Biomedical subjects

H E Jeffery

Publications and source records attributed to H E Jeffery.

At least 19 recordsLinked to original sources

PubMed2002

Sedatives for opiate withdrawal in newborn infants.

BACKGROUND: Neonatal abstinence syndrome (NAS) due to opiate withdrawal may result in disruption of the mother-infant relationship, sleep-wake abnormalities, feeding difficulties, weight loss and seizures. Treatments used to ameliorate symptoms and reduce morbidity include opiates, sedatives and non-pharmacological treatments. OBJECTIVES: To assess the effectiveness and safety of using a sedative compared to a non-opiate control for NAS due to withdrawal from opiates, and to determine which type of sedative is most effective and safe. SEARCH STRATEGY: The standard search strategy of the Neonatal Review Group was used. This included searches of the Cochrane Controlled Trials Register (The Cochrane Library, Issue 1, 2002) and MEDLINE 1966-2002. SELECTION CRITERIA: Trials enrolling infants with NAS born to mothers with an opiate dependence, with > 80% follow up and using random or quasi-random allocation to sedative or control. Control could include another sedative or non-pharmacological treatment. DATA COLLECTION AND ANALYSIS: Each author assessed study quality and extracted data independently. Primary outcomes included treatment failure (failure to achieve symptom control or use of additional drug treatment), seizure occurrence, mortality and neurodevelopment. Treatment effect was expressed using (RR), risk difference (RD), mean difference (MD) and weighted mean difference (WMD). Meta-analysis was performed using a fixed effect model. MAIN RESULTS: Five studies enrolling a total of 285 patients met inclusion criteria (Finnegan 1984, Kahn 1969, Kaltenbach 1986, Khoo 1995, Madden 1977); however, two (Finnegan 1984, Kaltenbach 1986) may be sequential reports that include some identical patients. Methodological concerns included the use of quasi-random rather than random patient allocation methods in three studies, and sizeable, largely unexplained differences in reported numbers allocated to each group in three studies. Phenobarbital compared to supportive care alone has not been shown to reduce treatment failure or time to regain birthweight (one study). However, the duration of supportive care required to be given to infants each day was significantly reduced (MD -162.1 minutes/day, 95% CI -249.2, -75.1). Comparing phenobarbital to diazepam, meta-analysis of two studies found that phenobarbital produced a significant reduction in treatment failure (typical RR 0.39, 95% CI 0.24, 0.62). There was no significant difference in duration of treatment or duration of hospital stay. Comparing phenobarbital with chlorpromazine, one study found no significant difference in treatment failure rate. No data for neurodevelopment were available, reported by treatment group as allocated. No trials were eligible that assessed clonidine for NAS. REVIEWER'S CONCLUSIONS: In newborn infants with NAS, there is no evidence that phenobarbital, compared with supportive care alone, reduces treatment failure; however, phenobarbital may reduce the daily duration of supportive care needed. Phenobarbital, compared to diazepam, reduces treatment failure. There is insufficient evidence to support the use of chlorpromazine or clonidine in newborn infants with NAS. Clonidine and chlorpromazine should only be used in the context of a randomised clinical trial. The results of this review, taken in conjunction with the related review, Opiate treatment for opiate withdrawal in newborn infants (Osborn 2002), indicate that treatment with opiates is the preferred initial therapy for NAS. It is hypothesised that this is particularly true for infants whose mothers have used only opiates during pregnancy. If a sedative is used, phenobarbital is preferred to diazepam. The results of an ongoing trial of the addition of phenobarbital to an opiate are awaited.

Chlorpromazine↗

PubMed2002

Opiate treatment for opiate withdrawal in newborn infants.

