Sedation in the ICU Debated

Ingrid Hein

February 19, 2020

Mortality rates are the same whether or not ventilated patients are sedated, results from a new Scandinavian study show.

In the multicenter trial, there was no difference in 90-day mortality between nonsedated and lightly sedated mechanically ventilated patients, said Palle Toft, MD, from Odense University Hospital in Denmark.

In a previous study, "to our surprise, we found a significant advantage with nonsedation," said Toft. But to determine whether nonsedation could improve 90-day survival, he and his colleagues hypothesized that they would "need 700 patients in a multicenter study."

Toft presented the results of that multicenter study during a late-breaker session at the Society of Critical Care Medicine (SCCM) 2020 Critical Care Congress in Orlando, coinciding with their publication in the New England Journal of Medicine.

In the 2010 study of critically ill patients, the mean number of days without ventilation was significantly higher in the group that received no sedation than in the group that received sedation with daily interruption (13.8 vs 9.6; P = .0191). In addition, nonsedation was associated with shorter ICU stays (hazard ratio [HR], 1.86; P = .0316) and shorter hospital stays (HR, 3.57; P = .0039) than sedation.

For their multicenter study, Toft and his team recruited eight centers in Denmark, Norway, and Sweden. They limited the number of participating centers because nonsedation is not the usual culture of care, and the change they were assessing is "more difficult than giving a drug," he explained.

You can only do nonsedation if there is cooperation between the nurses and the doctors.

A nurse was beside each patient's bed at all times. "In most of our units, we have a nurse-to-patient ratio of one to one, and the nurse is always bedside," he told the audience. "You can only do nonsedation if there is cooperation between the nurses and the doctors."

Median age of the 349 mechanically ventilated patients who received no sedation was 72 years, and of the 351 patients who received light sedation, with propofol and midazolam, with daily interruption was 70 years. Light sedation meant the ability to be aroused, and was indicated by a score of –3 or –2 on the Richmond Agitation and Sedation Scale (RASS).

Mortality at 90 days — the primary outcome — was not significantly different between the no-sedation and sedation groups (42.4% vs 37.0%; P = .65). ICU-free days and ventilator-free days were also comparable in the two groups.

However, major thromboembolic events were less common in the no-sedation group than in the sedation group (0.3% vs 2.8%; 1 vs 10 patients).

When required, patients in the no-sedation group did receive sedation, mainly for delirium. Sedation was administered to 27.0% of these patients on day 1, and to 38.4% at some point during their ICU stay. In the 2010 study, sedation was administered to 18.0% of the patients in the no-sedation group.

Although no survival advantage was shown with the no-sedation protocol, "nonsedation reduced thromboembolic events, improved kidney function, increased coma-free and delirium-free days, and preserved physical function to a larger extent," Toft reported.

It is also another way to provide patient care. Patients who are not sedated are "able to communicate with staff, might be able to enjoy food, and can maybe look at the television," he pointed out. They can also be mobilized and report their opinion of the treatment.

"It's not a drug I'm trying to sell, it's a change of culture," he explained.

Data from a substudy of the NONSEDA trial, which Toft was involved in, were also presented at the SCCM congress.

In the substudy, nurses assessed 151 patients — 78 sedated and 73 not sedated — for their ability to communicate their needs. The nurses found that nonsedated patients on mechanical ventilation "communicated at a higher level" during their first 5 days in the ICU. Nonsedation "could promote patient involvement and person-centered care," the substudy investigators conclude.

"My main message here is that we have to individualize patient treatment," said Toft. Some patients would benefit from nonsedation and some would benefit from light sedation with a daily wake-up.

It's 2020; "we have to respect patient autonomy and try to establish two-way communication with our patients," he added.

"The difference in the sedation scores really wasn't as different as we were expecting," said Sandra Kane Gill, PharmD, from the University of Pittsburgh, who reiterated that "38% in the nonsedated group at some point received sedation."

"And there isn't a huge difference in the RASS scores," she told Medscape Medical News.

Light Sedation vs No Sedation

A lot of patients who are mechanically ventilated are pretty ill; "we try to make their stay as comfortable as possible," she said. "This shows we need to stick to SCCM guidelines, which state that light sedation is where we should go. That's where the evidence lies at this time."

Others agreed that the results do not indicate that there should be any change in practice.

"A null hypothesis with negative results — it's not what they were expecting," said Claude Guérin, MD, PhD, from the University of Lyon in France.

But perhaps this study can be interpreted two ways. "We can now avoid sedation because there is no difference, or we can continue to give sedation. There is no benefit or harm," he told Medscape Medical News. "It's a null hypothesis, so let's calm down about sedation."

In his editorial that accompanied the published study results, Guérin critiques the study's inclusion criteria, writing that "the ratio of the partial pressure of arterial oxygen (measured in kilopascals) to the fraction of inspired oxygen that mandated that sedation be used, and was therefore an exclusion criterion for participation, was 9 or lower (or ≤68 if the partial pressure of arterial oxygen was measured in millimeters of mercury), which is a low threshold to forego sedation in the view of many intensivists."

Guérin also highlights the fact that 14.6% of the patients who were eligible for the study declined. "I was wondering whether the next of kin had concerns about not giving their relative sedation," he said.

Although there is a consensus to give patients sedation, "it is true that it has some drawbacks," he acknowledged. It has been shown to prolong ventilation and ICU stays, and might promote delirium. "It would have been nice to have shown that if you have no sedation, you reduce all this stuff, but they didn't demonstrate this."

This study will likely not "convince clinicians to avoid sedation," he said.

Society of Critical Care Medicine (SCCM) 2020 Critical Care Congress. Late-breaking trial presented February 16, 2020; NONSEDA substudy presented February 18, 2020.

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