Phototherapy device effectiveness in Nigeria: irradiance assessment and potential for improvement

This study investigated the effectiveness of simple-to-implement adjustments of phototherapy devices on irradiance levels in a cross-section of Nigerian hospitals. A total of 76 phototherapy devices were evaluated in 16 hospitals while adjustments were implemented for a subset of 25 devices for which consent was obtained. The mean irradiance level was 7.6 ± 5.9 µW/cm(2)/nm for all devices prior to adjustments. The average irradiance level improved from 9.0 µW/cm(2)/nm to 27.3 µW/cm(2)/nm for the adjusted group (n = 25) compared with 6.8 ± 5.4 µW/cm(2)/nm for the unadjusted group (n = 51). Simple, inexpensive adjustments to phototherapy devices with sub-optimal irradiance levels can significantly improve their effectiveness to acceptable international standards and should be widely promoted in resource-constrained settings.

The effect of hematocrit on the efficacy of phototherapy for neonatal jaundice

BACKGROUND

The therapeutic phototherapy action spectrum ranges from 420 to 500 nm. However, a recent report of improved efficacy of fluorescent "turquoise" light (~490 nm) as compared with blue light (~450 nm) underscores the need to define an optimal action spectrum for precision-targeted phototherapy using very narrow wavelength ranges.

METHODS

We used a current semi-empirical model of the optical properties of skin for robust calculations of the fraction of light absorbed by bilirubin at various wavelengths that could be confounded by hemoglobin (Hb), melanin, and skin thickness. Applying assumptions regarding the wavelength dependence of bilirubin photochemistry, "action spectra" were assembled from the calculated values.

RESULTS

All the calculated action spectra displayed a peak between 472 and 480 nm (most at 476 nm), which is a significant shift from the well-reported 460 nm absorption peak of bilirubin. Of note, the relative amplitudes of the action spectra showed an inverse relationship with hematocrit (Hct).

CONCLUSION

We speculate that a narrow range of light at 476 nm would be 60% more effective than blue (broadband) fluorescent lamps. Because Hb serves as a major competitor of bilirubin for light absorption, the calculations also predict that the efficacy of phototherapy is dependent on the Hct. A high Hct could reduce therapeutic efficiency.

Predischarge screening for severe neonatal hyperbilirubinemia identifies infants who need phototherapy

OBJECTIVE

To test whether the combined use of total plasma/serum bilirubin (TSB) levels and clinical risk factors more accurately identifies infants who receive phototherapy than does the use of either method alone.

STUDY DESIGN

We recruited healthy infants of ≥35 weeks' gestation at 6 centers that practiced universal predischarge TSB screening. Transcutaneous bilirubin (TcB) was measured at 24 hours, with TSB at 24-60 hours and at 3- to 5- and 7- to 14-day follow-up visits. Clinical risk factors were identified systematically.

RESULTS

Of 1157 infants, 1060 (92%) completed follow-up, and 982 (85%) had complete datasets for analysis. Infant characteristics included 25% were nonwhite and 55% were Hispanic/Latino; >90% were breastfed. During the first week, jaundice was documented in 84% of subjects. Predischarge TSB identified the 41 (4.2%) and 34 (3.5%) infants who received phototherapy before and after discharge, respectively. Prediction of postdischarge phototherapy was similar for combined clinical risk factors (earlier gestational age [GA], bruising, positive direct antiglobulin test, Asian race, exclusive breastfeeding, blood type incompatibility, jaundice extent) and age-adjusted TSB (area under the curve [AUC] = .86 vs .87), but combined screening was better (AUC = .95). TcB/TSB combined with GA alone was equally predictive (AUC = .95; 95% CI .93-.97).

CONCLUSIONS

Jaundice is present in 4 of 5 (84%) healthy newborns. Predischarge TcB/TSB (adjusted for postnatal age) combined with specific clinical factors (especially GA) best predicts subsequent phototherapy use. Universal implementation of this strategy in the US should improve outcomes of healthy newborns discharged early.

Phototherapy to prevent severe neonatal hyperbilirubinemia in the newborn infant 35 or more weeks of gestation

OBJECTIVE

To standardize the use of phototherapy consistent with the American Academy of Pediatrics clinical practice guideline for the management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation.

METHODS

Relevant literature was reviewed. Phototherapy devices currently marketed in the United States that incorporate fluorescent, halogen, fiber-optic, or blue light-emitting diode light sources were assessed in the laboratory.

