Chest
-
We studied hemodynamic and oxygen transport parameters in 12 stable critically ill patients on assist control (ACV), synchronized intermittent mandatory (SIMV), and pressure support (PSV) ventilatory modes. Patients were optimally ventilated on ACV, were awake, and capable of spontaneous breathing. After baseline measurements on ACV, patients were placed on SIMV and PSV for 30 min each and measurements were repeated at the end of each period. ⋯ Hemodynamic and oxygen transport parameters were not significantly different among the three groups, although there was a tendency toward higher cardiac index, oxygen transport, and oxygen consumption on SIMV and PSV. We conclude that in stable critically ill patients, SIMV and PSV used according to our study protocol for 30 min can provide adequate ventilation with lower airway pressure and possibly less adverse effects on hemodynamic and tissue oxygenation parameters compared with ACV. Because of a significant decrease in VT and an increase in f seen with SIMV, PSV may be a more desirable mode for ventilatory support.
-
To assess the usefulness of preoperative respiratory muscle training to increase muscle strength and its effects on postoperative pulmonary complications. ⋯ Preoperative respiratory muscle training may prevent postoperative pulmonary complications by increasing both inspiratory and expiratory muscle strength in patients undergoing thoracic surgery. Patients with respiratory muscle weakness have a higher risk of postoperative pulmonary complications.