High fractional exhaled nitric oxide and sputum eosinophils are associated with an increased risk of future virus-induced exacerbations: A prospective cohort study.

BACKGROUND: The major trigger of asthma exacerbations is infection with a respiratory virus, most commonly rhinovirus. Type 2 inflammation is known to be associated with an increased risk of exacerbations in general. Whether type 2 inflammation at baseline increases the risk of future virus-induced exacerbations is unknown. OBJECTIVE: To assess whether type 2 inflammation is associated with an increased risk of virus-induced exacerbations of asthma. METHODS: Stable asthmatics had spirometry, skin prick test, measurement of FeNO and sputum induced for differential cell counts. Patients were followed up for 18 months, during which they were assessed at the research unit when they had symptoms of an exacerbation. Nasal swabs collected at these assessments underwent viral detection by PCR. RESULTS: A total of 81 asthma patients were recruited, of which 22 (27%) experienced an exacerbation during the follow-up period. Of these, 15 (68%) had a respiratory virus detected at exacerbation. Sputum eosinophils >1% at baseline increased the risk of having a subsequent virus-induced exacerbation (HR 7.6 95% CI: 1.6-35.2, P=.010) as did having FeNO >25 ppb (HR 3.4 95% CI: 1.1-10.4, P=.033). CONCLUSION AND CLINICAL RELEVANCE: Established type 2 inflammation during stable disease is a risk factor for virus-induced exacerbations in a real-life setting. Measures of type 2 inflammation, such as sputum eosinophils and FeNO, could be included in the risk assessment of patients with asthma in future studies.

Lower anti-echovirus antibody responses in children presenting to hospital with asthma exacerbations.

BACKGROUND: Rhinoviruses from the Enterovirus genus cause frequent infections and induce remarkably high titres of anticapsid antigen antibodies in asthmatics, while the prevalence of neutralising antibodies to the gut-trophic echoviruses from the same genus is diminished. OBJECTIVE: To assess the absolute and specific antibody titres to VP1 antigens of the gut-trophic enteroviruses, echovirus 30 and Sabin 1 poliovirus, in asthmatic and non-asthmatic children. METHODS: Recombinant polypeptides representing the VP1 capsid antigens of echovirus 30 and Sabin poliovirus 1 were produced. Their ability to bind IgG1 antibodies from the plasma of asthmatic (n = 45) and non-asthmatic (n = 29) children were quantitated by immunoassays that incorporated immunoabsorptions to remove cross-reactivity. RESULTS: The IgG1 antibody titres and prevalence of antibody binding to echovirus 30 were significantly lower for asthmatic children compared to controls (P < 0.05) and inversely correlated with total IgE levels for the whole study population (r = -0.262; P < 0.05). There was no difference in the prevalence and titre between groups to the VP1 antigen of Sabin poliovirus. Anti-tetanus toxoid titres measured for comparison did not correlate with anti-echovirus or poliovirus, but correlated with anti-rhinovirus titres in controls but not asthmatics, where the titres were higher for the asthmatic group. CONCLUSIONS AND CLINICAL RELEVANCE: The associations of lower antibody titres of asthmatic children to echovirus reported here and those of our previous findings of a heightened response to rhinovirus suggest a dichotomy where respiratory enterovirus infection/immunity increases the probability of developing asthma and enteric infections lower the risk. This provides further support for the concept of intestinal infection playing a key role in the development of allergic respiratory disease.

Association between human rhinovirus C and severity of acute asthma in children.

A new and potentially more pathogenic group of human rhinovirus (HRV), group C (HRVC), has recently been discovered. We hypothesised that HRVC would be present in children with acute asthma and cause more severe attacks than other viruses or HRV groups. Children with acute asthma (n = 128; age 2-16 yrs) were recruited on presentation to an emergency department. Asthma exacerbation severity was assessed, and respiratory viruses and HRV strains were identified in a nasal aspirate. The majority of the children studied had moderate-to-severe asthma (85.2%) and 98.9% were admitted to hospital. HRV was detected in 87.5% and other respiratory viruses in 14.8% of children, most of whom also had HRV. HRVC was present in the majority of children with acute asthma (59.4%) and associated with more severe asthma. Children with HRVC (n = 76) had higher asthma severity scores than children whose HRV infection was HRVA or HRVB only (n = 34; p = 0.018), and all other children (n = 50; p = 0.016). Of the 19 children with a non-HRV virus, 13 had HRV co-infections, seven of these being HRVC. HRVC accounts for the majority of asthma attacks in children presenting to hospital and causes more severe attacks than previously known HRV groups and other viruses.

