Introducing a novel respiratory function monitor for neonatal resuscitation training.

Background: A respiratory function monitor (RFM) gives immediate feedback, allowing clinicians to adjust face mask ventilation to correct leak or inappropriate tidal volumes. We audited the satisfaction of clinicians with a neonatal resuscitation training package, incorporating a novel RFM. Methods: This was a mixed-methods study conducted at The Royal Women's Hospital, Melbourne, Australia. Clinicians were approached to complete a neonatal resuscitation training session. Participants watched a training video, then provided ventilation to term and preterm manikins first without, and then with, the RFM. Clinicians completed a survey after the session and undertook a follow-up session three months later. The primary outcome was participant satisfaction with the RFM. Secondary outcomes included participants' self-assessment of face mask leak and tidal volumes when using the RFM. Results: Fifty clinicians completed both the initial and follow-up session. Participants reported high levels of satisfaction with the RFM for both term and preterm manikins: on a scale from 0, meaning "not at all", and 100, meaning "yes, for all resuscitations", the median response (interquartile range, IQR) was 82 (74-94) vs 81.5 (69-94.5). Levels of satisfaction were similar for less experienced and more experienced clinicians: median (IQR) 83 (77-93) vs 81 (71.5-95) respectively. When using the monitor, clinicians accurately self-assessed that they achieved leak below 30% and tidal volumes within the target range at least 80% of the time. Conclusion: Clinicians of all experience levels had a high level of satisfaction with a training package including a novel RFM.

The α2,3-selective potentiator of GABAA receptors, KRM-II-81, reduces nociceptive-associated behaviors induced by formalin and spinal nerve ligation in rats.

Clinical evidence indicates that positive allosteric modulators (PAMs) of GABAA receptors have analgesic benefit in addition to efficacy in anxiety disorders. However, the utility of GABAA receptor PAMs as analgesics is compromised by the central nervous system side effects of non-selective potentiators. A selective potentiator of GABAA receptors associated with α2/3 subunits, KRM-II-81(5-(8-ethynyl-6-(pyridin-2-yl)-4H-benzo[f]imidazo[1,5-a][1,4]diazepin-3-yl)oxazole), has demonstrated anxiolytic, anticonvulsant, and antinociceptive effects in rodents with reduced motoric side effects. The present study evaluated the potential of KRM-II-81 as a novel analgesic. Oral administration of KRM-II-81 attenuated formalin-induced flinching; in contrast, diazepam was not active. KRM-II-81 attenuated nociceptive-associated behaviors engendered by chronic spinal nerve ligation (L5/L6). Diazepam decreased locomotion of rats at the dose tested in the formalin assay (10 mg/kg) whereas KRM-II-81 produced small decreases that were not dose-dependent (10-100 mg/kg). Plasma and brain levels of KRM-II-81 were used to demonstrate selectivity for α2/3- over α1-associated GABAA receptors and to define the degree of engagement of these receptors. Plasma and brain concentrations of KRM-II-81 were positively-associated with analgesic efficacy. GABA currents from isolated rat dorsal-root ganglion cultures were potentiated by KRM-II-81 with an ED50 of 32 nM. Measures of respiratory depression were reduced by alprazolam whereas KRM-II-81 was either inactive or produced effects with lower potency and efficacy. These findings add to the growing body of data supporting the idea that α2/3-selective GABAA receptor PAMs will have efficacy and tolerability as pain medications including those for neuropathic pain. Given their predicted anxiolytic effects, α2/3-selective GABAA receptor PAMs offer an additional inroad into the management of pain.

Evaluation of an exercise programme for post-bariatric surgery patients: views of participants.

