Can an adequate energy intake be able to reverse the negative nitrogen balance in mechanically ventilated critically ill patients?

Purpose: Adequate energy provision and nitrogen losses prevention of critically ill patients are essentials for treatment and recovery. The aims of this study were to evaluate energy expenditure (EE) and nitrogen balance (NB) of critically ill patients, to classify adequacy of energy intake (El), and to verify adequacy of El capacity to reverse the negative NB. Methods: Seventeen patients from an intensive care unit were evaluated within a 24-hour period. Indirect calorimetry was performed to calculate patient`s EE and Kjeldhal for urinary nitrogen analysis. The total El and protein intake were calculated from the standard parenteral and enteral nutrition infused. Underfeeding was characterized as El 90% or less and overfeeding as 110% or greater of EE. The adequacy of the El (El EE(-1) x 100) and the NB were estimated and associated with each other by Spearman coefficient. Results: The mean EE was 1515 +/- 268 kcal d(-1) and most of the patients (11/14) presented a negative NB (-8.2 +/- 4.7 g.d(-1)). A high rate (53%) of inadequate energy intake was found, and a positive correlation between El EE(-1) and NB was observed (r = 0.670; P = .007). Conclusion: The results show a high rate of inadequate El and negative NB, and equilibrium between El and EE may improve NB. Indirect calorimetry can be used to adjust the energy requirements in the critically ill patients. (C) 2010 Elsevier Inc. All rights reserved.

Small airways function declines after allogeneic haematopoietic stem cell transplantation.

Bronchiolitis obliterans (BO) following allogeneic haematopoietic stem cell transplantation (HSCT) affects peripheral airways. Detection of BO is presently delayed by the low sensitivity of spirometry. We examined the relationship between peripheral airway function and time since HSCT, and compared it with spirometry and clinical indices in 33 clinically stable allogeneic HSCT recipients. The following measurements were performed: lung function, exhaled nitric oxide, forced oscillatory respiratory system resistance and reactance, acinar (S(acin)) and conductive airways ventilation heterogeneity and lung clearance index (LCI) measured by multiple breath nitrogen washout. 22 patients underwent repeat visits from which short-term changes were examined. Median time post HSCT was 12 months. Eight patients were clinically diagnosed as having BO. In multivariate analysis, time since HSCT was predicted by S(acin) and forced expiratory volume in 1 s % predicted. 20 patients had abnormal S(acin) with normal spirometry, whereas none had airflow obstruction with normal S(acin). S(acin) and LCI were the only measures to change significantly between two visits, with both worsening. Change in S(acin) was the only parameter to correlate with change in chronic graft-versus-host disease grade. In conclusion, peripheral airways ventilation heterogeneity worsens with time after HSCT. S(acin) may be more sensitive than spirometry in detecting BO at an early stage, which needs confirmation in a prospective study.

BIOSSENSOR ELETROQUÍMICO BASEADO NA ENZIMA TIROSINASE PARA A DETERMINAÇÃO DE FENOL EM EFLUENTES

AbstractThis work describes the development of a biosensor based on the tyrosinase enzyme (Tyr) for the determination of phenol (PHEN) in laboratory effluent samples derived from ammoniacal nitrogen analysis of the water samples from the Muquém dam in the city of Cariús, CE, using square-wave voltammetry (SWV). The electrode modification consisted of the immobilization of gold nanoparticles, multi-walled carbon nanotubes, cobalt phthalocyanine, and Tyr on a glassy carbon electrode. The electrolyte, pH, enzyme quantity, and voltammetric parameters were optimized to detect PHEN. The analytical curves presented a linear range from 4.97 × 10-6 mol L-1 to 6.10 × 10-5 mol L-1, and the detection limit (DL) and quantitation limit (QL) values were 4.81 × 10-6 mol L-1 and 4.97 × 10-6mol L-1, respectively. The repetition of measurements with the same biosensor and repetition for three other prepared biosensors exhibited a relative standard deviation (RSD) of 5.50 and 1.75%, respectively. The percentage recovery of PHEN in effluent samples varied from 86.40 to 105.04%. The stability of the biosensor was evaluated (at 21 days) with satisfactory results, showing 97.86% of the initial response. Moreover, the DL and recovery percentages agreed with the established values from CONAMA and ABNT, respectively. Thus, the electrode configuration developed seems a promising tool in the detection and quantification of PHEN in complex samples.