The "sedation holiday" came up in Question 1 from the first paper of 2013 and Question 5 from the second paper of 2008, a time scale which is somewhat surprising in its lateness. You'd have expected it to come up closer to the year 2000, shortly after the seminal Kress paper was published in NEJM, or when Jacobi et al promoted the practice as the new standard of care in ICU. Instead, the college waited until 2008. The 3013 question at least makes more sense because the well-received Canadian trial of this practice was published in 2012 (Mehta et al). The best resource for a "critically evaluate" answer to such a question is PulmCCM, where the primary author, enraged and frothing, fell upon the practice and tore it limb from limb. Here, only a brief summary will be attempted.
Kress, John P., et al. "Daily interruption of sedative infusions in critically ill patients undergoing mechanical ventilation." New England Journal of Medicine342.20 (2000): 1471-1477.
Kress, John P., et al. "The long-term psychological effects of daily sedative interruption on critically ill patients." American journal of respiratory and critical care medicine 168.12 (2003): 1457-1461.
Girard, Timothy D., et al. "Efficacy and safety of a paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (Awakening and Breathing Controlled trial): a randomised controlled trial." The Lancet 371.9607 (2008): 126-134.
Mehta, Sangeeta, et al. "Daily sedation interruption in mechanically ventilated critically ill patients cared for with a sedation protocol: a randomized controlled trial." JAMA 308.19 (2012): 1985-1992.
Burry, L., et al. "Daily sedation interruption versus no daily sedation interruption for critically ill adult patients requiring invasive mechanical ventilation." The Cochrane Library 2014, Issue 7
Jacobi, Judith, et al. "Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult." Critical care medicine 30.1 (2002): 119-141.