Background This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. Methods This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score‐matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score‐matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery. Results A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score‐matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498). Conclusion There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast‐induced nephropathy should not be used as a reason to avoid contrast‐enhanced CT.

The peri-operative use of angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers is thought to be associated with an increased risk of postoperative acute kidney injury. To reduce this risk, these agents are commonly withheld during the peri-operative period. This study aimed to investigate if withholding angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers peri-operatively reduces the risk of acute kidney injury following major non-cardiac surgery. Patients undergoing elective major surgery on the gastrointestinal tract and/or the liver were eligible for inclusion in this prospective study. The primary outcome was the development of acute kidney injury within seven days of operation. Adjusted multi-level models were used to account for centre-level effects and propensity score matching was used to reduce the effects of selection bias between treatment groups. A total of 949 patients were included from 160 centres across the UK and Republic of Ireland. From this population, 573 (60.4%) patients had their angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers withheld during the peri-operative period. One hundred and seventy-five (18.4%) patients developed acute kidney injury; there was no difference in the incidence of acute kidney injury between patients who had their angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers continued or withheld (107 (18.7%) vs. 68 (18.1%), respectively; p = 0.914). Following propensity matching, withholding angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers did not demonstrate a protective effect against the development of postoperative acute kidney injury (OR (95%CI) 0.89 (0.58-1.34); p = 0.567).

Though propofol requirement is expected to decrease during cardiopulmonary bypass (CPB), a few studies have failed to demonstrate this. The factors affecting pharmacokinetics of propofol and, therefore, the requirement, are different during hypothermic and normothermic CPB. We evaluated and compared the requirement of propofol during hypothermic and normothermic CPB. Fifty adult patients scheduled for elective cardiac surgery on CPB were recruited and randomly allocated into hypothermic CPB (28-30 degrees C) (Group H) and normothermic CPB (35-37 degrees C) (Group N) groups. Patients were induced and maintained with propofol titrated to maintain a target bispectral index (BIS) of 50 +/- 10. Propofol requirement (mean +/- SD) was similar in normothermic and hypothermic groups, both before CPB (4.9 +/- 1.5 mg kg(-1)hr(-1) in Group N, 4.6 +/- 1.5 mg kg(-1)hr(-1) in Group H) and after cessation of bypass (p > 0.05) (4.6 +/- 1.8 mg kg(-1)hr(-1) in Group N and 4.3 +/- 1.7 mg kg(-1)hr(-1) in Group H). CPB significantly reduced (p < 0.001) propofol requirements in both arms of the study (Group N: 2.9 +/- 1.4 mg kg(-1)hr(-1)and Group H: 1.3 +/- 0.7 mg kg(-1)hr(-1)). This reduction was more pronounced in the hypothermic group (p < 0.001). The BIS (median +/- inter quartile range) remained constant during normothermic CPB (50 +/- 8.8), but declined significantly during hypothermic CPB (41 +/- 5.6) despite decreased usage of propofol during hypothermia. No patient had recall of intra-operative events. CPB decreases the magnitude of propofol requirements and the effect of hypothermic CPB is significantly more than that of normothermic CPB.

Lung cancer is one of the common malignancies with high mortality rate and a poor prognosis. Most lung cancer cases are diagnosed at an advanced stage either due to limited resources of infrastructure, trained human resources, or delay in clinical suspicion. Low-dose computed tomography (LDCT) has emerged as a screening tool for early lung cancer detection but may not be a feasible option for most developing countries. Electronic nose (eNOSE) is a unique non-invasive device that has been developed for lung cancer diagnosis and monitoring response by exhaled breath analysis of volatile organic compounds (VOCs). The breath-print have been shown to differ not only among lung cancer and other respiratory diseases, but also between various types of lung cancer. Hence, we postulate that the breath-print analysis by electronic nose could be a potential biomarker for the early detection of lung cancer along with monitoring treatment response in a resource-limited setting. In this review, we have consolidated the current published literature suggesting the use of an electronic nose in the diagnosis and monitoring treatment response of lung cancer.

Introduction. Close proximity of phrenic nerves to pericardium and internal mammary arteries (IMA) makes them liable to injury during cardiac surgery which occurs due to its transection, compromised vascularity or hypothermia.Methods. Between July, 1999 to August, 2000 fifty fresh cadavers were examined and the intrathoracic course of phrenic nerves was studied. This information was utilised while performing 200 open heart operations. Intermittent cooled saline (4~ was used instead of ice slush for topical cooling and pericardiophrenic branch of IMA was preserved while harvesting it.Results. Variations were observed in the anatomical relationship between the phrenic nerves and proximal internal mammary arteries. Incidence of unilateral phrenic nerve injury among patients who had open heart surgery was 1.5% and was 4% among patients in whom internal mammary artery was harvested.Conclusion. A thorough knowledge of anatomical variations in the course of phrenic nerves, preservation of pericardiophrenic branch of IMA while harvesting it for CABG and use of cooled saline instead of ice slush for topical cooling helps in avoiding phrenic nerve injury during cardiac surgery. (Ind J Thorac Cardiovasc Surg, 2001; 17: 225-229)