Corinna S. Peter

Pulse oximeters' reliability in detecting hypoxemia and bradycardia: comparison between a conventional and two new generation oximeters.

Objective: Pulse oximeters are increasingly used for patient monitoring; however, they are traditionally very prone to motion artifact. Newly developed instruments have lower false alarm rates. We wanted to know whether this is achieved at the expense of an increased proportion of false negative alarms such as missed or delayed identification of hypoxemia and/or bradycardia. Design: Observational study. Setting: Neonatal intensive care unit. Patients: A total of 17 unsedated preterm infants (median gestational age at birth, 25 wks; range, 24‐30 wks). Intervention: Long‐term recordings of transcutaneous partial pressure of oxygen (PTcO2), heart rate, pulse oximeter saturation (SpO2), and pulse rate from a conventional oximeter and two new generation oximeters. Measurements: Recordings were analyzed for episodes with PTcO2 <40 torr or with heart rate <80 beats/min for >5 secs. Hypoxemia was considered identified if SpO2 had fallen to <85% within 2 mins of PTcO2 reaching 40 torr, and bradycardia was considered identified if pulse rate had fallen to <80 beats/min within 2 mins of the heart rate reaching this threshold. Main Results: A total of 202 falls in PTcO2 to <40 torr occurred; 174 (86%) were identified by all three oximeters. Of the remaining episodes, manual analysis of red and infrared absorption signals confirmed that SpO2 had indeed been <85% for ≥10 secs in 11 episodes; therefore, these episodes should have been identified by all three oximeters. None of these had been missed by the conventional oximeter, but 10 (5.4% of the total) were missed by one of the new generation instruments (Nellcor), and one (0.5%) was missed by the other (Masimo). Of 54 bradycardias, only 14 were identified by all three oximeters; 17 (32%) were missed by the conventional, 37 (69%) by the Nellcor, and 4 (7%) by the Masimo instrument. Conclusion: One of the two new generation instruments investigated in this study missed 5.4% of hypoxemic episodes and 69% of bradycardias. It thus appears that this instruments reduced false alarm rate is achieved at the expense of an unreliable and/or delayed identification of hypoxemia and bradycardia. The other instrument identified both conditions equally as or more reliably than a conventional pulse oximeter.

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.

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.

False alarms in very low birthweight infants: comparison between three intensive care monitoring systems

Monitor alarms are a major burden on both patients and staff in intensive care units. We compared alarm rates from three different monitor systems (Hewlett Packard (HP), Kontron Instruments (KI), Marquette‐Hellige (MH)) in a tertiary neonatal intensive care unit. Monitors were used in random order on three consecutive days over 8h each in 16 preterm infants (median gestational age at birth 29 wk (range 24‐34), age at study 18 d (8‐53), weight at study 1160g (595‐1430)). Alarms were classified as true or false using flow sheets based on continuous observation of both the patient and related parameters. There was one alarm every 9 min of monitoring. The median number of true alarms did not differ significantly between systems, being 28 per 8 h (range 9‐87) for HP, 26 (3‐81) for KI, and 30 (5‐135) for MH. The median number of false alarms differed widely, with the HP system generating 32 (7‐77) such alarms per 8 h, compared to 8 (0‐19) for KI and 15 (2‐32) for MH (p < 0.01 HP vs KI and MH, p lt; 0.05 KI vs MH). These differences between systems were mainly due to differences in pulse oximeter and transcutaneous PO2 monitor alarm rates.

Procalcitonin and valuable clinical symptoms in the early detection of neonatal late-onset bacterial infection.

Aim:  To evaluate which clinical symptoms indicate proven neonatal bacterial infection (NBI) and whether measuring procalcitonin aside from C‐reactive protein and interleukin 6 improves sensitivity and specificity in diagnosis.