The importance of environment on respiratory genotype/phenotype relationships in the Inuit.

BACKGROUND: Genetic and environmental influences and their interactions are central to asthma pathogenesis. This study aimed to investigate the effects of different macro-environments on asthma genotype-phenotype associations in two geographically separated populations with common ancestry. METHODS: To accomplish this, two unselected populations of Inuit were recruited, one living in Greenland (n = 618) and the other in Denmark (n = 739). Subjects were genotyped for CD14 C-159T, SCGB1A1 A38G, ADRB2 Arg16Gly and Gln27Glu. The resulting genetic data were analysed for relationships with asthma-related parameters including lung function, ever asthma, atopy, rhinitis and dermatitis. RESULTS: The results showed contrasting magnitude and direction of genetic associations between the two geographically separate Inuit populations. In Greenland, the ADRB2 16Arg allele was associated with male-specific lower lung function, but in Denmark the same allele was associated with male-specific higher lung function. This allele was also associated with higher incidence of ever asthma in Denmark but not in Greenland. The SCGB1A1 38A allele was associated with lower rhinitis prevalence in Greenland but not in Denmark. CONCLUSIONS: These associations suggest that environment interacts with candidate asthma genes to modulate asthma pathogenesis in the Inuit.

Investigations into the role of ST2 in acute asthma in children.

The ST2 gene is a member of the interleukin-1 receptor family and is located on chromosome 2q12, an area of the genome that has been associated with asthma. The soluble product of the ST2 gene, serum ST2 (sST2), has previously been shown to be elevated in adult asthmatic patients. This study investigated the potential role of ST2 in children with acute asthma. Children aged 2-16 years (n = 186) were recruited on presentation with acute asthma in the emergency department. Blood was obtained on presentation and during convalescence. Variables assessed included sST2 levels, a comprehensive assembly of clinical parameters and two polymorphisms in the ST2 gene, -26999G/A, located in the distal promoter region, and ala78glu polymorphism, on exon 3. The A allele of the -26999G/A polymorphism occurred more frequently in asthmatics compared with an unselected control group (P = 0.031). Serum ST2 levels were substantially higher during acute asthma compared with levels after the attack: 0.29 ng/ml (95% confidence interval: 0.23-0.36) and 0.14 ng/ml (0.12-0.17), respectively (P = 0.001) and were inversely related to eosinophil counts during an acute asthma attack (P = 0.002). The -26999AA genotype, as well as the AC haplotype, was associated with asthma severity scores (P = 0.05 and 0.02) compared with the -26999GA and GG genotypes. Serum ST2 levels were not associated with any of the studied genotypes or haplotypes. The observed associations of ST2 genotypes and haplotypes with acute asthma and asthma severity scores as well as the phenotypic differences associated with ST2 polymorphisms suggest that ST2 may play a role in the pathophysiology of asthma.

Cross-sectional and longitudinal association of the secretoglobin 1A1 gene A38G polymorphism with asthma phenotype in the Perth Infant Asthma Follow-up cohort.

