Does supine positioning increase apnea, bradycardia, and desaturation in preterm infants? Effect of positioning on the breathing pattern of preterm infants. Effect of nursing in the head elevated tilt position (15 degrees) on the incidence of bradycardic and hypoxemic episodes in preterm infants.
The purpose of this study was to determine the effects of prone and supine positioning on the cardiorespiratory stability of preterm infants with apnea and bradycardia.
                A total of 22 preterm infants with symptomatic apnea and bradycardia (gestational age of 26.9 +/- 1.8 weeks and birth weight of 865 +/- 235 gm) were monitored for 24 hours (in four sequential 6-hour blocks) for apnea, bradycardia, and oxygen desaturation in alternating positions (prone or supine) following randomization. Postconceptional age at the time of study was 31.9 +/- 3.0 weeks. Respiratory rate, heart rate, and transcutaneous oxygen saturation were continuously monitored. All episodes of apnea (> or = 10 seconds), bradycardia (< 100 beats per minute), and oxygen desaturation (< 90%) were recorded on an event monitor. Episodes of apnea, bradycardia, and oxygen desaturation were defined as clinically significant if the following criteria were met: apnea, > or = 15 seconds; bradycardia, < 90 beats per minute; and oxygen desaturation, < 80%. All other recorded episodes were considered mild. The episodes were analyzed for statistical significance using the paired t-test.
                No significant differences (p > 0.05) in the incidence of clinically significant apnea, bradycardia, or desaturation between supine and prone positions were seen in these preterm infants.
                Our results suggest that the cardiorespiratory stability of preterm infants is not significantly compromised by supine positioning. Respiration, as judged by gas exchange and pulmonary function, is improved in preterm infants kept in the prone rather than the supine position. The influence of position on the breathing pattern as documented by the pneumogram was studied in 14 stable preterm infants with recent clinical apnoea. Ten of the infants had oximetry and nasal flow studies simultaneously with the impedance pneumogram. Each infant had consecutive nocturnal pneumograms, one in the prone, one in the supine position. The infants were kept for more than six hours in the assigned position. A significant increase in apnoea density and in periodic breathing was found in the supine v the prone position (mean (SE) 4.5 (0.7)% v 2.5 (0.5)%, and 13.6 (3.2)% v 7.7 (2.2)%, respectively). There was no positional difference in the incidence of bradycardia and prolonged apnoea. The examination of obstructive apnoea, mixed apnoea, and cyanotic spells did not reveal a consistent disparity between the two positions. These findings indicate an increase in central apnoea in preterm infants kept predominantly in the supine position. Possible relations of positional changes to lung mechanics are discussed. When evaluating pneumograms, attention must be given to the position in which they were performed. We investigated whether nursing in the head elevated tilt position (HETP), compared with the horizontal position, has any effect on the incidence of bradycardic and hypoxemic episodes in preterm infants.
                Twelve spontaneously breathing preterm infants with idiopathic recurrent apnea were studied in a randomized controlled crossover trial. Nine infants were treated with aminophylline. Each spent a total of 24 hours in the horizontal prone position and a total of 24 hours in HETP (prone, 15 degrees). The position was changed in random order every 6 hours. Thoracic impedance, heart rate, and arterial oxygen saturation were recorded continuously. The frequency of isolated hypoxemia (arterial saturation <80%), of isolated bradycardia (heart rate <90 beats per minute), and of mixed events was analyzed and compared without knowledge of the allocated position.
                In total, there were significantly fewer bradycardic and/or hypoxemic episodes (28.2%) in HETP compared with the horizontal position (mean difference, 13.35 episodes/24 hours; 95% confidence interval [CI]: 5.9- 20.8). The decrease was largest for isolated hypoxemic episodes (48.5%; mean difference, 11.74 episodes/24 hours; 95% CI: 6.1-17.4). Isolated bradycardic episodes (mean difference, 2.27 episodes/24 hours; 95% CI: -0.78-5.31) and mixed events were not decreased significantly in HETP.
                Nursing in a moderately tilted position (15 degrees) reduces hypoxemic events in preterm infants. This intervention is easy to apply, quickly reversible, and can be combined with drugs such as aminophylline.
There is insufficient evidence to determine the role of body positioning on apnoea, bradycardia, oxygen desaturation and oxygen saturation. Large randomised controlled trials are needed to determine the effect of body positioning on cardiorespiratory function in spontaneously breathing preterm infants.