American College Of Surgeons - Inspiring Quality: Highest Standards, Better Outcomes

Featured Commentary

The online formats of SRGS include access to What You Should Know (WYSK): commentaries on articles published recently in top medical journals. These commentaries, written by practicing surgeons and other medical experts, focus on the strengths and weaknesses of the research, as well as on the articles' contributions in advancing the field of surgery.

Below is a sample of one of the commentaries published in the current edition of WYSK.


Su X, Meng ZT, Wu XH, et al. Dexmedetomidine for prevention of delirium in elderly patients after non-cardiac surgery: a randomized, double-blind, placebo-controlled trial. Lancet. 2016;388(10054):1893-1902.

Commentary by: Thomas N. Robinson, MD, MS, FACS

Postoperative delirium represents acute brain dysfunction following surgery. The critical relevance of delirium is that it is often the presenting symptom of the stressed vulnerable older adult; a group that is rapidly becoming the most common patient population cared for in U.S. hospitals. Delirium is associated with increased complications, longer hospital stays, functional decline, elevated mortality, and increased healthcare cost.

Prevention of postoperative delirium is a clinically important strategy. In hospitalized patients, up to 40% of delirium is preventable when appropriate environmental supportive measures are implemented (e.g., orientation, mobilization, sensory support, sleep hygiene).1 Pharmacologic prevention of delirium is appealing given its relative simplicity compared to multidisciplinary supportive protocols. The most recent critical care clinical practice guideline regarding ICU delirium provided no recommendation on pharmacologic prevention of delirium; it stated that there was not sufficient evidence to support that pharmacologic prophylaxis would reduce the incidence or duration of delirium.2 A recent high-quality clinical practice guideline on postoperative delirium recommended against prescribing antipsychotics and cholinesterase inhibitors for prevention of postoperative delirium.3 Melatonin has been found to prevent postoperative delirium in single institution reports; however, the evidence has not been replicated enough to support broad recommendation.

Tension exists in the delirium research community regarding the conceptualization of pharmacologic prevention and the management of delirium. One viewpoint is that medications simply suppress the symptoms of agitation associated with delirium and that the deleterious alterations in the milieu of brain neurotransmitters that create delirium is not restored in any constructive way. Proponents of this perspective are against pharmacologic strategies to prevent delirium and only support pharmacologic treatment of delirium if the delirium symptoms are so severe that there is an immediate risk of harm to the patient or a member of the health care team. In contrast, the opposite viewpoint is that pharmacologic prevention and treatment of delirium goes beyond simply suppressing delirium symptoms, and is neuroprotective by restoring a healthier central nervous system neurotransmitter milieu. Currently, definitive evidence does not exist to support one or the other viewpoint.

Dexmedetomidine is a selective α2-adrenergic agonist that currently has Food and Drug Administration approval for sedation of mechanically ventilated patients in the ICU. Current randomized clinical trial data support the fact that sedating mechanically ventilated patients with dexmedetomidine rather than a benzodiazepine reduces delirium.4,5 The use of low-dose dexmedetomidine for postoperative delirium prophylaxis in nonventilated ICU patients is intriguing. Given that this finding has not been replicated in other clinical trials and that an increased number of medications carry increased risk in older adults, the prophylactic use of dexmedetomidine should not be considered standard of care to prevent postoperative delirium as this time.

References

  1. Inouye SK, Bogardus ST, Jr., Charpentier PA, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med. 1999;340(9):669-676. Free Full Text
  2. Barr J, Fraser GL, Puntillo K, et al. Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit. Crit Care Med. 2013;41(1):263-306.
  3. Clinical Practice Guideline for Postoperative Delirium in Older Adults. American Geriatrics Society Expert Panel on Delirium. October 10, 2014 ed2014.
  4. Pandharipande PP, Pun BT, Herr DL, et al. Effect of sedation with dexmedetomidine vs lorazepam on acute brain dysfunction in mechanically ventilated patients: the MENDS randomized controlled trial. JAMA.2007;298(22):2644-2653.
  5. Riker RR, Shehabi Y, Bokesch PM, et al. Dexmedetomidine vs midazolam for sedation of critically ill patients: a randomized trial. JAMA.2009;301(5):489-499.