OBJECTIVE: Exercise programmes typically are evaluated with fitness assessments and psychological survey measures but seldom include participants' insights. The purpose of this study was to evaluate the benefits, facilitators and barriers of a 12-week exercise programme for post-bariatric surgery patients from the participants' perspective. METHOD: Over a 2-year period, 20 patients recently having undergone bariatric surgery completed a 12-week programme that included participation in structured exercise and in focus groups designed to supplement standard evaluation data and provide insight into participants' views. RESULTS: Participants were highly adherent to the programme, and focus group results reflected a clear positive evaluations. Benefits included helpful information, developing commitment, physical fitness and social support; notably, weight was seldom mentioned. Participants cited structure, accountability and group support as facilitators of exercise. Participants cited few barriers, although very few had set plans for continuing exercise after programme completion. CONCLUSION: Participants saw many benefits to the exercise programme, and those benefits reflected lifestyle changes rather than a focus on weight. Programme structure, accountability and the support of the group were facilitators to exercise. Participants cited few barriers. However, the lack of plans for continued exercise suggested the need for a transition phase to help participants continue an active lifestyle after the 12-week structured programme.

The effect of skin-to-skin care on cerebral oxygenation during nasogastric feeding of preterm infants.

AIM: To describe cerebral oxygenation during gavage feeding of preterm infants during incubator and skin-to-skin care. METHODS: Further analysis of data from two crossover studies comparing cerebral oxygenation, heart rate and oxygen saturation during skin-to-skin care with incubator care. Data were analysed in three epochs; 10 minutes prefeed, during-feed and 10 minutes postfeed. Measurements from infants fed during incubator care were compared with those obtained during skin-to-skin care. RESULTS: In 39 infants [median (IQR) 27.8 (26.1-30.0) weeks' gestation], there was no difference in cerebral oxygenation between pre-, during- and postfeed. Heart rate increased by three beats per minute postfeed compared with during-feed. Twenty infants received two gavage feeds, one feed in the incubator and another during skin-to-skin care. There was no difference in cerebral oxygenation and heart rate; peripheral oxygen saturation decreased by 3% during feeding whilst skin-to-skin care compared with feeding in the incubator. CONCLUSION: Cerebral oxygenation remained stable before, during and after gavage feeding in an incubator and during skin-to-skin care. The small decrease in oxygen saturation whilst receiving gavage feeding during skin-to-skin care is unlikely to be clinically important, providing reassurance that preterm infants maintain physiological stability during skin-to-skin care.

International variations in application of the best-interest standard across the age spectrum.

OBJECTIVE: Ethically and legally, assertions that resuscitation is in a patient's best interest should be inversely correlated with willingness to forego intensive care (and accept comfort care) at the surrogate's request. Previous single country studies have demonstrated a relative devaluation of neonates when compared with other critically ill patients. STUDY DESIGN: In this international study, physicians in Argentina, Australia, Canada, Ireland, The Netherlands, Norway and the United States were presented with eight hypothetical vignettes of incompetent critically ill patients of different ages. They were asked to make assessments about best interest, respect for surrogate autonomy and to rank the patients in a triage scenario. RESULTS: In total, 2237 physicians responded (average response rate 61%). In all countries and scenarios, participants did not accept to withhold resuscitation if they estimated it was in the patient's best interest, except for scenarios involving neonates. Young children (other than neonates) were given high priority for resuscitation, regardless of existing disability. For neonates, surrogate autonomy outweighed assessment of best interest. In all countries, a 2-month-old-infant with meningitis and a multiply disabled 7-year old were resuscitated first in the triage scenario, with more variable ranking of the two neonates, which were ranked below patients with considerably worse prognosis. CONCLUSIONS: The value placed on the life of newborns is less than that expected according to predicted clinical outcomes and current legal and ethical theory relative to best interests. Value assessments on the basis of age, disability and prognosis appear to transcend culture, politics and religion in this domain.

High-flow support in very preterm infants in Australia and New Zealand.

