Determination of fumonisin content in maize using near-infrared hyperspectral imaging (NIR-HSI) technology and chemometric methods.

Maize (Zea mays L.) is of socioeconomic importance as an essential food for human and animal nutrition. However, cereals are susceptible to attack by mycotoxin-producing fungi, which can damage health. The methods most commonly used to detect and quantify mycotoxins are expensive and time-consuming. Therefore, alternative non-destructive methods are required urgently. The present study aimed to use near-infrared spectroscopy with hyperspectral imaging (NIR-HSI) and multivariate image analysis to develop a rapid and accurate method for quantifying fumonisins in whole grains of six naturally contaminated maize cultivars. Fifty-eight samples, each containing 40 grains, were subjected to NIR-HSI. These were subsequently divided into calibration (38 samples) and prediction sets (20 samples) based on the multispectral data obtained. The averaged spectra were subjected to various pre-processing techniques (standard normal variate (SNV), first derivative, or second derivative). The most effective pre-treatment performed on the spectra was SNV. Partial least squares (PLS) models were developed to quantify the fumonisin content. The final model presented a correlation coefficient (R2) of 0.98 and root mean square error of calibration (RMSEC) of 508 µg.kg-1 for the calibration set, an R2 of 0.95 and root mean square error of prediction (RMSEP) of 508 µg.kg-1 for the test validation set and a ratio of performance to deviation of 4.7. It was concluded that NIR-HSI with partial least square regression is a rapid, effective, and non-destructive method to determine the fumonisin content in whole maize grains.

Late complications of percutaneous tracheostomy using the balloon dilation technique. / Complicaciones tardías de la traqueotomía percutánea con la modalidad de dilatación con balón.

OBJECTIVE: The purpose of this study was to determine the late complications in critically ill patients requiring percutaneous tracheostomy (PT) using the balloon dilation technique. DESIGN: A prospective, observational cohort study was carried out. SCOPE: Two medical-surgical intensive care units (ICU). PATIENTS: All mechanically ventilated adult patients consecutively admitted to the ICU with an indication of tracheostomy. INTERVENTIONS: All patients underwent PT according to the Ciaglia Blue Dolphin® method, with endoscopic guidance. Survivors were interviewed and evaluated by fiberoptic laryngotracheoscopy and tracheal computed tomography at least 6 months after decannulation. VARIABLES: Intraoperative, postoperative and long-term complications and mortality (in-ICU, in-hospital) were recorded. RESULTS: A total of 114 patients were included. The most frequent perioperative complication was minor bleeding (n=20) and difficult cannula insertion (n=19). Two patients had severe perioperative complications (1.7%) (major bleeding and inability to complete de procedure in one case and false passage and desaturation in the other). All survivors (n=52) were evaluated 211±28 days after decannulation. None of the patients had symptoms. Fiberoptic laryngotracheoscopy and computed tomography showed severe tracheal stenosis (>50%) in 2patients (3.7%), both with a cannulation period of over 100 days. CONCLUSIONS: Percutaneous tracheostomy using the Ciaglia Blue Dolphin® technique with an endoscopic guide is a safe procedure. Severe tracheal stenosis is a late complication which although infrequent, must be taken into account due to its lack of clinical expressiveness. Evaluation should be considered in those tracheostomized critical patients who have been cannulated for a long time.

[Percutaneous tracheostomy through dilatation with the Ciaglia Blue Dolphin(®) method]. / Traqueotomía percutánea por dilatación con el método Ciaglia Blue Dolphin(®)

OBJECTIVE: To describe the perioperative and postoperative complications in critically ill patients requiring percutaneous tracheostomy using the Ciaglia Blue Dolphin(®) technique. DESIGN: A prospective, observational, cohort study was carried out. SCOPE: Two medical-surgical Intensive Care Units. PATIENTS: Adult patients subjected to prolonged mechanical ventilation. INTERVENTION: Percutaneous tracheostomy using Ciaglia Blue Dolphin(®) with an endoscopic guide. VARIABLES: Demographic variables, intraoperative and postoperative complications, and Intensive Care Unit and ward mortality were recorded. RESULTS: Seventy patients were included. Age: 68.6 ± 12 years (68.6% males). APACHE II score: 23.5±8.7. Duration of mechanical ventilation prior to percutaneous tracheostomy: 14.3 ± 5.5 days. Perioperative complications were recorded in 25 patients. In 23 of them the complications were mild: difficulty inserting the tracheostomy cannula (n=10), mild bleeding (n=7), partial atelectasis (n=3), cuff leak (n=2), and technical inability to complete the procedure (switch to Ciaglia Blue Rhino(®)) (n=1). Severe complications were recorded in 2 patients: severe bleeding that forced completion of the procedure via surgical tracheostomy (n=1), and false passage with desaturation (n=1). None of the complications proved life-threatening. Eleven complications occurred in the learning curve. As postoperative complications, mild peri-cannula bleeding was seen in 2 patients. CONCLUSIONS: Percutaneous tracheostomy using the Ciaglia Blue Dolphin(®) technique with an endoscopic guide is a safe procedure. As with other procedures, the learning curve contributes to increase the incidence of complications. Potential benefits versus other percutaneous tracheostomy techniques should be explored by randomized trials.

