Introduction: Outpatient ketamine infusions can be effective in relieving severe neuropathic pain... more Introduction: Outpatient ketamine infusions can be effective in relieving severe neuropathic pain for a period of weeks or months. The NMDA receptor is involved in learning and memory and antagonists such as ketamine may be associated with cognitive impairment (1,2). The objective of this study is to investigate whether repeat outpatient ketamine infusions are associated with cognitive dysfunction as measured by the Manos 10-point clock test, a validated screening tool for cognitive dysfunction(3). Methods: With IRB approval, patients undergoing repeat outpatient ketamine infusions were asked to complete a Manos 10 point clock test before and after each ketamine infusion and on the follow up clinic visit 2 to 4 weeks after the last infusion. The clock is scored using the Manos 10 point clock drawing criteria. Intact cognition was a score of 10, probable cognitive deficit, less than 8, and severely impaired at less than 4. Statistical analysis was done in two parts to evaluate the primary and secondary questions. Mean clock score, BMI, age, and ketamine dose were calculated across days 1-3 and times (pre,post), so there would only be 1 clock score and 1 covariate score for BMI, age, and dose for each subject at each episode. For the primary question of whether there is a change in cognition associated with additional episodes of care, we used fixed effects mixed model regression, with clock scores as the dependent variable. We were particularly interested in the adjusted effect of episode of care with later episodes’ clock scores being compared to episode 1. A significant effect would indicate that cognition changes over time within subjects. For the secondary questions, in order to determine whether the clock score pattern across episodes differed by age, ketamine dose, BMI, race, sex, or the presence of opioids or antidepressants, we used a random effects mixed model including each of the above variables as covariates, along with episode. If the term was significant, it meant that the pattern of clock scores across episodes of care differed across levels of the indicator variable. Results: Each patient was given ketamine infusions for 3 consecutive days constituting one episode. These episodes were repeated 4 to 16 weeks apart. Data from 60 patients, who collectively had 124+ repeat episodes, were collected. In the final adjusted fixed effects model, episodes 4 (p=.037) and 6 (p=.039) both had significantly lower clock scores than episode one. In the random effects mixed model, ketamine dose (mg/kg) was significantly positively associated with clock scores (p=.008): for each .1 mg/kg increase in dose, the clock score was .23 points higher. Other findings with the random effects model assessed use of adjuvant medications in the setting of the infusions. Clock scores among patients receiving opioids were significantly lower than those for patients without opioids starting with episode 4. Also those who did use antidepressants concurrently, had clock scores that declined more across episodes than those without antidepressants. Conclusion: Ketamine use may be associated with decreased cognition. In our study, patients with neuropathic pain receiving repeat outpatient infusions showed lower cognitive test scores after the 4th episode likely due to outliers in the data given the small sample size for each episode after the 4th episode of infusion. Analysis with the random effects model showed that dose had a positive correlation with cognitive test scores, while concurrent use of opioids or antidepressants had a negative correlation
The eye's unique anatomy and its physiological and anatomical barriers can limit effective dr... more The eye's unique anatomy and its physiological and anatomical barriers can limit effective drug delivery into the eye. An in vivo study was designed to determine the effectiveness and safety of ultrasound application in enhancing drug delivery in a rabbit model. Permeability of a steroid ophthalmic drug, dexamethasone sodium phosphate, was investigated in ultrasound- and sham-treated cases. For this study, an eye cup filled with dexamethasone sodium phosphate was placed on the cornea. Ultrasound was applied at intensity of 0.8 W/cm(2) and frequency of 400 or 600 kHz for 5 min. The drug concentration in aqueous humor samples, collected 90 min after the treatment, was determined using chromatography methods. Light microscopy observations were done to determine the structural changes in the cornea as a result of ultrasound application. An increase in drug concentration in aqueous humor samples of 2.8 times (p < 0.05) with ultrasound application at 400 kHz and 2.4 times (p < 0...
