Study of the transient nature of classical Be stars using multi-epoch optical spectroscopy

Variability is a commonly observed property of classical Be stars (CBe) stars. In extreme cases, complete disappearance of the H{\alpha} emission line occurs, indicating a disc-less state in CBe stars. The disc-loss and reappearing phases can be identified by studying the H{\alpha} line profiles of CBe stars on a regular basis. In this paper, we present the study of a set of selected 9 bright CBe stars, in the wavelength range of 6200 - 6700 {\AA}, to better understand their disc transient nature through continuous monitoring of their H{\alpha} line profile variations for 5 consecutive years (2015 -- 2019). Based on our observations, we suggest that 4 of the program stars (HD 4180, HD 142926, HD 164447 and HD 171780) are possibly undergoing disc-loss episodes, whereas one other star (HD 23302) might be passing through disc formation phase. The remaining 4 stars (HD 237056, HD 33357, HD 38708 and HD 60855) have shown signs of hosting a stable disc in recent epochs. Through visual inspection of the overall variation observed in the H{\alpha} EW for these stars, we classified them into groups of growing, stable and dissipating discs, respectively. Moreover, our comparative analysis using the BeSS database points out that the star HD 60855 has passed through a disc-less episode in 2008, with its disc formation happening probably over a timescale of only 2 months, between January and March 2008.Comment: 19 pages, 7 figures, 2 tables, accepted in JAp

Effect of intravenous midazolam on intracranial pressure during endotracheal suctioning in patients with severe head injury

Background: Patients with severe traumatic brain injury (TBI) require elective ventilation and sedation to decrease intracranial pressure (ICP) and any increase in ICP may be detrimental for the outcome in these patients. Methods: This prospective study was done in a neurotrauma intensive care unit (ICU )of a level 1 trauma centre in India over a one month period. All adult male patients with severe TBI on mechanical ventilation and monitored for ICP were included in this study. Baseline ICP was measured before starting endotracheal (ET) suctioning and serial readings were taken during and after ET suctioning. Patients were divided into two groups (control and intervention) with intervention group receiving intravenous bolus dose of 2 mg of midazolam before ET suction. Results: A total of 20 patients were enrolled during the study period. Both groups were well matched with regards to age and admission Glasgow coma scale (GCS). There were 10 patients in the midazolam group and 10 patients in the control group. The mean rise of ICP following ET suctioning in control group was found to be 24.1mm Hg ±11.1 as compared to 18.25 mm Hg ±-9.29 in the midazolam group (P < 0.05). Conclusions: Significant rise in ICP from baseline occurs following ET suctioning in ventilated, severe TBI patients. Our study suggests that additional intravenous bolus of midazolam prior to suctioning may significantly reduce the rise in ICP and should be practiced by ICU nurses