Incorporation of Al2O3 and ZrO2 ceramics to AZ31 magnesium alloys composite coating using micro-arc oxidation method.

In this research, a composite coating with Al2O3 and ZrO2 particles have been applied on AZ31 magnesium alloy by micro-arc oxidation (MAO) technique. The alkaline electrolyte included a constant based composition and different composition of the Al2O3 and ZrO2 additives. Microstructure observations reveal that the surface pores of composite coating reduced during addition of ZrO2 and Al2O3 ceramic particles. The hardness of coating increased from about 380 for non-added to 620 MPa for Al2O3+ZrO2 added coating and wear rate reduced about 8 times. Wettability of the coating increased by incorporation of Al2O3 and/or ZrO2 particles while, Al2O3 is more effective than ZrO2. Addition of the ceramic particles enhanced the hydrophilicity properties of surface in wettability test and a contact angle of 43° was obtained for coating including Al2O3+ZrO2. The antibacterial properties of MAO coatings showed that S. aureus bacterium is more sensitive to the zirconia and alumina particle than S. typhimurium bacterium after 24 h of incubation.

Intubation learning curve: comparison between video and direct laryngoscopy by inexperienced students.

Background: Direct laryngoscopy (DL) is considered the most common method of tracheal intubation. On the other hand, evidence shows the growing role of video laryngoscopy in danger airway administration. Objectives: Due to the importance of a proper training to accomplish an accurate and fast intubation by the student of anesthesia, this research was conducted to assess the effects of DL and video laryngoscopy (Glidescope VL) training on the success rate of tracheal intubation by low-skill students. Materials/Patients and styles: 50 undergraduate students of anesthesiology took part in this randomized control educational intervention. Having no considerable experience in intubation, they were selected and divided randomly into two equal groups (n = 25); video-laryngoscopy via GlideScope VL and direct laryngoscopy (DL) via a Macintosh blade were prepared by the same experienced anesthesiologist. All the participants practiced intubation six times on the same mannequin within a routine airway situation. The maximum acceptable time for each intubation was 3 minutes and three times of successful intubation was considered as an appropriate intubation skill. The required time for laryngoscopy and intubation at each stage, the grade of glottis view, the reasons for an unsuccessful intubation and the amount of successful intubations were recorded and compared between groups. Results: There was a clear variation between the 2 teams, in all the steps, based on the required time for laryngoscopy and intubation (p = 0.0001). Data analysis was performed by using repeated measures data which demonstrated that the necessary time for laryngoscopy and intubation during the study was clearly lower in the GlideScope VL team (p = .0001). In first five rounds of training, the glottis view in the DL group was significantly better than in the VL group (p < 0.05). Conclusion: Based on the result of today' study, routine airway intubation by using GlideScope VL is significantly faster than direct laryngoscopy. It seems that further studies are needed to investigate the effect of the educational program on different laryngoscopy and intubation situations.

Wire reinforced endotracheal tube compared with Parker Flex-Tip tube for oral fiberoptic intubation: a randomized clinical trial.

BACKGROUND: The aim of the study was to compare the Parker Flex-Tip (PFT) (group P) tube to a wire reinforced tracheal tube in two orientations, i.e., with posteriorly and anteriorly positioned tip bevels (WRP and WRA groups, respectively), for oral fiberoptic intubation. METHODS: This was a randomized clinical trial, carried out at the University-affiliated hospital. Ninety adult ASA physical status I-II patients who were scheduled to undergo either ophthalmic or urologic surgery were included in the study and randomly assigned to the P, WRA, or WRP group. Our primary outcome was the difficulty in advancing the tube over the fiberscope, which was quantified in grades (0, 1, or 2). Secondary outcomes were the time to visualize the carina after inserting the scope into the mouth and the time from this point to tracheal intubation. RESULTS: Endotracheal tube (ETT) advancement was easier and faster in the WRP and P groups than in the WRA. (Successful endotracheal intubation on the first attempt 67%, 60% and 20%, respectively; P=0.03) (ETT advancement time 6.9±3.5 s, and 8±3.1 s, 11.7±4.6, respectively; P<0.001). CONCLUSION: Advancement of the ETT over a fiberoptic bronchoscope was easier with the PFT tube and with a posteriorly positioned wire-reinforced tube than with an anteriorly positioned wire-reinforced tube.