RESULTS

The efficacy of phototherapy units varies widely because of differences in light source and configuration. The following characteristics of a device contribute to its effectiveness: (1) emission of light in the blue-to-green range that overlaps the in vivo plasma bilirubin absorption spectrum (~460-490 nm); (2) irradiance of at least 30 μW · cm(-2) · nm(-1) (confirmed with an appropriate irradiance meter calibrated over the appropriate wavelength range); (3) illumination of maximal body surface; and (4) demonstration of a decrease in total bilirubin concentrations during the first 4 to 6 hours of exposure. RECOMMENDATIONS (SEE APPENDIX FOR GRADING DEFINITION): The intensity and spectral output of phototherapy devices is useful in predicting potential effectiveness in treating hyperbilirubinemia (group B recommendation). Clinical effectiveness should be evaluated before and monitored during use (group B recommendation). Blocking the light source or reducing exposed body surface should be avoided (group B recommendation). Standardization of irradiance meters, improvements in device design, and lower-upper limits of light intensity for phototherapy units merit further study. Comparing the in vivo performance of devices is not practical, in general, and alternative procedures need to be explored.

The need for technologies to prevent bilirubin-induced neurologic dysfunction syndrome

Dramatic improvements in the overall socioeconomic conditions have yet to impact the unacceptably high maternal (approximately 1500 maternal deaths daily, worldwide) and neonatal morbidity and mortality (more than 10,000 deaths per daily 200,000 live-births, worldwide) in the developing nations. Thus, nations with emerging markets have unique health-societal needs. All infants require a safer transition from a birthing facility to home during the first week after birth and providing for a nurturing environment to prevent neonatal illnesses is integral to "good clinical practice." The unmonitored occurrence of severe hyperbilirubinemia and kernicterus are emblematic of a fractured maternal child healthcare system. The "know-do" gaps that span private versus public health care systems in the emerging markets have led us to conclude that building an interdisciplinary leadership approach to provide innovative strategies and affordable technologies will help bridge and access existing social barriers in the micro- and macro-health environments. Thus, unfettered access, global benchmarks, and culturally relevant strategies are dependent on evidence-based affordable technologies to successfully transform societal health care practices. Implementation of jaundice-related technologies should serve as a template for other affordable newborn health products.

The clinical syndrome of bilirubin-induced neurologic dysfunction

We believe that the syndrome of bilirubin-induced neurologic dysfunction [BIND] represents a spectrum of neurologic manifestations among vulnerable infants who have experienced an exposure to bilirubin of lesser degree than generally described in previous publications. Clinical neuro-motor manifestations extend to a range of subtle processing disorders with objective disturbances of visual-motor, auditory, speech, cognition, and language among infants with a previous history of moderate-to-severe hyperbilirubinemia of varied duration. Confounding effects include prematurity, hemolysis, perinatal-neonatal complications, altered bilirubin-albumin binding, severity and duration of bilirubin exposure, and the individual vulnerability of the infant related to genetic, family, social, and educational predilection, regardless of the cause of neonatal jaundice. Tools to better assess BIND specific domains of multisensory processing disorders, identified by pyschometric, audiologic, speech, language and visual-motor, and neuromotor examination would allow for prospective surveillance of infants at risk for the syndrome.

A global need for affordable neonatal jaundice technologies

Globally, health care providers worldwide recognize that severe neonatal jaundice is a "silent" cause of significant neonatal morbidity and mortality. Untreated neonatal jaundice can lead to death in the neonatal period and to kernicterus, a major cause of neurologic disability (choreo-athetoid cerebral palsy, deafness, language difficulty) in children who survive this largely preventable neonatal tragedy. Appropriate technologies are urgently needed. These include tools to promote and enhance visual assessment of the degree of jaundice, such as simpler transcutaneous bilirubin measurements and readily available serum bilirubin measurements that could be incorporated into routine treatment and follow-up. Widespread screening for glucose-6-phoshate dehydrogenase deficiency is needed because this is often a major cause of neonatal jaundice and kernicterus worldwide. Recognition and treatment of Rh hemolytic disease, another known preventable cause of kernicterus, is critical. In addition, effective phototherapy is crucial if we are to make kernicterus a "never-event." Finally it is essential that we conduct appropriate population-based studies to accurately elucidate the magnitude of the problem. However, knowledge alone is not sufficient. If we are to implement these and other programs and technologies to relegate severe neonatal jaundice and its sequelae to the history books, screening and interventions must be low cost and technologically appropriate for low and middle income nations.

