Bradycardia and desaturation during skin-to-skin care: no relationship to hyperthermia.

OBJECTIVE: We recently found increased temperature and increased bradycardia and desaturation during skin-to-skin care (SSC). We wanted to determine if these effects were related. STUDY DESIGN: Twenty-two infants (median gestational age at birth 28.5 weeks [range 24-31], median age at study 25.5 days [range 10-60 days], median birth weight 1025 g [range 550-1525 g], median weight at study 1320 g [range 900-2460 g]) underwent three 2-hour recordings of breathing movements, nasal airflow, heart rate, and pulse oximeter saturation (SpO 2 ): at thermoneutrality (TN) during incubator care, at TN during SSC, and at elevated temperature (ET) during incubator care. Core temperature was measured via a rectal probe. Recordings were analyzed for the summed rate of bradycardia and desaturation (heart rate <2/3 of baseline; SpO 2

Randomized, controlled trial of oral creatine supplementation (not effective) for apnea of prematurity.

BACKGROUND: Hypoxic ventilatory depression in mice and muscle fatigue in adult humans are improved by creatine supplementation (CS). Because these issues may be operative in apnea of prematurity (AOP), we hypothesized that CS reduces episodes of hypoxemia and bradycardia in infants with AOP. METHODS: Infants were eligible for this double-blind, controlled trial if gestational age was <32 weeks and AOP was severe enough to require treatment with caffeine. If they had > or = 1 desaturation (pulse oximeter saturation [SpO2] < or = 80%) or bradycardia (heart rate < or = two thirds of baseline) per hour in an initial 6-hour recording, they were randomized to a 2-week course of oral CS (200 mg/kg per day) or placebo (P). Infants then underwent 2 additional 6-hour recordings of breathing movements, nasal airflow, heart rate, pulse oximeter saturation (SpO2) and pulse waveforms after 7 and 14 days of treatment. Urinary creatine excretion was measured also. Recordings were analyzed for the frequency of bradycardia and desaturation, the primary outcome parameter, as well as for apnea (> or =10 seconds), baseline heart and respiratory rate, and SpO2. RESULTS: Of 38 infants enrolled, 34 completed the study (17 in each group). Median (range) gestational age at birth was 27 (25-30) vs 27 (25-30) weeks, and at study 29 (26-36) vs 29 (27-33) weeks. Oral CS was well tolerated; no side effects were noted. Urinary creatine excretion was low in the P group (median: 27 mmol/mol of creatinine; range: 18-102) and increased in the CS group (6949 mmol/mol of creatinine; range: 1427-11807). CS, however, had no effect on the combined rate of bradycardia and desaturation (P: 2.7 per hour [range: 0.2-10.3]; CS: 4.1 per hour [range: 0.6-12.1]), nor was there any decrease in apnea rate (P: 1.7 per hour [range: 0-4.5]; CS: 2.2 per hour [range: 0.2-5.1]). CONCLUSION: Despite a significant increase in creatine excretion, suggesting good enteral absorption, CS did not, in the dose and for the duration given in this study, improve symptoms of AOP in these infants.

Inter- and intraobserver agreement for gastroesophageal reflux detection in infants using multiple intraluminal impedance.

The multiple intraluminal impedance (MII) technique is a new method that allows pH-independent gastroesophageal reflux detection via changes in impedance caused by a liquid bolus inside the esophagus. We wanted to know whether this technique yields objective and reproducible results. Twenty 3- to 6-hour recordings of MII from 19 preterm infants (median gestational age at birth 30 weeks, range 24-34 weeks; age at study 26 days, range 13-93 days) were divided into 23-second segments and analyzed for reflux episodes by three investigators; one investigator analyzed the data set twice. Observer agreement was assessed using kappa statistics. Each investigator analyzed 16,627 23-second segments, with a median of 854 (range 486-979) segments per recording. Median kappa values for the 20 recordings were 0.79, 0.83, and 0.83 for the three pairs of investigators and 0.84 for the repeated scoring procedure. MII recordings could be analyzed with a high level of inter- and intraobserver agreement.

Early feeding after necrotizing enterocolitis in preterm infants.

