derivation of physiologic dead space bohr

Blood pressure was maintained within 20% of baseline with a low-dose infusion of metaraminol (0–0.05 mg/min). Anesthesia was maintained with inhalational isoflurane, rocuronium, and fentanyl, and the patients were mechanically ventilated (Cato anesthetic machine Dräger, Lübeck, Germany). Anesthesia was induced with 2 mg/kg propofol, 2 μg/kg fentanyl, and 0.8 mg/kg rocuronium intravenously, and a cuffed endotracheal tube was inserted. Other routine monitoring included pulse oximetry, electrocardiography, pharyngeal temperature, and capnometry. All patients received a radial artery cannula for clinical hemodynamic monitoring and blood gas sampling. None of the patients had clinically significant lung disease. 7Īfter approval by the ethics committee of the Royal Prince Alfred Hospital (Sydney, NSW, Australia) and written informed consent by the patients, 10 patients (6 male and 4 female) with American Society of Anesthesiologists physical status II or III who were undergoing lower limb vascular surgery were enrolled in this study.

Routine monitoring of dead space to tidal volume ratio in pediatric patients has been demonstrated to permit earlier extubation and to reduce unexpected extubation failures. 6found similar results in critically ill children with lung injury. 4In a prospective study of adults with acute respiratory distress syndrome, patients who died showed a significantly higher mean dead space fraction compared with survivors (0.63 vs.

3A physiologic dead space to tidal volume ratio higher than 0.6 was associated with a 1.5-fold increase in mortality rate in infants with congenital diaphragmatic hernia. It has been used in the diagnosis of pulmonary embolism 2and as a predictor of lung volume during controlled ventilation.

1Respiratory dead space measurement has found wide applications in respiratory physiology, clinical anesthesia, and critical care medicine. QUANTIFICATION of physiologic dead space (Vd phys) provides important insight regarding the efficiency of ventilation and its relation to pulmonary perfusion.

Derivation of physiologic dead space bohr