The need to implement effective phototherapy in resource-constrained settings

Phototherapy is the treatment of choice to reduce the severity of neonatal unconjugated hyperbilirubinemia regardless of its etiology. Its implementation requires a technical framework that conforms to existing evidence-based guidelines that promote its safer and effective use worldwide. Optimal use of phototherapy has been defined by specific ranges of total serum bilirubin thresholds configured to an infant's postnatal age (in hours) and potential risk for bilirubin neurotoxicity. Effective phototherapy implies its use at specific blue light wavelengths (peak emission, 450 ± 20 nm) and emission spectrum (range, 400-520 nm), preferably in a narrow bandwidth that is delivered at an irradiance of ≥30 μW/cm(2)/nm to up to 80% of an infant's body surface area. However, this is often not feasible in clinical settings with limited or constrained resources. To identify and bridge implementation barriers, we propose minimum criteria for device performance for safe and practical use of phototherapy as a prophylactic intervention to prevent severe hyperbilirubinemia.

Severe neonatal hyperbilirubinemia and adverse short-term consequences in Baghdad, Iraq

BACKGROUND

Severe neonatal hyperbilirubinemia, when unmonitored or untreated, can progress to acute bilirubin encephalopathy (ABE). Initiatives to prevent and eliminate post-icteric sequelae (kernicterus) are being implemented to allow for timely interventions for bilirubin reduction.

OBJECTIVES

We report an observational study to determine the clinical risk factors and short-term outcomes of infants admitted for severe neonatal jaundice.

METHODS

A post-discharge medical chart review was performed for a cohort of infants admitted for management of newborn jaundice to the Children Welfare Teaching Hospital during a 4-month period in 2007 and 2008. Immediate outcomes included severity of hyperbilirubinemia, association of ABE, need and impact of exchange transfusion, and survival. Short-term post-discharge follow-up assessed for post-icteric sequelae.

RESULTS

A total of 162 infants were admitted for management of severe jaundice. Incidences of severe sequelae were: advanced ABE (22%), neonatal mortality within 48 h of admission (12%) and post-icteric sequelae (21%). Among the cohort, 85% were <10 days of age (median 6 days, IQR 4-7 days). Readmission total serum bilirubin ranged from 197 to 770 μM; mean 386 ± 108 SD μM (mean 22.6 ± 6.3 SD mg/dl; median 360, IQR 310-445 μM). The major contributory risk factor for the adverse outcome of kernicterus/death was admission with advanced ABE (OR 8.03; 95% CI 3.44-18.7). Other contributory factors to this outcome, usually significant, but not so for this cohort, included home delivery, sepsis, ABO or Rh disease. Absence of any detectable signs of ABE on admission and treatment of severe hyperbilirubinemia was associated with no adverse outcome (OR 0.34; 95% CI 0.16-0.68).

CONCLUSIONS

Risks of mortality and irreversible brain injury among healthy infants admitted for newborn jaundice are urgent reminders to promote education of communities, families and primary health care providers, especially in a fractured health system. Known risk factors for severe hyperbilirubinemia were overwhelmed by the effect of advanced ABE.

Transcutaneous bilirubinometry reduces the need for blood sampling in neonates with visible jaundice

OBJECTIVES

We determined usefulness of transcutaneous bilirubinometry to decrease the need for blood sampling to assay serum total bilirubin (STB) in the management of jaundiced healthy Indian neonates.

METHODS

Newborns, > or =35 weeks' gestation, with clinical evidence of jaundice were enrolled in an institutional approved randomized clinical trial. The severity of hyperbilirubinaemia was determined by two non-invasive methods: i) protocol-based visual assessment of bilirubin (VaB) and ii) transcutaneous bilirubin (TcB) determination (BiliCheck). By a random allocation, either method was used to decide the need for blood sampling, which was defined to be present if assessed STB by allocated method exceeded 80% of hour-specific threshold values for phototherapy (2004 AAP Guidelines).

RESULTS

A total of 617 neonates were randomized to either TcB (n = 314) or VaB (n = 303) groups with comparable gestation, birth weight and postnatal age. Need for blood sampling to assay STB was 34% lower (95% CI: 10% to 51%) in the TcB group compared with VaB group (17.5% vs 26.4% assessments; risk difference: -8.9%, 95% CI: -2.4% to -15.4%; p = 0.008).

