RESUMO
Background: The purpose of study was to compare the changes in blood pressure in patients undergoing phacoemulsification cataract surgery under topical and peribulbar anaesthesia during preoperative, intraoperative and postoperative period. Methods: In this prospective cohort study, 240 patients undergoing phacoemulsification were divided into topical (Group 1) and peribulbar (Group 2) equally. Proparacaine 0.5% drops were used for topical anaesthesia, and Inj lignocaine with Inj bupivacaine were used to give peribulbar anaesthesia. Preoperative blood pressure was taken 30 min before surgery with automated sphygmomanometer. Intraoperative blood pressure was taken during phacoemulsification, and postoperative blood pressure was taken 1 h after surgery. Outcomes assessed were systolic, diastolic and mean blood pressure. Results: Systolic blood pressure in Group 1 was significantly increased in the intraoperative phase, whereas it was significantly decreased in Group 2 in the intraoperative phase. Diastolic and mean blood pressure in Group 1 showed no significant change, whereas in Group 2, both showed significant reduction in intraoperative and postoperative phases. Conclusion: The increase in intraoperative systolic blood pressure in topical group could be due to discomfort from microscope light, iris manipulation, irrigation and aspiration during surgery. The decrease in intraoperative systolic and diastolic blood pressure in peribulbar group could be due to systemic absorption of local anaesthetic. The mean preoperative systolic blood pressure was also higher in the topical group, which could be due to anxiety or stress under topical anaesthesia. The changes in blood pressure need to be observed so that timely intervention can be made to achieve favourable postoperative outcome.
RESUMO
Biochar has been evaluated globally to improve soil fertility and mitigate climate change. However, the long-term effects of successive biochar application on carbon (C) accumulation in soil irrigated with saline versus non-saline water (canal water) has not been investigated. A field experiment was conducted to study the effects of rice straw biochar addition rates (0, 2, 4, 8 Mg ha-1) on C storage in soil irrigated with water of different electrical conductivity [EC, dS m-1]; 0.3 (non-saline canal irrigation water; CIW), 5 (saline irrigation water; SIW5), 10 (SIW10), and 15 (SIW15) in a cotton-wheat system. Long-term irrigation with saline water of variable EC levels adversely affected soil functions, reducing above-ground biomass in cotton (12-48%) and wheat (5-27%). In contrast, plots irrigated with saline water but amended with rice straw biochar showed significant improvement in aboveground biomass (both in cotton and wheat), possibly due to its beneficial effects on soil properties such as soil EC, organic carbon, microbial population, water and nutrient availability, bulk density, soil aggregation, and proliferation of roots. Interestingly, the change in total organic C (TOC) stocks (8.5, 17, and 27.5 Mg C ha-1) after 5 years were found to be almost double the amount of biochar C added (4.3, 8.6, 17.2 Mg ha-1), indicating stabilization of belowground C inputs from the root biomass by the applied biochar and also possibly through its physical interaction with aggregates and minerals. Even though biochar application to saline water irrigated plots increased the contribution of plant-derived C to overall soil TOC stocks, it was still lower compared with canal water irrigated plots. The study conclusively established that the long-term stabilization of biogenic C through biochar has essential implications for mitigating climate change by accumulating additional C beyond the recalcitrant C contained in biochar.
