ABSTRACT
Objective To compare the ear baric function between 4000m altitude chamber test with inhaling air and 6900m altitude chamber test with inhaling pure oxygen.Methods Eleven healthy male volunteers attended two tests as two groups by self-comparison. As the air group the volunteers inhaled air at 4000m, while as the pure oxygen group they inhaled pure oxygen at 6900m altitude, and the time interval between the two tests was more than two weeks. During the test, the volunteers breathed air or pure oxygen at random for 1h, and then were exposed at a speed of 20m/s to the target altitude for 5min. Hereafter they were sent back to the ground at the same speed. The changes of subjective symptoms, degree of tympanic congestion, acoustic immitance index and pure-tone auditory threshold were recorded before and after the test. The acoustic impedance index and pure-tone threshold were statistically analyzed.ResultsFour volunteers (4 ears) in air group and 7 volunteers (7 ears) in pure oxygen group reported ear pain in altitude chamber exposures, respectively. The pain-triggering altitude was higher in the pure oxygen group. Immediately after tests, there were 3 (3 ears) and 5 volunteers (5 ears) with Ⅲ degree congestion of the tympanic membrane in the two groups respectively. Four volunteers (6 ears) developed gradually aggravated hemorrhages after altitude exposure. And the tympanic membrane congestion difference between groups was statistically significant at 3 and 24h after tests (P<0.01). The type A tympanogram appeared in 11 (15 ears) and 11 (14 ears) volunteers respectively immediately after tests. The increase of static compliance value was significantly greater in pure oxygen group than in air group immediately after tests (P<0.05), the decrease of middle ear pressure was more significant in pure oxygen group than in air group at 3 and 24h after tests (P<0.05). Both the two altitude exposure tests resulted in eustachian tube dysfunction. At 3 and 24h after the tests, the increase of individual frequency pure-tone threshold was significantly higher in pure oxygen group than in air group (P<0.05).Conclusion Breathing pure oxygen and lifting height could increase the screening degree of ear baric function test in hypobaric chamber, and have greater influence on degree of tympanic congestion, acoustic immittance and pure-tone auditory threshold in 24 hours.
ABSTRACT
Objective To study the effects of use of cyclamic acid on monitoring D-Dimer and predicting deep venous thrombosis on lower limbs during total hip arthroplasty.Methods Ninety-three cases patients who received total hip arthroplasty operations at Joint Surgery Department of the Central Hospital of Zhuzhou city and Zhuzhou Hospital Affiliated to Xiangya Medical College of Central South University from December 2015 to May 2016 were selected as subjects and randomly assigned into study group with 50 cases and control group with 43 cases.During the operations,cyclamic acid was used intravenously and locally as a routine in the study group while saline was utilized instead in the control group.The D-Dimer was dynamically monitored before operation and 1,3,5,7,9 d after the operation,and venous color ultrasonography of both lower limbs were taken 3,6,9 d after the operation to check the conformation of thrombosis.Results The total blood loss after treatment in the study group was (350.5 ± 65.2) ml,intraoperative blood loss of (129.3 ± 43.1) ml,postoperative drainage volume of (80.9± 12.6) ml,occult blood loss of (141.9± 20.6) ml,corresponding to the control group were (560.8±60.6) ml,(208.9± 57.8) ml,(150.8 ± 18.9) ml,(202.9±23.9) ml.The above indicators were lower in the study group than in the control group,the differences between the two groups were statistically significant(t =16.02,7.59,21.24,13.22,P＜0.05).There were significant differences in terms of D2-dimer level of 1,3,5 d after the operation between the study group and the control group (P＜0.05),but at 7,9 d after the operation,the difference between the two groups were not statistically significant(P＞0.05).The study group and the control group at 9 d after operation with color Doppler ultrasound examination showed that there were 1 cases of patients with calf vein thrombosis both in two groups,there was no significant difference between the two groups(2.00％ vs.2.32％,x2 =0.012,P＞ 0.05).Conclusion The proper use of cyclamic acid can reduce blood loss and will not increase the risk of thrombosis.Monitoring dynamically on D-Dimer and deep venous color ultrasonography on lower limbs is helpful for early detection of thrombosis after total hip arthroplasty.However,the use of cyclamic acid during total hip arthroplasty will affect the monitoring on D-Dimer and therefore needs to be taken seriously.