Under-recognition of alarms in a neonatal intensive care unit

BACKGROUND

Treatment decisions for apnoea of prematurity (AOP) are usually based on nursing staff's documentation of pulse oximeter and heart rate alarms.

OBJECTIVE

In an observational study, to compare the accuracy of oxygen saturation (SpO2) and heart rate alarm documentation, and the resulting interventions by nursing staff, with objectively registered events using polysomnographic and video recording.

METHODS

Data on 21 preterm neonates (12 male) with a diagnosis of AOP were analysed. Nursing staff's desaturation (<80% SpO2) and bradycardia (<80/min) alarm documentation was compared with events registered objectively using simultaneous polysomnography. Interventions by nursing staff were evaluated using 24 h video recordings and compared with their chart documentation. Nursing staff had been unaware that the polygraphic and video recordings would be used subsequently for this purpose.

RESULTS

Median (minimum-maximum) postnatal age was 15.5 (3-65) days. 968 SpO2 desaturation events and  415 bradycardias were documented by polysomnography. Nursing staff registered 23% of these desaturation events, and 60% of bradycardias (n=223, and n=133, respectively). Intraclass correlation coefficient (95% CI) between objectively measured desaturation events and those documented by nursing staff was 0.14 (-0.31 to 0.53); and for bradycardias 0.51 (0.11 to 0.78). 225 nursing staff interventions were registered on video, of which 87 (39%) were documented.

CONCLUSIONS

The alarm documentation by neonatal intensive care unit staff does not appear to be sufficiently accurate to permit further understanding and treatment of AOP. It is unclear if the alarms missed here would have led to clinical consequences had they been documented.

Randomised crossover trial of four nasal respiratory support systems for apnoea of prematurity in very low birthweight infants

BACKGROUND

Apnoea of prematurity (AOP) is a common problem in preterm infants which can be treated with various modes of nasal continuous positive airway pressure (NCPAP) or nasal intermittent positive pressure ventilation (NIPPV). It is not known which mode of NCPAP or NIPPV is most effective for AOP.

OBJECTIVE

To assess the effect of four NCPAP/NIPPV systems on the rate of bradycardias and desaturation events in very low birthweight infants.

METHODS

Sixteen infants (mean gestational age at time of study 31 weeks, 10 males) with AOP were enrolled in a randomised controlled trial with a crossover design. The infants were allocated to receive nasal pressure support using four different modes for 6 h each: NIPPV via a conventional ventilator, NIPPV and NCPAP via a variable flow device, and NCPAP delivered via a constant flow underwater bubble system. The primary outcome was the cumulative event rate of bradycardias (< or =80 beats per minute) and desaturation events (< or =80% arterial oxygen saturation), which was obtained from cardio-respiratory recordings.

RESULTS

The median event rate was 6.7 per hour with the conventional ventilator in NIPPV mode, and 2.8 and 4.4 per hour with the variable flow device in NCPAP and NIPPV mode, respectively (p value<0.03 for both compared to NIPPV/conventional ventilator). There was no significant difference between the NIPPV/conventional ventilator and the underwater bubble system.

CONCLUSION

A variable flow NCPAP device may be more effective in treating AOP in preterm infants than a conventional ventilator in NIPPV mode. It remains unclear whether synchronised NIPPV would be even more effective.

Randomised crossover trial of different postural interventions on bradycardia and intermittent hypoxia in preterm infants

BACKGROUND

Apnoea of prematurity has been shown to respond to changes in posture.

OBJECTIVE

To investigate the effect of three postural interventions on the rate of bradycardia and desaturation events.

METHODS

18 infants (< or =32 weeks' gestational age; 11 boys) with apnoea of prematurity underwent recordings of breathing movements, electrocardiogram and instantaneous heart rate, pulse oximeter saturation (SpO2), photoplethysmographic waveforms and digital video frame while in one of three different prone positions. The following interventions were applied in random order: horizontal position (HP), 15 degrees head-up tilt position (TP) and three-level position (3P) according to Kinaesthetics Infant Handling. The primary study variable was the combined event rate of desaturations (SpO2 <85%) and bradycardias (heart rate <80 bpm). One secondary study variable was the duration of body movements.

RESULTS

The median (range) combined event rate was 26.7/h (0.3-72.7) in HP, 25.2/h (0.3-70.5) in TP and 21.2/h (0-66.3) in 3P (p>0.05). The median (range) duration of body movements was 10.8 s/h (0-48.2) in HP, 7.1 s/h (0-72.4) in TP and 7.0 s/h (0-47.7) in 3P (p>0.05).

CONCLUSIONS

No significant advantage of a head-up tilt or a three-level position over a standard horizontal position could be confirmed.

Inhaled drugs for the prevention and treatment of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is one of the most common long-term complications and treatment challenges in preterm infants. Theoretically, inhaled corticosteroids may suppress pulmonary inflammation without causing systemic side-effects, while bronchodilators will improve airway resistance and thereby work of breathing. This article reviews current data on these drugs in BPD prevention or treatment. Trials published to date have not demonstrated that regular bronchodilator administration influences the incidence of BPD or improves long-term outcome. Inhaled steroids started before 2 weeks of age may improve rates of successful extubation and reduce the need for rescue systemic glucocorticoids, but have not been shown to reduce the incidence of BPD. Thus, their use cannot be generally recommended. The data currently available are not sufficient to give any clearer recommendation on the use of these drugs in infants at high risk of, or established, BPD.