BACKGROUND: Randomised trials suggest that high-flow (HF) therapy is comparable with continuous positive airway pressure (CPAP) for postextubation respiratory support in neonates, and HF has been widely adopted in neonatal intensive care. METHODS: We conducted a population-based study of very preterm infants born <32 weeks' gestation within the Australian and New Zealand Neonatal Network (ANZNN) data set from 2009 to 2012, who received respiratory support with HF. RESULTS: 3372 very preterm infants were treated with HF. HF use in this population increased significantly from 15% in 2009 to 35% in 2012. In 2012, 53% (542/1029) of extremely preterm infants born <28 weeks' gestation received HF. 98% (3308/3372) of infants had received endotracheal ventilation or CPAP prior to receiving HF. The maximum HF gas flow was ≤8 L/min in almost all infants. CONCLUSIONS: HF use in extremely preterm and very preterm infants increased significantly within the ANZNN from 2009 to 2012.

Randomized controlled trial to compare sleep and wake in preterm infants less than 32weeks of gestation receiving two different modes of non-invasive respiratory support.

AIM: To determine whether respiratory support via heated humidified high flow nasal cannulae (HHHFNC) results in infants <32weeks gestation spending a greater proportion of time in sleep compared to those receiving nasal continuous positive airway pressure (NCPAP). METHODS: A subgroup of infants enrolled in a randomized controlled trial to compare HHHFNC or NCPAP post-extubation had sleep and wake activity measured by actigraphy for 72hours post-extubation. Activity diaries were completed contemporaneously to record episodes of infant handling. Actigraphy data were downloaded with known periods of handling excluded from the analysis. RESULTS: 28 infants with mean gestation of 28.3weeks (SD 2) and birth weight 1074g (SD 371) were studied. Infants receiving HHHFNC spent a lesser proportion of time in sleep 59.8% (SD 18.5) than those on NCPAP 82.2% (SD 23.8) p=0.004. Infants receiving HHHFNC had a lower sleep efficiency and higher mean activity score than those on NCPAP (p=0.003, p=0.002, respectively). CONCLUSION: Infants receiving HHHFNC had a higher mean activity score and spent less time in sleep than those allocated NCPAP. Further study of sleep wake activity in preterm infants receiving respiratory support is required as this may impact on neurodevelopmental outcomes.

International survey on periextubation practices in extremely preterm infants.

OBJECTIVE: To determine periextubation practices in extremely preterm infants (<28 weeks gestation). DESIGN: A survey consisting of 13 questions related to weaning from mechanical ventilation, assessment of extubation readiness and postextubation respiratory support was developed and sent to clinical directors of level III NICUs in Australia, Canada, Ireland, New Zealand and USA. A descriptive analysis of the results was performed. RESULTS: 112/162 (69%) units responded; 36% reported having a guideline (31%) or written protocol (5%) for ventilator weaning. Extubation readiness was assessed based on ventilatory settings (98%), blood gases (92%) and the presence of clinical stability (86%). Only 54% ensured that infants received caffeine ≤24 h prior to extubation. 16% of units systematically extubated infants on the premise that they passed a Spontaneous Breathing Test with a duration ranging from 3 min (25%) to more than 10 min (35%). Nasal continuous positive airway pressure was the most common type of respiratory support used (84%) followed by nasal intermittent positive pressure ventilation (55%) and high-flow nasal cannula (33%). Reintubation was mainly based on clinical judgement of the responsible physician (88%). There was a lack of consensus on the time frame for definition of extubation failure (EF), the majority proposing a period between 24 and 72 h; 43% believed that EF is an independent risk factor for increased mortality and morbidity. CONCLUSIONS: Periextubation practices vary considerably; decisions are frequently physician dependent and not evidence based. The definition of EF is variable and well-defined criteria for reintubation are rarely used. High-quality trials are required to inform guidelines and standardise periextubation practices.

Assessing the tongue colour of newly born infants may help to predict the need for supplemental oxygen in the delivery room.

