Gerardo Tusman

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OBJECTIVE We tested whether the continuous monitoring of dynamic compliance could become a useful bedside tool for detecting the beginning of collapse of a fully recruited lung. DESIGN Prospective laboratory animal investigation. SETTING Clinical physiology research laboratory, University of Uppsala, Sweden. SUBJECTS Eight pigs submitted to repeated(More)
The objective of this study was to evaluate the effects of lung perfusion on the slopes of phases II (S(II)) and III (S(III)) of a single-breath test of CO(2) (SBT-CO(2)). Fourteen patients submitted to cardiac surgery were studied during weaning from cardiopulmonary bypass (CPB). Pump flow was decreased in 20% steps, from 100% (total CPB = 2.5(More)
BACKGROUND General anesthesia is known to promote atelectasis formation. High inspiratory pressures are required to reexpand healthy but collapsed alveoli. However, in the absence of positive end-expiratory pressure (PEEP), reexpanded alveoli collapse again. Using magnetic resonance imaging, the impact of an alveolar recruitment strategy on the amount and(More)
Dead space is the portion of a tidal volume that does not participate in gas exchange because it does not get in contact with blood flowing through the pulmonary capillaries. It is commonly calculated using volumetric capnography, the plot of expired carbon dioxide (CO(2)) versus tidal volume, which is an easy bedside assessment of the inefficiency of a(More)
BACKGROUND Changes in the shape of the capnogram may reflect changes in lung physiology. We studied the effect of different ventilation/perfusion ratios (V/Q) induced by positive end-expiratory pressures (PEEP) and lung recruitment on phase III slope (S(III)) of volumetric capnograms. METHODS Seven lung-lavaged pigs received volume control ventilation at(More)
BACKGROUND Anesthesia workstations with pressure support ventilation (PSV) are available, but there are few studies published on how to program flow-triggered PSV using a laryngeal mask airway (LMA) under general anesthesia in pediatric patients. METHODS We studied 60 ASA I and II patients, from 2 mo to 14 yr, scheduled for ambulatory surgery under(More)
Abnormalities in gas exchange during general anaesthesia are caused partly by atelectasis. Inspiratory pressures of approximately 40 cm H2O are required to fully re-expand healthy but collapsed alveoli. However, without PEEP these re-expanded alveoli tend to collapse again. We hypothesized that an initial increase in pressure would open collapsed alveoli;(More)
BACKGROUND Deterioration of gas exchange during one lung ventilation (OLV) is caused by both total collapse of the nondependent lung and partial collapse of the dependent lung. A previous report demonstrated that an alveolar recruitment strategy (ARS) improves lung function during general anesthesia in supine patients. The objective of this article was to(More)
BACKGROUND The aim of this study was to test the accuracy of lung sonography (LUS) to diagnose anesthesia-induced atelectasis in children undergoing magnetic resonance imaging (MRI). METHODS Fifteen children with American Society of Anesthesiology's physical status classification I and aged 1 to 7 yr old were studied. Sevoflurane anesthesia was performed(More)
To test the usefulness of dead space for determining open-lung PEEP, the lowest PEEP that prevents lung collapse after a lung recruitment maneuver. Prospective animal study. Department of Clinical Physiology, University of Uppsala, Sweden. Eight lung-lavaged pigs. Animals were ventilated using constant flow mode with VT of 6 ml/kg, respiratory rate of 30(More)