BACKGROUND: Neonatal abstinence syndrome (NAS) due to opiate withdrawal may result in disruption of the mother-infant relationship, sleep-wake abnormalities, feeding difficulties, weight loss and seizures. Treatments used to ameliorate symptoms and reduce morbidity include opiates, sedatives and non-pharmacological treatments. OBJECTIVES: To assess the effectiveness and safety of using an opiate, compared to a sedative or non-pharmacological treatment, for treatment of NAS due to withdrawal from opiates. The evidence for use of different opiates was assessed in subgroup analyses. SEARCH STRATEGY: The standard search strategy of the Cochrane Neonatal Review Group including searches (up to March 2002) of the Oxford Database of Perinatal Trials, Cochrane Controlled Trials Register (The Cochrane Library, Issue 1, 2002), MEDLINE (1966-March 2002), previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, journal handsearching mainly in the English language. SELECTION CRITERIA: Trials enrolling infants with NAS born to mothers with an opiate dependence, with > 80% follow up and using random or quasi-random allocation to opiate or control. Control could include an opiate, sedative or non-pharmacological treatment. DATA COLLECTION AND ANALYSIS: Each author assessed study quality and extracted data independently. Primary outcomes included control of symptoms, seizure occurrence, mortality and neurodevelopment. Treatment effect was expressed using relative risk (RR), risk difference (RD), mean difference (MD) and weighted mean difference (WMD). Meta-analysis was performed using a fixed effect model. MAIN RESULTS: Six studies enrolling a total of 511 infants met inclusion criteria (Carin 1983, Finnegan 1984, Kaltenbach 1986, Kandall 1983, Khoo 1995, Madden 1977); however, two (Finnegan 1984, Kaltenbach 1986) may be sequential reports that include some identical patients. The studies enrolled infants of mothers who had used opiates with or without other drugs during pregnancy. Methodological concerns included the use of quasi-random rather than random patient allocation methods in three studies, and sizeable, largely unexplained differences in reported numbers allocated to each group in four studies. Opiate (morphine) vs supportive care only: One study (Khoo 1995) found no significant effect on treatment failure (RR 1.29, 95% CI 0.41, 4.07), a significant increase in hospital stay (MD 15.0 days, 95% CI 8.9, 21.1) and significant reductions in time to regain birthweight (MD -2.8 days, 95% -5.3, -0.3) and duration of supportive care (MD -197.2 minutes/day, 95% CI -274.2, -120.3). Opiate vs phenobarbital: Meta-analysis of three studies found no significant difference in treatment failure (typical RR 0.78, 95% CI 0.46, 1.32). One of these studies (Finnegan 1984) reported that opiate treatment resulted in a significant reduction in treatment failure among infants of mothers who had used only opiates; however, as this was a post-hoc analysis, this result should be interpreted with caution. One study (Kandall 1983) reported a reduction in seizures, of borderline statistical significance, with the use of opiate. Opiate vs diazepam: Meta-analysis of two studies found a significant reduction in treatment failure (RR 0.43, 95% CI 0.23, 0.80) with the use of opiate. No study reported neurodevelopment by allocated treatment group. REVIEWER'S CONCLUSIONS: Opiates, as compared to supportive care only, appear to reduce the time to regain birth weight and reduce the duration of supportive care, but increase the duration of hospital stay; there is no evidence of effect on treatment failure. When compared to phenobarbital, opiates may reduce the incidence of seizures but, overall, there is no evidence of effect on treatment failure. When compared to diazepam, opiates reduce the incidence of treatment failure. A post-hoc analysis generates the hypothesis that treatment effects may vary according to whether the population includes infants born to all opiate users (i.e. with or without other drug exposure) or is restricted to infants of mothers who used opiates only. In view of the methodologic limitations of the included studies the conclusions of this review should be treated with caution. Further research is needed.

Humans↗

PubMed2002

Sleep deprivation, disorganization and fragmentation during opiate withdrawal in newborns.

