Comparison of effectiveness of hand-carried ultrasound to bedside cardiovascular physical examination

This study compared the accuracy of cardiovascular diagnoses by medical students operating a small hand-carried ultrasound (HCU) device with that of board-certified cardiologists using standard physical examinations. Sixty-one patients (38% women; mean age 70 +/- 19 years) with clinically significant cardiac disease had HCU studies performed by 1 of 2 medical students with 18 hours of training in cardiac ultrasound and physical examinations by 1 of 5 cardiologists. Diagnostic accuracy was determined by standard echocardiography. Two-hundred thirty-nine abnormal findings were detected by standard echocardiography. The students correctly identified 75% (180 of 239) of the pathologies, whereas cardiologists found 49% (116 of 239) (p <0.001). The students' diagnostic specificity of 87% was also greater than cardiologists' specificity of 76% (p <0.001). For nonvalvular pathologies (115 findings), students' sensitivity was 61%, compared with 47% for cardiologists (p = 0.040). There were 124 clinically significant valvular lesions (111 regurgitations, 13 stenoses). Students' and cardiologists' sensitivities for recognizing lesions that cause a systolic murmur were 93% and 62% (p <0.001), respectively. Students' sensitivity for diagnosing lesions that produce a diastolic murmur was 75%; cardiologists recognized 16% of these lesions (p <0.001). The diagnostic accuracy of medical students using an HCU device after brief echocardiographic training to detect valvular disease, left ventricular dysfunction, enlargement, and hypertrophy was superior to that of experienced cardiologists performing cardiac physical examinations.     

Comparison of transthoracic and intraoperative transesophageal color flow Doppler assessment of mitral and aortic regurgitation

BACKGROUND: We examined the agreement between transthoracic echocardiography (TTE) and intraoperative prepump transesophageal echocardiography (TEE) in the assessment of left-sided regurgitant lesions and echocardiographic variables associated with grading discrepancies. METHODS: The TTE and prepump TEE studies of 54 patients undergoing aortic-valve replacement for aortic stenosis were reviewed. Agreement and correlation in assessment of aortic (AR) and mitral regurgitation (MR) severity were evaluated. RESULTS: There was no significant difference between mean TTE and prepump TEE grading of MR (0.23 +/- 0.19 vs. 0.21 +/- 0.15 jet area/area of the left atrium, p = 0.49), but the correlation between the two methods was weak (r = 0.40, p = 0.003), with an exact agreement of 54%. Prepump TEE tended to grade AR as more severe (mean grade 1.43 +/- 0.94 vs. 1.24 +/- 0.75, p = 0.058). The correlation between the two methods in AR assessment was fair (r = 0.70, p = 0.0001) with an agreement of 59%. For MR and AR grading, no significant correlations between valvular regurgitation severity and blood pressure differences between preoperative TTE and prepump TEE were found. In 17% of cases, discrepancies in identifying severe mitral or aortic valve regurgitation could have affected patient management. CONCLUSIONS: There is modest agreement in MR and AR assessment between TTE and prepump TEE. Cardiologists, cardiac surgeons, and anesthesiologists must be aware of differences between these methods when using prepump TEE to guide intraoperative decisions.     

Diagnosis and Management of Acute Ischemic Stroke

Acute ischemic stroke (AIS) is among the leading causes of death and long-term disability. Intravenous tissue plasminogen activator has been the mainstay of acute therapy. Recently, several prospective randomized trials documented the value of endovascular revascularization in selected patients with large-vessel occlusion within the anterior circulation. This finding has led to a paradigm shift in the management of AIS, including wide adoption of noninvasive neuroimaging to assess vessel patency and tissue viability, with the supplemental and independent use of intravenous tissue plasminogen activator to improve clinical outcomes. In this article, we review the landmark studies on management of AIS and the current position on the diagnosis and management of AIS. The review also highlights the importance of early stabilization and prompt initiation of therapeutic interventions before, during, and after the diagnosis of AIS within and outside of the hospital.     