AIM: It takes several minutes for infants to become pink after birth. Preductal oxygen saturation (SpO2) measurements are used to guide the delivery of supplemental oxygen to newly born infants, but pulse oximetry is not available in many parts of the world. We explored whether the pinkness of an infant's tongue provided a useful indication that supplemental oxygen was required. METHODS: This was a prospective observational study of infants delivered by Caesarean section. Simultaneous recording of SpO2 and visual assessment of whether the tongue was pink or not was made at 1-7 and 10 min after birth. RESULTS: The 38 midwives and seven paediatric trainees carried out 271 paired assessments on 68 infants with a mean (SD) birthweight of 3214 (545) grams and gestational age of 38 (2) weeks. When the infant did not have a pink tongue, this predicted SpO2 of <70% with a sensitivity of 26% and a specificity of 96%. CONCLUSION: Tongue colour was a specific but insensitive sign that indicated when SpO2 was <70%. When the tongue is pink, it is likely that an infant has an SpO2 of more than 70% and does not require supplemental oxygen.

Effects of synchronisation during SiPAP-generated nasal intermittent positive pressure ventilation (NIPPV) in preterm infants.

OBJECTIVE: The SiPAP flow driver (Care Fusion, Dublin, Ohio, USA) offers synchronised nasal intermittent positive pressure ventilation (sNIPPV) using an abdominal capsule. This study aims to describe the accuracy and effects of synchronised NIPPV using SiPAP in preterm infants. DESIGN: Ten infants, born <28 weeks' gestation, receiving synchronised SiPAP-generated NIPPV, in 'biphasic trigger' mode, were observed. Abdominal capsule signals, delivered pressures, respiratory pattern and oxygen saturations were recorded. Tidal volume (VT), apnoeas, proportion of breaths supported by SiPAP and time between inspiration onset and SiPAP pressure rise were analysed. RESULTS: Infants were of median 26(+0) weeks' gestational age and birth weight 776 g. Mean (SD) respiratory rate (RR) was 53 (14)/min. 82% (17) of spontaneous breaths triggered a SiPAP pressure peak. Mean time between inspiration and SiPAP pressure rise was 28 (20) ms. There was no difference in VT when breaths triggered a SiPAP pressure peak compared with breaths without a pressure peak. No VT was generated by pressure peaks delivered during apnoea. Capsule signals were not recognised following >10% of breaths, resulting in asynchronous NIPPV delivery. Movements resulted in irregular SiPAP pressures and desaturation. When the RR was faster, >55/min, breaths irregularly triggered a SiPAP pressure peak (p=0.003). Compared with times when every breath resulted in a pressure peak, lower mean pressures were achieved, 7.9 vs 8.4 cm H2O (p=0.02). CONCLUSIONS: The SiPAP synchronisation system triggered rapidly with most spontaneous breaths, but did not result in larger tidal volumes. When the RR was >55/min, the SiPAP delivered fewer pressure peaks at lower pressures.

Are high flow nasal cannulae noisier than bubble CPAP for preterm infants?

BACKGROUND: Noise exposure in the neonatal intensive care unit is believed to be a risk factor for hearing loss in preterm neonates. Continuous positive airway pressure (CPAP) devices exceed recommended noise levels. High flow nasal cannulae (HFNC) are an increasingly popular alternative to CPAP for treating preterm infants, but there are no in vivo studies assessing noise production by HFNC. OBJECTIVE: To study whether HFNC are noisier than bubble CPAP (BCPAP) for preterm infants. METHODS: An observational study of preterm infants receiving HFNC or BCPAP. Noise levels within the external auditory meatus (EAM) were measured using a microphone probe tube connected to a calibrated digital dosimeter. Noise was measured across a range of frequencies and reported as decibels A-weighted (dBA). RESULTS: A total of 21 HFNC and 13 BCPAP noise measurements were performed in 21 infants. HFNC gas flows were 2-5 L/min, and BCPAP gas flows were 6-10 L/min with set pressures of 5-7 cm of water. There was no evidence of a difference in average noise levels measured at the EAM: mean difference (95% CI) of -1.6 (-4.0 to 0.9) dBA for HFNC compared to BCPAP. At low frequency (500 Hz), HFNC was mean (95% CI) 3.0 (0.3 to 5.7) dBA quieter than BCPAP. Noise increased with increasing BCPAP gas flow (p=0.007), but not with increasing set pressure. There was a trend to noise increasing with increasing HFNC gas flows. CONCLUSIONS: At the gas flows studied, HFNC are not noisier than BCPAP for preterm infants.