OBJECTIVE: To determine specific sleep characteristics in neonatal opiate withdrawal, referred to as the Neonatal Abstinence Syndrome (NAS), by measuring sleep efficiency, deprivation, disorganization and fragmentation in three groups: (i) healthy term neonates; (ii) opiate-exposed neonates who were treated for opiate withdrawal; and (iii) a group of opiate-exposed neonates who did not require treatment. METHODS: A cohort study recording sleep patterns of neonates at 2-10 days of age (after 36 or more weeks of gestation) was carried out. Twenty-one neonates were exposed to opiates during pregnancy and 15 neonates were healthy controls. Sleep characteristics were predefined, and treated newborns were divided into early and stabilized treatment groups. Polygraphic recordings of sleep, movement and breathing were made continuously after a daytime feed. RESULTS: Sleep deprivation, disorganization and fragmentation were found in newborns with NAS and were associated with the severity of the withdrawal. Neonates treated for NAS displayed increased wakefulness during early treatment (deprivation), but were similar to controls once stabilized. Both treated and non-treated groups had reduced amounts of quiet sleep (deprivation). Treated newborns showed an increase in indeterminate sleep (disorganization) and arousals-to-wakefulness (fragmentation). CONCLUSION: This study determined the exact nature and degree of sleep disturbances in newborns during acute opiate withdrawal. The findings contribute to a further understanding of the physiology underlying neonatal opiate withdrawal and suggest that some changes in sleep are due to opiate withdrawal but others may reflect opiate dependency in utero.

Electroencephalography↗

PubMed2001

Airway protection following simulated gastro-oesophageal reflux in sedated and sleeping neonatal piglets during active sleep.

1. In infants, promethazine has been implicated in the pathogenesis of sleep apnoea, apparent life threatening events (ALTE) and the Sudden Infant Death syndrome (SIDS). The aim of the present study was to investigate, in a neonatal animal, the effects of a commonly used promethazine-containing medication on airway protective mechanisms and cardiorespiratory reflexes following simulated gastro-oesophageal reflux (GER) to different levels in the oesophagus and pharynx. 2. Physiological and radiographic recordings were made in 21 naturally sleeping (controls) and 21 sedated (1.5 mg/kg, p.o., promethazine) piglets. On 3 consecutive days physiological recordings were made in all piglets during active sleep. Gastro-oesophageal reflux was simulated by the injection of boluses of 0.5 mL HCl, pH 2 or 3, or NaCl (0.9%) at 37 degrees C into the pharynx, upper or lower oesophagus. 3. In healthy neonatal piglets, minimal sedation with promethazine, which did not affect behaviour during wakefulness, revealed previously unreported findings during active sleep. 4. The most significant effects were observed following simulated GER to the pharynx, with no effect observed in the lower oesophagus. In sedated piglets, compared with naturally sleeping piglets, there was a significant reduction in swallowing (P < 0.01), delayed radiological clearance of fluid (P < 0.05), a reduction in breathing rate, oxygen saturation and heart rate and an increase in apnoea. 5. These findings are consistent with a low dose of promethazine producing a significant attenuation of airway protective mechanisms and, thus, stimulation of the laryngeal chemoreflex. The results suggest a mechanism for the association observed between promethazine use and the occurrence of ALTE and SIDS. The results support continued caution and suggest the need for greater regulation of promethazine-containing medications in infants.

Animals↗

PubMed2000

The role of swallowing during active sleep in the clearance of reflux in term and preterm infants.

OBJECTIVES: To investigate swallowing and peristalsis in sleep and during gastroesophageal reflux (GER) in both healthy term and preterm infants at term equivalent age. STUDY DESIGN: Multichannel recordings were made in 12 healthy term and 11 preterm infants, under the same conditions, after feeding. Sleep state, cardiorespiratory variables, esophageal pH, and pharyngeal swallowing and peristalsis were measured. GER was defined as pH <4 for > or = 15 seconds, and swallows were classified as pharyngeal only, primary peristalsis (propagated, dropped, interrupted), or secondary peristalsis. RESULTS: Spontaneous swallowing rate was not significantly different between term and preterm infants and was sleep state-related, occurring in active sleep but rarely in quiet sleep. In response to acid GER, term infants significantly increased pharyngeal swallowing from a median of 0.7 (25th-75th interquartile range, 0.5-0.9) to 1.7 (1.0-3.0) swallows/min and secondary peristalsis from a median of 0.5 (25th-75th interquartile range, 0.3-0.8) to 1.1 (0.8-2.0) waves/min (P <.05). In contrast, the preterm infants demonstrated a significantly higher proportion of fully propagated peristaltic swallows compared with the term infants (53% and 27%, respectively) (P <.05). CONCLUSION: The occurrence of swallowing is sleep state-related. In active sleep, term infants clear GER by increasing swallowing and secondary peristalsis, whereas preterm infants at term equivalent age clear GER by increasing propagated peristalsis. This method of clearance would explain the mechanism by which preterm infants have significantly shorter episodes of reflux than term infants.

