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To endorse the hypothesis, that from these benefits we can obtain a reduced mortality rate in patients who
receive volatile agents, there are numerous studies. These results led to an ordinary use of volatile anesthet-
ics compared to TIVA, although propofol is a drug that has a much lower cost than halogenated drugs. For
example, a bottle of sevoflurane costs 74 euro, while a bottle of 2% propofol costs 1.6 euro.

[33]
There are no studies that discourage the use of propofol but we must remember that when using TIVA
[34]
in cardiac surgery we do not have remote ischemic preconditioning , due to the inhibition of the organo-
[35]
protective properties of this technique . Furthermore, there are at least 8 studies showing an increase
in mortality with the use of TIVA, while there is no study that demonstrates an increase in survival with
TIVA [32,36,37] .

DISCUSSION
[38]
In the meta-analysis of Zangrillo et al. , it has been shown that halogenated agents can decrease mortality
and have additional cardioprotective effects compared to TIVA. In this meta-analysis, it has been shown that
in patients undergoing cardiac surgery, the use of volatile agents and/or the combination of volatile agents
with remote preconditioning produces lower mortality compared to TIVA with longer follow-up. The meta-
analysis of the Bayesian network compares different groups of patients both directly and indirectly, with a
consolidated method in clinical research. This meta-analysis includes all randomized trials in adult cardiac
systems that compare volatile agents, TIVA and remote ischemic preconditioning. This study is an invitation
to use volatile anesthetics during general anesthesia because there is no evidence of beneficial properties of
TIVA except when combined with volatile agents. This meta-analysis has some limitations: most of the stud-
ies included in the study are small, single centers and not double-blind. In fact, for example, some authors do
not preside over whether patients taking drugs such as sulfonylurea, theophylline or allopurinol have been
excluded, as these drugs appear to influence the preconditioning mechanism. Another limitation may be the
use of intraoperative opioids. In fact, opioids reduce the cardiovascular effect and can hinder the cardiopro-
[38]
tective effects of volatile agents .
Furthermore, ischemic preconditioning can lower postoperative cardiac biomarker levels [39,40] and even mor-
[41]
tality during cardiac surgery .
[32]
The first study , published in 2007, which showed a greater survival of patients subjected to halogenated
agents compared to TIVA, was a meta-analysis of small randomized clinical trials. The meta-analysis showed
that sevoflurane and desflurane were associated with significant reductions in myocardial infarction (2.4%
vs. 5.1%) and mortality (0.4% vs. 1.6%). In a large multi-center study, patients who received sevoflurane
[36]
showed a 30-day lower postoperative mortality than those who received TIVA (2.2% vs. 3.1%) . Instead,
[42]
De Hert et al. did not find any difference in the post-operative troponin T release between volatile anes-
thetics and TIVA but showed a significant difference in one-year mortality among the various groups (3.3%
[42]
in the sevoflurane group, 6.7% in the desflurane group and 12.3% in the TIVA group (P = 0.034) . A large
multi-center study analyzed the 30-day mortality rate in patients undergoing CABG where halogenated
anesthetics or TIVA was used. Mortality was lower with halogenates and the mortality rate was lower than
[43]
with the use of halogenated anesthetics . A recent meta-analysis by Landoni showed a 50% reduction in
[44]
mortality compared to TIVA (desflurane 1.8% vs. 4.0%, isoflurane 0.7% vs. 2.0% and sevoflurane 1.2% vs. 3.0%) .
In contrast, some authors have shown that patients with severe preoperative ischemic stress benefit from
[45]
TIVA because of its antioxidant effects . However, no increase in survival with TIVA has been demonstrat-
[36]
ed, indeed some studies have shown worse outcomes if propofol is compared with halogenates .
There is disagreement about the type of cardiac surgery that benefits most from halogenated cardiac protec-
tion. Most studies have shown that cardioprotection occurs mainly in CABG while the evidence of haloge-