Use of electronic clinical decision support (eCDS) has been recommended to improve implementation... more Use of electronic clinical decision support (eCDS) has been recommended to improve implementation of clinical decision rules. Many eCDS tools, however, are designed and implemented without taking into account the context in which clinical work is performed. Implementation of the pediatric traumatic brain injury (TBI) clinical decision rule at one Level I pediatric emergency department includes an electronic questionnaire triggered when ordering a head computed tomography using computerized physician order entry (CPOE). Providers use this CPOE tool in less than 20% of trauma resuscitation cases. A human factors engineering approach could identify the implementation barriers that are limiting the use of this tool. The objective was to design a pediatric TBI eCDS tool for trauma resuscitation using a human factors approach. The hypothesis was that clinical experts will rate a usability-enhanced eCDS tool better than the existing CPOE tool for user interface design and suitability for clinical use. This mixed-methods study followed usability evaluation principles. Pediatric emergency physicians were surveyed to identify barriers to using the existing eCDS tool. Using standard trauma resuscitation protocols, a hierarchical task analysis of pediatric TBI evaluation was developed. Five clinical experts, all board-certified pediatric emergency medicine faculty members, then iteratively modified the hierarchical task analysis until reaching consensus. The software team developed a prototype eCDS display using the hierarchical task analysis. Three human factors engineers provided feedback on the prototype through a heuristic evaluation, and the software team refined the eCDS tool using a rapid prototyping process. The eCDS tool then underwent iterative usability evaluations by the five clinical experts using video review of 50 trauma resuscitation cases. A final eCDS tool was created based on their feedback, with content analysis of the evaluations performed to ensure all concerns were identified and addressed. Among 26 EPs (76% response rate), the main barriers to using the existing tool were that the information displayed is redundant and does not fit clinical workflow. After the prototype eCDS tool was developed based on the trauma resuscitation hierarchical task analysis, the human factors engineers rated it to be better than the CPOE tool for nine of 10 standard user interface design heuristics on a three-point scale. The eCDS tool was also rated better for clinical use on the same scale, in 84% of 50 expert-video pairs, and was rated equivalent in the remainder. Clinical experts also rated barriers to use of the eCDS tool as being low. An eCDS tool for diagnostic imaging designed using human factors engineering methods has improved perceived usability among pediatric emergency physicians.
The eye's unique anatomy and its physiological and anatomical barriers can limit effective dr... more The eye's unique anatomy and its physiological and anatomical barriers can limit effective drug delivery into the eye. An in vivo study was designed to determine the effectiveness and safety of ultrasound application in enhancing drug delivery in a rabbit model. Permeability of a steroid ophthalmic drug, dexamethasone sodium phosphate, was investigated in ultrasound- and sham-treated cases. For this study, an eye cup filled with dexamethasone sodium phosphate was placed on the cornea. Ultrasound was applied at intensity of 0.8 W/cm(2) and frequency of 400 or 600 kHz for 5 min. The drug concentration in aqueous humor samples, collected 90 min after the treatment, was determined using chromatography methods. Light microscopy observations were done to determine the structural changes in the cornea as a result of ultrasound application. An increase in drug concentration in aqueous humor samples of 2.8 times (p < 0.05) with ultrasound application at 400 kHz and 2.4 times (p < 0...
Introduction: Outpatient ketamine infusions can be effective in relieving severe neuropathic pain... more Introduction: Outpatient ketamine infusions can be effective in relieving severe neuropathic pain for a period of weeks or months. The NMDA receptor is involved in learning and memory and antagonists such as ketamine may be associated with cognitive impairment (1,2). The objective of this study is to investigate whether repeat outpatient ketamine infusions are associated with cognitive dysfunction as measured by the Manos 10-point clock test, a validated screening tool for cognitive dysfunction(3). Methods: With IRB approval, patients undergoing repeat outpatient ketamine infusions were asked to complete a Manos 10 point clock test before and after each ketamine infusion and on the follow up clinic visit 2 to 4 weeks after the last infusion. The clock is scored using the Manos 10 point clock drawing criteria. Intact cognition was a score of 10, probable cognitive deficit, less than 8, and severely impaired at less than 4. Statistical analysis was done in two parts to evaluate the primary and secondary questions. Mean clock score, BMI, age, and ketamine dose were calculated across days 1-3 and times (pre,post), so there would only be 1 clock score and 1 covariate score for BMI, age, and dose for each subject at each episode. For the primary question of whether there is a change in cognition associated with additional episodes of care, we used fixed effects mixed model regression, with clock scores as the dependent variable. We were particularly interested in the adjusted effect of episode of care with later episodes’ clock scores being compared to episode 1. A significant effect would indicate that cognition changes over time within subjects. For the secondary questions, in order to determine whether the clock score pattern across episodes differed by age, ketamine dose, BMI, race, sex, or the presence of opioids or antidepressants, we used a random effects mixed model including each of the above variables as covariates, along with episode. If the term was significant, it meant that the pattern of clock scores across episodes of care differed across levels of the indicator variable. Results: Each patient was given ketamine infusions for 3 consecutive days constituting one episode. These episodes were repeated 4 to 16 weeks apart. Data from 60 patients, who collectively had 124+ repeat episodes, were collected. In the final adjusted fixed effects model, episodes 4 (p=.037) and 6 (p=.039) both had significantly lower clock scores than episode one. In the random effects mixed model, ketamine dose (mg/kg) was significantly positively associated with clock scores (p=.008): for each .1 mg/kg increase in dose, the clock score was .23 points higher. Other findings with the random effects model assessed use of adjuvant medications in the setting of the infusions. Clock scores among patients receiving opioids were significantly lower than those for patients without opioids starting with episode 4. Also those who did use antidepressants concurrently, had clock scores that declined more across episodes than those without antidepressants. Conclusion: Ketamine use may be associated with decreased cognition. In our study, patients with neuropathic pain receiving repeat outpatient infusions showed lower cognitive test scores after the 4th episode likely due to outliers in the data given the small sample size for each episode after the 4th episode of infusion. Analysis with the random effects model showed that dose had a positive correlation with cognitive test scores, while concurrent use of opioids or antidepressants had a negative correlation
The eye's unique anatomy and its physiological and anatomical barriers can limit effective dr... more The eye's unique anatomy and its physiological and anatomical barriers can limit effective drug delivery into the eye. An in vivo study was designed to determine the effectiveness and safety of ultrasound application in enhancing drug delivery in a rabbit model. Permeability of a steroid ophthalmic drug, dexamethasone sodium phosphate, was investigated in ultrasound- and sham-treated cases. For this study, an eye cup filled with dexamethasone sodium phosphate was placed on the cornea. Ultrasound was applied at intensity of 0.8 W/cm(2) and frequency of 400 or 600 kHz for 5 min. The drug concentration in aqueous humor samples, collected 90 min after the treatment, was determined using chromatography methods. Light microscopy observations were done to determine the structural changes in the cornea as a result of ultrasound application. An increase in drug concentration in aqueous humor samples of 2.8 times (p < 0.05) with ultrasound application at 400 kHz and 2.4 times (p < 0...
Use of electronic clinical decision support (eCDS) has been recommended to improve implementation... more Use of electronic clinical decision support (eCDS) has been recommended to improve implementation of clinical decision rules. Many eCDS tools, however, are designed and implemented without taking into account the context in which clinical work is performed. Implementation of the pediatric traumatic brain injury (TBI) clinical decision rule at one Level I pediatric emergency department includes an electronic questionnaire triggered when ordering a head computed tomography using computerized physician order entry (CPOE). Providers use this CPOE tool in less than 20% of trauma resuscitation cases. A human factors engineering approach could identify the implementation barriers that are limiting the use of this tool. The objective was to design a pediatric TBI eCDS tool for trauma resuscitation using a human factors approach. The hypothesis was that clinical experts will rate a usability-enhanced eCDS tool better than the existing CPOE tool for user interface design and suitability for clinical use. This mixed-methods study followed usability evaluation principles. Pediatric emergency physicians were surveyed to identify barriers to using the existing eCDS tool. Using standard trauma resuscitation protocols, a hierarchical task analysis of pediatric TBI evaluation was developed. Five clinical experts, all board-certified pediatric emergency medicine faculty members, then iteratively modified the hierarchical task analysis until reaching consensus. The software team developed a prototype eCDS display using the hierarchical task analysis. Three human factors engineers provided feedback on the prototype through a heuristic evaluation, and the software team refined the eCDS tool using a rapid prototyping process. The eCDS tool then underwent iterative usability evaluations by the five clinical experts using video review of 50 trauma resuscitation cases. A final eCDS tool was created based on their feedback, with content analysis of the evaluations performed to ensure all concerns were identified and addressed. Among 26 EPs (76% response rate), the main barriers to using the existing tool were that the information displayed is redundant and does not fit clinical workflow. After the prototype eCDS tool was developed based on the trauma resuscitation hierarchical task analysis, the human factors engineers rated it to be better than the CPOE tool for nine of 10 standard user interface design heuristics on a three-point scale. The eCDS tool was also rated better for clinical use on the same scale, in 84% of 50 expert-video pairs, and was rated equivalent in the remainder. Clinical experts also rated barriers to use of the eCDS tool as being low. An eCDS tool for diagnostic imaging designed using human factors engineering methods has improved perceived usability among pediatric emergency physicians.
The eye's unique anatomy and its physiological and anatomical barriers can limit effective dr... more The eye's unique anatomy and its physiological and anatomical barriers can limit effective drug delivery into the eye. An in vivo study was designed to determine the effectiveness and safety of ultrasound application in enhancing drug delivery in a rabbit model. Permeability of a steroid ophthalmic drug, dexamethasone sodium phosphate, was investigated in ultrasound- and sham-treated cases. For this study, an eye cup filled with dexamethasone sodium phosphate was placed on the cornea. Ultrasound was applied at intensity of 0.8 W/cm(2) and frequency of 400 or 600 kHz for 5 min. The drug concentration in aqueous humor samples, collected 90 min after the treatment, was determined using chromatography methods. Light microscopy observations were done to determine the structural changes in the cornea as a result of ultrasound application. An increase in drug concentration in aqueous humor samples of 2.8 times (p < 0.05) with ultrasound application at 400 kHz and 2.4 times (p < 0...
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