Critical care medicine
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Critical care medicine · May 1983
Comparative StudyThe use of conventional ventilators for high frequency positive pressure ventilation.
Ten randomly selected patients were ventilated for defined periods with 2 ventilatory modes: (a) high frequency positive pressure ventilation (HFPPV) (frequency 66-70 min; tidal volume 1-3 ml/kg body weight), (b) conventional IPPV (frequency 16/min; tidal volume (VT) 10-15 ml/kg). This was done successfully using conventional ventilators, and keeping other variables (FIO2, PEEP) constant. Various ventilatory and hemodynamic variables were measured and compared during both modes of ventilation. ⋯ Peak tracheal pressure was significantly lower during HFPPV. An increase in mean systemic arterial pressure and in oxygen transport was observed during HFPPV, whereas transpulmonary shunt and pulmonary vascular resistance (PVR) decreased during HFPPV. These findings are in accordance with previously reported advantages of HFPPV, and might be of importance in the treatment of patients with bronchopleural fistula, adult respiratory distress syndrome (ARDS), left ventricular failure and other conditions in which conventional positive pressure ventilation (PPV) fails.
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We present a case of cerebral air embolism after a gunshot wound to the lung, combined with mechanical ventilation. Hyperbaric and pharmacologic therapy resulted in complete recovery. The discussion focuses on hyperbaric therapy as the mainstay of treatment, the importance of prophylactic measures, and prompt diagnosis.
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Critical care medicine · May 1983
Laryngotracheal injury due to endotracheal intubation: incidence, evolution, and predisposing factors. A prospective long-term study.
The purpose of this study was to assess the incidence, evolution and long-term effects of laryngotracheal lesions due to endotracheal intubation and to evaluate the import of factors in the genesis of laryngotracheal injury. Over a 12-month period, we performed fiberoptic bronchoscopy (FBS) in 19 critically ill patients with endotracheal intubation. ⋯ In 6 (31%) patients, early tracheal lesions appeared in the form of ring-shaped tracheitis at the cuff level and granulomas at the tube-tip level; in 2 (10%) patients, an established tracheal stenosis developed and early detected ring-shaped tracheitis preceded circumferential fibrous stenosis. Severe respiratory failure, high cuff pressure, and secretion infection showed a statistical correlation to tracheal injury.
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Critical care medicine · Apr 1983
Comparative StudyCompared effects of selected colloids on extravascular lung water in dogs after oleic acid-induced lung injury and severe hemorrhage.
While the hemodynamic effects of hydroxyethyl starch (HES) have been reported, the effect of this material upon extravascular lung water (EVLW) has not been investigated. Twenty mongrel dogs were subjected to both an oleic acid-induced lung injury and a 2-h period of hemorrhagic shock (MAP = 40 mm Hg). After reinfusion of shed blood, 5 dogs in each of 4 groups were given either 0.5 L of lactated Ringer's solution or 0.5 L of 5% albumin, 6% dextran 75, or 6% HES. ⋯ EVLW was 25.5 +/- 3 ml/kg in the HES dogs, and 29.5 +/- 2 ml/kg in the group given albumin. Differences between albumin and lactated Ringer's solution and between the HES and lactated Ringer's groups were significant (p less than 0.02 and p less than 0.05). Measurements of oxygen, ventilation, CI, and oxygen delivery were not significantly different between the albumin and HES subjects.
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Critical care medicine · Apr 1983
Comparative StudyCentral venous versus esophageal pressure changes for calculation of lung compliance during mechanical ventilation.
Esophageal and CVP changes were measured simultaneously during mechanical ventilation in 12 patients with acute respiratory failure (ARF). The results of these measurements were different and showed no correlation. Values of transpulmonary pressure changes and calculated lung compliances correlated well, because of the higher airway pressure changes. ⋯ Clinical awareness of factors influencing thoracic cage compliance is important. The difference in transpulmonary and transthoracic pressure relationships during mechanical ventilation and during spontaneous breathing is emphasized. In spontaneous breathing, intrapleural pressure changes are determined primarily by the elastic properties of the lungs; in mechanical ventilation, on the other hand, by the elastic properties of the thoracic cage.