Background. Recently, epidemiological and clinical data have revealed important changes with regard to clinical adenovirus infection, including alterations in antigenic presentation, geographical ...distribution, and virulence of the virus. Methods. In an effort to better understand the epidemiology of clinical adenovirus infection in the United States, we adopted a new molecular adenovirus typing technique to study clinical adenovirus isolates collected from 22 medical facilities over a 25-month period during 2004–2006. A hexon gene sequence typing method was used to characterize 2237 clinical adenovirus-positive specimens, comparing their sequences with those of the 51 currently recognized prototype human adenovirus strains. In a blinded comparison, this method performed well and was much faster than the classic serologic typing method. Results. Among civilians, the most prevalent adenovirus types were types 3 (prevalence, 34.6%), 2 (24.3%), 1 (17.7%), and 5 (5.3%). Among military trainees, the most prevalent types were types 4 (prevalence, 92.8%), 3 (2.6%), and 21 (2.4%). Conclusions. For both populations, we observed a statistically significant increasing trend of adenovirus type 21 detection over time. Among adenovirus isolates recovered from specimens from civilians, 50% were associated with hospitalization, 19.6% with a chronic disease condition, 11% with a bone marrow or solid organ transplantation, 7.4% with intensive care unit stay, and 4.2% with a cancer diagnosis. Multivariable risk factor modeling for adenovirus disease severity found that age <7 years (odds ratio OR, 3.2; 95% confidence interval CI, 1.4–7.4), chronic disease (OR, 3.6; 95% CI, 2.6–5.1), recent transplantation (OR, 2.7; 95% CI, 1.3–5.2), and adenovirus type 5 (OR, 2.7; 95% CI, 1.5–4.7) or type 21 infection (OR, 7.6; 95% CI, 2.6–22.3) increased the risk of severe disease.
It is presumed that stentless aortic bioprostheses are hemodynamically superior to stented bioprostheses. A prospective randomized controlled trial was undertaken to compare stentless versus modern ...stented valves.
Patients with severe aortic valve stenosis (n=161) undergoing aortic valve replacement (AVR) were randomized intraoperatively to receive either the C-E Perimount stented bioprosthesis (n=81) or the Prima Plus stentless bioprosthesis (n =80). We assessed left ventricular mass (LVM) regression with transthoracic echocardiography (TTE) and magnetic resonance imaging (MRI). Transvalvular gradients were measured postoperatively by Doppler echocardiography to compare hemodynamic performance. There was no difference between groups with regard to age, symptom status, need for concomitant coronary artery bypass surgery, or baseline LVM. LVM regressed in both groups but with no significant difference between groups at 1 year. In a subset of 50 patients, MRI was also used to assess LVM regression, and again there was no significant difference between groups at 1 year. Hemodynamic performance of the 2 valves was similar with no difference in mean and peak systolic transvalvular gradients 1 year after surgery. In patients with reduced ventricular function (left ventricular ejection fraction LVEF <60%), there was a significantly greater improvement in LVEF from baseline to 1 year in stentless valve recipients.
Both stented and stentless bioprostheses are associated with excellent clinical and hemodynamic outcomes 1 year after AVR. Comparable hemodynamics and LVM regression can be achieved using a second-generation stented pericardial bioprosthesis. In patients with ventricular impairment, stentless bioprostheses may allow for greater improvement in left ventricular function postoperatively.
Abstract Objective : To compare the diagnostic test properties of automated and visually read urine dipstick screening for detection of a random protein:creatinine ratio (PrCr) ≥ 30 mg/mmol. Methods ...: Urine samples were collected prospectively from 160 women attending high-risk maternity clinics at a tertiary care facility. Samples were divided into two aliquots; one aliquot was tested using two different urine test strips, one read visually and one by an automated reader. A second aliquot of the same urine was analyzed for urinary protein and creatinine. Performance of visual and automated dipstick results (proteinuria ≥ 1 +) were compared for detection of PrCr ≥ 30 mg/mmol using non-dilute urine samples (urinary creatinine ≥ 3 mmol/L). Results : Both urine test strips showed low sensitivity (visual 56.0% and automated 53.8%). Positive likelihood ratios were 15.0 for visual dipstick testing (95% CI 5.9 to 37.9) and 24.6 for automated (95% CI 7.6 to 79.6). Negative likelihood ratios were 0.46 for visual dipstick testing (95% CI 0.29 to 0.71) and 0.47 for automated (95% CI 0.31 to 0.72). Conclusion : Automated dipstick testing was not superior to visual testing for detection of proteinuria in pregnant women in a primarily outpatient setting. Sensitivity may depend on the test strips and/or analyzer used.
