The effects of nebulized ketamine and intravenous magnesium sulfate on corticosteroid resistant asthma exacerbation; a randomized clinical trial

Background and aims Asthma exacerbation is defined as an acute attack of shortness of breath with more than 25% decrease in morning peak flow compared to the baseline on 2 consecutive days, which requires immediate standard therapy. The majority of asthmatic patients are considered to be steroid-sensitive; however, corticosteroid-resistant asthma is a subset of asthma with poor response to corticosteroids and is responsible for frequent hospital admissions. In this study we aimed to compare the effects of two enhancing strategies, the nebulized ketamine and IV magnesium sulfate, in treatment of severe steroid resistant asthma. Materials and methods This double-blind randomized clinical trial was conducted on patients who presented to a referral clinic in Alborz, Iran. Using random allocation, patients were divided into two groups. The first group was treated with nebulized ketamine and the second group was treated with intravenous magnesium sulfate. Peak expiratory flow rates were assessed before the intervention, 30 and 60 min after the intervention and compared with the aid of SPSS software. Results The Peak expiratory flow rates before the intervention, 30 min and 60 min after the intervention was statistically significantly different in both ketamine and magnesium sulfate groups. Peak expiratory flow rates change between 0 and 60 min were 29.4 and 15.2% in the ketamine and magnesium sulfate group respectively. Although the ketamine group showed much higher increase in mean PEFR compared to the MgSO4 groups, there was no statistically significant difference across both groups. Conclusion Our study concluded that combined with standard therapy, both ketamine and IV magnesium sulfate are effective agents in the improvement of PEFR in patients with acute severe asthma that failed to respond to traditional therapies. However, there were no statistically significant difference between the two groups.

Assessment Of Ratio Of Peak Expiratory Flow Rate To Vital Capacity For Identifying Pulmonary Fibrosis

Background: Pulmonary fibrosis (PF) is associated with reduction in vital capacity (VC) and increase in expiratory flow rates, including peak expiratory flow (PEF). Full pulmonary function testing and computed tomography chest scans are limited resources in some geographic areas and a simple and sensitive screening test would be of value. We hypothesized that increase in the ratio of % predicted PEF over % predicted VC (%PEF/%VC), from spirometry alone might be sensitive to screen for pulmonary fibrosis. Methods: The %PEF/%VC from 1,000 consecutive spirometric flow volume curves was nearly normally distributed: 7.5% (approximately 1.5 standard deviations) had a ratio ≥ 1.4. We evaluated the sensitivity and specificity of this cut point for a diagnosis of PF in a retrospective chart review of 391 patients with good quality spirometry and respirologists’ confirmed diagnoses. Results: Of the 391 patients analyzed, 98 had PF, 79 were normal, 70 had a combined obstructive and restrictive processes, 57 had obstructive lung disease, 61 had extra-parenchymal restriction and 26 had non-fibrotic interstitial lung disease. A %PEF/%VC ≥ 1.4 was only 54.1% sensitive in predicting PF, however it had a specificity of 94.9%. There was a 95.1% specificity for ruling in intra-parenchymal opposed to extra-parenchymal restriction. Conclusion: A %PEF/%VC ≥ 1.4 was not sensitive enough to screen for PF but did demonstrate high specificity and thus may be helpful in identifying intraparenchymal restriction.

Changes in Inspiratory and Expiratory Flow Rates with Sustained Hand Grip and their Correlation with Fat Free Mass Index in Healthy Young Adults

Introduction: Aerobic exercises which are isotonic in nature have been proved to be beneficial in a number of cardiovascular and lifestyle diseases. But the effect of isometric exercises on cardiovascular and respiratory system is not fully evaluated. Existing literature on effect of isometric exercise on respiratory flow parameters are scanty and needs to be studied. Further, the impact of muscle mass on respiratory flow parameters need to be evaluated. Aim: To investigate the change in respiratory flow parameters (Peak Inspiratory Flow (PIF), Maximal Inspiratory Flow (MIF) 50, Peak Expiratory Flow (PEF), Maximum Expiratory Flow (MEF) 25-75, MEF 25, MEF 50 and MEF 75) in response to Sustained hand grip exercise and to find out any correlation between these flow parameters and Fat Free Mass Index (FFMI). Materials and Methods: A cross-sectional study was conducted at Department of Physiology, MKCG Medical College, Berhampur University, Odisha between October 2011 and August 2014. A total of 150 healthy volunteers aged between 17 to 25 years were included in the study. Anthropometric measurements were recorded using standardised instruments. Body fat percentage was measured by Bioelectric Impedance Analysis technique and then Fat Free Mass (FFM) and FFMI were calculated using standard formulae. Respiratory Flow parameters were assessed using Flow handy Spirometer as per the American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines. Sustained hand grip exercise was performed with Physilab Grip Dynamometer. IBM SPSS Statistics Version 24.0, was used for statistical analysis. Paired sample t-test was used to compare lung volumes at baseline and after 3 minutes of sustained hand grip exercise. The p-value <0.05 was considered statistically significant. Karl Pearson Correlation coefficient was used to study the linear relationship between FFMI and various inspiratory and expiratory flow rates. Results: The mean values of all respiratory flow parameters under study decreased at 3 minutes of sustained hand grip exercise as compared to baseline values. This change was statistically significant for PEF (p-value 0.012), MEF 25-75 (p-value 0.041), MEF 50 (p-value 0.001), MEF 75 (p-value 0.012) and MIF50 (p-value 0.004) (p<0.05). All the flow rates studied except MEF 25 showed significant positive correlation with FFMI (r-values between 0.231 to 0.380, p<0.05) but the strength of association was low. Conclusion: There was a statistically significant reduction in both inspiratory and expiratory flow parameters with isometric sustained hand grip exercise. So, isometric exercises should be avoided in patients with obstructive airway diseases. But muscle mass should be improved for better ventilation as authors observed a positive correlation between FFMI and respiratory flow rates.