Deglutition↗

PubMed2000

Targeted early rescue surfactant in ventilated preterm infants using the click test.

OBJECTIVE: To determine whether use of the click test, a rapid bedside test of surfactant function, results in earlier and more appropriate surfactant administration in ventilated preterm infants than does usual early rescue treatment. STUDY DESIGN: Ventilated preterm infants (n = 126) with inspired oxygen >/=25% and mean airway pressure >/=7 cm H(2)O were randomized in gestational strata (<28 weeks and 28-36 weeks) to have surfactant therapy determined by the click test or by usual clinical and chest radiograph criteria. The treatment group had the click test performed on a tracheal aspirate as soon as possible after intubation and, if negative or equivocal (surfactant deficient), surfactant was given. The control group had surfactant given as soon as possible based on clinical and chest radiograph diagnoses of respiratory distress syndrome. RESULTS: In infants of <28 weeks' gestation, use of the click test resulted in significantly earlier surfactant therapy (median time: 50 vs 159 minutes) and a reduction in the number of infants receiving surfactant (48% vs 79%). In infants of 28 to 36 weeks' gestation, there was no difference in time to surfactant (median time: 300 vs 268 minutes) or in the number of infants receiving surfactant. Neonatal morbidity and mortality were similar in click test and control groups. CONCLUSIONS: Use of the click test in ventilated, extremely premature infants results in significantly earlier and more appropriately targeted administration of surfactant than does early rescue therapy based on clinical and radiograph criteria. A randomized trial of targeted early rescue surfactant therapy versus prophylactic surfactant therapy in infants of <28 weeks' gestation is warranted. The click test has the potential to improve clinical outcomes and reduce costs.

Diagnostic Techniques, Respiratory System↗

PubMed1999

Sedation with promethazine profoundly affects spontaneous airway protection in sleeping neonatal piglets.

1. Phenothiazine use in infants has been implicated in apparent life-threatening events, sleep apnoea and Sudden Infant Death Syndrome. 2. The aim of this study was to investigate the cumulative effects of a commonly used antihistamine medication containing promethazine on airway protective mechanisms and cardiorespiratory responses in 42 healthy neonatal piglets (21 naturally sleeping, 21 sedated sleeping). 3. Sedated piglets were given 1.5 mg/kg, p.o., promethazine 2 h prior to each recording session. Control animals slept naturally with no sedative given. On three consecutive days in all piglets, physiological recordings were made during sleep; on at least one of these days, simultaneous physiological and radiological observations were made. 4. Following sedation, sleep time and time in active sleep were increased significantly (P < 0.01). The spontaneous occurrence of swallowing, arousal, body movement, gastrooesophageal reflux and apnoea was compared between naturally and sedated sleeping piglets. Sedation with promethazine significantly decreased the spontaneous occurrence of swallowing (P < 0.05) and arousal (P < 0.05) and increased the occurrence of both central (P < 0.05) and obstructive sleep apnoea (P < 0.0001). 5. By the third day, a cumulative effect of promethazine was seen; the rate of swallowing and body movement significantly decreased (P < 0.01). 6. In summary, a low dose of promethazine profoundly altered sleep characteristics, airway protective mechanisms and cardiorespiratory responses in normal healthy sleeping piglets. Continued use of promethazine over several days may attenuate airway protective mechanisms to a potentially life-threatening degree. Our findings support continued caution in the use of promethazine-containing medications for the sedation of infants.