Objective: The indications for aortic root replacement in acute type A dissection are unclear. We reviewed the immediate and long-term outcome of consecutive patients in a series in which a ...low-threshold policy of composite aortic root replacement had evolved. Methods: From a prospectively compiled aortic surgery database, we identified 162 patients who had either supracoronary interposition grafting, Group A (n=89), or composite root replacement, Group B (n=73) for acute type A dissection. Patients receiving total arch replacements were excluded. Operative and clinical details were analyzed and patient survival was compared to an age and gender matched census cohort. Need for reoperation on the proximal or distal aorta was also noted. Follow-up totaled 795.5 patient-years. Results: Hospital mortality rates were identical in both groups (12.3%: 11 deaths in group A; 9 in group B). Chronic pulmonary disease, diabetes, malperfusion, hemodynamic compromise and aortic root dilatation were independent risk factors for hospital death. Actuarial survival estimates at 1, 5 and 10 years were 79% (71–88%), 64% (53–75%), and 55% (41–68%) for group A, and 79% (70–86%), 73% (62–83%), and 65% (52–78%) for group B (P=0.48). Age and operative patency of the ascending false lumen were independent risk factors for death after hospital discharge. Proximal aortic reoperation was required for four patients in group A and none in group B (P=0.085). Conclusion: A strategy of replacement rather than repair of the dissected aortic root for specific indications in type A dissection yielded high survival and low proximal reoperation rates. These results support an aggressive policy of composite root replacement in acute type A dissection.
Background Stentless aortic bioprostheses were shown to be hemodynamically superior to earlier generations of stented bioprostheses. Modern stented valve designs have improved hemodynamics. A ...prospective randomized controlled trial was undertaken to compare stentless versus modern stented valves. Our aim was to determine any differences in early postoperative clinical and hemodynamic outcomes. Methods Patients with severe aortic valve stenosis (n = 161) undergoing aortic valve replacement were randomized intraoperatively to receive either the C-E Perimount (Edwards Lifesciences, Irvine, CA) pericardial stented bioprosthesis (n = 81) or the Prima Plus (Edwards Lifesciences) (porcine stentless bioprosthesis (n = 80). Transthoracic echocardiograms were performed at one week and eight weeks postoperatively to assess left ventricular mass (LVM) and transvalvular gradients (TVG). Results There were no differences between the two groups in baseline characteristics. Cardiopulmonary bypass and ischemic times were longer in the stentless group. Despite similar native aortic annular diameters, the mean size of the prosthesis used in the stentless group was 2.1 mm (SD = 2.8) larger ( p < 0.001). Early (30-day) mortality (stentless 3.7% vs stented 2.5%; p = 0.68) and morbidity was similar between groups. Eight weeks postoperatively, LVM (stentless 199 ± 70 vs stented 204 ± 66 grams; p = 0.32) and TVG decreased in both groups (mean systolic gradient; stentless 10 ± 3 vs stented 10 ± 4 mm Hg; p = 0.54) but there was no significant difference between groups. Conclusions Despite longer ischemic times in the stentless group, early postoperative outcomes were similar. Both stented and stentless aortic valve replacement offers excellent hemodynamics and can be achieved with low perioperative mortality.
Background This study was designed to determine if testing the first ∼40 nasal washings (interval) each month for 1 year, could be used as an epidemiologic tool for seasonality and prevalence of ...respiratory viruses such as human metapneumovirus in an adult and pediatric population in the southeastern United States. Materials and Methods Results of interval polymerase chain reaction (PCR) testing of 469 specimens for 8 viruses were compared with our current procedures using PCR, culture, or respiratory synctial virus antigen for all 7435 specimens (routine). Results One hundred thirty-six viruses out of 469 specimens (29.0%) and 1,495 viruses out of 7,435 specimens (20.1%) were identified by interval and routine testing, respectively. Seasonal detection varied among viruses and to some degree between interval and routine testing. A higher percent of positives and dual infections were detected by interval testing of pediatric specimens, likely due to the use of PCR for viruses commonly seen in this population. Human metapneumovirus was detected in both pediatric and adult specimens between January and August. Conclusions Interval testing can be used to provide a snapshot of prevalence and seasonality of respiratory viruses, although as currently designed they may not be sensitive enough to identify the beginning of a specific virus season. Exclusive use of interval PCR testing identified several dual infections, including human metapneumovirus, throughout most of the year in Florida. A rapid turnaround time to results translates into improved infection control and improved patient care.