BACKGROUND: Associations between Clara cell secretory protein gene variants (SCGB1A1, also known as CC16, CC10, CCSP and uteroglobin) and the asthma phenotype have been found in five out of eight studies world-wide. No study has investigated the contribution of SCGB1A1 polymorphisms to the development and/or persistence of the asthma phenotype in a birth cohort followed over time. OBJECTIVE: The aim of this study was to determine the role of the SCGB1A1 gene in the development of the asthma phenotype. METHODS: The Perth Infant Asthma Follow-up (PIAF) cohort (n=231 unrelated infants, unselected for asthma and recruited at birth) were seen at 1 month, 6 and 11 years of age, and had a questionnaire, lung function, airway responsiveness (AR) and skin prick tests (SPTs) completed. Blood was taken at 6 and 11 years for total and specific immunoglobulin E (sIgE) and DNA extraction. SPT positivity had at least one positive SPT. SIgE>4 kU/L had at least one sIgE above 4 kU/L. SCGB1A1 A38G (rs3741240), that alters gene transcription, was genotyped using Sau96I restriction digestion of exon 1 PCR products. RESULTS: At 6 and 11 years of age, 33.0% and 29.7% of those genotyped had doctor-diagnosed asthma, and 35.8% and 52.1% had SPT positivity. In cross-sectional analyses, children with 38G/38A or 38A/38A had increased AR at 1 month (1.72-fold, P=0.013); sIgE>4 kU/L [odds ratio (OR)=6.95, 95% confidence interval (CI)=1.35-35.91, P=0.021]; house dust mite (HDM) SPT positivity (OR=7.21, 95% CI=1.09-47.78, P=0.041) and sIgE (4.57-fold, P=0.045) at 6 years; and doctor-diagnosed asthma (OR=3.93, 95% CI=1.24-12.47, P=0.02) and cat SPT positivity (OR=4.34, 95% CI=1.01-18.77, P=0.049) at 11 years. Longitudinal analyses of 6 and 11 years paired data showed that children with 38A/38A had increased persistent sIgE>4 kU/L (OR=11.87, 95% CI=1.97-71.53, P=0.007) and persistent HDM SPT positivity (OR=7.84, 95% CI=1.04-58.92, P=0.045). CONCLUSION: SCGB1A1 A38G may play a role in the development and persistence of the asthma phenotype in childhood.

Anti-bacterial IgE in the antibody responses of house dust mite allergic children convalescent from asthma exacerbation.

BACKGROUND: Atopic sensitization to the house dust mite (HDM) is associated with altered antibody responses to the nasopharyngeal colonizing bacterium Haemophilus influenzae and children admitted to the emergency department for asthma exacerbation have reduced IgG responses to HDM allergens. OBJECTIVE: To investigate anti-bacterial and anti-allergen antibody responses during convalescence from asthma exacerbation and differences found in exacerbations associated with and without viral infection. RESULTS: IgE antibodies to the P6 bacterial antigen increased in 60% of sera during convalescence and for many children achieved titres as high as IgE titres to allergens. In contrast IgE anti-HDM titres declined during convalescence. The anti-bacterial IgE titres were the same in subjects with and without virus infection while the anti-HDM IgE declined more rapidly in virus-infected subjects. IgG titres to the major HDM allergens showed no consistent increase and the overall IgG anti-HDM titres even declined in subjects without a virus infection. Anti-bacterial IgG antibodies in contrast to IgE did not change. Patients with frequent episodic or persistent asthma had similar IgE anti-bacterial titres to patients with infrequent asthma during the acute phase, although they had reduced IgG titres to both the bacteria and the HDM. CONCLUSIONS: During the period following an acute exacerbation of asthma there was a marked and specific increase in anti-bacterial IgE compared with a reduced IgE response to HDM. This provides further support for the concept of T-helper type 2 responses to bacterial antigens playing a role in asthma pathogenesis.

Association of haplotypes of beta2-adrenoceptor polymorphisms with lung function and airway responsiveness in a pediatric cohort.

We evaluated the influence of haplotypes of beta(2)-adrenergic receptor (ADRB2) polymorphisms on lung function and airway responsiveness (AR) in a pediatric cohort recruited before birth and followed up to 11 years of age. The subjects (180) were the participants in a prospective study of lung function and AR. They have been assessed five times (at 1 month, 6 months, 12 months, 6 and 11 years of age) for lung function and AR. The two ADRB2 single nucleotide polymorphisms (SNPs): Arg16Gly and Gln27Glu were genotyped by PCR-RLFP and their haplotypes inferred using the program PHASE. An association between the haplotype arg16gln27 and the prevalence of positive AR was found at age 6 years (P = 0.009). The gly16gln27 haplotype was associated with higher FEV1 (P = 0.015) at age 6 and both higher FEV1 and FVC (P = 0.018 and P = 0.001, respectively) at age 11. In contrast, arg16gln27 was associated with both lower FEV1 and FVC (P = 0.028 and P = 0.011, respectively) at age 11. Children with the gly16gln27 haplotype were less likely to have asthma-ever or doctor-diagnosed asthma at age 11 (OR: 0.38; P = 0.019 and OR: 0.31; P = 0.041, respectively). In conclusion, haplotypes of beta(2)-adrenoceptor polymorphisms are associated with lung function, AR, and asthma susceptibility in childhood.

