Imai

Hyperbaric oxygenation and edaravone were associated with a greater chance of favourable recovery following acute embolic stroke.

Clinical Bottom Line: 1. More patients had a favourable outcome, judged by a neurologic outcome scale, when treated with a combination of edaravone and HBOT.

Citation/s:1. Imai K, Mori T, Izumoto H, Takabatake N, Kuneida T, Watanabe M. Hyperbaric oxygen combined with intravenous edaravone for treatment of acute embolic stroke: a pilot clinical trial. Neurological Medicine and Surgery (Tokyo) 2006; 46:373-378.

Three-part Clinical Question: For patients with acute embolic stroke, does the administration of hyperbaric oxygen in addition to standard therapy, result in any decrease in morbidity or mortality?Search Terms: stroke, free radical scavengers, cerebral embolus The Study:Non-blinded randomised controlled trial with intention-to-treat. The Study Patients: Adults with a clinical diagnosis of embolic stroke in the anterior cerebral circulation with an NIHSS of more than 4, and who presented within 48 hours of onset. Control group (N = 19; 19 analysed): Usual supportive treatment including heparin 10,000 units intravenously daily for 7 days. Experimental group (N = 19; 19 analysed): As above plus 100% oxygen at 2.0 ATA for one hour daily for seven days and edaravone 30mg IV before and after each session.

The Evidence:

Outcome	Time to Outcome	Control group	HBOT group	Relative risk reduction	Absolute risk reduction	Number needed to treat
Favourable outcome (Rankin 0 or 1)	90 days	0.053	0.32	496%	0.26	-4
^			95% Confidence Intervals:	934% to 58%	0.50 to 0.03	-32 to -2
Death	90 days	0.053	0.16	-198%	-0.11	-10
^			95% Confidence Intervals:	-561% to 100%	-0.30 to 0.09	NNT 11 to INF NNH 3 to INF

Non-Event Outcomes	Time to outcome/s	Control group	HBOT group	P-value
Median NIHSS	7 days	8 [2 - 30]	13 [1 - 21]	> 0.05

Comments: 1. It is not clear which of the two agents (or the combination) is responsible for the observed improvement in outcome. 2. Significantly improved modified Rankin Scale at 90 days, but not NIHSS at 7 days. The Rankin Scale is a simple 6 point descriptive scale from well to death - favourable outcome here is no significant functional disability or better), The NIHSS is a quantified measure of neurologic status (lower is better). 3. No attempt at blinding this study. 4. Edaravone is a free radical scavenger that has been suggested as a neuroprotective agent in acute ischaemic stroke. It was combined with HBOT in this trial in an attempt to ameliorate any adverse effects from the oxygen administration. 5. There were no serious adverse effects of therapy noted, but more subjects died in the HBOT group. 6. Only about 50% of embolic stroke patients satisfied the inclusion criteria.

Appraised by: Mike Bennett, POWH Sydney ; Tuesday, 5 June 2007Email: m.bennett@unsw.edu.au

Kill or Update By: July 2022