Assessment of toxic metals in raw and processed milk samples using electrothermal atomic absorption spectrophotometer

Milk and dairy products have been recognized all over the world for their beneficial influence on human health. The levels of toxic metals (TMs) are an important component of safety and quality of milk. A simple and efficient microwave assisted extraction (MAE) method has been developed for the determination of TMs (Al, Cd, Ni and Pb), in raw and processed milk samples. A Plackett–Burman experimental design and 2³ + star central composite design, were applied in order to determine the optimum conditions for MAE. Concentrations of TMs were measured by electrothermal atomic absorption spectrometry. The accuracy of the optimized procedure was evaluated by standard addition method and conventional wet acid digestion method (CDM), for comparative purpose. No significant differences were observed (P > 0.05), when comparing the values obtained by the proposed MAE method and CDM (paired t-test). The average relative standard deviation of the MAE method varied between 4.3% and 7.6% based on analyte (n = 6). The proposed method was successfully applied for the determination of understudy TMs in milk samples. The results of raw and processed milk indicated that environmental conditions and manufacturing processes play a key role in the distribution of toxic metals in raw and processed milk.     

Determination of toxic elements in infant formulae by using electrothermal atomic absorption spectrometer

In present work concentrations of toxic elements (TEs), aluminum (Al), cadmium (Cd), and lead (Pb) in seventeen imported samples of infant milk-based (IMF) and infant soy-based formulae (ISF), were measured, to evaluate whether the intakes of understudy TEs accomplished within recommended permissible levels. The TEs were analyzed by electrothermal atomic absorption spectrometer, prior to microwave induced acid digestion. The validity of methodology was tested by simultaneously analyzing certified reference material and standard addition method. It was observed that ISF contains higher concentration of understudy toxic analytes as compared to IMF. The all three TEs, Al, Cd and Pb were detected in different branded infant formulae, in the range of (1070–2170), (10.5–34.4), and (28.7–119) μg/kg, respectively. The estimated intakes of TEs as μg/kg/week for infants (>1 year) through milk formulae are well below the recommended tolerable levels of these elements.     

Evaluation of essential and toxic metals by ultrasound-assisted acid leaching from scalp hair samples of children with macular degeneration patients

BACKGROUND: The causes of night blindness in children are multifactorial and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence hair composition. METHOD: An ultrasonic-assisted acid leaching procedure was developed as a sample pretreatment for the determination of Zn, Cu, Cd, As and Pb in human scalp hair samples of night blindness male children with age between 5 to 15 y and compared with the children without vision anomalies that lived in the same localities. The effects of different factors on acid leaching of metals, such as preintensification time (without ultrasonic stirring) after treatment of acid mixture, exposure time to ultrasound and temperature of the ultrasonic bath have been investigated. The proposed method was validated by certified reference samples of scalp hair CRM 397. The wet acid digestion method was used to obtain the total metal concentration in both scalp hair and CRM samples. Cu and Zn in leachates and digests were measured by flame atomic absorption spectrometry (FAAS) using a conventional air/acetylene flame, while Cd and Pb were determined by electrothermal atomic absorption spectrometry (ETAAS) under optimized conditions. RESULTS: It was observed that at optimal conditions, the recovery for Zn, Cd, Pb, As and Cu were 98%, 98.5%, 96%, 97.2% and 94% respectively. The mean values of Zn and Cu in scalp hair samples of children having night blindness were significantly lower as compared to normal healthy children (p for Zn<0.001 and Cu<0.003), while the level of toxic metals As, Cd and Pb were significantly higher in children having ocular problems as related to normal children (p As<0.0074, Cd<0.001 and lead<0.004). CONCLUSION: These data present guidance to clinicians and other professional investigating deficiency of essential trace metals and excessive level of toxic metals in biological samples.