ABSTRACT
Objective:To evaluate the effects of wearing N95 mask on the quality of chest compression and fatigue.Methods:A total of 80 participants from Zhongnan Hospital with basic life support (BLS) certification conferred by American Heart Association (AHA) within two years were enrolled. After reviewing the key points of cardiopulmonary resuscitation (CPR) and grasping the operation on the manikin, they were randomized (random number) into two groups: wearing surgical masks (SM group, n=40) and wearing N95 masks (N95 group, n=40) during CPR. Each participant performed a 2-minute chest compression-only CPR on the manikin. Participants' height, body weight, Borg scores and physiological parameters before and after CPR were recorded. The quality of chest compression (including compression depth, compression rate, adequate depth proportions, adequate rate proportions, hand position and complete chest recoil) were recorded by Laerdal QCPR ? software. Student's t test and Mann-Whitney test were used to compare the differences of chest compression quality indexes between the two groups. Results:Compared with the SM group, participants in the N95 group had significantly increased median of Borg scores after CPR (16 vs 14, P=0.027), and decreased quality of chest compression, including the decline in compression depth (mean 47 mm vs 52 mm, P=0.020), compression rate (107 times/min vs 118 times/min, P=0.004), complete chest recoil rate (89.8% vs 98.1%, P=0.046), adequate depth proportions (67.4% vs 89.6%, P<0.01) and adequate rate proportions (60.6% vs 74.8%, P<0.01). Conclusions:Wearing N95 masks during CPR decreases the quality of chest compression and aggravates rescuers’ fatigue. Therefore, it is necessary to exchange rescuers more frequently to ensure the quality of chest compression when wearing N95 masks.
ABSTRACT
Objective To investigate the variations of glomerular function in rabbits with partial unilateral ureteral obstruction (PUUO). Methods Thirty healty adult Japanese White Rabbits were randomly divided into the control group (6 rabbits) and the obstruction group (24 rabbits). The right PUUO model was established according to Cheng′s method. According to the PUUO duration, they were eaqually divided into four subgroups:the 7 day PUUO group, the 14 d PUUO group, the 28 d PUUO group and the 56 d PUUO group. The dynamic renal imaging was performed on all rabbits, and the glomerular filtration rate (GFR) was also calculated. The correlation between the renal function and PUUO duration was analyzed , and functional variations in the healthy kidneys were observed. Results (1)To the control group, no significant difference in the renal function was found between the left and the right kidneys (t = -0.145, P = 0.894). However, to the PUUO group, the right renal GFRs were significantly lower than the left renal GFRs (P 0.05), (3)No significant differences were found in the left renal GFRs among the five groups. Conclusions The function of PUUO kidneys is characterized by an obvious decrease in the early stage, followed with a steady state. The basic function of the opposite healthy kidney does not present the compensation phenomenon.