Objective To investigate the preventive effect of rapid preoxygenation technique on hypoxia caused by respiratory depression during outpatient obstetrics-gynecology operations. Methods According to a computer-generated random sequence, a total of 120 ASA I-II patients undergoing outpatient obstetrics-gynecology operations were randomly allocated into the trial group or the control group, 60 in each group. Patients in the control group received preoxygenation with tidal volume breathing. Patients in the trial group received preoxygenation with eight deep breaths (DB) in 1 min before anesthesia. All patients were induced with midazolam 1 mg, fentanyl 1μg /kg and propofol 2 mg/kg, and were maintained with propofol when needed. The following parameters were observed, including the incidences of respiratory depression and apnea, the onset time of anesthesia, the total doses of propofol as well as the changes in PetCO2 and SpO2. Results No significant differences were observed in demographic characteristics, the onset time of anesthesia, the total doses of propofol, and the incidences of respiratory depression and apnea between the two groups (P gt;0.05). However, the SpO2 in the control group was decreased significantly with a higher incidence of hypoxia (Plt;0.05). Conclusions Rapid preoxygenation technique may increase the oxygen reserves and improve the tolerance to hypoxia. It is effective in avoiding hypoxia caused by respiratory depression and apnea during outpatient obstetrics-gynecology operations.
ObjectiveTo observe the effect of different preoxygenation methods for emergency intubation in severe patients in intensive care unit (ICU). MethodsProspective randomized study was performed in the intensive care unit between June 2013 and January 2014. Forty patients were randomly divided into 4 groups:group A (control group, n=10), group B (bag-valve-mask preoxygenation group, n=10), group C (noninvasive ventilator-mask preoxygenation group, n=10), and group D (invasive ventilator-mask preoxygenation group, n=10). Standardized rapid sequence intubation was performed without preoxygenation in group A; preoxygenation was performed by using a bag-valve-mask rose pulse oxygen saturation (SpO2) to 90% before a rapid sequence intubation in group B; preoxygenation was performed by using noninvasive ventilator through a face mask rose SpO2 to 90% before a rapid sequence intubation in group C; and preoxygenation was performed by using invasive ventilator through a face mask rose SpO2 to 90% before a rapid sequence intubation in group D. We recorded the time when SpO2 was more than or equal to 90% in group B, C, and D, and arterial blood gases and complications were observed. ResultsThere was no significant difference in the basic indexes before preoxygenation among the four groups (P>0.05). The time of the patients in group D and C was significantly lower than that of group B. The arterial oxygen saturation (SaO2) and arterial oxygen partial pressure (PaO2) in the group C and D were higher than those in group B after preoxygenation (P<0.05). After intubation, SpO2 in group B, C and D was significantly higher than that in group A (P<0.05). At the same time, SpO2 in group C and D was higher than that in group B (P<0.05); PaO2 and SaO2 in group C and D were higher than in those in group A and B (P<0.05); SaO2 in group D was higher than that in group B (P<0.05). The incidence of abdominal distension in group D was significantly lower than that of group B and C (P<0.05). ConclusionFor emergency tracheal intubation in critically ill patients in the ICU, preoxygenation is more effective than the rapid sequence intubation without preoxygenation in improving oxygenation indicators. Invasive ventilator-mask preoxygenation efficacy and safety are superior to other methods.
ObjectiveTo investigate whether noninvasive positive pressure ventilation (NIV) will improve preoxygenation in critically ill patients in intensive care unit (ICU) before intubation, when compared with bag-valve-mask (BVM).MethodsThis was a single-centered, prospective and randomized study. The patients in the study were those who required tracheal intubation in the ICU of the First Affiliated Hospital of Guangzhou Medical University and Guangzhou Institute of Respiratory Health from June 2015 to June 2017. These critically ill patients were provided with BVM or NIV assisted preoxygenation randomly. The data of the NIV group and the control group were compared and the application values of NIV in preoxygenation of critically ill patients were evaluated.ResultsA total of 106 patients participated in this study, including 75 males and 31 females and with an average age of (65.0±12.6) years. The patients were classified either into the control group (BVM assisted preoxygenation, n=53), or the NIV group (NIV assisted pre-oxygenation, n=53). The causes of intubation in the control group and the NIV group were as follows: pneumonia [40 patients (75.5%) vs. 39 patients (73.6%)], chronic obstructive pulmonary disease [12 patients (22.6%) vs. 11 patients (20.8%)], and other disease [1 patient (1.9%) vs. 3 patients (5.7%)], which showed no significant difference between the two groups. The scores of the Acute Physiology and Chronic Health Evaluation System Ⅱ of the control group and the NIV group were 20 (17, 26) vs. 20 (16, 26), P=0.86, which also showed no significant difference. The oxygen saturation of the pulse (SpO2) before preoxygenation were similar in both the control group and the NIV group 92% (85%, 98%) vs. 91% (85%, 98%), P=0.87. After preoxygenation, SpO2 was significantly higher in the NIV group than in the control group 99% (96%, 100%) vs. 96% (90%, 99%), P=0.001. For the subgroup of patients with SpO2 less than 90% before preoxygenation, the respective SpO2 in the control group and the NIV group were 83% (73%, 85%) vs. 81% (75%, 86%), P=0.75; after preoxygenation, SpO2 in the NIV group was significantly higher than in the control group 99% (96%, 100%) vs. 94%(90%, 99%), P=0.000. For the subgroup of patients with SpO2 of 90% or more before preoxygenation, the respective SpO2 in the control group and the NIV group were similar 95.5% (92%, 99%) vs. 96% (94%, 99%), P=0.52; and continued to be similar after preoxygenation 98% (95%, 100%) vs. 99% (96%, 100%), P=0.1. The duration of mechanical ventilation of the control group and the NIV group was 17 (10, 23)d vs. 19 (11, 26)d (P=0.86). The 28 days survival rate of the control group and the NIV group was 73.6% vs. 71.7% (P=0.34). The mortality rate in the control group and NIV group were 31.3% and 31.7% (P=0.66).ConclusionsWhen compared with the use of BVM, NIV assisted preoxygenation is effective and safe for critically ill patients. Critically ill patients with severe hypoxemia will benefit more from NIV assisted preoxygenation.