Guided Imagery Improves Sleep, Reduces Inflammation After Cardiac Surgery

Researchers from the University of Michigan School of Nursing tested whether guided imagery plus usual care improved sleep and reduced inflammation over usual care alone, in a study with 52 patients immediately after cardiac surgery, in the ICU and the step-down unit. 

Outcomes measured at post-op days 1-4 were time to sleep onset, total sleep time, stress (as measured by salivary cortisol), and inflammatory response (as measured by C-RP levels),

Patients in the experimental group (n=27) got a pre-loaded MP3 player with the Health Journeys Healthful Sleep audio and a fleece headband with thin earphones in them.  They also wore wrist actigraphs to document their sleep. The controls (n=25) received treatment as usual (TAU).

In spite of randomization, there were significant differences between the experimental group and the control group. The GI group had a greater percentage of women, much more ethnic diversity, more on-pump procedures (valves, CABG), longer procedures, and less use of beta blockers than the control group. They were also older. (On-pump surgeries are associated with greater sleep difficulty and more inflammation.)

The investigators found a high compliance rate (85% at T-1, 100% at T-2 and T-3, and high   satisfaction with the guided imagery as a way of promoting sleep.

There were distinct trends (but short of significance) in the GI group for steadier improvement in sleep onset and sleep activity over the TAU controls. Similarly, there was a trend toward a more consistent decline in cortisol and C-RP levels in the GI group over the controls.

The researchers posit that the daunting conditions in the ICU environment are so antagonistic to sound sleep, that guided imagery is not enough to alone replace sleep medication, but adds value when used adjunctively.. They also call for a larger study to equalize the dramatic differences in the characteristics of subjects in the two conditions.

Citation: Casida JM, Yaremchuk KL, Shpakoff L, Marrocco A, Babicz G, Yarandi H. The effects of guided imagery on sleep and inflammatory response in cardiac surgery: a pilot randomized controlled trial. Journal of Cardiovascular Surgery (Torino). 2013 Apr;54 (2):PP 269-79. Epub 2012 Nov 9.

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