Animals↗

PubMed1999

Why the prone position is a risk factor for sudden infant death syndrome.

INTRODUCTION: The laryngeal chemoreflex may explain why prone sleeping increases the risk of sudden infant death syndrome (SIDS). Swallowing and arousal are crucial to prevent laryngeal chemoreflex stimulation. Our aim was to examine these reflexes and breathing responses in healthy neonates after pharyngeal infusion of water in the supine versus the prone position, controlling for sleep state. METHODS: A total of 10 term infants were recruited after parental consent and ethics approval. Polygraphic recordings included sleep state (active and quiet sleep by electroencephalogram, eye movements, breathing, and behavior), cardiorespiratory measurements (nasal airflow, chest wall movements, heart rate, and oxygen saturation), swallowing, and esophageal activity (solid state pressure catheter). Initial sleeping position was assigned randomly. Measurements were made for 1 minute before and after 0.4 mL of water was instilled into the oropharynx. To detect a 30% decrease in swallowing, power analysis indicated that >/=10 babies were required. Analysis, blinded to position, was made using nonparametric statistics. RESULTS: Of the 164 infusions, the most commonly evoked airway protective responses to pharyngeal infusion were swallowing (95%) and arousal (54%). After infusion in active sleep, there was a significant reduction in swallowing and breathing when the prone position was compared with the supine position (prone: 21.3 [1.0] swallows/min and -9.6 [2.1] breaths/min; and supine: 32 (2.2) and -2. 9 (1.5), respectively). However, there was no difference in the occurrence of arousal after water infusion. CONCLUSION: These data suggest that airway protection is compromised in the prone sleeping position during active sleep, even in healthy infants exposed to minute pharyngeal fluid volumes of 0.4 mL. This is because swallowing rate is reduced significantly, and there is no compensatory increase in arousal. The reduction in airway protective reflexes when in the prone position and in active sleep may be the mechanism for the increased risk of SIDS in the prone position.

Arousal↗

PubMed1998

Sleep states and neonatal pulse oximetry.

AIM: Pulse oximetry is a quick, easy, noninvasive method widely used for monitoring oxygen saturation (SaO2) in the neonatal period. The greatest recognized problem with SaO2 readings measured from the oximeter is artifact, arising from an inability to record accurately during movement. The aim of this study was to determine the proportion of pulse oximeter readings affected by movement artifact during sleep in term and preterm infants. METHOD: Polygraphic recordings were obtained from 11 term and 6 preterm infants at postconceptional ages (SD) of 39.8 (0.8) and 39.3 (1.5) weeks respectively. The polygraphic and computer recordings were divided into epochs of 30 seconds duration and identified as active sleep (AS), quiet sleep (QS), indeterminate sleep (IS), or wakefulness (AW), using electrophysiological parameters and behavioral observations. Movement artifact was identified by visual examination of polygraphic computer recordings using strict criteria. Signal containing artifact was removed from recordings and the percentage of artifact time present per recording calculated. RESULTS: Signal artifact was present in recordings of all infants studied, comprising an average state time of 19% during quiet sleep, 49% of active sleep, 49% of indeterminate sleep and 91% of wakefulness. A significant difference in the proportion of artifact present in recordings of term and preterm was observed only during quiet sleep. CONCLUSION: Movement artifact during pulse oximetry recordings is dependent on behavioral state, and overall affects up to 50% of recorded traces. A reliable and more accurate noninvasive method of recording oxygen saturation is thus needed, for use in both neonatal nurseries and in sleep studies, to aid in accurate clinical decision-making.

Female↗

PubMed1998

Interobserver reliability of the click test: a rapid bedside test to determine surfactant function.