Background Sacrifice of intercostal and lumbar arteries simplifies thoracoabdominal aneurysm surgery and enables endovascular stenting. Little is known about alterations in cord perfusion after ...extensive segmental artery sacrifice. We explored this question using hypothermia to reduce metabolism. Methods Twelve juvenile Yorkshire pigs (mean weight, 22.3 kg) were randomized to segmental artery sacrifice at 32°C or 37°C. Cord integrity was assessed with myogenic-evoked potential (MEP) monitoring. Stepwise craniocaudal sacrifice of segmental arteries was continued until MEP diminution occurred; the last segmental artery was then reopened. Fluorescent microspheres were used to measure spinal cord blood flow (SCBF) at baseline, 5 minutes, 1 hour, and 3 hours after segmental artery sacrifice. Hind limb function was monitored for 5 days. Results All animals recovered normal hind limb function. At 32°C, more segmental arteries, 16.5 versus 15 ( p = 0.03), could be sacrificed without MEP loss. Baseline SCBF at 32°C was 50% that at 37°C ( p = 0.003) and remained fairly stable throughout. At 37°C, SCBF to the craniocaudal extremes of the cord (C1 to T3 and L2 to L6) increased markedly ( p = 0.01) at 1 hour and returned toward normal at 3 hours. Concomitantly, SCBF fell in the middle portion of the cord (T9 to T13) at 1 hour before returning to normal at 3 hours. Conclusions Almost all segmental arteries can be sacrificed with preservation of spinal cord function. No major change occurs in the central cord in normothermic animals, but there is significant transient hyperemia in segments adjacent to extrasegmental vessels. Hypothermia reduces SCBF and abolishes this possible steal phenomenon. Metabolic and hemodynamic manipulation should enable routine sacrifice of all segmental arteries without spinal cord injury.
Background Selective cerebral perfusion (SCP) may enhance the neuroprotective benefits of hypothermia during aortic surgery. However, despite its widespread adoption, there is no consensus regarding ...optimal implementation of SCP. We used a survival porcine model to explore the physiologic characteristics and behavioral benefits of various protocols involving hypothermic circulatory arrest (HCA) and SCP. Methods Thirty pigs (26.3 ± 1.4 kg), cooled to 15°C on cardiopulmonary bypass, using alpha-stat pH management (mean hematocrit 30%), were randomly allocated to differing brain protection strategies: 90 minutes of HCA (group A); 30 minutes of HCA, then 60 minutes of SCP (group B); or 90 minutes of SCP (group C). Using fluorescent microspheres and sagittal sinus sampling, cerebral blood flow (CBF mL · 100g−1 · min−1 ) and cerebral metabolic rate for oxygen (CMRO2 mL · 100g−1 · min−1 ) were assessed at baseline, after cooling, during SCP (where applicable), and for 2 hours after cardiopulmonary bypass. Neurobehavioral scores were assessed blindly from standardized videotaped sessions for 7 days postoperatively. Results Cerebral blood flow was significantly higher ( p = 0.0001) during SCP (60 and 90 minutes) if preceded by HCA. The CMRO2 was also significantly higher in group B versus group C ( p = 0.016) at 60 minutes. The CMRO2 in all three groups rebounded promptly toward baseline after weaning from cardiopulmonary bypass. Postoperative neurobehavioral scores were significantly worse in group A. Conclusions Continuous SCP provides the best brain protection overall. However, an initial period of HCA does not seem to impair late outcome; perhaps the elevated CBF and CMRO2 observed reflect a beneficial cerebral response to a recoverable insult. Clearly, 90 minutes of HCA induces permanent brain injury, even in this carefully controlled setting.
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