Abstract - American Society of Anesthesiologists

Scientific Abstracts
A024
October 16, 2010
8:00:00 AM - 9:30:00 AM
Room Mezzanine 15A
The Effect of Helium on the Immune System Ex-Vivo
** Gezina T.M.L. Oei, M.S., B.S., Kirsten F. Smit, M.D., Djai v. d. Vondervoort, Benedikt Preckel,
M.D., M.A., D.E.A.A., Nina C. Weber, Ph.D.
Anesthesiology, Laboratory of Experimental Intensive Care and Anesthesiology (L.E.I.C.A.),
Academic Medical Center (AMC), Amsterdam, Netherlands
Background and Goal: Experimental studies showed that helium-conditioning protects
myocardial [1,2] and neuronal tissue [3,4] against ischemia/reperfusion damage. If helium is
introduced in clinical practice as a therapeutic against ischemia/reperfusion injury, it has to be
evident that this noble gas does not negatively affect other organ systems, such as the immune
system. From other organ protective inhalational gases such as volatile anesthetics and xenon
immunomodulatory effects are known [5,6]. We investigated whether a 30-minute episode of
helium breathing (79%He/21%O 2 ) in healthy volunteers affects the ability of the immune system
to respond to ex vivo stimulation in whole blood, sampled at different time points before, during
and after helium inhalation. The concerted action of cytokines and chemokines are pivotal for
the defense against bacterial infections. Therefore, we looked at proinflammatory cytokines TNFalpha,
IL-1beta and IL-6 and chemokine Il-8 measured after stimulation with lipopolysaccharide
(LPS).
Materials and Methods: The study was approved by the ethical committee of the Academic
Medical Center (METC), written informed consent was obtained from all subjects. Experiments
were conducted in a quiet room in which circumstances were kept as standardized as possible.
Healthy, male volunteers (n=12) underwent two experimental 'cycles': one with heliox (79%
helium and 21% oxygen) inhalation and one with inhalation of normal room air, with two weeks
between experimental cycles. Inhalation of heliox or room air through a mask was done for 30
minutes. Blood was sampled at T0 (baseline), T1 (25 min inhalation), T2 (1 h after inhalation), T3
(2 h after inhalation), T4 (6 h after inhalation), T5 (24 h after inhalation). C-reactive protein (CRP)
was measured at T0 of each experimental cycle, leukocyte counts and differentials were
analyzed at T0, T3 and T5 of each cycle. After sampling, whole blood was immediately incubated
with (LPS) or with RPMI (as control, CON) for 2, 4 and 24 hours or not incubated (0 h). The

Scientific Abstracts
amount of TNF-alpha, IL-1beta, IL-6 and Il-8 in the samples was analyzed by cytometric bead
array (Human Inflammatory Kit, BD) measured by FACS. Statistical analysis: Wilcoxon test for
matched samples, all data are shown as mean ± SEM.
Results: Data shown (see figure) are TNF-alpha levels.[figure1]After 0, 2, 4 and 24 hours of
incubation with LPS, the amount of TNF-alpha, Il-1beta, Il-6 and Il-8 (pg/ml) was not affected by
heliox inhalation in comparison to room air at all timepoints. There were no differences in CRP at
T0 between groups, and no differences in leukocytes and lymfocytes at T0, T3 and T5 between
groups.
Conclusion: A 30-minute episode of helium inhalation does not alter TNF-alpha, Il-1beta, Il-6 and
Il-8 levels in whole blood after incubation with LPS.
Literature: [1] J Pharmacol Exp Ther. 2009; 329:600-7 [2] Br J Anaesth. 2009; 107:1807-13 [3] Crit
Care Med. 2008; 36:588-95 [4] Neurosci Lett. 2009; 460:232-6 [5] Anesthaesia. 1996; 51:465-473
[6] Eur J Anaesthesiol. 2004; 21:139-143.
From Proceedings of the 2010 Annual Meeting of the American Society Anesthesiologists.

Figure 1
Scientific Abstracts