OBJECTIVE: To determine the interobserver reliability of the click test, a rapid bedside test of surfactant function. METHODOLOGY: One hundred samples (48 amniotic fluid, 28 gastric aspirates, 24 tracheal aspirates) were obtained from pregnant women, term and preterm infants managed at two perinatal centres. Gestational ages of the pregnancies or infants at time of sampling ranged from 24 to 40 weeks (mean +/- s.d.: 31+/-5). The click test was performed independently by two observers, with differing levels of experience, and blinded to each other's results. Interobserver reliability was determined for samples classified as negative (no clicking bubbles), equivocal (a few clicking bubbles seen after 2 min of looking), and positive (clicking bubbles seen easily on first look). As negative and equivocal test results suggest surfactant dysfunction, these results were also combined to provide a dichotomised result. RESULTS: For samples classified as negative, equivocal and positive the interobserver agreement was 0.83, with agreement beyond chance shown by a quadratic weighted Kappa of 0.74 (95% CI = 0.62-0.86). When negative and equivocal results were combined, the simple Kappa was 0.73 (95% CI = 0.59-0.87). CONCLUSIONS: The click test has a high level of interobserver reliability. It is rapid, simple, accurate and able to be taught to medical and nursing staff with appropriate training. It has many potential applications including the prediction of fetal lung maturity in women with premature rupture of membranes, and in term and preterm infants who require the bedside testing of surfactant function.

Amniotic Fluid↗

PubMed1998

Early onset group B streptococcal neonatal infection in Oxford 1985-96.

Of 74,920 babies live born in Oxford between 1985 and 1996, 41 (0.5 per 1000 95% CI 0.4-0.7) developed definite, culture confirmed, early onset (< 48 hours) group B streptococcal infection and 32 (0.4 per 1000 95% CI 0.3-0.6) developed probable infection (sepsis plus colonisation). There was no significant variation in incidence with time. The mortality from definite infection was 19.5%, and from probable infection 6%. These data suggest that the incidence of group B streptococcal infection in Oxford is considerably lower than that reported in the USA.

Confidence Intervals↗

PubMed1998

Airway protection in sleeping infants in response to pharyngeal fluid stimulation in the supine position.

This study was designed to evaluate upper airway protective mechanisms in response to pharyngeal fluid stimulation in healthy term and preterm infants at term equivalent age. Five term and seven preterm infants were studied and the following recorded: sleep state, cardiorespiratory function, and swallowing. Infusions of 0.9% saline and sterile water of volumes of 0.04, 0.2, and 0.35 mL were made during active (AS) and quiet sleep (QS). The effect of these variables on apnea (> or = 2 and > or = 5 s), swallowing, and arousal was examined. After pharyngeal infusion, apnea of > or = 2 and > or = 5 s did not change from spontaneous rates for both term and preterm infants. The most common response to pharyngeal infusion was swallowing. In AS, swallowing occurred after 65 and 73% and in QS after 40 and 64% of infusions in term and preterm infants, respectively. Swallowing was volume-related and occurred significantly more often in term infants after larger infusions of 0.35 and 0.2 mL (83 and 67%) compared with the 0.04 mL (19%) and after 0.2 mL compared with 0.04 mL for preterm infants (94 and 44%). At 0.2 mL, this was significantly higher in preterm compared with term infants (p < 0.01) and was the only significant difference between these infants. In response to pharyngeal fluid stimulation, airway defense in both full-term and preterm infants is maintained primarily by swallowing with no evidence of apnea.

Deglutition↗

PubMed1998

Eight-year outcome of universal screening and intrapartum antibiotics for maternal group B streptococcal carriers.

