Noninvasive Intracranial Cerebral Flow Velocity Evaluation in the Emergency Department by Emergency Physicians

Transcranial Doppler (TCD) is an accepted modality for the evaluation of cerebral blood flow velocities. OBJECTIVES: The purpose of this study was to test the feasibility of bedside TCD measurement in the emergency department (ED) with critically ill, intubated patients. METHODS: A prospective convenience sample of patients presenting to a university hospital over a two-month period underwent TCD evaluation of the middle cerebral artery. Intubated patients with head trauma and any patient requiring tracheal intubation were eligible. A 2-MHz Doppler probe was positioned over the temporal bone to acquire blood flow velocities. An emergency medicine resident and research assistant obtained measurements. Continuous TCD tracings were recorded on a video cassette recorder tape for quality assurance review and data collection. Vital signs and therapeutic interventions were also recorded. Flow velocities were measured in cm/s; the peak Resistance Index (RI) was calculated for each patient. RESULTS: A total of 30 patients were enrolled in the study. Adequate tracings were obtained in 25 patients (83%) without a disruption of resuscitation. Tracings could not be obtained in five patients; they were listed as TCD failures. However, in two of these patients, adequate flow velocity tracings were obtained after resuscitation. Four patients were evaluated during tracheal intubation. One patient was monitored successfully during cardiopulmonary resuscitation. The median time required for data acquisition was 1.9 minutes. The mean highest RI for those who expired was 0.84. For those who survived, the mean highest RI was 0.52. The difference of 0.32 was statistically significant (p = 0.04). CONCLUSIONS: Noninvasive blood flow velocity monitoring of the middle cerebral artery using TCD is feasible in the ED when performed at the bedside on intubated patients with traumatic brain injury and others during tracheal intubation and resuscitation.     

Influence on binding of third-order torque to second-order angulation

Using an earlier model, which described the critical contact angle for binding from second-order angulation alone, a more generalized model is derived that combines the effects of angulation and torque. From this vantage point, the onset of binding is evaluated for 3 scenarios: second-order angulation alone, third-order torque only, and a combination of second-order angulation and third-order torque. These scenarios are detailed by plotting the critical contact angle for binding against the torque angle as a function of 10 wire dimensions (16 x 16, 16 x 22, 17 x 17, 17 x 22, 17 x 25, 18 x 18, 18 x 22, 18 x 25, 19 x 25, and 21 x 25 mil), 4 bracket widths (70, 100, 130, and 160 mil), and 4 bracket slots (18, 20.5, 22, and 24.5 mil). From these plots, we learn that each wire base dimension (eg, an 18-mil base as found in 18 x 18-mil, 18 x 22-mil and 18 x 25-mil archwires) has a common maximum critical contact angle for binding. Moreover, each wire-slot combination has a common maximum torque angle, which is independent of bracket width. Finally, we learn that archwire-bracket combinations that use a metric 0.5-mm slot might have some advantages with regard to torquing--given the current philosophy that light, continuous forces are more favorable.     

Curcumin Reduces Burn Progression in Rats

Objectives Cutaneous burns are dynamic injuries with a central zone of necrosis surrounded by a zone of ischemia. Conversion of this ischemic zone to full necrosis over the days following injury is due in part to highly reactive oxygen radicals. Curcumin is a component of the Oriental spice turmeric that has been shown to have antioxidant and antiapoptotic properties. The authors hypothesized that treatment of burns with curcumin would reduce the conversion of the ischemic zone to full necrosis. Methods This was a randomized controlled experiment. Twenty Sprague‐Dawley rats were used. Two burns were created on each animal's dorsum using a brass comb with four rectangular prongs preheated in boiling water and applied for 30 seconds, resulting in four rectangular 10 × 20–mm full‐thickness burns separated by three 5 × 20–mm unburned interspaces (zone of ischemia). Animals were randomized to curcumin or vehicle by oral gavage 30 minutes before injury and at 24, 48, and 72 hours after injury. Wounds were observed at one, two, and three days after injury for visual evidence of necrosis in the unburned interspaces. Full‐thickness biopsy specimens from the interspaces were evaluated with hematoxylin and eosin staining seven days after injury for evidence of necrosis. The percentage of interspaces that progressed to necrosis was compared with chi‐square tests. Results Forty comb burns with 120 unburned interspaces were created, evenly distributed between curcumin and vehicle alone. The percentage of interspaces that progressed to full‐thickness necrosis at one, two, three, and seven days after injury in the curcumin and vehicle groups were 30% versus 63% (p = 0.003), 30% versus 70% (p < 0.001), 63% versus 95% (p = 0.02), and 63% versus 95% (p = 0.02), respectively. Conclusions Pretreatment of rats with oral curcumin followed by once‐daily oral treatment for three days reduced the percentage of unburned skin interspaces that progressed to full necrosis.     

National Study of Emergency Department Visits for Acute Exacerbation of Chronic Obstructive Pulmonary Disease, 1993–2005

Objectives: Little is known about recent trends in U.S. emergency department (ED) visits for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) or about ED management of AECOPD. This study aimed to describe the epidemiology of ED visits for AECOPD and to evaluate concordance with guideline‐recommended care. Methods: Data were obtained from National Hospital Ambulatory Medical Care Survey (NHAMCS). ED visits for AECOPD, during 1993 to 2005, were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD‐9‐CM) codes. Concordance with guideline recommendations was evaluated using process measures. Results: Over the 13‐year study period, there was an average annual 0.6 million ED visits for AECOPD, and the visit rates for AECOPD were consistently high (3.2 per 1,000 U.S. population; P_trend = 0.13). The trends in the use of chest radiograph, pulse oximetry, or bronchodilator remained stable (all P_trend > 0.5). By contrast, the use of systemic corticosteroids increased from 29% in 1993–1994 to 60% in 2005, antibiotics increased from 14% to 42%, and methylxanthines decreased from 15% to <1% (all P_trend < 0.001). Multivariable analysis showed patients in the South (vs. the Northeast) were less likely to receive systemic corticosteroids (odds ratio [OR] = 0.6; 95% confidence interval [CI] = 0.4 to 0.9). Conclusions: The high burden of ED visits for AECOPD persisted. Overall concordance with guideline‐recommended care for AECOPD was moderate, and some emergency treatments had improved over time.     

Advances in Magnetic Resonance Imaging for the assessment of degenerative disc disease of the lumbar spine

The intervertebral disc is characterized by a tension-resisting annulus fibrosus, and a compression-resisting nucleus pulposus composed largely of proteoglycan. Both the annulus and the nucleus function in concert to provide the disc with mechanical stability. Early disc degeneration begins in the nucleus with proteoglycan depletion. Quantitative MRI techniques have been developed to non-invasively quantify the earliest degenerative changes that occur within the disc. Our ability to identify and quantify these early biochemical changes will provide a better understanding of the pathophysiology of disc degeneration and facilitate the study of interventions that aim to halt or reverse the degenerative process.