Introduction:
Aneurysmal subarachnoid hemorrhage (aSAH) is a common cause of death and disability, accounting for as many as 10% of stroke cases in the United States. While much of the resulting injury to the nervous system is caused by the initial bleeding from the aneurysm, many of these patients develop cerebral vasospasm, pathological constriction of the blood vessels supplying the brain, several days following hemorrhage. This delayed brain injury accounts for a significant percentage of poor outcomes following aneurysm rupture. Remote ischemic preconditioning (RIPC) by transient limb ischemia (produced by inflation of a blood pressure cuff on the arm or leg) has been shown to minimize ischemic injury to other organs, most notably studied in the heart. In other forms of stroke the onset of ischemia cannot be predicted in the general population, following aneurysm rupture the investigators know patient’s risk of developing vasospasm. Therefore, we applied RIPC to see if it would confer protective effects from delayed ischemic injury
Methods:
In this pilot trial, 25 patients with SAH were randomized to undergo maximum of 6 cycles of treatment vs sham from days 3-14 post-aSAH. Inflating a manual blood pressure cuff 20 mmHg above the systolic blood pressure (SBP) and loss of a distal pulse for 5 minutes with 5 minutes break and four cycles total was considered a single treatment. Sham treatment group received an inflation of the blood pressure cuff to 20mmHg below the SBP, with the rest of the procedures the same as the treatment group. Outcomes noted were one month and six month modified Rankin Scores (mRankin), ICU and hospital length of stay, and mortality.
Results:
At conclusion of the study we had eleven patients in the treatment group and fourteen in the sham group. The age, baseline mRankin score, Hunt and Hess score, Fisher Grade and admission GCS were not significantly different between the treatment group and the sham group. The one month and six month mRankin score, ICU length of stay, hospital length of stay and mortality were not significantly different between the treatment and sham groups.
Conclusion:
This pilot study showed that inducing RIPC in patients with aSAH patients is easy and safe, the vitals stayed within the 20% variation range for both the treatment and sham groups. Patients who were alert and awake only noted mild tolerable discomfort with the treatment. Although there were no significant differences in the outcomes we believe that can be due to the small nature of this pilot study, the wide variability in patient presentation, and clinical treatments (most notably coiling vs clipping). Further studies should be focused on the patients at greatest risk of delayed ischemia (Fisher grade 3 and 4), possibly remove patients with complications that can be attributed to a clinical treatment and will likely need a much larger sample size to elucidate true effects of RIPC on aSAH.
