3
O 2 saturation: How far must the pendulum swing? — Clyde Wright, MD P ractice changes based on interpretation of the Surfactant, Positive Pressure, and Oxygenation Randomized Trial (SUPPORT), Canadian Oxygen Trial (COT), and Benefits of Oxygen Saturation Targeting (BOOST) II Trial stand to impact prema- ture infants in every neonatal care unit around the world. How should we interpret the data? What practice changes should we make? Arguments for targeting higher satura- tions (91%-95%) have been made based on both the SUPPORT and BOOST II Trial. In contrast, results of COT demonstrate that targeting lower saturations (85%-90%) may be safe when alarm limits are strictly enforced. Balancing potential morbidities associated with high saturation targets (retinopathy of prematurity and bronchopul- monary dysplasia) and the potential of increased mortality risk with lower saturation targets becomes paramount when selecting oxygen saturation targets. In this issue of The Journal, Darlow et al present the 2-year outcomes of 340 infants randomized to high versus low oxygen saturation targets in the New Zealand BOOST II Trial. No sig- nificant difference was found in the primary outcome of death or major disability at 2 years, or in mortality. In an accompanying editorial, Schmidt places these results into context with re- ported 2-year outcomes of SUPPORT and COT. She argues that before broad changes are made, results of these individual trials must be interpreted in light of their differ- ences. To otherwise do so unnecessarily places these vulnerable patients at increased risk of retinopathy of prematurity or death. The history of neonatology is marred with large swings in how much oxygen is administered to premature infants, and without thoughtful consideration of the differences between these individual trials, we run the risk of repeating errors of the past. Article page 30< Editorial page 6< Immunization exemptions leave kindergarten entrants at higher risk for vaccine-preventable diseases — Sarah S. Long, MD S chool immunization laws have contributed substantially to the decline in vaccine- preventable disease in the US. Immunization laws are made at the state level: 2 states permit medical exemptions only, 46 states and the District of Columbia permit religious exemptions, and 18 states permit philosophical or personal-belief exemp- tions. States that do not permit personal-belief exemptions have lower rates of reli- gious exemptions, but religious exemptions have increased in these states, suggesting that some parents might be using religious rather than personal-belief exemptions. It is noteworthy that except for Christian Scientists, opposition to immunization is not part of any organized religious doctrine. Shaw et al compared immunization in kindergarten entrants in private versus pub- lic schools using Centers for Disease Control and Prevention data for the school year 2009 and 2010 in 36 states with complete relevant data. The overall exemption rate was higher in US private schools (4.25%) compared with US public schools (1.91%) (P = .0001). Private schools had higher rates for all types of exemptions—medical, reli- gious, and personal belief. Overall exemption rates were significantly higher in states that allow personal-belief exemptions. How are parents of children attending private school, who themselves are likely to have had the benefits of a sound education that distinguishes fact from fear, so mistrustful of doctors who completed medical school and are steeped in medicine based on evidence, and yet so confident in their own musings? At the same time 1 July 2014 Volume 165 Number 1 Copyright ª 2014 Elsevier Inc.

Long-term effects of severe lower respiratory tract infections in early childhood

Embed Size (px)

Citation preview

July 2014 � Volume 165 � Number 1 Copyright ª 2014 Elsevier Inc.

O2 saturation:How far must thependulum swing?

— Clyde Wright, MD

Practice changes based on interpretation of the Surfactant, Positive Pressure, andOxygenation Randomized Trial (SUPPORT), Canadian Oxygen Trial (COT),

and Benefits of Oxygen Saturation Targeting (BOOST) II Trial stand to impact prema-ture infants in every neonatal care unit around the world. How should we interpret thedata? What practice changes should we make? Arguments for targeting higher satura-tions (91%-95%) have been made based on both the SUPPORT and BOOST II Trial.In contrast, results of COT demonstrate that targeting lower saturations (85%-90%)may be safe when alarm limits are strictly enforced. Balancing potential morbiditiesassociated with high saturation targets (retinopathy of prematurity and bronchopul-monary dysplasia) and the potential of increased mortality risk with lower saturationtargets becomes paramount when selecting oxygen saturation targets. In this issue ofThe Journal, Darlow et al present the 2-year outcomes of 340 infants randomized tohigh versus low oxygen saturation targets in the New Zealand BOOST II Trial. No sig-nificant difference was found in the primary outcome of death or major disability at 2years, or in mortality.

In an accompanying editorial, Schmidt places these results into context with re-ported 2-year outcomes of SUPPORT and COT. She argues that before broad changesare made, results of these individual trials must be interpreted in light of their differ-ences. To otherwise do so unnecessarily places these vulnerable patients at increasedrisk of retinopathy of prematurity or death. The history of neonatology is marredwith large swings in how much oxygen is administered to premature infants, andwithout thoughtful consideration of the differences between these individual trials,we run the risk of repeating errors of the past.

Article page 30<Editorial page 6<

Immunizationexemptions leave

kindergarten entrantsat higher risk for

vaccine-preventablediseases

— Sarah S. Long, MD

School immunization laws have contributed substantially to the decline in vaccine-preventable disease in the US. Immunization laws are made at the state level: 2

states permit medical exemptions only, 46 states and the District of Columbia permitreligious exemptions, and 18 states permit philosophical or personal-belief exemp-tions. States that do not permit personal-belief exemptions have lower rates of reli-gious exemptions, but religious exemptions have increased in these states, suggestingthat some parents might be using religious rather than personal-belief exemptions. Itis noteworthy that except for Christian Scientists, opposition to immunization is notpart of any organized religious doctrine.