CONCLUSION

Routine use of transcutaneous bilirubinometry compared with systematic visual assessment of bilirubin significantly reduced the need for blood sampling to assay STB in jaundiced term and late-preterm neonates. (ClinicalTrials.gov number, NCT00653874).

Screening for severe neonatal hyperbilirubinemia

Screening for severe neonatal hyperbilirubinemia is integral to newborn care. Predischarge risk assessment relies on documentation of visual jaundice: age at onset and progression; identification of clinical risk such as late prematurity and bruising; with determination of total bilirubin (blood or transcutaneous assay) adjusted for age in hours. Along with promotion of breastfeeding, coordination between birthing hospital and medically supervised outpatient follow-up, a systems approach allows for a safer and effective means to prevent adverse effects of extreme hyperbilirubinemia.

Inhibition of heme oxygenase activity in newborn mice by azalanstat

Inhibition of heme oxygenase (HO), the rate-limiting enzyme in heme catabolism, may be an ideal strategy for preventing neonatal jaundice. Although natural and synthetic heme analogs, called metalloporphyrins (Mps), have been extensively investigated for this purpose, some Mps are phototoxic, affect the activity of other enzymes, or induce HO-1 transcription-properties that may limit their clinical use. Another class of compounds, imidazole-dioxolanes, has been shown to selectively inhibit the inducible isozyme HO-1. Therefore, we investigated the efficacy of azalanstat (AZA), an imidazole-dioxolane, towards inhibiting HO activity in 7-day-old mice. We found that a single dose of AZA at 500 micromol.kg(-1) body mass (BM) administered i.p. significantly inhibited HO activity and reduced in vivo bilirubin production. In the spleen, HO inhibition (>50%) was observed within 0.25-3 h after administration. After 24 h, however, spleen HO activity, HO-1 protein, and HO-1 mRNA levels significantly increased 1.2-, 2.4-, and 4.0-fold, respectively. We conclude that AZA effectively inhibits in vivo HO activity only at a high dose and that it also induces spleen HO-1 gene transcription. Therefore, other imidazole-dioxolanes should be evaluated to determine whether they are more potent than AZA for use in treating neonatal jaundice.

A comparison of alternative risk-assessment strategies for predicting significant neonatal hyperbilirubinemia in term and near-term infants

OBJECTIVE

The purpose of this work was to compare the predictive accuracy of alternative risk-assessment strategies used to screen for the risk of significant neonatal hyperbilirubinemia.

PATIENTS AND METHODS

We conducted a prospective cohort study of 823 term and near-term newborns admitted to the well-infant nursery at the Hospital of the University of Pennsylvania. Maternal, infant, and delivery risk factors for significant hyperbilirubinemia were obtained from chart review, structured interviews with parents, and nurse assessments before discharge. Transcutaneous bilirubin measurement was performed daily until discharge and once by a visiting home nurse between 3 and 8 days of life. We used the c statistic to compare the predictive accuracy of 3 risk-assessment strategies for estimating the risk of significant neonatal hyperbilirubinemia, defined as a bilirubin level that at any time after birth exceeded or was within 1 mg/dL (17 micromol/L) of the hour-specific phototherapy treatment threshold recommended by the American Academy of Pediatrics in 2004. The compared strategies included those that use (1) a predischarge bilirubin level (obtained before 52 hours) expressed as a risk zone on an hour-specific bilirubin nomogram, (2) clinical risk factors other than the predischarge bilirubin level, and (3) a combination of the predischarge bilirubin risk zone and additional clinical risk factors.

RESULTS

Forty-eight patients (6%) developed significant neonatal hyperbilirubinemia. The predischarge (<52 hours) bilirubin level expressed as a risk zone on the bilirubin nomogram and a prediction model that combined multiple other clinical risk factors had similar accuracy for predicting significant hyperbilirubinemia. The only clinical risk factor that could be added to the predischarge risk zone to improve overall predictive accuracy was gestational age. The predischarge bilirubin risk zone and gestational age could be used to stratify patients into a large group (n = 523 [70%]) of infants with a very low (0.2%) risk of developing significant hyperbilirubinemia, a small group of infants (n = 127 [17%]) with a low (4%) risk of developing significant hyperbilirubinemia, and an even smaller group of infants (n = 100 [13%]) with a high (42%) risk of developing significant hyperbilirubinemia.