CD14 C-159T and early infection with Pseudomonas aeruginosa in children with cystic fibrosis.

Early acquisition of Pseudomonas aeruginosa is associated with a poorer prognosis in patients with cystic fibrosis. We investigated whether polymorphisms in CD14, the lipopolysaccharide receptor, increase the risk of early infection. Forty-five children with cystic fibrosis were investigated with annual bronchoalveolar lavage (BAL) and plasma sCD14 levels. Plasma sCD14 levels were significantly lower in children from whom P.aeruginosa was subsequently isolated (492.75 microg/ml vs. 1339.43 microg/ml, p = 0.018). Those with the CD14 -159CC genotype had a significantly increased risk of early infection with P.aeruginosa suggesting that CD14 C-159T plays a role in determining the risk of early infection with P.aeruginosa.

How has research in the last five years changed my clinical practice?

Although the practice of neonatology is increasingly evidence based, much of our assessment and treatment of newborn infants is still founded on experience, common sense, guesswork, and myth. Research may put a particular issue beyond dispute, but it often raises new questions. This review looks at the benefits of research in one area: temperature control.

Reliability of clinical assessments of respiratory system compliance (Crs) made by junior doctors.

OBJECTIVE: To assess the reliability of estimates of static respiratory system compliance (Crs) made by junior hospital doctors caring for ventilated newborn infants. DESIGN: A prospective comparison of junior doctors' estimates of Crs to the Crs measured immediately afterwards. SETTING: A regional neonatal intensive care nursery in Edinburgh, Scotland. PATIENTS: 46 ventilated newborn infants. MEASUREMENTS AND RESULTS: Crs was estimated by three grades of junior doctor (Senior House Officer, Registrar and Research Fellow) using two different methods, (i) based on visual assessment of tidal volume in relation to inflation pressure (optical Crs) and (ii) directly using a visual analogue scale (analogue Crs). The Crs was then measured immediately afterwards using the single breath passive expiratory flow technique. The differences between the estimates and the measurements were calculated for each grade of observer and plotted against the corresponding measurements. The relationship between estimates and measurements was also expressed in terms of the coefficients of determination r2 calculated by least squares regression. With both methods of estimation observers tended to overestimate the Crs of infants with lower measured Crs and underestimate that of infants with higher measured Crs with many estimates differing from the measurements by more than 50%. Values of r2 ranged from 0.086 to 0.481 indicating a weak relationship between the estimates and the measurements. CONCLUSIONS: Junior doctors' estimates of Crs were unreliable and did not represent a useful method of assessing respiratory function. The clinical use of compliance measurements merits wider evaluation.

Follow up care of bereaved parents after treatment withdrawal from newborns.

OBJECTIVE: To explore parents' experiences of bereavement care after withdrawal of newborn intensive care. DESIGN: Face to face interviews with 108 parents of 62 babies born over two calendar years in the East of Scotland. RESULTS: Only 22% were seen by six weeks after the death, 10% were not recalled before 6-11 months, and 8% were not seen at all in the first year. All except one couple saw the neonatologist who had cared for their baby. Only 33% remembered a neonatal nurse being present. Most (88%) were seen in the study hospital. Parents highlighted a number of specific needs. Appointments should be: (a) scheduled soon after the death of the baby and certainly within two months of the death irrespective of whether or not autopsy results are available; (b) with the named neonatologist; (c) in a setting away from the hospital if possible. Parents value: (a) efforts to find out how they are coping; (b) full frank information given sensitively to enable them to build up a cohesive picture of what happened and assess their future risks; (c) reassurance where possible, but half truths, false reassurances, and broken promises are unacceptable. CONCLUSIONS: Follow up care is a crucial part of the management of families from whose babies treatment has been withdrawn. Resources devoted to it should be re-examined to provide a service more in tune with parental need. In choosing the place, timing, and conduct of the meeting, staff should be sensitive to the expressed wishes of the parents themselves.

Effect of absent end diastolic flow velocity in the fetal umbilical artery on subsequent outcome.

