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Background: Stepwise recruitment maneuvers (RM) applied with high airway pressures may optimize lung recruitment, but this kind of intervention may lead to widely heterogeneous responses with possible side effects. To assess the clinical impact of these maneuvers, we performed a stepwise maximal-recruitment strategy superimposed on routine mechanical ventilation., Methods: We studied 13 adults with early-phase acute lung injury/acute respiratory distress syndrome (ALI/ARDS). We used pressure-control ventilation at an FiO(2) of 1. Starting from a Pplat/positive end-expiratory pressure (PEEP) of 40/25, we sequentially increased airway pressure in 5 cmH(2)O steps until a PaO(2)/FiO(2) of 350 mmHg or a Pplat/PEEP of 60/40 cmH(2)O was reached. The PEEP was then progressively reduced until the PaO(2) decreased by more than 10% of the maximum PaO(2); the PEEP was subsequently set to 2 cmH(2)O above this level. An intra-arterial catheter continuously displayed blood gas measures. The respiratory mechanics and hemodynamics were monitored at each phase and during the two-hour follow-up., Results: Two hours after the RM, the PaO(2)/FiO(2) was higher than at baseline (187±102 versus 339±136 mmHg, P<0.001). In 8 patients, the PEEP increased from 12±3 cmH(2)O to 15±4 cmH(2)O after the RM (P<0.001). In the other five, it closely mirrored the basal PEEP. Seven patients did not reach the 350-mmHg PaO(2) target. The respiratory system compliance decreased in seven patients. The RM was discontinued due to severe complications in four patients., Conclusion: Although stepwise-RM improves oxygenation, it has a heterogeneous impact on respiratory mechanics and may cause adverse hemodynamic effects and transient hypoxemia. If the use of this kind of RM is considered, it should be adapted to individual patient needs, applied carefully and closely monitored.

Purpose: To compare the effects of two humidifier systems on endotracheal tube (ETT) resistance during mechanical ventilation, either an active heated humidifier (HH) or a passive heat and moisture exchanger (HME) was selected using current clinical recommendations., Methods: This was a prospective clinical cohort study performed in an intensive care unit. Gas conditioning was performed using the HH in 22 patients and the HME in another 22. Patients were matched for endotracheal tube diameter, days of mechanical ventilation, simplified acute physiology score II (SAPS II), and fluid balance., Results: Used-ETT resistance was measured immediately after extubation. Unused-ETT resistance was calculated with an identical, clean ETT. No differences were found between the HH and HME groups in ETT diameter (7.9 ± 0.4 vs. 7.9 ± 0.3 mm; p = 0.98), days of mechanical ventilation (11.3 ± 7.7 vs. 9.5 ± 4.5; p = 0.34), SAPS II (41.0 ± 13.6 vs. 42.0 ± 11.7; p = 0.79), or fluid balance (-2,552 ± 6,268 vs. -2,579 ± 5,422 mL; p = 0.98). ETT resistance increased from intubation to extubation: from 6.8 ± 1.1 to 10.6 ± 4.3 cmH(2)O L(-1) s(-1) in the HH group, (p < 0.001) and from 6.8 ± 1.1 to 10.2 ± 3.8 cmH(2)O L(-1) s(-1) in the HME group (p < 0.001), which is a 53% average increase in resistive load., Conclusions: We did not find differences between the two types of humidifiers in terms of airflow resistance during prolonged mechanical ventilation when the devices were selected on the basis of individual clinical needs. The increase in resistive load is physiologically relevant.

Background: The risk of nosocomial infection in pediatric patients undergoing heart surgery is high and proportional to the days of stay, mainly in intensive care units. Our objective was to determine the incidence and associated factors to nosocomial infections after a heart surgery., Methods: Descriptive, retrospective clinical study with 64 pediatric patients underwent to a heart surgery. The χ(2) with Yates fix for nonparametric data test, relative risk, as well as incidence rate were performed., Results: Nosocomial infection prevalence rate was 52; a fatality in infected 21.2, rate not infected of 16.1; the type of nosocomial infection with the highest rate of 65.6 was pneumonia, and the microorganism most common (rate 12.5) was the Candida. The largest number of infection events were 24 with a 37.5 rate. The most significant variables for infection were heart surgery, parenteral nutrition, nasogastric intubation and tracheotomy., Conclusions: The pediatric patients underwent to a heart surgery presented nosocomial infection in the half of the cases and the fatality rate was higher than the rate reported in literature.