OBJECTIVES: To report the outcome of intervention to reduce early-onset group B streptococcal disease (EOGBSD) at a tertiary maternity hospital in Sydney and to review all cases of EOGBSD since intervention to improve outcomes further. METHODOLOGY: A prospective study was made of all cases of EOGBSD in the 16 months before and 8 years after an intervention that comprised universal screening and intrapartum ampicillin for all maternal carriers of group B streptococcus. Carriers were detected by screening all women at 28 weeks, or 24 weeks with known risk factors for preterm birth, by low vaginal swab, cultured onto blood agar and treated with intravenous ampicillin in labor, 1 g every 6 hours until delivery. Women with a routine midstream urine test positive for group B streptococcus, a previous neonate with EOGBSD, or preterm labor with an unknown carrier status were also treated. EOGBSD was detected by screening all neonates with maternal and/or neonatal risk factors for sepsis. RESULTS: The incidence of blood culture-positive EOGBSD for all live births before intervention was 1.4 per 1000 compared with a rate after intervention of 0.2 per 1000 live births. The incidence, if there were clinical signs of infection and the urine tested positive for streptococcal antigen, decreased from 3.5 per 1000 before intervention to 0.6 per 1000 live births. There was a statistically significant reduction in neonatal morbidity outcomes after intervention, including requirement for admission and treatment in a neonatal unit and the need for ventilation. An audit indicated that by the 8th year, 90% of all pregnant women were screened by a low vaginal swab at 28 weeks and 10.5% were carriers. After intervention, of the 28 neonates with EOGBSD, 64% were associated with departure from the protocol. CONCLUSION: The intervention has coincided with a significant decrease in the incidence of blood culture-positive EOGBSD to 0.2 and urine streptococcal antigen-positive disease to 0. 6 per 1000 live births. The 84% reduction in EOGBSD has been obtained by treating 244 neonates in labor to prevent disease in one neonate. Additional reduction seems possible by improving the compliance by staff with the protocol. By contrast, before intervention and in maternity units throughout Australia with no intervention, the rates for EOGBSD remain largely unchanged at approximately 2 per 1000 live births.

Adult↗

PubMed1997

Prediction of surfactant dysfunction in term infants by the click test.

Pulmonary surfactant dysfunction (inactivation, deficiency) has been implicated in term neonates with respiratory failure. This study has evaluated the click test, a biophysical test for surfactant function, which will be useful in rapidly and reliably identifying term neonates with surfactant dysfunction. Samples of tracheal and or gastric aspirates (0.2 ml) from 55 neonates, varying from 36 to 42 weeks of gestational age, with respiratory distress and fractional inspired oxygen concentration requirements of > 0.5 were shaken with 95% ethanol. Once bubbles formed the samples were examined in air-free water under a microscope. In a positive click test, the bubbles rhythmically increase and then decrease in size, denoting the presence of active surfactant. When few bubbles were observed, the specimen was labelled as equivocal, and if none were seen, it was called negative. Surfactant dysfunction (negative or equivocal test) was consistently seen in respiratory distress syndrome (RDS), transient tachypnea of the newborn, and severe meconium aspiration syndrome (MAS). Preliminary data suggest that the click test will provide a rapid and early diagnosis of surfactant dysfunction in term neonates. This should facilitate early treatment with exogenous surfactant in RDS, by early diagnosis of surfactant deficiency, and provide justification for immediate and ongoing surfactant treatment in newborns with MAS. The click test can provide a diagnostic tool for surfactant dysfunction and deficiency in randomized controlled trials of therapy in those disease states in which exogenous surfactant therapy may be useful.

Biophysical Phenomena↗

PubMed1996

Competency-based learning in neonatology.

An educational model integrating structured teaching with clinical experience, or clerkship, has been designed to enable students to learn the core knowledge, skills and attitudes necessary to care for the newborn. The programme is run for fifth year medical students as part of four, 9-week periods in Obstetrics and Gynaecology each year. A SCORPIO teaching session is held in week 1 to introduce students to the core competencies in the subject areas of newborn examination, breastfeeding, resuscitation, respiratory distress and anthropometry. Groups of four students rotate through each topic, which is conducted by a neonatologist or registrar in training. Eight problem-based learning sessions are held during weeks 2-9. Several students assess a clinical problem, identify learning issues and meet colleagues and a facilitator to share their learning experiences and resolve the problem. The clinical experience, or clerkship, is based in the neonatal nursery where 2-3 students spend a week consolidating their clinical and procedural skills. A study group was assessed at the end of the programme by an Objective Structured Clinical Examination (OSCE) and a Multiple Choice Questionnaire (MCQ). A control group did the same assessment in week 1. All students were asked to rate the educational value of the three learning methods on a 5-point Likert scale. The study group (n = 20) achieved a mean composite mark of 66% (SD 10%). This was significantly higher (P < 0.001) than that of the control group (n = 18), mean 45% (SD 7%). All students (100%) rated the educational value of SCORPIO as high or very high, and the comparative rating for problem-based learning and clerkship was 65%, respectively. The programme was enthusiastically received by the students and resulted in mastery of a range of core competencies necessary for care of the newborn.

