade of mucosal INH severity was associated with various outcomes among adult burn patients. We conducted a retrospective review of all patients requiring greater than or equal to 48 hours of mechanical ventilation who were admitted between January 1, 2007 and June 1, 2014 to an adult regional American Burn Association-verified burn center. Bronchoscopy was performed on all subjects at burn center admission and grading of severity was documented using the grades 0 to 4 abbreviated injury score (AIS). Subjects with grade 1 or 2 injury formed the low-grade INH group, whereas those with grade 3 or 4 injury formed the high-grade INH group. Values are shown as the median (first to third quartiles). A P value less than .05 was considered significant. The study population consisted of 160 subjects (age, 48 [35-60] years; %TBSA burn, 28 [19-39.9]; % full thickness burn, 12.8 [0-30]; and 61% with INH). There were no significant differences in age, %TBSA burn, or % full thickness burn between subjects with different individual INH severity grades. Oxygenation on the day of injury worsened significantly as the severity of INH increased, but otherwise there were no significant differences in 24 and 48-hour fluid requirements, duration of ventilation, ventilator free days, incidence of acute respiratory distress syndrome, or mortality between subjects with different individual grades of INH severity. Subjects with high-grade INH showed statistically insignificant trends toward larger 48-hour fluid volumes (P = .07), poorer oxygenation over the first 3 post burn days (P = .055), longer duration of ventilation (P = .08), and fewer ventilator free days (P = .047) than low-grade INH. High-grade and low-grade INH subjects did not differ significantly in the incidence of acute respiratory distress syndrome or mortality. The individual grades of the 0 to 4 AIS INH severity grading scale were not particularly robust in the prediction of various outcomes among a population of adult burn patients. However, clinically relevant trends toward worsened oxygenation over postburn days 0 to 3, longer duration of mechanical ventilation, and reduced ventilator-free days in association with more severe INH were identified when subjects were broadly stratified into low-grade (grades 1and 2) INH and high-grade (grades 3 and 4) INH. This suggests that there may clinically meaningful differences between patients with less and more severe INH, and that further refinement of the grades 0 to 4 AIS INH severity should be subjected to additional investigation.

The Acute Respiratory Distress Syndrome (ARDS) in mechanically ventilated burn patients: An analysis of risk factors, clinical features, and outcomes using the Berlin ARDS definition.

BACKGROUND: The Berlin definition of Acute Respiratory Distress Syndrome (ARDS) has been applied to military burns resulting from combat-related trauma, but has not been widely studied among civilian burns. This study's purpose was to use the Berlin definition to determine the incidence of ARDS, and its associated respiratory morbidity, and mortality among civilian burn patients. METHODS: Retrospective study of burn patients mechanically ventilated for ≥48h at an American Burn Association-verified burn center. The Berlin criteria identified patients with mild, moderate, and severe ARDS. Logistic regression was used to identify variables predictive of moderate to severe ARDS, and mortality. The outcome measures of interest were duration of mechanical ventilation and in-hospital mortality. Values are shown as the median (Q1-Q3). RESULTS: We included 162 subjects [24% female, age 48 (35-60), % total body surface area (TBSA) burn 28 (19-40), % body surface area (BSA) full thickness (FT) burn 13 (0-30), and 62% with inhalation injury]. The incidence of ARDS was 43%. Patients with ARDS had larger %TBSA burns [30.5 (23.1-47.0) vs. 24.8 (17.1-35), p=0.007], larger FT burns [20.5(5.4-35.5) vs. 7 (0-22.1), p=0.001], but had no significant difference in the incidence of inhalation injury (p=0.216), compared to those without ARDS. The % FT burn predicted the development of moderate to severe ARDS [OR 1.034, 95%CI (1.013-1.055), p=0.001]. ARDS developed in the 1st week after burn in 86% of cases. Worsening severity of ARDS was associated with increased days of mechanical ventilation in survivors (p=0.001), a reduction in ventilator-free days/1st 30 days in all subjects (p=0.004), and a strong indication of increased mortality (0% in mild ARDS vs. 50% in severe ARDS, unadjusted p=0.02). Neither moderate ARDS nor severe ARDS were significant predictors of death. CONCLUSIONS: ARDS is common among mechanically ventilated civilian burn patients, and develops early after burn. The extent of full thickness burn predicted development of moderate to severe ARDS. Increasing severity of ARDS based upon the Berlin definition was associated with a significantly greater duration of mechanical ventilation and a trend toward higher mortality.

Factors associated with clinical skill remediation in dental hygiene education programs.

PURPOSE: The purpose of this study was to examine the challenges related to formal clinical remediation in dental hygiene programs, which include timing of student identification, policy development, and the issues of methodology and scheduling. METHODS: A 23 item investigator-designed survey was electronically distributed to all 303 U.S. entry-level dental hygiene program directors. This questionnaire included 23 forced-choice questions with the options to add comments to 8 of the questions. A total of 111 surveys were returned yielding a response rate of 36%. Descriptive statistics and Chi-square analyses were utilized to analyze relationships between responses and the degree earned from the dental hygiene program. RESULTS: All schools reported having a remediation policy; however, 13.6% of the respondents revealed this information was not readily available to students. The majority of respondents (67.8%) reported identifying students with clinical deficiencies in the preclinical semester, and 15.5% identified students in the second year, second clinical semester. Instrumentation technique was identified as the area in greatest need of remediation (81%), followed by critical thinking and problem solving skills (12%). Coordination of faculty and student schedules to conduct remediation was identified as one of the greatest challenges by respondents (25.2%). Results of this study suggest that challenges exist with the process of remediation. Some of these challenges include involving the student in remedial plan development, the academic consequences associated with remediation and scheduling time and space for remedial activities. CONCLUSION: These findings indicate that respondents are well aware of the need for remediation policies in dental hygiene programs. The point in time varies when students in need of remediation are identified. Therefore, further research needs to be conducted to determine the reasons for this difference. Some reasons may include inability to grasp the foundational skills and/or the complexity of advanced instrumentation in the second year. Also, it is suggested that investigation regarding methods used to address the challenge of faculty and student scheduling for remediation sessions would be useful.