The Effect of Anaesthesia Management with Different Fresh Gas Flows on Cognitive Functions of Geriatric Patients: A Randomized Double-blind Study.

Objective: The present study aimed to compare the effects of two different fresh gas flows (FGFs) (0.5 L min-1 and 2 L min-1) applied during maintenance of anaesthesia on recovery from anaesthesia and early cognitive functions in geriatric patients. Methods: In this prospective, randomised, double-blind study, sixty patients were divided into two groups according to the amount of FGF. Minimal-flow anaesthesia (0.5 L min-1 FGF) was applied to group I and medium-flow anaesthesia (2 L min-1 FGF) was applied to group II during maintenance of anaesthesia. Following the termination of inhalation anaesthesia, recovery times were recorded. The evaluation of cognitive functions was performed using the Addenbrooke's Cognitive Examination (ACE-R). Results: There was no significant difference between the two groups in terms of demographic characteristics and recovery (P > 0.05). There was no significant difference between the two groups in terms of the preoperative day, the first postoperative day, and the third postoperative day; ACE-R scores (P > 0.05). In group II, on the third postoperative day ACE-R scores were found to be significantly lower than the preoperative ACE-R scores (P=0.04). In group II, third postoperative day ACE-R memory sub-scores (14.53 ± 3.34) were found to be significantly lower than preoperative ACE-R memory sub-scores (15.03 ± 3.57) (P=0.04). Conclusion: In geriatric patients, minimal-flow anaesthesia was not superior to medium-flow anaesthesia in terms of recovery properties and cognitive functions. Keeping in mind that hypoxaemia and changes in anaesthesia levels may occur with the reduction of FGF, both minimal- and medium-flow anaesthesia can be applied with appropriate monitoring without adverse effects on recovery and cognitive functions.

Evaluation of Postoperative Complication with Medically Necessary, Time-Sensitive Scoring System During Acute COVID-19 Pandemic: A Prospective Observational Study.

BACKGROUND: High scores in the Medically Necessary, Time-Sensitive (MeNTS) scoring system, used for elective surgical prioritization during the coronavirus disease 2019 pandemic, are assumed to be associated with worse outcomes. We aimed to evaluate the MeNTS scoring system in patients undergoing elective surgery during restricted capacity of our institution, with or without moderate or severe postoperative complications. STUDY DESIGN: In this prospective observational study, MeNTS scores of patients undergoing elective operations during May and June 2020 were calculated. Postoperative complication severity (classified as Group Clavien-Dindo < II or Group Clavien-Dindo ≥ II), as well as Duke Activity Index, American Society of Anesthesiologists (ASA) physical status, presence of smoking, leukocytosis, lymphopenia, elevated C-reactive protein (CRP), operation and anesthesia characteristics, intensive care requirement and duration, length of hospital stay, rehospitalization, and mortality were noted. RESULTS: There were 223 patients analyzed. MeNTS score was higher in the Clavien-Dindo ≥ II Group compared with the Clavien-Dindo < II Group (50.98 ± 8.98 vs 44.27 ± 8.90 respectively, p < 0.001). Duke activity status index (DASI) scores were lower, and American Society of Anesthesiologists physical status class, presence of smoking, leukocytosis, lymphopenia, elevated CRP, and intensive care requirement were higher in the Clavien-Dindo ≥ II Group (p < 0.01). Length of hospital stay was longer in the Clavien-Dindo ≥ II Group (15 [range 2-90] vs 4 [1-30] days; p < 0.001). Mortality was observed in 8 patients. Area under the receiver operating characteristic curve of MeNTS and DASI were 0.69 and 0.71, respectively, for predicting moderate/severe complications. CONCLUSIONS: Although significant, MeNTS score had low discriminating power in distinguishing patients with moderate/severe complications. Incorporation of a cardiovascular functional capacity measure could improve the scoring system.

Analysis of surface ozone and nitrogen oxides at urban, semi-rural and rural sites in Istanbul, Turkey.

Ozone (O(3)) mixing ratios were measured at three different sites (urban/traffic, semi-rural and rural/island) in Istanbul from September 2007 to December 2009 in order to determine the diurnal, monthly and seasonal variations of O(3) and nitrogen oxides (NO(x)) and to study the local and regional impacts. This is the first study that evaluates the O(3) levels in semi-rural and rural sites in Istanbul in addition to the urban sites. The diurnal O(3) variations are generally characterized by afternoon maxima (64 ppb at the urban, 80 ppb at the semi-rural and 100 ppb at the rural site) and the nighttime minimum being more pronounced at the polluted urban site. The monthly mean O(3) mixing ratios start to increase in March, reaching their maximum values in August for the urban (~25 ppb) and semi-rural sites (30 ppb). However, at the rural site, the monthly mean O(3) levels reach their maximum value in June (35 ppb). The O(3) mixing ratios for weekends were higher than those on weekdays at each site by up to 28%, possibly due to changes in VOC sensitivity and reduction in NO(x) levels. In order to better understand and characterize the relationship between air masses and O(3) levels, cluster analysis was applied to the back-trajectories calculated by the HYSPLIT model for the semi-rural site. The analyses clearly showed that major transport is characterized by northern and western clusters, particularly from the Eastern Europe and the Mediterranean region, as well as recirculation over Istanbul due to high pressure systems leading to accumulated levels of O(3). The results clearly suggest that extended measurement networks from urban to rural sites should be considered for a more comprehensive evaluation of O(3) levels.

The impact of anthropogenic and biogenic emissions on surface ozone concentrations in Istanbul.

Surface ozone concentrations at Istanbul during a summer episode in June 2008 were simulated using a high resolution and urban scale modeling system coupling MM5 and CMAQ models with a recently developed anthropogenic emission inventory for the region. Two sets of base runs were performed in order to investigate for the first time the impact of biogenic emissions on ozone concentrations in the Greater Istanbul Area (GIA). The first simulation was performed using only the anthropogenic emissions whereas the second simulation was performed using both anthropogenic and biogenic emissions. Biogenic NMVOC emissions were comparable with anthropogenic NMVOC emissions in terms of magnitude. The inclusion of biogenic emissions significantly improved the performance of the model, particularly in reproducing the low night time values as well as the temporal variation of ozone concentrations. Terpene emissions contributed significantly to the destruction of the ozone during nighttime. Biogenic NMVOCs emissions enhanced ozone concentrations in the downwind regions of GIA up to 25ppb. The VOC/NO(x) ratio almost doubled due to the addition of biogenic NMVOCs. Anthropogenic NO(x) and NMVOCs were perturbed by ±30% in another set of simulations to quantify the sensitivity of ozone concentrations to the precursor emissions in the region. The sensitivity runs, as along with the model-calculated ozone-to-reactive nitrogen ratios, pointed NO(x)-sensitive chemistry, particularly in the downwind areas. On the other hand, urban parts of the city responded more to changes in NO(x) due to very high anthropogenic emissions.