Sixty babies, delivered over a six and a half year period, who had absent end diastolic frequency (AEDF) in the umbilical artery, were studied. Individually matched control pregnancies for gestational age, birth-weight, maternal clinical condition and date of delivery, in whom umbilical artery recordings showed end diastolic frequency, were also studied. Matching was achieved in 36 cases. Neonates from case pregnancies showed no increase in necrotising enterocolitis, intraventricular haemorrhage, pneumothorax, neonatal death or bronchopulmonary dysplasia. However, they were significantly less likely to require ventilation for respiratory distress syndrome (P = 0.02). Although AEDF indicates a fetus under vascular stress, this finding alone will include a spectrum of response in the baby, from the well compensated to the irreversibly damaged. Delivery at different points in the deteriorating fetal environment may explain discrepant study results. This intrauterine stress, by increasing fetal corticosteroid and thyroid hormones, may account for enhanced lung maturity. Predictions of neonatal course need to be based on more comprehensive awareness of fetal status.

A comparison of transcutaneous bilirubinometers: SpectRx BiliCheck versus Minolta AirShields.

BACKGROUND: Two devices are available for making transcutaneous estimates of serum bilirubin (SBR): the Minolta AirShields JM102 and the new SpectRx BiliCheck. OBJECTIVES: (a) To measure how well the readings produced by these devices agree with SBR measured in the laboratory; (b) to estimate for each device, the proportion of infants with clinical jaundice who would require blood sampling if the device was used as a screening tool to detect infants with SBR > or = 250 micromol/l. DESIGN: Prospective cohort study of jaundiced infants who required SBR at < or = 20 days of postnatal age. Those who had received phototherapy or exchange transfusion were excluded. SETTING: Tertiary neonatal service in South-East Scotland. INTERVENTIONS: Within 30 minutes of SBR sampling, transcutaneous bilirubinometry was performed using one Minolta and two SpectRx devices (designated A and B). RESULTS: Sixty-four neonates were enrolled, 19 of which were preterm (31-35 weeks). The 95% confidence intervals of a device reading corresponding to SBR were +/- 66.7, +/- 67.9, and +/- 66.4 micromol/l respectively. Using the devices to identify all SBR > or = 250 micromol/l would reduce SBR sampling by 23%, 16%, and 20% respectively. CONCLUSIONS: Given that SBR levels range from 50 to 400 micromol/l in jaundiced infants, the 95% confidence intervals of the devices are wide at +/- 67 micromol/l. The SpectRx can be used as a screening tool for hyperbilirubinaemia but there is no advantage in using it over the Minolta.

Randomised controlled trial of respiratory system compliance measurements in mechanically ventilated neonates.

AIM: To determine whether outcomes of neonatal mechanical ventilation could be improved by regular pulmonary function testing. METHODS: Two hundred and forty five neonates, without immediately life threatening congenital malformations, were mechanically ventilated in the newborn period. Infants were randomly allocated to conventional clinical management (control group) or conventional management supplemented by regular measurements of static respiratory system compliance, using the single breath technique, with standardised management advice based on the results. RESULTS: Fifty five (45%) infants in each group experienced one or more adverse outcomes. The median (quartile) durations of ventilation and oxygen supplementation were 5 (2-12) and 6 (2-34) days for the control group, and 4 (2-9) and 6 (3-36) days for the experimental group (not significant). On post-hoc secondary analysis, control group survivors were ventilated for 1269 days with a median (quartile) of 5 (2-13) days, and experimental group survivors were ventilated for 775 days with a median (quartile) duration of 3 (2-8) days (p = 0.03). CONCLUSIONS: Although primary analysis did not show any substantial benefit associated with regular measurement of static respiratory system compliance, this may reflect a type II error, and a moderate benefit has not been excluded. Larger studies are required to establish the value of on-line monitoring techniques now available with neonatal ventilators.

Consent to autopsy for neonates.

OBJECTIVES: To determine parents' views on autopsy after treatment withdrawal. DESIGN: Face to face interviews with 59 sets of bereaved parents (108 individual parents) for whose 62 babies there had been discussion of treatment withdrawal. RESULTS: All except one couple were asked for permission for postmortem examination; 38% refused. The main reasons for declining were concerns about disfigurement, a wish to have the child left in peace, and a feeling that an autopsy was unnecessary because the parents had no unanswered questions. The diagnosis, the age of the child, and the approach of the consultant appeared to influence consent rates. Of those who agreed to autopsies, 92% were given the results by the neonatologist concerned. Whether or not they had agreed to the procedure, at 13 months no parent expressed regrets about their decision. CONCLUSIONS: Autopsy rates in the East of Scotland stand at 62%. Parents' perceptions are an important element in consent to postmortem examination.

