To administer exogenous surfactant by thin catheter to a preterm infant with RDS receiving noninvasive respiratory support, most usually nasal continuous positive airway pressure (CPAP).

Exogenous surfactant has been a mainstay of therapy for the preterm infant with RDS for over 30 years, delivered via an endotracheal tube with dose repetition as necessary. Nowadays, however, many preterm infants are managed from the outset on noninvasive respiratory support, in particular nasal CPAP, and thus lack the usual conduit by which surfactant is administered. Amongst infants on CPAP, many of those with RDS are adequately supported with CPAP alone, with gradual improvement in surfactant status and thus lung function. Some infants continue to exhibit features of RDS, including significant oxygen requirements, raising the dilemma of whether to continue with CPAP or to intubate for the purpose of giving surfactant.

Whilst the obvious resolution of the CPAP-surfactant dilemma is to briefly intubate for surfactant delivery, several recent randomized controlled trials have not shown a major benefit of this approach, mostly related to difficulty with extubation (1, 2). For this reason, a number of different techniques of delivering surfactant in a nonintubated spontaneously breathing infant have been pursued (3, 4). There is now wide experience of surfactant administration via a thin catheter briefly placed in the trachea (5, 6, 7), and enthusiasm for this method is burgeoning. A number of randomized controlled trials have suggested that this approach is a more effective means of delivering surfactant than standard intubation (8, 9), most likely related to a positive effect of spontaneous breathing on surfactant distribution.

Two main methods of thin catheter placement for surfactant delivery have emerged, both of which are performed with the aid of direct laryngoscopy.

1. The Cologne method, in which the tip of a flexible feeding tube is directed through the vocal cords with Magill forceps (10)

2. The Hobart method, where the tip of a semirigid catheter (e.g., a vascular catheter) is guided into the trachea without Magill forceps (11)

Numerous variations on these methods now exist.