Effects of Air Pollutant Exposure on Acute Myocardial Infarction.

BACKGROUND: Air pollution is a consequence of industrial development that is exacerbated as a result of population growth, and urbanisation. AIM: The goal of the study is to investigate the effects of air pollution on the number of cases of acute myocardial infarction (AMI) according to gender using the Zero-inflated Poisson Regression model in Hamadan, Iran. METHODS: The study used an ecological design, and data collected from March 2016 to September 2020 in Hamadan were included. The intended response was the number of cases of AMI recorded in the investigated period. The time lag of the pollutants was used to investigate the effect of air pollution on the number of AMIs. RESULTS: The number of AMI recorded for men and women was 1,195 and 553, respectively. The average age (±SD) for men and women was 64.60 (±12.27) and 70.98 (±11.79) years, respectively. According to the air quality index in Hamadan, the values of particulate matter < 2.5 µm (PM2.5), SO2, O3, and CO were below moderate levels. Also, according to NO2 and particulate matter between 25 µm-10 µm (PM10), the air quality index of Hamadan was in the very unhealthy mode just for 2 and 3 days, respectively. The O3 and NO2 are significant positive effects on AMI among men. But, PM2.5, PM10, and SO2 are negative impacts on hospitalisation in men due to AMI. For women, PM2.5 and O3 had positive effects on AMI. But, NO2 and PM10 had a significant negative impact on hospitalisation in women during different time lags. CONCLUSIONS: The results of the study showed that if the analyses are based on gender, the responses to pollutants are different and hence the stratified analysis is important.

The Effect of Low Tidal Volume Ventilation during Cardiopulmonary Bypass on Postoperative Pulmonary Function.

BACKGROUND: Postoperative pulmonary dysfunction is one of the most frequent complications after cardiac surgery and it is believed to result from the use of cardiopulmonary bypass (CPB). In this study, we investigated the effect of low tidal volume ventilation during CPB on postoperative gas exchange and lung mechanics. METHODS: This prospective randomized study included 100 patients undergoing elective coronary artery bypass grafting. In 50 patients, low tidal volume ventilation [tidal volume (TV) = 3 ml/kg, respiratory rate (RR) = 12/min, fraction of inspiratory oxygen (FIO(2))= 1.0, positive end expiratory pressure (PEEP) = 5 cmH(2)O] was applied during CPB (group I); and in the other 50 patients (group II), the lungs were open to the atmosphere without ventilation. Measurements were taken preoperatively, after CPB, and before discharge. RESULTS: Post-bypass PaO(2) (just after CPB 85 versus75) was higher significantly in group I (P value < 0.05). Decrease in postoperative forced expiratory volume in 1 second (25% versus 30%) and forced vital capacity (32% versus 35%) was less significant in group I. Also, time to extubation (5 hrs versus 5.5 hrs) was shorter in group I. CONCLUSION: Continued low tidal volume ventilation during CPB improved post-bypass oxygenation and lung mechanics.