Static respiratory compliance in the newborn. III: Early changes after exogenous surfactant treatment.

Static respiratory system compliance (Crs) was measured by a single breath passive expiratory flow technique in 73 newborn infants treated with exogenous surfactant. The first 39 received Curosurf, a natural porcine surfactant. The other 34 received Exosurf Neonatal, a synthetic surfactant. All had a diagnosis of respiratory distress syndrome with an arterial/alveolar oxygen ratio < 0.22. Static Crs and arterial blood gases were measured shortly before, and at three and 12 hours after the first dose of surfactant. In 32 infants treated with Curosurf with initial static Crs < 1.8 ml/cm H2O/m body length, which is consistent with surfactant deficiency, static Crs improved by 18% at three hours and by 39% at 12 hours along with a median reduction in fractional inspired oxygen (FIO2) at three hours by 0.32. In 26 infants treated with Exosurf with initial Crs < 1.8 ml/cm H2O/m, Crs did not improve three and 12 hours after treatment and oxygenation improved less than after Curosurf, with a median reduction in FIO2 at three hours of 0.11. Fifteen of the 73 (21%) infants had initial static Crs of > or = 1.8 ml/cm H2O/m, not consistent with surfactant deficiency. Thirteen of these 15 infants showed a fall in static Crs after surfactant treatment, raising the question whether exogenous surfactant did them more harm than good. Initial static Crs and surfactant type both appear to determine the early response to the first dose of surfactant. Only a considerably larger, randomised study can show which surfactant is more effective in reducing adverse clinical outcome.

Prevention of subglottic stenosis in neonatal ventilation.

Mechanical ventilation of the newborn is now widely used in neonatal intensive care. The oro-tracheal route of intubation is simpler, but for long-term ventilation has been considered unstable. A method of fixation of oro-tracheal tubes is described which overcomes this instability. Five hundred consecutive ventilated infants were intubated by the oro-tracheal route and the tube was fixed by the method described. Of the 500 ventilated infants, 213 died without being extubated. Of the 287 survivors, 44 developed a degree of post-extubation stridor. No surviving infant developed clinical evidence of subglottic stenosis and in almost 200 postmortem examinations laryngeal narrowing was not identified. The method of oro-tracheal fixation described is stable and may reduce the incidence of subglottic stenosis.

As time goes by.

The timing of birth-related events may influence neonatal outcome and is often pivotal in medicolegal cases. This prospective observational study determined the variation in displayed time on timepieces in a regional maternity unit which could result in inaccuracies of time documentation. The mean (95% CI) difference between time displayed and true time was sec (+/- 2 min 4 sec) for delivery room clocks and +1 m 8 s (+/- 7 m 12 s) for resuscitation room clocks. The maximum discrepancy between delivery room and resuscitation room clocks was 7 m 52 s. The abilities of staff to estimate the duration of time passed was also assessed. The mean (95% CI) five-minute estimate was 4 m 52 s (+/- 3 m 12 s). These disparities could have considerable medicolegal significance, and should be taken into consideration in risk management studies. Maternity units should move towards synchronising all timepieces. Meanwhile, statements about the precise timing of events should be regarded with suspicion.

Transcutaneous bilirubinometry as a screening tool for neonatal jaundice.

Between 25 and 50% of all term newborns develop clinical jaundice, and a serum bilirubin level above 260 microml/l (15 mg/dl) is found in 3% of normal term infants. In the United Kingdom many newborn infants with clinical jaundice have blood samples sent to biochemistry laboratories for assessment of the plasma bilirubin concentration. We planned to assess the cost in terms of finance, medical staff time, numbers of blood samples, and family delay in leaving hospital. We demonstrated that reflectance bilirubinometry is a reliable screening method for identifying which caucasian infants require to have plasma bilirubin concentrations measured in the laboratory. The Minolta Airshields transcutaneous bilirubinometer provided reproducible data, saved time and costs, and often spared infants a capillary or venous blood sample. The transcutaneous bilirubinometer provides a digital assessment of skin pigmentation by xenon reflectance. It has previously been shown to be possible to derive an estimate of plasma bilirubin from the number displayed by the meter and it is suggested as a method for identifying which infants need plasma bilirubin estimations.