OBJECTIVE: To report our experience with an early initiation of enteral feedings after necrotizing enterocolitis (NEC). STUDY DESIGN: Over a 4-year period, all inborn infants with NEC Bell stage II or greater received enteral feedings, increased by 20 mL/kg/d, once no portal vein gas had been detected on ultrasound for 3 consecutive days (group 1). Infants were compared with a historic comparison group (group 2). RESULTS: Necrotizing enterocolitis rates were 5% (26/523) in the early feeding group and 4% (18/436) in the comparison group. One early feeding infant and two comparison group infants died of NEC, whereas two and one, respectively, had recurrent NEC. Enteral feedings were restarted at a median of 4 days (range, 3-14) versus 10 days (range, 8-22) after onset of NEC. Early feeding was associated with shorter time to reach full enteral feedings (10 days [range, 7-31] vs 19 days [range, 9-76], P<.001), a reduced duration of central venous access (13.5 days [range, 8-24] vs 26.0 days [range, 8-39], P<.01), less catheter-related septicemia (18% vs 29%, P<.01), and a shorter duration of hospital stay (63 days [range, 28-133] vs 69 days [range, 36-150], P<.05). CONCLUSION: Early enteral feeding after NEC was associated with significant benefits and no apparent adverse effects. This study was underpowered, however, to exclude a higher NEC recurrence risk potentially associated with this change in practice.

Detection of small bolus volumes using multiple intraluminal impedance in preterm infants.

BACKGROUND: Multiple intraluminal impedance (MII) is a new technique that allows detection of reflux and swallows via changes in impedance caused by a liquid bolus inside the esophagus. The method is independent of pH. The authors studied the ability of this technique to detect the small bolus volumes potentially occurring in young infants. METHODS: Ten preterm infants (median gestational age at birth, 33 weeks; range, 25-36 weeks; age at study, 9 days; range, 2-39 days) underwent 10 instillations each of 0.1 mL to 0.5 mL saline while MII was recorded via a 2.4-mm nasogastric catheter. MII signals were analyzed for swallows, defined as a decrease in impedance starting within 1 minute. From the liquid instillation in the most proximal channel and extending downward, impedance changes during these induced swallows were compared with those occurring during spontaneous swallows. RESULTS: All 100 liquid instillations resulted in a typical impedance pattern, occurring after a median interval of 4.4 seconds (range, 1.8-8.9 seconds). The decrease in impedance was more pronounced than after spontaneous swallows (30% vs. 24%, P < 0.03) and extended downward more rapidly (12.3 cm/s vs. 5.8 cm/s, P < 0.01). CONCLUSION: Bolus transport of small liquid volumes can be detected via MII.

Influence of nasogastric tubes on gastroesophageal reflux in preterm infants: a multiple intraluminal impedance study.

To investigate whether a nasogastric tube predisposes to gastroesophageal reflux, 16 preterm infants underwent 48-hour recordings of multiple intraluminal impedance with the catheter tip in the lower esophagus or stomach for 24 hours each. There were 72 (range, 40-145) reflux episodes with the esophageal placement and 122 (range, 60-147) during the gastric position (P <.01).

Gastroesophageal reflux and apnea of prematurity: no temporal relationship.

OBJECTIVE: A relationship between gastroesophageal reflux (GER) and apnea of prematurity (AOP) has long been suspected but is difficult to prove because most GER in this age group is nonacidic and thus undetectable by pH monitoring, the current standard for GER detection. The new multiple intraluminal impedance (MII) technique allows pH-independent reflux detection via changes in impedance caused by a liquid bolus inside the esophagus. We used this technique to investigate whether there is a temporal relationship between GER and AOP and whether GER occurs predominantly before a cardiorespiratory (CR) event. METHODS: Nineteen infants with AOP (median gestational age at birth: 30 weeks; range: 24-34; age at study: 26 days [13-93]) underwent 20 6-hour recordings of MII, breathing movements, nasal airflow, electrocardiogram, pulse oximeter saturation, and pulse waveforms. MII signals were analyzed, independent of CR signals, for reflux episodes (RE), defined as a fall in impedance in at least the 2 most distal channels. CR signals were analyzed for CR events, ie, apneas of >/=4-second duration, desaturations to