Papers by David Kwabena Amponsah
Indian Journal of Ophthalmology, 2020
Purpose: To report the clinical presentation, microbiology, and management outcome of endogenous ... more Purpose: To report the clinical presentation, microbiology, and management outcome of endogenous endophthalmitis in Indian patients. Methods: Retrospective chart review of culture-positive (vitreous/urine/blood) endogenous endophthalmitis cases treated in tertiary eye care facility in India was done. Results: The study included 173 eyes of 117 patients. Mean patient age was 25.41 ± 20.46 years (median 24 years). Pre-disposing systemic illness could not be elicited in 79 (67.63%) patients. Commonest predisposing systemic condition in patients where it could be detected (n = 79) was pyrexia of unknown origin (25/79 = 32.0%). Following treatment, 45 out of 173 (26.0%) eyes regained vision of ≥20/400. Commonest isolated organism from vitreous was Streptococcus pneumoniae (36 eyes, 20.8%) and fungi were isolated in 24 (13.8%) eyes, the commonest being Candida spp. (8/24, 33.33%). Favorable functional outcome was seen in 26% eyes and favorable anatomic outcome in 43% eyes. Those with an underlying systemic illness were older (P = 0.02), had greater urine culture positivity (P = 0.003), lesser vitreous culture positivity (0.001), greater gram negative etiology (P = 0.0006), and greater fungal etiology (P = 0.01) as compared to those cases without underlying systemic illness. Conclusion: Endogenous endophthalmitis in India often presents in young immunocompetent individuals without any underlying systemic illness and with negative blood or urine microbiologic work up. Underlying systemic illness leads to greater gram-negative and fungal etiology. Overall visual outcome is poor inspite of prompt management.
Clinical Practice and Cases in Emergency Medicine, 2019
We present a case of a patient who underwent ultrasound evaluation for potential blunt ocular tra... more We present a case of a patient who underwent ultrasound evaluation for potential blunt ocular trauma. She was found to have multiple, freely mobile, scintillating hyperechoic opacities within the vitreous that was diagnosed as asteroid hyalosis, a rare but benign condition easily confused with vitreous hemorrhage, retinal detachment, lens dislocation, or foreign body on ocular ultrasound.
American Journal of Physiology-Heart and Circulatory Physiology, 1999
The purpose of this study was to expand classic heart period analysis methods by techniques from ... more The purpose of this study was to expand classic heart period analysis methods by techniques from ethnomusicology that explicitly take complex musical rhythm principles into consideration. The methods used are based on the theory of African music, the theory of symbolic dynamics, and combinatorial theory. Heart period tachograms from 192 24-h electrocardiograms of 96 healthy subjects were transformed into binary symbol sequences that were interpretable as elementary rhythmic (percussive) patterns, the time lines in African music. Using a hierarchical rhythm pattern scheme closely related to the Derler Rhythm Classification (from jazz theory), we calculated the predominance and stability of pattern classes. The results show that during sleep certain classes, specific to individuals, occurred in a cyclically recurrent manner and many times more often than expected. Simultaneously, other classes disappeared more or less completely. Moreover, the most frequent classes obviously originate...
Journal of Africana Religions, 2013
This article examines the short but eventful life and writings of Jacobus Johannes Elisa Capitein... more This article examines the short but eventful life and writings of Jacobus Johannes Elisa Capitein, the eighteenth-century Gold Coast mulatto ex-slave turned missionary who defended slavery as necessary for the eventual salvation of Africans. I examine the racial assumptions and assertions that were at play in Capitein's writings and place his views and actions within the context of the religious, political, and economic climates of eighteenth-century Netherlands, Europe more broadly, and the Gold Coast. I complicate the narrative that interprets Capitein's defense of slavery as a mere alibi intended to garner support for his missionary agenda, contending that reducing his position to his missionary ambition underplays the import of Capitein's position and the particular circumstances of his life in the Gold Coast. I further explore the existential dilemma that Capitein, an African ex-slave missionary, faced upon his return to his native Gold Coast, and I conclude by sugg...
Clinical Practice and Cases in Emergency Medicine, 2017
We report the case of a 45-year-old woman who presented to the emergency department (ED) after an... more We report the case of a 45-year-old woman who presented to the emergency department (ED) after an acute ankle inversion injury. After history and physical exam suggested a potential fracture, point-of-care ultrasound (POCUS) demonstrated a cortical defect of the distal fibula, consistent with fracture. Plain radiography failed to demonstrate a fracture. Later, the fracture was identified as a Weber B distal fibular fracture by stress-view radiography. This case reviews the evaluation of acute ankle injuries in the ED and the utility of POCUS as a supplemental imaging modality in the evaluation of ankle fracture.
