Effects of ventilation mode and manual chest compression on flow bias during the positive end- and zero end-expiratory pressure manoeuvre in mechanically ventilated patients: a randomised crossover trial.

OBJECTIVES: To investigate the effects of ventilation mode and manual chest compression (MCC) application on the flow bias generated during positive end-expiratory pressure-zero end-expiratory pressure (PEEP-ZEEP) in mechanically ventilated patients. PEEP-ZEEP is an airway clearance manoeuvre with the potential to exceed the flow bias required to remove secretions. However, the ventilation mode applied during the manoeuvre has not been standardised. DESIGN: Randomised crossover trial. PARTICIPANTS: Nineteen mechanically ventilated patients. INTERVENTIONS: Patients were randomised to receive PEEP-ZEEP in volume-controlled and pressure-controlled modes, and with or without MCC. MAIN OUTCOME MEASURES: The difference in flow bias - assessed by the peak expiratory flow (PEF) and peak inspiratory flow (PIF) ratio and difference - between PEEP-ZEEP applied in both ventilation modes, and with and without MCC. RESULTS: The expiratory flow bias was significantly higher in the volume-controlled mode than the pressure-controlled mode. This result was caused by a lower PIF in the volume-controlled mode. PEEP-ZEEP applied in the pressure-controlled mode did not achieve the PEF-PIF difference threshold to clear mucus. Moreover, in the majority of cycles of PEEP-ZEEP applied in the pressure-controlled mode, an inspiratory flow bias was generated, which might embed mucus. PEF was 8l/minute higher with MCC compared with without MCC, which increased the PEF-PIF difference by the same amount. No haemodynamic or respiratory adverse effects were found. CONCLUSIONS: If applied in the volume-controlled mode, PEEP-ZEEP can achieve the flow bias needed to expel pulmonary secretions. However, this is not the case in the pressure-controlled mode. MCC can augment the flow bias generated by PEEP-ZEEP, but its application may be dispensable. CLINICAL TRIAL REGISTRATION: http://www.ensaiosclinicos.gov.br/rg/RBR-223xv8/.

Total polyphenol intake, polyphenol subtypes and incidence of cardiovascular disease: The SUN cohort study.

BACKGROUND AND AIMS: Polyphenol-rich diets have been associated with reduced risk of cardiovascular disease (CVD). However, few prospective epidemiological studies have examined the relationship between classes of ingested polyphenols and risk of CVD. Our aim was to evaluate the association between polyphenol intake and risk of major cardiovascular events in a prospective Spanish cohort. METHODS AND RESULTS: We included 17,065 university graduates (60.7% women, mean age: 37.2 years, age range: 20-89) followed-up for a mean of 10.1 years. Polyphenol intake was assessed at baseline using a validated semi-quantitative 136-item food frequency questionnaire and matching food consumption data with the Phenol-Explorer database. Cox proportional hazards models were used to estimate the adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) for incident cardiovascular events (myocardial infarction, stroke or cardiovascular death). Cherries, chocolate, coffee, apples, and olives were the major sources of variability in polyphenol intake. Participants with higher flavonoids intake (fifth quintile) had a 47% lower incidence of cardiovascular events compared to those in the lowest quintile (HR: 0.53, 95% CI: 0.29-0.98; P for trend = 0.09) after adjusting for potential confounders. The results were non-significant for other polyphenol types. CONCLUSION: The intake of flavonoids showed an inverse association with risk of cardiovascular events in a prospective cohort of Spanish middle-aged adult university graduates. REGISTRATION NUMBER FOR CLINICAL TRIALS: NCT02669602 in Clinical Trials.

Piezoelectric voltage coupled reentrant cavity resonator.

A piezoelectric voltage coupled microwave reentrant cavity has been developed. The central cavity post is bonded to a piezoelectric actuator allowing the voltage control of small post displacements over a high dynamic range. We show that such a cavity can be implemented as a voltage tunable resonator, a transducer for exciting and measuring mechanical modes of the structure, and a transducer for measuring comparative sensitivity of the piezoelectric material. Experiments were conducted at room and cryogenic temperatures with results verified using Finite Element software.

Rigorous analysis of highly tunable cylindrical transverse magnetic mode re-entrant cavities.

Cylindrical re-entrant cavities are unique three-dimensional structures that resonate with their electric and magnetic fields in separate parts of the cavity. To further understand these devices, we undertake rigorous analysis of the properties of the resonance using "in-house" developed Finite Element Method (FEM) software capable of dealing with small gap structures of extreme aspect ratio. Comparisons between the FEM method and experiments are consistent and we illustrate where predictions using established lumped element models work well and where they are limited. With the aid of the modeling we design a highly tunable cavity that can be tuned from 2 GHz to 22 GHz just by inserting a post into a fixed dimensioned cylindrical cavity. We show this is possible, as the mode structure transforms from a re-entrant mode during the tuning process to a standard cylindrical transverse magnetic mode.

Comparison of objective methods to classify the pattern of respiratory sinus arrhythmia during mechanical ventilation and paced spontaneous breathing.

