IntroductionPatients undergoing mechanical ventilation (MV) are frequently administered prolonged and/or high doses of opioids which when removed can cause a withdrawal syndrome and difficulty in weaning from MV. We tested the hypothesis that the introduction of enteral methadone during weaning from sedation and analgesia in critically ill adult patients on MV would decrease the weaning time from MV.MethodsA double-blind randomized controlled trial was conducted in the adult intensive care units (ICUs) of four general hospitals in Brazil. The 75 patients, who met the criteria for weaning from MV and had been using fentanyl for more than five consecutive days, were randomized to the methadone (MG) or control group (CG). Within the first 24 hours after study enrollment, both groups received 80% of the original dose of fentanyl, the MG received enteral methadone and the CG received an enteral placebo. After the first 24 hours, the MG received an intravenous (IV) saline solution (placebo), while the CG received IV fentanyl. For both groups, the IV solution was reduced by 20% every 24 hours. The groups were compared by evaluating the MV weaning time and the duration of MV, as well as the ICU stay and the hospital stay.ResultsOf the 75 patients randomized, seven were excluded and 68 were analyzed: 37 from the MG and 31 from the CG. There was a higher probability of early extubation in the MG, but the difference was not significant (hazard ratio: 1.52 (95% confidence interval (CI) 0.87 to 2.64; P = 0.11). The probability of successful weaning by the fifth day was significantly higher in the MG (hazard ratio: 2.64 (95% CI: 1.22 to 5.69; P < 0.02). Among the 54 patients who were successfully weaned (29 from the MG and 25 from the CG), the MV weaning time was significantly lower in the MG (hazard ratio: 2.06; 95% CI 1.17 to 3.63; P < 0.004).ConclusionsThe introduction of enteral methadone during weaning from sedation and analgesia in mechanically ventilated patients resulted in a decrease in the weaning time from MV.

Potential drug interactions prevalence in intensive care units Prevalência de potenciais interações medicamentosas droga-droga em unidades de terapia intensiva ORIGINAL ARTICLE INTRODUCTION A drug interaction takes place when the effects and/or toxicity of a drug are affected by another drug. (1,2) Although results may be positive (increased efficacy) or negative (decrease of efficacy, toxicity or idiosyncrasy), in pharmacotherapy they are usually unforeseen and undesirable. (3) With the continued development of new drugs and subsequent prescriptions with increasingly more complex combinations it has become difficult for physicians and pharmaceutics to be familiar with all potential interactions. (4) Risk of occurrence and severity rest upon several factors, among them