Self-inflating bags versus T-piece resuscitator to deliver sustained inflations in a preterm lamb model.

OBJECTIVE: In neonatal resuscitation, the use of a sustained inflation (SI) may facilitate lung aeration. Previous studies comparing different resuscitation devices have shown that one model of self-inflating bag (SIB) could not deliver an SI. We aimed to compare the delivery of an SI using four SIBs with that of a T-piece. STUDY DESIGN: In intubated preterm lambs, we compared four models of SIB fitted with a positive end expiratory pressure (PEEP) valve to a T-piece using a gas flow of 8 L/min. Four operators aimed to deliver three SIs of 20 cm H2O for 30 s. The study was repeated with the PEEP valve removed and again with no flow. We measured duration of SI, average inflation pressure (IP) and analysed the shape of the pressure curves. RESULTS: 204 combinations were analysed. Mean (SD) duration of SI was Ambu 6(2)s, Laerdal 14(8)s, Parker Healthcare 5(1)s, Mayo Healthcare 33(2)s and T-piece 33(1)s. Mean (SD) average IP was Ambu 17(3)cm H2O, Laerdal 17(3)cm H2O, Parker Healthcare 12(5)cm H2O, Mayo Healthcare 21(2)cm H2O and T-piece 20(0)cm H2O. Duration of SI and average IP was significantly different between SIBs (all p<0.001). The findings were substantially unchanged when PEEP valve and flow were removed (all p>0.05). Only the Mayo system delivered SIs with duration and average IP not significantly different from the T-piece (p>0.05). CONCLUSIONS: The performance of the four SIBs tested varied considerably. Some are able to deliver an SI even in the absence of gas flow. This may be useful in a resource-limited setting with no gas supply.

The precision and accuracy of Nellcor and Masimo oximeters at low oxygen saturations (70%) in newborn lambs.

BACKGROUND: Administration of oxygen in the delivery room is informed by oxygen saturation (SpO2). An oxygen saturation range of 60%-70% is the threshold for administering oxygen in the first minutes after birth. The accuracy of newer generation oximeters to measure SpO2 has not been compared against the 'gold standard', direct arterial blood oxygen saturation (SaO2) when SaO2 is low. The aim of this study was to determine the accuracy and precision of Nellcor and Masimo oximeters to measure SpO2 when SaO2 <70%. METHOD: Prospective observational study in ventilated anaesthetised newborn lambs with an indwelling carotid artery catheter. Ventilation was adjusted to achieve hypoxaemia. Nellcor (Oxi-Max 600 with Max-N sensor) and Masimo (Rad 4 with low noise optical probe (LNOP) sensor) sensors were applied to the right forelimb (preductal). An arterial blood sample was collected at 1-5 min intervals when the animal was hypoxic. The displayed SpO2 was recorded. We used Bland-Altman analysis to determine precision and accuracy of each oximeter when SaO2 <70%. RESULTS: 17 lambs were studied, 165 measurements were obtained, 123 were SaO2 <70%. The mean difference (±1.96 SD) Nellcor SpO2-SaO2 when SaO2 <70% was 17% (-12% to 46%). The mean difference (±1.96 SD) Masimo SpO2-SaO2 when SaO2 <70% was 13% (-19% to 45%). CONCLUSIONS: At SaO2<70%, both monitors overestimated oxygen saturation (SpO2) compared with the gold standard. Both oximeters were equally inaccurate when SaO2 was low.

A comparison of nasal trauma in preterm infants extubated to either heated humidified high-flow nasal cannulae or nasal continuous positive airway pressure.