Perhaps no word has had a longer association with African religious thought, material, and cultur... more Perhaps no word has had a longer association with African religious thought, material, and culture than the “fetish.” Identified as a marker of African heathenism and the inferiority of the African mind, the term would become the very antithesis of civilization and Christianity in Western thought throughout the nineteenth century. Along with a host of beliefs and practices, the fetish would also serve as an alibi for the moralizing imperative and momentum of colonialism. Although the “fetish” embodied both European and African conceptions of materiality and spirit, its African dimensions have been underemphasized. So too has its political significance. This is all the more surprising given that the fetish arose under specific historical context of cross-cultural and commercial engagement between Europeans and Africans. This paper seeks to correct this by positioning the fetish as an important lens with which power and state formation in colonial Ghana. I argue that the “fetish” has been integral to the making of the state. I use both the invisible and material attributes of the fetish to complicate previous theorizations of the fetish that takes as paramount what William Pietz has termed its “material irreducibility.”
Students are often organized into groups to perform projects for their marketing classes. Student... more Students are often organized into groups to perform projects for their marketing classes. Student reactions to group projects for their classes were assessed through a twenty-three item questionnaire. A factor analysis organized these items into five factors named self-improvement, group process, group scheduling, individual performance, and communication difficulty. These factors were then analyzed and suggestions for improving group projects in
Aerospace Medicine and Human Performance, 2015
N umerous publications on ultrasound (US) imaging in actual and analogue spacefl ight environment... more N umerous publications on ultrasound (US) imaging in actual and analogue spacefl ight environments report reliance on remote guidance (RG) of minimally trained caregivers or research operators with no professional expertise in US. 1 , 2 , 4 High-quality US images from multiple organ systems (e.g., cardiovascular, respiratory, musculoskeletal, genitourinary) have been obtained consistently, attesting to the general maturity of the remotely guided diagnostic US capability in orbital spacefl ight and in remote terrestrial settings with communication latency of up to 2 s. 7 , 8 , 14 However, increased latency in data fl ow and voice communication associated with greater distances is expected to impair the eff ectiveness of these techniques. Th e actual communication delay that would render RG ineff ective has not been objectively established. Th e two-way communication delay on missions to the Moon is expected to reach ; 5-6 s and the delay on missions to Mars is expected to last 10 to 45 min. 3 , 5 , 13 A simulated Mars mission with a 15-min communication delay demonstrated successful use of US by a
Western Journal of Emergency Medicine, 2015
The curriculum in most emergency medicine (EM) clerkships includes very little formalized trainin... more The curriculum in most emergency medicine (EM) clerkships includes very little formalized training in point-of-care ultrasound. Medical schools have begun to implement ultrasound training in the pre-clinical curriculum, and the EM clerkship is an appropriate place to build upon this training. The objectives are (1) to evaluate the effectiveness of implementing a focused ultrasound curriculum within an established EM clerkship and (2) to obtain feedback from medical students regarding the program. Methods: We conducted a prospective cohort study of medical students during an EM clerkship year from July 1, 2011, to June 30, 2012. Participants included fourth-year medical students (n=45) enrolled in the EM clerkship at our institution. The students underwent a structured program focused on the focused assessment with sonography for trauma exam and ultrasound-guided vascular access. At the conclusion of the rotation, they took a 10-item multiple choice test assessing knowledge and image interpretation skills. A cohort of EM residents (n=20) also took the multiple choice test but did not participate in the training with the students. We used an independent samples t-test to examine differences in test scores between the groups. Results: The medical students in the ultrasound training program scored significantly higher on the multiple-choice test than the EM residents, t(63)=2.3, p<0.05. The feedback from the students indicated that 82.8% were using ultrasound on their current rotations and the majority (55.2%) felt that the one-on-one scanning shift was the most valuable aspect of the curriculum. Discussion: Our study demonstrates support for an ultrasound training program for medical students in the EM clerkship. After completing the training, students were able to perform similarly to EM residents on a knowledge-based exam.
