Objectives To 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 model

Objective To examine the effects of short-term cyclic stretch on apoptosis in alveolar type II cells (A549). To study in vitro the direct influence of alveolar type II cells on mechanical stretch. Methods A549 were treated with different doses of lipopolysaccharide (LPS), 0 ng/ml, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1000 ng/ml, and then A549 were lengthened 5%, 15%, 30% using a FLEXCELL tension unit 4000, a vacuum-driven device that applies strain to cells, which were cultured in six-well plates coated with collagen-I, and 12 cycles/min for 4 hours. Apoptosis was measured using the flow cytometry method that measures annexin V and propidium iodide (PI) staining. The morphological changes of apoptotic cells were observed by transmission electron microscope. Results Apoptosis could be induced in alveolar type II cells (A549) by mechanical stretch. The percentage of annexin V + PI cells increased after being treated with cyclic stretch for 4 hours by 5%, 15%, 30% in all groups. The morphological features of apoptotic cells demonstrated by transmission electron microscope were as follows: shrinkage of the cell, chromatin condensation and aggregation under the nuclear membrane as a crescent or lump, membrane-encapsulated nuclear fragment or cell organ formed by invagination of the cell membrane, and apoptotic body formation followed by vacuolization. Conclusion Apoptosis induced by mechanical stretch and LPS is dose dependent. Mechanical stretch aggravates apoptosis especially in cells treated with LPS. Annexin V and PI double staining is a specific, sensitive, and quantitative method for analyzing apoptotic cells. It is also helpful to clarify the protective mechanism of low-volume ventilation in ARDS. Acknowledgement The study was funded by the 'One Hundred People' project of Shanghai Sanitary Bureau (03-77-20). Introduction Although extrapulmonary ALI/ARDS is a common clinical entity, most animal models used to study this disease are induced by direct lung injuries. Our intention was therefore to investigate whether a condition resembling ALI/ARDS develops during the course of a fecal peritonitis in pigs; in that case experimental peritonitis would also prove as a clinically relevant ARDS model. Methods In 10 anesthetized, mechanically ventilated, and instrumented pigs fecal peritonitis was induced by inoculating autologue feces pellets suspended in saline. Mechanical ventilation was set with VT = 8 ml/kg, FiO 2 to reach a SaO 2 target of >90%, PEEP = 10 cmH 2 O if PaO 2 /FiO 2 > 300 and 12 cmH 2 O if PaO 2 /FiO 2 < 300, and respiratory rate to obtain a PaCO 2 of 35-45 mmHg. Before as well as 12 and 24 hours after peritonitis induction we measured the PaO 2 /FiO 2 ratio, the total compliance of the respiratory system (C), calculated as VT/(P plateau -PEEP) and inspiratory airway resistance (R i ) calculated as (P max -P plateau ) / mean inspiratory flow. Data are mean [range]. Results For data see Table 1. During the course of the 24-hour study period, six of 10 animals developed gas exchange deteriorations consistent w...

No abstract

Introduction Many authors have written about the need to treat patients closer to their beds, in order to observe them more as distinct people. The FAST HUG mnemonic, which consists of a checklist, was suggested as an idea to be employed everyday, by professionals dealing with patients who are critically ill. Minding these questions and motivated by an idea of follow patients' treatment closer, we have put into practice the instrument developed by Jean-Louis Vincent, evaluating the seven most important procedures in critically ill patients, and performed the FAST HUG. This checklist consists of seven items to be evaluated: Feeding, Analgesia, Sedation, Thromboembolic prophylaxis, Head-of-bed elevation, stress Ulcer prevention, and Glucose control. Knowing that the pressure ulcer is one of the challenges faced by ICU nurses, related to patients' need to stay at rest, to be under rigorous control or more complex therapy, it was decided to create the eighth item on the checklist: S, for skin. It stands for skin treatment, with the techniques used in the unit (Braden Scale), monitoring and evaluating closer skin integrity, and allowing nurses to calculate the scoring average of the Braden Scale, and greater incidence of ulcer in interned patients. Objective To expose the shortcomings found during the FAST HUG application, and to show results obtained with the eighth item of the FAST HUG mnemonic: S-Skin. Methods A descriptive study, based on institutional data, was carried out in the adult ICU of a private hospital. It was performed from 2 to 27 June 2008, except on weekends. Three hundred and twenty-three patients were involved. The checklist was carried out during the afternoons by the head nurse, or the assistant nurse of the unit. In order to do this job, a spreadsheet was elaborated to control data, updated every week. This spreadsheet provided graphics for a more objective control of the results obtained. The idea was exposed to the team, during a training program, and so we started the activities. Results and discussion For 20 days of the checklist, 323 patients were evaluated for the eight items. The real shortcomings most frequently found were related to thromboembolic prophylaxis (85%) and glucose control (90%). These shortcomings were immediately evaluated and, depending on this analysis, this item would go on or not, according to the patient's clinical situation. The shortcomings found were tracked just as they were detected, and their cause would be discussed in a multidisciplinary group, and a solution was found. If the item was not observed, it would be 1. Vincent JL: Give your patient a fast hug (at least) once a day.

No abstract