***TASK***
the task is to simplify the input abstract of a biomedical literature

***INPUT***
the input is the abstract of a biomedical literature

***OUTPUT***
the output is the simplified abstract for the input abstract of a biomedical literature

***DOCUMENTATION***

***EXAMPLES***

Input: We included four studies with a total of 115 patients randomised to undergo a vascular procedure with remote ischaemic preconditioning and 117 patients randomised to have the procedure without remote ischaemic preconditioning. None of the trials were of low risk of bias. There was no significant difference in mortality between the two groups (RR 1.70, 95% CI 0.51 to 5.72). Similarly, there was no statistically significant difference between the two groups for all other outcomes except reduced risk of myocardial infarction in the remote ischaemic preconditioning group, which was significant by the fixed-effect model (RR 0.31, 95% CI 0.10 to 0.90) but not by the random-effects model (RR 0.34, 95% CI 0.11 to 1.08). This positive effect was from the results of only one trial and was not consistently observed. Furthermore, it was noted that there was an observed trend of high incidence of unplanned critical care admission in the remote ischaemic preconditioning group, although this was not statistically significant (RR 2.15, 95% CI 0.87 to 5.33). Based on current evidence from small pilot trials, there are too few data to be able to say whether remote ischaemic preconditioning has any beneficial or harmful effects. The safety of this technique needs to be confirmed in adequately powered trials. Therefore, further randomised trials on this technique are required.
Output:

We performed a systematic search of the literature to identify all the randomised controlled trials conducted on this topic. A total of 232 patients in four trials were randomised to remote ischaemic preconditioning or no preconditioning for three different operations on blood vessels. Based on the evidence from these small trials, there were too few data to be able to say whether remote ischaemic preconditioning has any beneficial or harmful effects. The studies varied in the surgical procedures, outcome measures and the way remote ischaemia was induced. The number of deaths around the time of surgery was not clearly different between the two groups. Heart attacks (myocardial infarction) may have been reduced in the remote ischaemic preconditioning group but this was apparent in only one trial and was not consistent across the trials. Unplanned critical care admissions tended to increase in the remote ischaemic preconditioning group. All the trials had a high risk of bias and the safety of this technique needs to be confirmed in trials with adequate numbers of participants.