Journal of Ultrasound, 2015
Purpose Point-of-care ultrasound evaluates inferior vena cava (IVC) and internal jugular vein (IJ... more Purpose Point-of-care ultrasound evaluates inferior vena cava (IVC) and internal jugular vein (IJV) measurements to estimate intravascular volume status. The reliability of the IVC and IJV collapsibility index during increased thoracic or intra-abdominal pressure remains unclear. Methods Three phases of sonographic scanning were performed: spontaneous breathing phase, increased thoracic pressure phase via positive pressure ventilation (PPV) phase, and increased intra-abdominal pressure (IAP) phase via laparoscopic insufflation to 15 mmHg. IVC measurements were done at 1-2 cm below the diaphragm and IJV measurements were done at the level of the cricoid cartilage during a complete respiratory cycle. Collapsibility index was calculated by (max diameter-min diameter)/max diameter 9 100 %. Chi square, t test, correlation procedure (CORR) and Fisher's exact analyses were completed. Results A total of 144 scans of the IVC and IJV were completed in 16 patients who underwent laparoscopic surgery. Mean age was 46 ± 15 years, with 75 % female and 69 % African-American. IVC and IJV collapsibility correlated in the setting of spontaneous breathing (r 2 = 0.86, p \ 0.01). IVC collapsibility had no correlation with the IJV in the setting of PPV (r 2 = 0.21, p = 0.52) or IAP (r 2 = 0.26, p = 0.42). Maximal IVC diameter was significantly smaller during increased IAP (16.5 mm ± 4.9) compared to spontaneous breathing (20.6 mm ± 4.8, p = 0.04) and PPV (21.8 mm ± 5.6, p = 0.01). Conclusion IJV and IVC collapsibility correlated during spontaneous breathing but there was no statistically significant correlation during increased thoracic or intra-abdominal pressure. Increased intra-abdominal pressure was associated with a significant smaller maximal IVC diameter and cautions the reliability of IVC diameter in clinical settings that are associated with intra-abdominal hypertension or abdominal compartment syndrome.
Current reviews in musculoskeletal medicine, 2009
Snowboarding has become a popular recreational and professional sport. Participants suffer a vari... more Snowboarding has become a popular recreational and professional sport. Participants suffer a variety of injuries, especially of the extremities, that require medical evaluation. This article reviews the reported injuries to both leisure and elite athletes. To many, an injured extremity requires travel to a medical facility for accurate evaluation. Musculoskeletal ultrasound is an accurate and portable technology that can be used for real time, mountainside diagnoses of these injuries.
Current Opinion in Critical Care, 2010
Purpose of review To examine the role of fluid therapy in the pathogenesis of severe sepsis and s... more Purpose of review To examine the role of fluid therapy in the pathogenesis of severe sepsis and septic shock. The type, composition, titration, management strategies and complications of fluid administration will be examined in respect to outcomes. Recent findings Fluids have a critical role in the pathogenesis and treatment of early resuscitation of severe sepsis and septic shock. Summary Although this pathogenesis is evolving, early titrated fluid administration modulates inflammation, improves microvascular perfusion, impacts organ function and outcome. Fluid administration has limited impact on tissue perfusion during the later stages of sepsis and excess fluid is deleterious to outcome. The type of fluid solution does not seem to influence these observations.
Critical Ultrasound Journal, 2009
Background Evaluation of pupillary light reflex (PLR) is an important neurological test with a va... more Background Evaluation of pupillary light reflex (PLR) is an important neurological test with a variety of clinical applications. Obstacles such as severe soft tissue damage or hyphema may obstruct the visual access to the pupil, thus rendering direct PLR observation difficult or impossible. Multipurpose ultrasonic systems, however, can overcome this problem. Methods Using ultrasound imaging, a coronal view of the iris and pupil allowed visualization of PLR upon contralateral stimulation with a penlight. The technique was tested in ten healthy volunteers and a trauma case study. Results Satisfactory visualization of the iris was achieved in all subjects, in an average time of 1 min 10 s. Temporal parameters of pupillary constriction, oscillations (hippos) and relaxation could also be measured on M-mode displays. Conclusions Real-time coronal imaging of the iris using multipurpose ultrasound imaging is found to be a practical, fast and recordable method that can be used for evaluating...
Textbook of Rapid Response Systems, 2010
The transition from sepsis to severe life-threatening disease frequently develops well before adm... more The transition from sepsis to severe life-threatening disease frequently develops well before admission to an intensive care unit (ICU), often in the pre-hospital setting, the emergency department (ED), general medical-surgical floors, operating room or the outpatient clinic setting. One ...
