Vascular air embolism: a rare complication of nasal CPAP

Which continuous positive airway pressure system is best for the preterm infant with respiratory distress syndrome?

Various commercial and home-made continuous positive airway pressure (CPAP) systems are described in this article. CPAP may be delivered via a range of device-patient interfaces; nasal CPAP is most common, and short binasal prongs impose the least extrinsic load impedance on the infant. The source of pressure generation is categorized as either constant pressure or constant flow. The efficacy of different systems may vary according to whether lung volume recruitment, airway patency, minimization of work of breathing, or central nervous system stimulation are the primary goal of the clinical decision to use CPAP therapy.

[Nasal continuous positive airway pressure in preterm infants: comparison of two low-resistance models]

OBJECTIVE

To compare the safety and efficacy of two low expiratory resistance models of nasal continuous positive airway pressure (n-CPAP) in preterm infants.

MATERIAL AND METHODS

A 1-year prospective trial was performed in the Neonatal Intensive Care Unit of La Fe Hospital to compare the Infant Flow (IF) and Medijet (MJ) devices. All preterm infants requiring n-CPAP for respiratory distress at birth (group I), infants weighting less than 1500 g requiring postextubation (group II) and those with apnea-bradycardia syndrome (ABS) (group III) were included. The patients were randomly assigned to IF or MJ.

RESULTS

A total of 125 patients received 226 treatments (IF: n 5 126: MJ: n 5 110). The mean gestational age was 29.4 weeks and the mean birth weight was 1340 g.Efficacy. In group I (n 5 73) no difference were found between systems and 6 hours' after initiation of n-CPAP decreases in FiO2, CO2 and respiratory effort were similar. The need for intubation was also similar (IF: 34.6 %; MJ: 24.1 %). In group II (n 5 73) the need for reintubation at 48 hours was similar with both treatments (IF:19 %; MJ: 8 %). In group III (n 5 80) resolution of ABS was similar after 24 hours of n-CPAP (IF: 46 %; MJ: 58 %). The need for intubation was also similar (IF: 26 %; MJ: 10 %).Complications. Air leaks occurred in six preterm infants (IF: 4; MJ: 2). Severe abdominal distension occurred in 5 % with both systems. Five infants had significant nasal lesions (IF: 1; MJ: 4).

CONCLUSIONS

The efficacy and safety of both systems was similar in the variables studied and no significant differences were found.

Risks and benefits of therapies for apnoea in premature infants

Apnoea in infants can result from a wide range of causes, and requires thorough evaluation before deciding on appropriate treatment. Continuous monitoring of premature infants with apnoea is mandatory in order to define the pathophysiology and type of apnoea; selection of treatment involves careful assessment of aetiology, as well as efficacy and tolerability in each individual case. The objective of treatment is to prevent the deleterious consequences of apnoeas that last >20 seconds and/or are associated with bradycardia, cyanosis or pallor, and occur more often than once an hour over a 12-hour period. Apnoea management involves both pharmacological and nonpharmacological treatment. We suggest methylxanthines as first-line therapy for idiopathic apnoeas; evidence suggests that caffeine is better tolerated and as efficacious as theophylline (since it is particularly efficacious against the 'central' component of idiopathic apnoea of prematurity). If treatment fails, additional measures such as doxapram may be appropriate when hypoventilation is present, or nasal continuous positive airway pressure when upper airway instability or obstructive apnoeas are predominant. Apnoea prophylaxis is an additional reason to advocate prenatal maturation with betamethasone. Weaning from treatment is attempted 4 to 5 days after complete resolution of apnoea, beginning with the last treatment introduced. Monitoring should be maintained for 4 to 5 days to detect any relapse of recurrent and severe apnoeas, which would lead to the resumption of the most recently withdrawn treatment.