Mechanical ventilation without sedation

Hanne T. Olsen, Helene K. Nedergaard et el published a trial of no sedation versus light sedation in mechanically ventilated patients in NEJM.


Multi center  randomized controlled trial,  in a 1 : 1 ratio,  comparing be mechanically ventilated ICU patients to  no sedation  versus  light sedation strategy( RASS  Richmond agitation and sedation Scale score of -2 to -3).  Trial was conducted in  8 intensive care units in Denmark,  Norway and  Sweden.


Adult patients 18 years  and above,  who received endotracheal intubation in last 24 hours and were expected to have mechanical ventilation for 24 more hours.  A total of 710  patients underwent  randomization and 700 were included in the  study( 354 in non sedation group and 356 in sedation group).

Following patients were excluded-

Head injury, therapeutic hypothermia, status epilepticus, intubation more than for 24 hours ago, brain dead, patient were in prone position, if sedation was anticipated as the necessity for oxygenation.


Non sedation group  patients were allowed to have  bolus doses of morphine for analgesia.  if despite both nonpharmacologic ( reassurance or mobilization)  and pharmacologic( analgesia),  it became necessary to sedate the patient patient was given medication similar to those used in sedation group.

Patients in sedation group received a continues infusion of sedatives with the goal of achieving light sedation.  Propofol was used for 1st 48 hours and then was replaced by  midazolam.  Daily sedation vacation was done.


Primary –  all cause mortality at 90 days.

Secondary-  number of days until death,  thromboembolic events,  number of days free from coma or delirium,  acute kidney injury, length  of stay in ICU.

Exploratory outcomes-  all cause mortality at 28 days,  length of stay in ICU up to death  or 90 day,  length of hospital stay within 90 days,  organ failure,  number of accidental extubation which led to re-intubation within 1 hours,  number of accidental removal of central venous catheter  which led to read insertion within 4 hours.


No difference in all cause mortality at 90 days {148 patients (42.4%) in the nonsedation group and 130 patients (37.0%) in the sedation group  (difference, 5.4 percentage points; 95% confidence interval [CI], −2.2 to
12.2; P = 0.65)}.

No significant difference in secondary outcomes.

Accidental extubation that led to reintubation within 1 hour occurred in four patients (1.1%) in the nonsedation group and in one patient (0.3%) in the sedation group (unadjusted risk difference, 0.8 percentage points; 95% CI, −0.7 to 2.6; P = 0.20).  No events of accidental removal of central line  in either group.


The aim of sedation is to minimize oxygen consumption and  keep patient comfortably connected to a ventilator.  However,   deep sedation has known to  cause  delay in weaning, delirium  and impair neuromuscular function.    Omitting sedation  is met by resistance from caregivers.

We also know  that early implementation of daily interruption of sedation combined with a weaning protocol  leads to early extubation,   shorter ICU stay  and  improved survival.

 Same investigators  earlier published a single center trial   comparing  no sedation with light sedation.

This trial showed no difference between the 2 groups in terms of  90 day mortality,  and other secondary outcomes including accidental extubations.  Thromboembolism was probably more in the sedation group,  though  not significant.

Results of this trial should be applied to only selected group of patients,  patients with low FiO2 requirement,  who were older( average  age 70).

Lower rate of self-extubation  can also be explained by  1:1  nurse to patient ratio.

This trial shows that some patients can be managed without sedation,  and   those who are being managed with sedation,  need 24/7  evaluation to  adjust the dose of sedation.  As we know from previous trials that deep sedation is  harmful.  And light sedation does not increase any  adverse events.  Sedation should be tailored to individual patient.


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