The usefulness of protocols for reducing the time children spend mechanically ventilated in the intensive care unit

In a children’s intensive care unit, mechanical ventilation is used to help children to breathe when they are very ill and their spontaneous ventilation is inadequate to sustain life. Yet, if used for long periods of time, mechanical ventilation can cause problems. Ventilation is associated with complications such as ventilator-induced lung injury, pneumonia, sedation complications and negative recollections of the experience. For this reason, it is important to recognize when the child has recovered enough to start breathing for himself and to reduce (or wean) the ventilator support. Unfortunately, no agreement has been reached on the best way to wean children off the ventilator.

In adults, researchers have studied the usefulness of standardized protocols to help guide doctors and nurses in intensive care to wean patients from the ventilator in a safe and timely manner. The purpose of this Cochrane review was to look at the weaning protocol studies in children to see whether a conclusion can be drawn regarding their usefulness in children.

We found three randomized controlled studies that analysed 321 children older than 28 days and younger than 18 years. The studies were of good quality and were carried out in Brazil, Canada and the United States. The largest study showed that weaning by protocol reduced the length of time on mechanical ventilation by an average of 32 hours; the other two studies did not show a significant effect. Two studies reported significant reductions in the time it took from start to end of weaning from the ventilator. Weaning protocols did not affect the child’s length of time in the intensive care unit or hospital, nor did they affect the number of complications associated with mechanical ventilation.

In two studies, participants represented a broad population of children in intensive care, although these studies did not include children undergoing heart surgery or with chronic neuromuscular, heart or lung disease. The third study included only those with pneumonia, bronchiolitis and acute respiratory distress syndrome. The included studies used a variety of criteria to establish readiness to wean, and their protocols took different approaches to the process of weaning. These studies were at low or unclear risk of bias.

Limited evidence suggests that weaning protocols reduce the duration of mechanical ventilation, but evidence is inadequate to show whether the achievement of shorter ventilation by protocolized weaning causes children benefit or harm.  

Authors' conclusions: 

Limited evidence suggests that weaning protocols reduce the duration of mechanical ventilation, but evidence is inadequate to show whether the achievement of shorter ventilation by protocolized weaning causes children benefit or harm.

Read the full abstract...

Mechanical ventilation is a critical component of paediatric intensive care therapy. It is indicated when the patient’s spontaneous ventilation is inadequate to sustain life. Weaning is the gradual reduction of ventilatory support and the transfer of respiratory control back to the patient. Weaning may represent a large proportion of the ventilatory period. Prolonged ventilation is associated with significant morbidity, hospital cost, psychosocial and physical risks to the child and even death. Timely and effective weaning may reduce the duration of mechanical ventilation and may reduce the morbidity and mortality associated with prolonged ventilation. However, no consensus has been reached on criteria that can be used to identify when patients are ready to wean or the best way to achieve it.


To assess the effects of weaning by protocol on invasively ventilated critically ill children. To compare the total duration of invasive mechanical ventilation of critically ill children who are weaned using protocols versus those weaned through usual (non-protocolized) practice. To ascertain any differences between protocolized weaning and usual care in terms of mortality, adverse events, intensive care unit length of stay and quality of life.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, Issue 10, 2012), MEDLINE (1966 to October 2012), EMBASE (1988 to October 2012), CINAHL (1982 to October 2012), ISI Web of Science and LILACS. We identified unpublished data in the Web of Science (1990 to October 2012), ISI Conference Proceedings (1990 to October 2012) and Cambridge Scientific Abstracts (earliest to October 2012). We contacted first authors of studies included in the review to obtain further information on unpublished studies or work in progress. We searched reference lists of all identified studies and review papers for further relevant studies. We applied no language or publication restrictions.

Selection criteria: 

We included randomized controlled trials comparing protocolized weaning (professional-led or computer-driven) versus non-protocolized weaning practice conducted in children older than 28 days and younger than 18 years.

Data collection and analysis: 

Two review authors independently scanned titles and abstracts identified by electronic searching. Three review authors retrieved and evaluated full-text versions of potentially relevant studies, independently extracted data and assessed risk of bias.

Main results: 

We included three trials at low risk of bias with 321 children in the analysis. Protocolized weaning significantly reduced total ventilation time in the largest trial (260 children) by a mean of 32 hours (95% confidence interval (CI) 8 to 56; P = 0.01). Two other trials (30 and 31 children, respectively) reported non-significant reductions with a mean difference of -88 hours (95% CI -228 to 52; P = 0.2) and -24 hours (95% CI -10 to 58; P = 0.06). Protocolized weaning significantly reduced weaning time in these two smaller trials for a mean reduction of 106 hours (95% CI 28 to 184; P = 0.007) and 21 hours (95% CI 9 to 32; P < 0.001). These studies reported no significant effects for duration of mechanical ventilation before weaning, paediatric intensive care unit (PICU) and hospital length of stay, PICU mortality or adverse events.