Respiratory sinus arrhythmia (RSA) is a fluctuation of heart period that occurs during a respiratory cycle. It has been suggested that inspiratory heart period acceleration and expiratory deceleration during spontaneous ventilation (henceforth named positive RSA) improve the efficiency of gas exchange compared to the absence or the inversion of such a pattern (negative RSA). During mechanical ventilation (MV), for which maximizing the efficiency of gas exchange is of critical importance, the pattern of RSA is still the object of debate. In order to gain a better insight into this matter, we compared five different methods of RSA classification using the data of five mechanically ventilated piglets. The comparison was repeated using the data of 15 volunteers undergoing a protocol of paced spontaneous breathing, which is expected to result in a positive RSA pattern. The results showed that the agreement between the employed methods is limited, suggesting that the lack of a consensus about the RSA pattern during MV is, at least in part, of methodological origin. However, independently of the method used, the pattern of RSA within the respiratory cycle was not consistent among the subjects and conditions of MV considered. Also, the outcomes showed that even during paced spontaneous breathing a negative RSA pattern might be present, when a low respiratory frequency is imposed.

Surveillance of pediatric infections in a teaching hospital in Mato Grosso do Sul, Brazil.

Nosocomial infections (NI) result in considerably high mortality and morbidity rates, especially among pediatric patients. Considering current worldwide changes, information about the occurrence of pathogens and susceptibility tests are now seen as decisive for optimizing treatment. The purpose of this research was to determine the frequency of microorganisms, antimicrobial and genetic profiles, and risk factors associated with nosocomial infections in a teaching hospital in Campo Grande, Mato Grosso do Sul. From January 1998 to December 1999, 108 patients were characterized as having nosocomial infection, from which 137 pathogens were isolated. Identification and antimicrobial susceptibility was determined by conventional and automated techniques. Staphylococcus aureus and Klebsiella pneumoniae strains were characterized by Pulsed Field Gel Electrophoresis (PFGE). Pathogens were most often isolated from infants one-month old or younger, and bloodstream infections were the most frequent. The main isolated agents isolated were: coagulase-negative staphylococci (38), Pseudomonas aeruginosa (19), S. aureus (26), K. pneumoniae (18), and Candida spp. (13). The risk conditions that were most closely related to NI acquisition were: prolonged hospital stays (69.4%), prematurity (60.9%) and exposure to high-risk device procedures (95.4%). Ciprofloxacin and imipenem were the most effective drugs, inhibiting all or almost all of the Enterobacteriaceae, P. aeruginosa and Acinetobacter calcoaceticus isolates. Only 23% of the S. aureus samples were resistant to oxacillin. Genomic typing revealed 10 distinct patterns for S. aureus and 13 for K. pneumoniae, suggesting that most them did not belong to the same clone. PFGE was effective in differentiating the strains.

Surveillance of pediatric infections in a teaching hospital in Mato Grosso do Sul, Brazil

Nosocomial infections (NI) result in considerably high mortality and morbidity rates, especially among pediatric patients. Considering current worldwide changes, information about the occurrence of pathogens and susceptibility tests are now seen as decisive for optimizing treatment. The purpose of this research was to determine the frequency of microorganisms, antimicrobial and genetic profiles, and risk factors associated with nosocomial infections in a teaching hospital in Campo Grande, Mato Grosso do Sul. From January 1998 to December 1999, 108 patients were characterized as having nosocomial infection, from which 137 pathogens were isolated. Identification and antimicrobial susceptibility was determined by conventional and automated techniques. Staphylococcus aureus and Klebsiella pneumoniae strains were characterized by Pulsed Field Gel Electrophoresis (PFGE). Pathogens were most often isolated from infants one-month old or younger, and bloodstream infections were the most frequent. The main isolated agents isolated were: coagulase-negative staphylococci (38), Pseudomonas aeruginosa (19), S. aureus (26), K. pneumoniae (18), and Candida spp. (13). The risk conditions that were most closely related to NI acquisition were: prolonged hospital stays (69.4 percent), prematurity (60.9 percent) and exposure to high-risk device procedures (95.4 percent). Ciprofloxacin and imipenem were the most effective drugs, inhibiting all or almost all of the Enterobacteriaceae, P. aeruginosa and Acinetobacter calcoaceticus isolates. Only 23 percent of the S. aureus samples were resistant to oxacillin. Genomic typing revealed 10 distinct patterns for S. aureus and 13 for K. pneumoniae, suggesting that most them did not belong to the same clone. PFGE was effective in differentiating the strains

Efeito da restriçäo alimentar inicial e da temperatura ambiente sobre o desenvolvimento de vísceras e ganho compensatório em frangos de corte / Effect of early quantitative feed restriction and environmental temperature on viscera growth and compensatory gain of broiler chickens

O presente trabalho teve como objetivo estudar o efeito da restriçäo alimentar quantitativa inicial e da temperatura ambiente sobre o desenvolvimento de vísceras e ganho compensatório em frangos de corte. Foram utilizados 540 frangos machos, em um delineamento inteiramente ao acaso, segundo esquema fatorial 2 x 3, com os fatores programa alimentar (ad libitum e restrito do 7§ ao 14§ dia de idade) e temperatura ambiente (quente, termoneutra e fria). A restriçäo alimentar näo afetou o peso relativo do fígado e do coraçäo, mas reduziu significamente o peso e o comprimento dos intestinos ao final do período de restriçäo (14 dias de idade). Näo foi observado efeito significativo da restriçäo alimentar sobre o desenvolvimento das vísceras estudadas aos 42 dias de idade. Peso vivo, ganho de peso e consumo de raçäo dos frangos com restriçäo alimentar foram significamente menores aos 28 dias de idade, porém näo foram observadas diferenças entre essas variáveis aos 42 dias de idade, demonstrando ganho compensatório durante o período de realimentaçäo. O peso relativo das vísceras näo foi afetado pela temperatura de criaçäo aos 42 dias de idade, exceto o coraçäo. Consumo de raçäo, ganho de peso e peso vivo aos 42 dias de idade foram significativamente menores nas aves mantidas em altas temperaturas