Rates of successful intubation performed with a stylet in infants compared with rates of successful intubation performed without a stylet

Review question: Does use of a stylet increase success rates of newborn intubation without increasing risk of harm?

Background: Intubation consists of placement of a breathing tube (endotracheal tube) into the baby’s windpipe or trachea to maintain an open airway. This common procedure may be needed both at birth and in the neonatal intensive care unit if the baby is not able to breathe well for himself. Trainee doctors must learn this difficult skill and sometimes must make more than one attempt to get the tube in the right place. The breathing tube is a narrow, plastic, flexible tube. A stylet, which is a malleable metal wire coated with plastic, can be inserted into the breathing tube to make it more rigid; this might make it easier to get the tube in the right place on the first attempt. However, use of a stylet may increase the risk of harm to the patient during the procedure.

Study characteristics: In literature searches updated in April 2017, we found one randomised controlled trial (302 intubations) that met the inclusion criteria of this review.

Results: Rates of successful intubation at first attempt with or without use of a stylet as an aid were similar, at 57% and 53%, respectively. Success rates with and without use of a stylet did not differ between infants of different weights, or between trainee paediatric doctors with different levels of experience. The length of time it took to intubate and the number of attempts made before successful intubation were comparable between groups. The incidence of a drop in a patient’s oxygen level and in heart rate was equivalent between groups, as was the reported incidence of trauma to the airway associated with the procedure.

Quality of the evidence: The quality of evidence was low. We downgraded the level because we included only one unblinded study.

Authors' conclusions: 

Current available evidence suggests that use of a stylet during neonatal orotracheal intubation does not significantly improve the success rate among paediatric trainees. However, only one brand of stylet and one brand of endotracheal tube have been tested, and researchers performed all intubations on infants in a hospital setting. Therefore, our results cannot be generalised beyond these limitations.

Read the full abstract...

Neonatal endotracheal intubation is a common and potentially life-saving intervention. It is a mandatory skill for neonatal trainees, but one that is difficult to master and maintain. Intubation opportunities for trainees are decreasing and success rates are subsequently falling. Use of a stylet may aid intubation and improve success. However, the potential for associated harm must be considered.


To compare the benefits and harms of neonatal orotracheal intubation with a stylet versus neonatal orotracheal intubation without a stylet.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE; Embase; the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and previous reviews. We also searched cross-references, contacted expert informants, handsearched journals, and looked at conference proceedings. We searched clinical trials registries for current and recently completed trials. We conducted our most recent search in April 2017.

Selection criteria: 

All randomised, quasi–randomised, and cluster-randomised controlled trials comparing use versus non-use of a stylet in neonatal orotracheal intubation.

Data collection and analysis: 

Two review authors independently assessed results of searches against predetermined criteria for inclusion, assessed risk of bias, and extracted data. We used the standard methods of the Cochrane Collaboration, as documented in the Cochrane Handbook for Systemic Reviews of Interventions, and of the Cochrane Neonatal Review Group.

Main results: 

We included a single-centre non-blinded randomised controlled trial that reported a total of 302 intubation attempts in 232 infants. The median gestational age of enrolled infants was 29 weeks. Paediatric residents and fellows performed the intubations. We judged the study to be at low risk of bias overall. Investigators compared success rates of first-attempt intubation with and without use of a stylet and reported success rates as similar between stylet and no-stylet groups (57% and 53%) (P = 0.47). Success rates did not differ between groups in subgroup analyses by provider level of training and infant weight. Results showed no differences in secondary review outcomes, including duration of intubation, number of attempts, participant instability during the procedure, and local airway trauma. Only 25% of all intubations took less than 30 seconds to perform. Study authors did not report neonatal morbidity nor mortality. We considered the quality of evidence as low on GRADE analysis, given that we identified only one unblinded study.