[Percutaneous tracheostomy in the ventilated patient]. / Traqueotomía percutánea en el paciente ventilado.

The medical indications of tracheostomy comprise the alleviation of upper airway obstruction; the prevention of laryngeal and upper airway damage due to prolonged translaryngeal intubation in patients subjected to prolonged mechanical ventilation; and the facilitation of airway access for the removal of secretions. Since 1985, percutaneous tracheostomy (PT) has gained widespread acceptance as a method for creating a surgical airway in patients requiring long-term mechanical ventilation. Since then, several comparative trials of PT and surgical tracheostomy have been conducted, and new techniques for PT have been developed. The use of percutaneous dilatation techniques under bronchoscopic control are now increasingly popular throughout the world. Tracheostomy should be performed as soon as the need for prolonged intubation is identified. However a validated model for the prediction of prolonged mechanical ventilation is not available, and the timing of tracheostomy should be individualized. The present review analyzes the state of the art of PT in mechanically ventilated patients--this being regarded by many as the technique of choice in performing tracheostomy in critically ill patients.

Agentes inalatórios halogenados empregados pelo método quantitativo de anestesia / Inhalatory halogenated agents employed by the quantitative method of anesthesia

Neste ensaio clínico, o enflurano, o isoflurano e o halotano foram usados com baixos fluxos de gases e absorçäo total do dióxido de carbono. Participaram do estudo, 90 pacientes adultos (30 em cada grupo), estado físico I ou II sem doença cardiopulmonar e escalados para diferentes tipos de cirurgias. Diazepan foi usado como medicaçäo pré-anestésica em todos os casos, por via oral, na dose de 0,2 a 0,4 mg.kg-1. A induçäo da anestesia, em todos os pacientes, foi realizada com pancurônio 1 mg. tiopental 4 a 5 mg.kg-1 e succinilcolina 1,5 mg. kg-1, para facilitar a intubaçäo orotraqueal (IOT). O teste "t" de Student foi usado na análise estatística de todos os dados. Foi observada uma predominância de pacientes do sexo feminino nos três grupos. A idade média dos enfermos foi de 38,8 + ou - 12,4 anos no grupo do enflurano, 39,0 + ou - 16,7 anos no grupo do isoflurano e 40,1 + ou - 14,1 anos de idade no grupo do halotano. A duraçäo média das cirurgias foi de 190,7 + ou - 51,7 minutos no grupo do enflurano, 205,4 + ou - 70,7 minutos no grupo do isoflurano e 206,4 + ou - 76,0 minutos no grupo do halotano. A dose média de tiopental para a induçäo da anestesia foi de 340,8 + ou - 79,4 mg no grupo do enflurano, 303,4 + ou - 81,2 mg no grupo do isoflurano e 295,7 + ou - 65,7 mg no grupo do halotano. O fluxo de O2 usado foi de 249,0 + ou - 42,2 ml no grupo do enflurano, 225,0 + ou - 38,8 ml no grupo do isoflurano e 265,0 + ou - 63,9 ml no grupo do halotano. O volume de anestésico injetado foi menor que o previsto em todos os grupos, com diferenças estatisticamente significantes apenas nos grupos do enflurano e isoflurano. O volume total de enflurano, isoflurano e halotano foi de 421,5 ml, 327,7 ml e 335,4 ml gastos em cada grupo. Conclui-se o método quantitativo de anestesia diminui dramaticamente o consumo de anestésicos inalatórios e que proporcionalmente, parece que o enflurano é o mais econômico dos anestésicos halogenados estudados