Objective: To compare, in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) patients, the short-term effects of heat and moisture exchangers (HME) and heated humidifiers (HH) on gas exchange, and also on respiratory system mechanics when isocapnic conditions are met., Design: Prospective open clinical study., Setting: Intensive Care Service., Patients: Seventeen invasively ventilated ALI/ARDS patients., Intervention: The study was performed in three phases: (1) determinations were made during basal ventilatory settings with HME; (2) basal ventilatory settings were maintained and HME was replaced by an HH; (3) using the same HH, tidal volume (Vt) was decreased until basal PaCO2 levels were reached. FiO2, respiratory rate and PEEP were kept unchanged., Measurements and Results: Respiratory mechanics, Vdphys, gas exchange and hemodynamic parameters were obtained at each phase. By using HH instead of HME and without changing Vt, PaCO2 decreased from 46+/-9 to 40+/-8 mmHg (p<0.001) and Vdphys decreased from 352+/-63 to 310+/-74 ml (p<0.001). Comparing the first phase with the third, Vt decreased from 521+/-106 to 440+/-118 ml (p<0.001) without significant changes in PaCO2, Vd/Vt decreased from 0.69+/-0.11 to 0.62+/-0.12 (p<0.001), plateau airway pressure decreased from 25+/-6 to 21+/-6 cmH2O (p<0.001) and respiratory system compliance improved from 35+/-12 to 42+/-15 ml/cmH2O (p<0.001). PaO2 remained unchanged in the three phases., Conclusions: Reducing dead space with the use of HH decreases PaCO2 and more importantly, if isocapnic conditions are maintained by reducing Vt, this strategy improves respiratory system compliance and reduces plateau airway pressure.

Acute respiratory distress syndrome/acute lung injury is characterised by profound hypoxaemia due to a permeability pulmonary oedema. In this setting, recruitment manoeuvres (RMs) can be a useful tool as adjuncts to lung protective ventilatory strategies to prevent cyclic alveolar stress and avoid alveolar collapse. Many experimental and physiological studies have discussed the use of RMs but only a few heterogeneous clinical experiences have demonstrated the beneficial and deleterious effects that can occur using these manoeuvres. Besides, a lot of questions remain to be answered to find the best way to perform optimal RMs. Further experimental and clinical trials are needed to understand the potential beneficial effects of recruitment manoeuvres when using a protective mechanical ventilation strategy. This paper is a general review of experimental works that support application of recruitment manoeuvres emphasising the clinical studies that have been published to date in acute respiratory distress syndrome patients.

The persistence of serological positivity was studied in 21 children with surgically proven hydatidosis. The children had been previously operated on between 10 months and 7 4/12 years before serum samples were extracted. Forty-eight people (19 adult and 39 children) were included as a control group. E.L.I.S.A. specific IgE and indirect hemagglutination techniques were used for the diagnosis of hydatid disease. Studies of the immunoglobulins and complement components IgG, IgA, IgM, IgE, C3, C4, C5 and factor B were done on the sera from the 21 children with histories of equinococciasis. The results are expressed according to the location and physical condition of the cyst, the time passed after surgery, the number of cysts and the number of surgical operations. We found persistence of positivity of up to 5 4/12 years for indirect hemagglutination and up to 6 7/12 years for specific IgE, in cases without evidence of clinical parasitation so we think that the postoperative control must be based on several serological determinations. The concordance between the two specific serological tests (specific IgE and indirect hemagglutination) was 80.95%; specific IgE having appeared more sensitive especially in cases of hepatic location. The results concerning the total IgE determination were highlighted in the immunoglobulin studies. We consider total IgE as being only orientative, because of the frequency with which it is found elevated in childhood diseases.

The model developed by Barreiro, Salas and Herrera (7) for the prediction of nutrient losses during the thermal processing of conduction heated foods was used in this work to optimize the thermal processing, maximizing nutrient retention in processes with equivalent sterilization values. The processes were stimulated in a digital computer (taking pea purée canned in cans 307 x 409 as the product analyzed). Aall of the processes had equivalent sterilization values with respect to Clostridium botulinum. The thiamine retention associated with each process was calculated by the model of Barreiro, Salas and Herrera (7). The maximum fraction of thiamine retained was of 0.688 for a process at 114.2 degrees C (237.5 degrees F) for 95 minutes. Also, the possibility of the existence of a can with optimum dimensions for maximum thiamine retention, with the same sterilization values, was studied. It was found that this optimum, with the same does not exist; on the contrary, the retention was at a minimum when the diameter approaches infinite and the height zero, and viceversa. For this reason, from the nutrient retention point of view, it is better to process the product in flat or slender cans for a given sterilization value.

It have been studied 90 children (obese 73, non obese or control 17), trying to analyze the following parameters: mean and standard deviation values, its circadian rhythms and relation between cortisol and insulin, correlation between both hormones and anthropometric parameters of obesity and sexual influence with all the studied parameters. The plasmatic cortisol values were higher in male, obese (180.4 +/- 11.2 ng/ml) and control (377.5 +/- 49.2 ng/ml) children. The plasmatic insulin values higher in obese children (55.3 +/- 9.5 microU/ml) verifying the hyperinsulinemia observed in obesity. There was not correlation between cortisol and insulin values with body fat. All the children showed cortisol and insulin circadian rythm. In the groups of obese children the cortisol circadian rythm was similar to the control one. However, the insulin circadian rythm was disturb. So, the acrophase was delayed two hours when male and female were analyzed all together and only one hour in the obese female group. The acrophase of cortisol and insulin rhythms in obese group is delayed in relation with the degree of obesity. The circadian rhythms of cortisol and insulin, in both obese and control groups, are not dependent. The duration of obesity do not have any relation with the mentioned alterations.