ObjectivesTo characterize an experimental model of pulmonary embolism by studying hemodynamics, lung mechanics and histopathologic derangements caused by pulmonary microembolism in pigs. To identify lung alterations after embolism that may be similar to those evidenced in pulmonary inflammatory conditions. Materials and methods Ten Large White pigs (weight 35-42 kg) were instrumented with arterial and pulmonary catheters, and pulmonary embolism was induced in five pigs by injection of polystyrene microspheres (diameter ~300 µM), in order to obtain a pulmonary mean arterial pressure of twice the baseline value. Five other animals injected with saline served as controls. Hemodynamic and respiratory data were collected and pressure x volume curves of the respiratory system were performed by a quasi-static low flow method. Animals were followed for 12 hours, and after death lung fragments were dissected and sent to pathology. Results Pulmonary embolism induced a significant reduction in stroke volume (71 ± 18 ml/min/bpm pre vs 36 ± 9 ml/min/bpm post, P < 0.05), an increase in pulmonary mean arterial pressure (27 ± 4 mmHg pre vs 39 ± 6 mmHg post, P < 0.05) and pulmonary vascular resistance (193 ± 122 mmHg/l/min pre vs 451 ± 149 mmHg/l/min post, P < 0.05). Respiratory dysfunction was evidenced by significant reductions in the PaO 2 /FiO 2 ratio (480 ± 50 pre vs 159 ± 55 post, P < 0.05), the dynamic lung compliance (27 ± 6 ml/cmH 2 O pre vs 19 ± 5 ml/cmH 2 O post, P < 0.05), the increase in dead space ventilation (20 ± 4 pre vs 47 ± 20 post, P < 0.05) and, the shift of pressure x volume curves to the right, with reduction in pulmonary hysteresis. Pathology depicted inflammatory neutrophil infiltrates, alveolar edema, collapse and hemorrhagic infarctions. Conclusion This model of embolism is associated with cardiovascular dysfunction, as well as respiratory injury characterized by a decrease in oxygenation, lung compliance and hysteresis. Pathology findings were similar to those verified in inflammatory pulmonary injury conditions. This model may be useful to study pathophysiology, as well as pharmacologic and ventilatory interventions useful to treat pulmonary embolism. P6 Hemodynamic and metabolic features of a porcine systemic low flow state modelObjective To describe a new experimental systemic low flow state model induced by cardiac tamponade. Methods Ten Large White pigs (43 ± 5 kg) were instrumented with arterial and pulmonary catheters, cystostomy and splenectomy, and a latex balloon was inserted anterior to the heart. Pigs were randomized to a shock group or a control group. The shock group had the balloon inflated with 620 ± 344 ml to keep the mean arterial blood pressure at 45-55 mmHg (mean = 49 ± 4 mmHg) for 1 hour. Hemodynamic data were collected and shown as the mean ± SD. Two-way ANOVA was used with Bonferroni's correction. Results During shock, the SvO 2 was 34 ± 8%, the heart rate was 173 ± 36 bpm, and the stroke volume was 18 ± 12 ml/min/beat. After shock, see Table 1. Conclusion In our model, transient...

Introduction Noninvasive ventilation is a safe and eff ective method to treat acute respiratory failure, minimizing the respiratory workload and oxygenation. Few studies compare the effi cacy of diff erent types of noninvasive ventilation interfaces and their adaptation. Objective To identify the most frequently noninvasive ventilation interfaces used and eventual problems related to their adaptation in critically ill patients. Methods We conducted an observational study, with patients older than 18 years old admitted to the intensive care and step-down units of the Albert Einstein Jewish Hospital that used noninvasive ventilation. We collected data such as reason to use noninvasive ventilation, interface used, scheme of noninvasive ventilation used (continuously, periods or nocturnal use), adaptation, and reasons for nonadaptation. Results We evaluated 245 patients with a median age of 82 years (range of 20 to 107 years). Acute respiratory failure was the most frequent cause of noninvasive ventilation used (71.3%), followed by pulmonary expansion (10.24%), after mechanical ventilation weaning (6.14%) and sleep obstructive apnea (8.6%). The most frequently used interface was total face masks (74.7%), followed by facial masks in 24.5% of the patients, and 0.8% used performax masks. The use of noninvasive ventilation for periods (82.4%) was the most common scheme of use, with 10.6% using it continuously and 6.9% during the nocturnal period only. Interface adaptation occurred in 76% of the patients; the 24% that did not adapt had their interface changed to improve adaptation afterwards. The total face mask had 75.5% of interface adaptation, the facial mask had 80% and no adaptation occurred in patients that used the performax mask. The face format was the most frequent cause of nonadaptation in 30.5% of the patients, followed by patient's related discomfort (28.8%), air leaking (27.7%), claustrophobia (18.6%), noncollaborative patient (10.1%), patient agitation (6.7%), facial trauma or lesion (1.7%), type of mask fi xation (1.7%), and 1.7% patients with other causes. Conclusion Acute respiratory failure was the most frequent reason for noninvasive ventilation use, with the total face mask being the most frequent interface used. The most common causes of interface nonadaptation were face format, patient-related discomfort and air leaking, showing improvement of adaptation after changing the interface used. P2 Exercise training reduces oxidative damage in skeletal muscle of septic rats