UNLABELLED: The objectives of this study were (1) to devise a nasal trauma score for preterm infants receiving non-invasive respiratory support, (2) to compare the incidence of nasal trauma in preterm infants <32 weeks gestation randomised to either nasal continuous positive airway pressure (NCPAP) or heated humidified high-Flow nasal cannulae (HHHFNC), in the first 7 days post-extubation and (3) to assess the effect of two different nasal dressings in those assigned to NCPAP. We randomly assigned preterm ventilated infants to receive Vapotherm® HHHFNC or NCPAP post-extubation. Infants receiving HHHFNC were treated with Sticky Whiskers® and infants receiving NCPAP received either Sticky Whiskers® or Cannualaide® nasal dressings. Bedside nursing staff scored six sites on each infant's nose for erythema, bleeding or ulceration. Scores were recorded three times daily for the first 7 days post-extubation. The sum of these 21 scores was used as the summary measure of nasal trauma. The mean nasal trauma score for infants assigned HHHFNC was 2.8 (SD 5.7) compared to 11.7 for NCPAP (SD 10.4), p < 0.001. There was no difference in mean trauma score between infants on NCPAP assigned Sticky Whiskers® 14.4 (SD 12.5) or Cannualaide® 9.5 (SD 7.3), p = 0.06. CONCLUSION: HHHFNC resulted in significantly less nasal trauma in the first 7 days post-extubation than NCPAP and was most significant in infants <28 weeks of gestation. The use of protective dressings was not associated with decreased nasal trauma for infants on NCPAP.

Methylxanthine use for apnea of prematurity among an international cohort of neonatologists.

BACKGROUND: A recent multinational clinical trial in preterm infants has demonstrated pulmonary and neurodevelopmental benefits from caffeine therapy. Indications for caffeine use in that study were predominantly for treatment of apnea and facilitation of extubation rather than prophylaxis. There are no recent studies that describe current practice of neonatologists and regional differences in regards to indications for starting, monitoring and discontinuing methylxanthine therapy in premature infants. OBJECTIVE: To characterize the spectrum of current practice and demonstrate the extent to which methylxanthine therapy varies by location. METHODS: A cross-sectional survey of all neonatologists in Thailand, Lebanon, Australia, and a representative sample in the USA regarding management of apnea of prematurity. RESULTS: The response rate was 50% (342/681). The methylxanthine of choice varied greatly across study locations. Prophylactic methylxanthine use is common (62%) among neonatologists in all four study locations. Significant variation exists in almost all aspects of apnea pharmacotherapy practice among neonatologists in different international locations. CONCLUSIONS: Prophylactic use of methylxanthine therapy for apnea of prematurity is widespread. We speculate that this expanded use is possibly attributed to the beneficial effects of caffeine therapy in the Caffeine for Apnea of Prematurity (CAP) Trial.

Neonatal non-invasive respiratory support: synchronised NIPPV, non-synchronised NIPPV or bi-level CPAP: what is the evidence in 2013?

Nasal continuous positive airway pressure (NCPAP) has proven to be an effective mode of non-invasive respiratory support in preterm infants; however, many infants still require endotracheal ventilation, placing them at an increased risk of morbidities such as bronchopulmonary dysplasia. Several other modes of non-invasive respiratory support beyond NCPAP, including synchronised and non-synchronised nasal intermittent positive pressure ventilation (SNIPPV and nsNIPPV) and bi-level positive airway pressure (BiPAP) are now also available. These techniques require different approaches, and the exact mechanisms by which they act remain unclear. SNIPPV has been shown to reduce the rate of reintubation in comparison to NCPAP when used as post-extubation support, but the evidence for nsNIPPV and BiPAP in this context is less convincing. There is some evidence that NIPPV (whether synchronised or non-synchronised) used as primary respiratory support is beneficial, but the variation in study methodology makes this hard to translate confidently into clinical practice. There is currently no evidence to suggest a reduction in mortality or important morbidities such as bronchopulmonary dysplasia, with NIPPV or BiPAP in comparison to NCPAP, and there is a lack of appropriately designed studies in this area. This review discusses the different approaches and proposed mechanisms of action of SNIPPV, nsNIPPV and BiPAP, the challenges of applying the available evidence for these distinct modalities of non-invasive respiratory support to clinical practice, and possible areas of future research.

Comparison of heart rate and oxygen saturation measurements from Masimo and Nellcor pulse oximeters in newly born term infants.