This study tested Hunt's (2002) resource-advantage theory of competition in the setting of c... more This study tested Hunt's (2002) resource-advantage theory of competition in the setting of country competition in sub-Saharan Africa. Specifically, it investigated the relationship between the economic, political-legal, cultural-social, and technological environments of these countries with their income and growth rates. The results showed that environments more favorable to investors were positively related to higher income and growth rates, providing evidence for Hunt's theory and validating the use of these environments as categories for analysis.
Journal of General Internal Medicine, 2010
INTRODUCTION: Ultrasound, a versatile diagnostic modality that permits real-time visualization at... more INTRODUCTION: Ultrasound, a versatile diagnostic modality that permits real-time visualization at the patient's bedside, can be used as an adjunct in teaching physical diagnosis (PD). Aims: (1) to study the feasibility of incorporating ultrasound into PD courses and (2) determine whether learners can demonstrate image recognition and acquisition skills. PROGRAM DESCRIPTION: Three hundred seven second-year medical students were introduced to cardiovascular and abdominal ultrasound scanning after training in the physical examination. This consisted of a demonstration of the ultrasound examination, followed by practice on standardized patients (SPs). Prepost tests were administered to evaluate students' knowledge and understanding of ultrasound. Students performed an ultrasound examination during the PD final examination. PROGRAM EVALUATION: Pre-post test data revealed significant improvements in image recognition. On the final exam, the highest scores (98.4%) were obtained for the internal jugular vein and lowest scores (74.6%) on the Focused Assessment with Sonography for Trauma images. Eighty-nine percent of students' surveyed felt ultrasound was a valuable tool for physicians. DISCUSSION: An introductory ultrasound course is effective in improving medical students' acquisition and recognition of basic cardiovascular and abdominal ultrasound images. This innovative program demonstrates the feasibility of incorporating portable ultrasound as a learning tool during medical school.
Journal of Clinical Ultrasound, 2014
Purpose. To investigate whether providing sonographic (US)/MRI fusion images will enhance the abi... more Purpose. To investigate whether providing sonographic (US)/MRI fusion images will enhance the ability of medical students and radiology residents to identify MSK anatomy on sonograms alone. Methods. Medical students (n 5 31) and radiology residents (n 5 23) were each randomly divided into two groups: Group A and Group B. Subjects in Group A were shown 10 MSK sonograms with arrows pointing to a specific anatomic structure or anatomic region. Subjects in Group B were shown the exact same 10 annotated sonograms as Group A as well as an additional fusion image consisting of an MRI of the same anatomy in the same plane fused with the sonogram without arrows. Sonograms and MRI were obtained from adult patients who consented to have their images used. The anatomic regions included the shoulder, hip, and pelvis. Both groups were given the same 10-question multiple choice examination to identify the anatomic structure that the arrow was marking on the sonogram. The transducer's location was given for every question. One minute was allowed to answer each question. The Wilcoxon rank sum test was used to assess if there was a difference between Group A and Group B in both the medical student and the radiology resident cohorts. Results. Medical students: subjects in Group A (n 5 16) gave the correct answers in 33.8% of the cases (54/160). Subjects in Group B (n 5 15) gave correct answers in 26.0% of the cases (39/150) (p value <0.110). Radiology residents: subjects in Group A (n 5 11) gave correct answers in 40.9% of the cases (45/ 110). Subjects in Group B (n 5 12) gave correct answers in 72.5% of the cases (87/120) (p value <0.001). Conclusion. The addition of a fusion MRI/US image enhances radiology residents' ability to identify MSK US anatomy accurately compared with the sonogram alone. The medical students, however, did not show improvement with the addition of the fusion MRI/sonogram. V
Critical Care Medicine, 2003
If the pathogenic landscape of sepsis were a proverbial painting, it would have to be broadened o... more If the pathogenic landscape of sepsis were a proverbial painting, it would have to be broadened on a much larger canvas involving a greater number of artists today compared with yesteryear. The reality is that patients presenting with sepsis are admitted to the intensive ...
Clinics in Chest Medicine, 2008
Key links in the chain of survival for the management of severe sepsis and septic shock are early... more Key links in the chain of survival for the management of severe sepsis and septic shock are early identification and comprehensive resuscitation of high-risk patients. 1 Multiple studies have shown Emanuel P. Rivers receives research support from the National Institute of Allergy and Infectious Disease, and from Hutchinson Technologies. In the last 2 years, he has performed as a consultant, delivered lectures, or served as a panelist for Biosite, Edwards Lifesciences, Elan, and Eli Lilly and Co.
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Papers by David Kwabena Amponsah