Daniel J. Pallin, MD, MPH reviewing Laitio R et al. JAMA 2016 Mar 15.

Among victims of witnessed arrest with initially shockable rhythms, novel MRI techniques revealed less brain damage in those treated with inhaled xenon.

Inhaled xenon has shown promise as a neuroprotective agent after cardiac arrest in animal models and is routinely used in Europe as an inhalational anesthetic. Investigators in Finland randomized 110 comatose victims of witnessed cardiac arrest with initially shockable rhythms to receive cooling to 33°C alone or with xenon inhalation for 24 hours.

The primary outcome was cerebral white matter damage, assessed by global fractional anisotropy on diffusion-tensor magnetic resonance imaging (MRI) 36 to 52 hours after arrest. Secondary outcomes included 6-month mortality and functional status (measured with modified Rankin Scale and Cerebral Performance Category scores). Outcomes were assessed by researchers blinded to treatment group.

Among 97 patients with MRI data, there was a small but significant difference in global fractional anisotropy between groups, indicating 3.8% less brain damage in the xenon group. Functional outcomes did not differ between groups. At 6 months, mortality was lower in the xenon group by an impressive margin (adjusted hazard ratio, 0.49), but the difference did not reach statistical significance (P=0.053).

Citation(s):

Laitio R et al. Effect of inhaled xenon on cerebral white matter damage in comatose survivors of out-of-hospital cardiac arrest: A randomized clinical trial. JAMA 2016 Mar 15; 315:1120.

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