CONCLUSIONS

An infant's risk of developing significant hyperbilirubinemia can be simply and accurately assessed by using just the infant's predischarge bilirubin level and gestational age.

Management of jaundice and prevention of severe neonatal hyperbilirubinemia in infants >or=35 weeks gestation

Kernicterus is still occurring but should be largely preventable if health care personnel follow the recommendations listed in this guideline. These recommendations emphasize the importance of universal, systematic assessment of the risk of severe hyperbilirubinemia, lactation support, close follow-up, and prompt intervention when necessary. A systems-based approach to prevent severe neonatal hyperbilirubinemia should be implemented at all birthing facilities and coordinated with continuing ambulatory care. Translational research is needed to better understand the mechanisms of bilirubin neurotoxicity and potential therapeutic interventions.

A systems approach for neonatal hyperbilirubinemia in term and near-term newborns

OBJECTIVE

To propose and implement a family-centered systems approach to manage newborn jaundice for safer outcomes.

DESIGN

Observational study for known adverse outcomes.

SETTING

Semiprivate urban birthing hospital.

PATIENTS/PARTICIPANTS

31,059 well babies discharged as healthy from a cohort of 41,961 live births (1990-2000).

INTERVENTIONS

Incremental implementation of a systems approach that incorporated a hospital policy to (a) authorize nurses to obtain a bilirubin (total serum/transcutaneous) measurement for clinical jaundice, (b) universal predischarge total serum bilirubin (at routine metabolic screening), and (c) targeted follow-up, using the bilirubin nomogram (hour-specific, percentile-based total serum bilirubin/transcutaneous bilirubin).

MAIN OUTCOME MEASURES

Known adverse outcomes assessed for early- and late-onset severe hyperbilirubinemia before, during, and after systems approach implementation.

RESULTS

Adverse outcomes decreased for well babies: exchange transfusion, intensive phototherapy, and readmission. During the study period, there were no "never events" (total serum bilirubin greater than or equal to 30 mg/dl), while "close calls" (total serum bilirubin greater than or equal to 25 mg/dl) were 1 in 15,000 as compared to a reported incidence of 1 in 625.

CONCLUSIONS

Reduced adverse events, significant reduction in close calls, and no never events met family expectations for safer experiences with this approach.

Early inhaled nitric oxide therapy in premature newborns with respiratory failure

BACKGROUND

The safety and efficacy of early, low-dose, prolonged therapy with inhaled nitric oxide in premature newborns with respiratory failure are uncertain.

METHODS

We performed a multicenter, randomized trial involving 793 newborns who were 34 weeks of gestational age or less and had respiratory failure requiring mechanical ventilation. Newborns were randomly assigned to receive either inhaled nitric oxide (5 ppm) or placebo gas for 21 days or until extubation, with stratification according to birth weight (500 to 749 g, 750 to 999 g, or 1000 to 1250 g). The primary efficacy outcome was a composite of death or bronchopulmonary dysplasia at 36 weeks of postmenstrual age. Secondary safety outcomes included severe intracranial hemorrhage, periventricular leukomalacia, and ventriculomegaly.

RESULTS

Overall, there was no significant difference in the incidence of death or bronchopulmonary dysplasia between patients receiving inhaled nitric oxide and those receiving placebo (71.6 percent vs. 75.3 percent, P=0.24). However, for infants with a birth weight between 1000 and 1250 g, as compared with placebo, inhaled nitric oxide therapy reduced the incidence of bronchopulmonary dysplasia (29.8 percent vs. 59.6 percent); for the cohort overall, such treatment reduced the combined end point of intracranial hemorrhage, periventricular leukomalacia, or ventriculomegaly (17.5 percent vs. 23.9 percent, P=0.03) and of periventricular leukomalacia alone (5.2 percent vs. 9.0 percent, P=0.048). Inhaled nitric oxide therapy did not increase the incidence of pulmonary hemorrhage or other adverse events.

CONCLUSIONS

Among premature newborns with respiratory failure, low-dose inhaled nitric oxide did not reduce the overall incidence of bronchopulmonary dysplasia, except among infants with a birth weight of at least 1000 g, but it did reduce the overall risk of brain injury. (ClinicalTrials.gov number, NCT00006401 [ClinicalTrials.gov].).