Cognitive change affecting patients after anaesthesia and surgery has been recognised for more than 100 yr. Research into cognitive change after anaesthesia and surgery accelerated in the 1980s when multiple studies utilised detailed neuropsychological testing for assessment of cognitive change after cardiac surgery. This body of work consistently documented decline in cognitive function in elderly patients after anaesthesia and surgery, and cognitive changes have been identified up to 7.5 yr afterwards. Importantly, other studies have identified that the incidence of cognitive change is similar after non-cardiac surgery. Other than the inclusion of non-surgical control groups to calculate postoperative cognitive dysfunction, research into these cognitive changes in the perioperative period has been undertaken in isolation from cognitive studies in the general population. The aim of this work is to develop similar terminology to that used in cognitive classifications of the general population for use in investigations of cognitive changes after anaesthesia and

A lthough a high perioperative inspiratory oxygen fraction (80%) has been recommended to avoid perioperative wound infections, one of the largest recent trials, the PROXI (perioperative oxygen inspired) trial, found no reduction in surgical site infection and a higher 30-day mortality rate in the group receiving 80% oxygen. In this follow-up study of the PROXI trial, the association between long-term mortality and perioperative oxygen fraction was assessed in patients undergoing abdominal surgery. From patients underwent elective or emergency laparotomy and were randomized to receive either 80% or 30% oxygen during for 2 hours after surgery. At follow-up, on February 4, 2010, survival was analyzed using Kaplan-Meier statistics and the Cox proportional hazards model. Vital status was obtained on 1382 of the 1386 patients after a median follow-up of 2.3 years (range, 1.3Y3.4 years). One hundred fifty-nine (23.2%) of 685 patients died in the 80% oxygen group compared with 128 (18.3%) of 701 patients in the 30% oxygen group (hazard ratio [HR], 1.30; 95% confidence interval [CI], 1.03Y1.64). In patients undergoing cancer surgery, the HR was 1.45 (95% CI, 1.10Y1.90), and after noncancer surgery, the HR was 1.06 (95% CI, 0.69Y1.65). Administration of 80% oxygen in the perioperative period was related to markedly increased long-term mortality, which appeared to be statistically significant in patients undergoing cancer surgery but not in noncancer patients. COMMENTOccasionally, studies are published that turn conventional thinking on its head; this is one such study. For a number of years, investigators have been studying the advantages of administering high-concentration oxygen in the operating room and postanesthesia care unit (PACU). This line of inquiry was stimulated by several studies that showed a benefit of decreased abdominal wound infections with administration of 80% oxygen during surgery and for the first 2 hours in the PACU. 1 A large subsequent trial, the PROXI study, however, showed no difference in wound infection with high-concentration oxygen administration. 2 That study also examined 30-day mortality, which was not different between the groups.The current study examines the long-term mortality of those enrolled in the PROXI trial. The trial was conducted in Denmark, which has a comprehensive medical record collection system. Indeed, there were only 4 of 1386 patients who were lost to follow-up. In the original PROXI trial, patients scheduled for elective or emergent laparotomy were randomized to receive 30% or 80% oxygen in the operating room and for 2 hours in the PACU.Surprisingly, there was a greater chance of not surviving the follow-up period in the 80% oxygen group. Looking at subgroups, it was apparent that the increased mortality was seen in patients undergoing laparotomy for cancer surgery. The HR was 1.45 with the 95% CI of 1.10Y1.90, which is a very notable difference. The noncancer laparotomy patients had no different outcome. The authors speculate as to the cause of increased mortality in ...

Melatonin significantly changed sleep efficiency and wake after sleep onset after surgery, but had no effects on other objective sleep outcomes or on subjective sleep quality (VAS and KSS).

Antibodies to hepatitis C virus (anti-HCV) were determined in an unselected group of 340 patients with chronic renal failure treated with maintenance dialysis. A second generation hepatitis C virus (HCV) enzyme-linked immunosorbent assay (ELISA) was used and confirmation made by a second generation recombinant immunoblot assay (RIBA). Sixteen patients (4.7%) were anti-HCV positive and 8 (2.4%) were anti-HCV indeterminate. All anti-HCV positive and anti-HCV indeterminate patients had received blood transfusions. No statistically significant differences were found between anti-HCV positive and indeterminate patients considering blood transfusions, dialysis and liver disease. The combined group of anti-HCV positive and indeterminate patients had had more blood transfusions (P < 0.005) and had been on dialysis for a longer period (P < 0.01) compared with anti-HCV negative patients. Further, significant correlation with elevation of transaminases and anti-HCV was observed (P < 0.001). Thirty patients (8.8%) had elevated transaminase levels and 13 (43%) of these were anti-HCV positive or indeterminate. In conclusion, HCV infection accounts for a substantial proportion of liver disease in dialysis patients, probably most often transmitted by blood transfusions but other routes of transmission could not be excluded.