Australia↗

PubMed1996

Factors affecting the neonatal response to artificial surfactant.

OBJECTIVE: To define the individual neonatal response to the artificial surfactant, Exosurf, and factors that may influence the response. METHODOLOGY: Eighty-two consecutive, preterm neonates with respiratory distress syndrome, who received Exosurf at < 12 h of age were studied. Their response was categorized from the graphical change in the oxygenation index with postnatal age, for 12 h after each of two doses of surfactant and assessed independently by two observers. Clinical factors were analysed for their effect on the four pre-defined categories of response, namely: none; mild; good: relapsed; and good: sustained. RESULTS: Within the first 12 h, 11% of the neonatas showed no response, 5% a mild response and 84% a good response, but 34% relapsed. By 24 h, 6% still showed no response (all died), 11% showed a mild response and 83% a good response, of whom half relapsed. At 24 h, no response was significantly associated with low gestational age and asphyxia, mild response with less severe lung disease. According to the response there was a gradation in the risk of death during the first week. CONCLUSIONS: The response to Exosurf can be individually and reproducibly categorized and demonstrated that 83% of neonates had a good response but half relapsed. No response was associated with extreme prematurity and asphyxia.

Administration, Inhalation↗

PubMed1995

Physiological studies of gastro-oesophageal reflux and airway protective responses in the young animal and human infant.

1. The mechanisms that underlie the Sudden Infant Death Syndrome (SIDS) must explain its two unique features; age at death and death during apparent sleep. 2. The occurrence of gastro-oesophageal reflux (GOR) during active sleep in infants presenting with apparent life threatening episodes (ALTE) and their similar age distribution to SIDS infants, suggested that reflux could be a cause of asphyxia. 3. Sleep related GOR was found to be a physiological and not a pathological event in normal, healthy term infants. 4. In healthy term infants, those infants that were formula-fed (who have a higher incidence of SIDS) had significantly longer oesophageal clearance times for acid reflux and significantly more active sleep compared with breast fed infants. 5. In very preterm infants (who are at increased risk for SIDS), both the frequency and duration of reflux during active sleep was significantly less at term equivalent age compared with healthy term infants, suggesting additional factors must operate to promote an ALTE. 6. One mechanism which may explain the pathogenesis of GOR could be that the reflux reaches the level of the pharynx and this, in turn, stimulates laryngeal receptors to produce apnoea. 7. Simulated reflux to the level of the pharynx in the sleeping piglet evoked airway protective responses, namely swallow, arousal and occasionally expectoration, but neither apnoea nor oxygen desaturation. 8. In the same piglets treated with pentobarbitone sodium, swallowing was impaired and arousal depressed. Simulated reflux to the pharynx produced significant apnoea and oxygen desaturation and death in two of five piglets.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Factors that influence the choice of infant feeding.

UNLABELLED: To consider some of the many factors that influence the choice to initiate and continue breast-feeding. CONCLUSION: There is increasing recognition of the nutritional value and related health outcomes of breast-fed infants. Further research is essential to appraise the medical and social determinants of infant feeding practices, particularly the early discontinutation of breast-feeding. Paediatricians are in an ideal position to foster, encourage and support such research and to accept a wider role in advocacy of the infant's right to obtain optimal nutrition.

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