By Marcus A. Banks
Light sedation is generally preferable to deep sedation, given the latter technique’s link to reduced function at hospital discharge and increased mortality, experts noted during a session at the Critical Care Congress 2025, in Orlando, Fla. 

Although set up as a point/counterpoint debate to facilitate a review of divergent data, both speakers agreed that light sedation in the ICU is the best management strategy. 

There are reasons why some debate is even possible. In the case of light sedation, for example, there is no universal definition of the condition. Authors of a 2018 SCCM guideline noted that a Richmond Agitation-Sedation Scale from –2 to 1 qualifies as light sedation, but the authors stressed that researchers have used other definitions, including the Sedation-Agitation Scale (Crit Care Med 2018;46[9]:e825-e873).

When it comes to heavy sedation, definitions aren't really the issue as much as the negative consequences of the procedure. Indeed, “deep sedation is associated with lots of worse outcomes,” said Pratik Pandharipande, MD, FCCM, an anesthesiologist at Vanderbilt University Medical Center, in Nashville, Tenn. 

Those sequelae include prolonging use of mechanical ventilation (Chest 1998;114[2]:541-548) and the aforementioned increased risk for mortality, which occurs within six months after patients undergo heavy sedation. This effect has been attributed to the severely decreased brain wave activity that occurs in patients who are heavily sedated (Crit Care Med 2008;36[12]:3171).

Dr. Pandharipande co-authored the 2008 study about heavy sedation and mortality risk, as well as the 2018 SCCM guidelines. He noted that, due to those risks, the guidelines call for light sedation in critically ill, mechanically ventilated patients whenever possible.

That's not to say that heavy sedation is never needed. One rationale for deep sedation, Dr. Pandharipande noted, is to spare people in intensive care from having to think about or remember this painful time in their life. However, although well-meaning, there is some evidence that deep sedation leads to declines in executive functioning, processing speed and spatial skills at hospital discharge (J Int Neuropsychol Soc 2007;13[4]:595-605).

"Factual memories, even if they are painful, are better for outcomes than delusional memories,” Dr. Pandharipande said.

A Critical Care Pharmacist’s View 

In what was jokingly billed as a “rebuttal” to Dr. Pandharipande’s remarks, Joanna Stollings, PharmD, FCCM, a pharmacist in the ICU Recovery Center at Vanderbilt, spoke up for the role of deep sedation. Dr. Stollings noted that the evidence Dr. Pandhariapnde cited has some flaws.

For instance, the 2018 SCCM guidelines recommending light sedation during mechanical ventilation is rated as low certainty, she noted, adding that this may be because the guideline authors did not find an association between light sedation and 90-day mortality improvements. Moreover, there was low evidence found for a reduced tracheostomy rate in people who received light sedation.

However, the rebuttal was in jest because Drs. Stollings and Pandharipande stressed that they do not really disagree. Dr. Stollings pointed out that there is at least 25 years of evidence documenting the harms of excessive sedation, which the COVID-19 pandemic only exacerbated.

“COVID was associated with sedation, which was associated with coma, which was associated with mortality,” Dr. Stollings said (Crit Care Med 2021;49[9]:1524-1534).

Still, sometimes deep sedation is necessary, Dr. Stollings reiterated. “Obviously in paralysis you will have to deeply sedate the patient” to provide analgesia, she said. Offering rescue therapy for acute respiratory distress syndrome also sometimes calls for deep sedation (Intensive Care Med 2020;46[12]:2342-2356), she added, but stressed that any episodes of deep sedation should be as brief as possible.

The sources reported no relevant financial disclosures.