Journal of Tongji Medical University = Tong ji yi ke da xue xue bao
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J. Tongji Med. Univ. · Jan 1997
Randomized Controlled Trial Clinical TrialMultiple respiratory gas monitoring causes changes of inspired oxygen concentration in closed anesthesia system.
Effect of multiple respiratory gas monitoring (MRGM) on inspired concentration of oxygen in circuit system during closed anesthesia was studied in 51 adult patients scheduled for abdominal surgery. Required flow rate of fresh oxygen (OFR), inspired oxygen concentration (FiO2) and oxygen saturation of pulse oximeter (SpO2) were measured continuously. Patients were equally divided into three groups at random, group C (no MRGN used), group M1 (using MRGM with its tail gas returned to circuit system), group M2 (using MRGM without tail gas returned). ⋯ In group M1, FiO2 decreased by 16% at 60 min and 34% at 180 min and the decrease was significantly greater than that in group C (P < 0.01). In group M2, FiO2 remained constant during closed anesthesia, which was much higher than those in group C and M1. The tail gas of Capnomac Ultima MRGM contained less oxygen than its sample gas drawn from circuit system simultaneously.
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J. Tongji Med. Univ. · Jan 1992
Randomized Controlled Trial Comparative Study Clinical TrialClinical studies on high frequency two-way jet ventilation.
A new mode of jet ventilation, high frequency two-way jet ventilation (HFTJV) was devised and introduced to increase carbon dioxide elimination during jet ventilation. Its ventilatory efficiency and features were investigated and compared with those of high frequency jet ventilation (HFJV) in 10 patients with normal cardiopulmonary function. Random sample selection and randomized cross-over trial were used for comparison between HFTJV and HFJV at the same ventilatory settings of driving pressure 1 kg/cm2 (14.22 Psi), respiratory rate 100/min and I/E ratio 1:2. ⋯ PaCO2 with HFTJV was significantly lower than that with HFJV, but PaO2 and pH with HFTJV were significantly higher than those with HFJV. HFTJV was shown to have a ventilatory feature of decreasing airway pressure and simultaneously increasing carbon dioxide elimination, as compared with HFJV. Whether this ventilatory feature of HFTJV can be utilized for various respiratory support in patients with abnormal cardiopulmonary function needs to be further studied.