AIM: To compare heart rate (HR) measurements from Masimo and Nellcor pulse oximeters (POs) against HR measured via a three lead electrocardiograph (ECG) (HRECG ). We also compared peripheral oxygen saturation (SpO2 ) measurements between Nellcor and Masimo oximeters. METHOD: Term infants born via elective caesarean section were studied. ECG leads were placed on the infant's chest and abdomen. Masimo and Nellcor PO sensors were randomly allocated to either foot. The monitors were placed on a trolley, and data from each monitor screen captured by a video camera. HR, SpO2 measurements and signal quality were extracted. Bland-Altman analysis was used to determine agreement between HR from the ECG and each oximeter, and between SpO2 from the oximeters. RESULTS: We studied 44 infants of whom 4 were resuscitated. More than 8000 pairs of observations were used for each comparison of HR and SpO2. The mean difference (±2SD) between HRECG and HRN ellcor was -0.8 (±11) beats per minute (bpm); between HRECG and HRM asimo was 0.2 (±9) bpm. The mean (±2SD) difference between SpO2Masimo and SpO2Nellcor was -3 (±15)%. The Nellcor PO measured 20% higher than the Masimo PO at SpO2 <70%. CONCLUSION: Both oximeters accurately measure HR. There was good agreement between SpO2 measurements when SpO2 ≥70%. At lower SpO2 , agreement was poorer.

Determining the best method of Nellcor pulse oximeter sensor application in neonates.

AIM: To identify the optimal sensor application method that gave the quickest display of accurate heart rate (HR) data using the Nellcor OxiMax N-600x pulse oximeter (PO). METHODS: Stable infants who were monitored with an electrocardiograph were included. Three sensor application techniques were studied: (i) sensor connected to cable, then applied to infant; (ii) sensor connected to cable, applied to investigator's finger, and then to infant; (iii) sensor applied to infant, then connected to cable. The order of techniques tested was randomized for each infant. Time taken to apply the PO sensor, to display data and to display accurate data (HR(PO) = HR(ECG) ± 3 bpm) were recorded using a stopwatch. RESULTS: Forty infants were studied [mean (SD) birthweight, 1455 (872) g; gestational age, 31 (4) weeks; post-menstrual age, 34 (4) weeks]. Method 3 acquired any data significantly faster than methods 1 (p = 0.013; CI, -9.6 to -3.0 sec) and 2 (p = 0.004; CI, -5.9 to -1.2 sec). Method 3 acquired accurate data significantly faster than method 1 (p = 0.016; CI, -9.4 to -1.0 sec), but not method 2 (p = 0.28). CONCLUSION: Applying the sensor to the infant before connecting it to the cable yields the fastest acquisition of accurate HR data from the Nellcor PO.

Postnatal ultrasound reliability in cerebellar vermis assessment.

BACKGROUND: Cerebellar growth in late gestation is impeded by prematurity which may adversely affect neurocognitive development. Assessment of cerebellar growth should be easily attainable, reliable and reproducible. OBJECTIVE: To assess the reliability of linear sonographic cerebellar vermis measurement. METHOD: Cranial ultrasounds of 110 infants ranging from 24 to 41 weeks' gestation were retrospectively reviewed. Cerebellar vermian height, craniocaudal diameter and superior and inferior vermis widths were independently measured on the first midline sagittal image by three neonatal sonologists of varying experience. Interobserver and intraobserver reliability were calculated using the intraclass correlation coefficient (ICC) (2 way mixed model, SPSS V.15.0). RESULTS: 61 images were technically adequate. Interobserver ICCs (95% CI) were: cerebellar vermian height 0.88 (0.82 to 0.92); craniocaudal diameter 0.91 (0.86 to 0.94); superior vermis width 0.84 (0.77 to 0.89); inferior vermis width 0.92 (0.89 to 0.95). Intraobserver ICCs were similar. CONCLUSION: With adequate images, linear ultrasound measurements of cerebellar vermis are reliable.