Oral versus Nasal Route for Placing Feeding Tubes: No Effect on Hypoxemia and Bradycardia in Infants with Apnea of Prematurity

Background: Raised upper airway resistance may be involved in apnea of prematurity (AOP). Objectives: To determine the effects of an oral versus a nasal gastric tube on episodes of hypoxemia and bradycardia in infants with AOP. Methods: In a randomized controlled cross-over trial, 32 infants (median gestational age 29 (range 24–31) weeks, postmenstrual age at study 32 (range 30–35) weeks) with the need for tube feeding and symptoms of AOP underwent a 24-hour recording of breathing movements, nasal airflow, heart rate, pulse oximeter saturation and pulse waveforms. A 5-Fr feeding tube was placed orally or nasally for 12 h each, the position selected first was randomly assigned. When the feeding tube was placed nasally, always the smaller nostril was selected. Each infant acted as his/her own control. Recordings were analyzed for the summed rate of bradycardia and desaturation (heart rate <2/3 of baseline, saturation ≤80%). Results: The route of placing the feeding tube had no significant effect on the summed rate of bradycardia and desaturation (nasal route: median 1.6, CI 0.8–1.9; oral route: median 1.0, CI 0.9–1.6, p = 0.25). Conclusion: We could not confirm an advantage of placing a feeding tube orally in these infants with AOP, as the oral route did not improve their symptoms of AOP. Possible explanations include: (i) the increase in nasal airway resistance by the 5-Fr nasogastric tube, inserted into the smaller nostril, is too small to have any effect on AOP; (ii) any benefit of the oral route is neutralized by the negative effects of an enhanced vagal stimulation, or (iii) study duration was too short to detect a difference in AOP.

Prescription of home oxygen therapy to infants in Germany.

There is no consensus on home oxygen therapy in infancy. We hypothesised that this might lead to considerable variability in the practice of prescribing home oxygen to infants. To assess this variability, a structured questionnaire was sent to all departments of Paediatrics in Germany (n = 380). Response rate was 92% (n = 349). Indications were mostly (86%) based on long-term recordings of pulse oximeter saturation (SPO2). There was, however, a wide range (85–94%, mean 90%) of SPO2-values below which oxygen therapy was considered indicated. Hospitals more experienced with this therapy tended to prescribe oxygen at SPO2 values closer to the physiological range. Similarly, SPO2 values aimed for during therapy ranged from 86 to 100%, with hospitals prescribing home oxygen more frequently aiming for higher values. These differences would argue for concentrating home oxygen therapy to centers with the largest experience.

Successful treatment of vancomycin-resistant Enterococcus faecium ventriculitis with combined intravenous and intraventricular chloramphenicol in a newborn.

Vancomycin-resistant Enterococcus faecium (VRE) infection is a rare event in paediatric patients and often occurs under immunosuppression or after surgical intervention. We report what we believe to be the first paediatric case of ventriculitis due to VRE (in a 2-month-old infant) to be successfully treated with combined intravenous (i.v.) and intraventricular chloramphenicol after failure of i.v. linezolid and intraventricular gentamicin.

Closed versus Open Endotracheal Suctioning in Extremely Low-Birth-Weight Neonates: A Randomized, Crossover Trial

Background: Endotracheal suctioning, which is frequently necessary in mechanically ventilated patients, might cause complications, especially in patients with compromised lung function such as extremely low-birth-weight (ELBW) neonates. Objectives: To investigate whether closed endotracheal suctioning (CS) reduces the frequency of hypoxemia and bradycardia in ELBW neonates compared to open suctioning (OS). Methods: In a randomized, crossover trial, 15 ventilated ELBW neonates (mean birth weight 655 g) underwent suctioning with both techniques. Data on oxygen saturation (Spo2), heart rate (HR), arterial blood pressure, arterial blood gases, duration of the suctioning procedure and recovery time were collected. Statistical analysis was done using the SPSS t test for paired samples. Results: The mean frequency of hypoxemia <85% was significantly decreased (p = 0.012) during CS (0.5) versus OS (1.1). The mean minimum Spo2 was significantly higher (p = 0.012) during CS (87%) compared to OS (84%), and a significantly less steep drop in mean Spo2 (p = 0.007) (CS: –5%, OS: –8%) was found. Mean arterial Po2 (p = 0.035; CS: 59 mm Hg, OS: 53 mm Hg) and mean oxygenation ratio (p = 0.016; CS: 197, OS: 171) were significantly higher after CS. No significant differences were found in HR, incidence or duration of bradycardia, recovery time, arterial blood pressure, duration of suctioning, number of complications, or duration of hypoxemia. Conclusion: CS was superior to OS on oxygenation values. To prove its overall superiority, further research is required. So, in this group of patients, CS should currently be administered on an individual basis.