Shaw et al compared immunization in kindergarten entrants in private versus pub-lic schools using Centers for Disease Control and Prevention data for the school year2009 and 2010 in 36 states with complete relevant data. The overall exemption rate washigher in US private schools (4.25%) compared with US public schools (1.91%) (P =.0001). Private schools had higher rates for all types of exemptions—medical, reli-gious, and personal belief. Overall exemption rates were significantly higher in statesthat allow personal-belief exemptions.

How are parents of children attending private school, who themselves are likely tohave had the benefits of a sound education that distinguishes fact from fear, somistrustful of doctors who completed medical school and are steeped in medicinebased on evidence, and yet so confident in their own musings? At the same time

1

2

that they are attempting to advantage their children by attending a private school, theyare putting their children in harm’s way.

Article page 129<

Fluid therapy inchildren: How much

salt? Howmuch water?

— Thomas R. Welch, MD

Over the past few years, there has been a renewal of interest in a topic that manythought was settled long ago:What is the appropriate fluid prescription for hospital-

ized children? The topic has engendered fierce debates, and probably even sparked scoresof lawsuits. The basic question: Is the provision of hypotonic “maintenance” fluids adangerous practice that leads to potentially devastating neurologic consequences?

This issue of The Journal features one of the most carefully performed and reportedsystematic reviews of the subject, which is accompanied by a thoughtful, helpful edito-rial; the two pieces should be read together.

Like many others, Foster et al demonstrate that children receiving hypotonic fluidstend to have lower serum sodium concentrations than do those receiving isotonicfluid. As pointed out by both the authors and the editorialist, the differences in serumsodium were significant statistically, but exceedingly modest. More importantly, thebulk of patients were either in a postoperative state or in critical care units and notcandidates for what historically has been referred to as “maintenance” fluid therapy.

Conceptually, “maintenance” fluid therapy was designed for otherwise healthy, eu-volemic children who had no excess ongoing losses of fluid and normal renal sodiumand water handling. The reality of pediatric care today is that we hospitalize fewer andfewer children who meet these criteria. As Friedman reminds us in the editorial, fluidtherapy is a prescription like any drug; it must be tailored to the specific child and hisor her clinical state. Sadly, we often confabulate with shorthand references to thingslike “twice maintenance” or “half maintenance” fluids. Children with ongoing diar-rhea and dehydration are not candidates for “maintenance” fluids, hypotonic orotherwise!

Article page 163<Editorial page 14<

Brain imaging andbacterial meningitis

— Sarah S. Long, MD

In this issue of The Journal, Oliveira et al report on clinical and brain magnetic reso-nance imaging (MRI) data on 75 infants with cerebrospinal fluid (CSF) culture-

proven bacterial meningitis compiled from 2001 through 2011. The brain MRIswere performed on 68% of 111 infants with culture-proven bacterial meningitis caredfor during the study period. The studies were performed at a mean of 4 days into hos-pitalization, presumably for a clinical reason. In fact, the 75 infants who had an MRIperformed compared with 36 infants who did not were significantly more likely tohave apnea, seizures, lethargy, and irritability; had more profoundly abnormal CSFfindings; and were more likely to require mechanical ventilation.

The reading of brain MRIs for this report was done by a single neuroradiologistblinded to clinical data and prior interpretation. Imaging was abnormal in 81% ofthe 75 infants; interpretation did not differ from that at the time of clinical care. Find-ings frequently were directly relevant to important management decisions and includedsubdural empyema (52%), brain abscess (11%), hydrocephalus (20%). Indeed, afterperformance of MRI, 45% of infants had at least one change in management (eg, pro-longation of antibiotic therapy [30%] or neurosurgical intervention [25%] or both).The report includes careful delineation of factors such as age, clinical course, pathogen,neurologic and CSF findings, and their association with MRI findings.

This report should be used to calculate neither incidence of normal or abnormalbrain MRIs in infants with bacterial meningitis nor relative rates of specific abnormal-ities. Studies were performed in a subset of patients at one moment in time duringtreatment. That said, the majority of infants had an MRI performed and findingsled to important changes in management in almost one-half.

The authors’ conclusions are focused appropriately within the narrow constructs oftheir data. Pediatric infectious diseases subspecialists, however, are developing

Vol. 165, No. 1

Ju

ly 2014

approaches to the management of bacterial meningitis based on experience andbolstered by reports such as this. My experiences as a pediatric infectious diseases sub-specialist lead to the following conclusions and evolved practices: (1) infants and chil-dren with bacterial meningitis are managed optimally with input of a pediatricinfectious diseases subspecialist (current experience of any other physician group islimited; both bacteria and potential management options are more complicatedthan they were previously); (2) a head imaging study should be performed for all caseswith a complicated course, with certain pathogens (eg, Cronobacter and Citrobacterspecies and Staphylococcus aureus, all of which are prone to cause brain or extra-axialabscesses), or with persistently positive CSF (3) a head imaging study should be per-formed before discontinuing therapy in neonates with bacterial meningitis or older in-fants with neonatal pathogens (eg, Streptococcus agalactiae, enteric gram-negativebacilli, Listeria monocytogenes), even when the clinical course is uncomplicated (thesebacteria or these infants or both are prone to infections more complicated than lepto-meningitis and clinical clues can be limited); and (4) finding of a subdural empyema orbrain abscess does not necessarily mandate neurosurgical intervention (optimal man-agement decisions require consideration of size, physiologic effects, clinical andneurologic state of improvement, and time of occurrence in the treatment course).An MRI provides superior delineation of parenchymal abnormalities, but the re-duced sedation requirement for computed tomography sometimes can allow thatstudy to be performed more safely when the primary purpose is to exclude brain orextra-axial abscess or hydrocephalus, the presence of which may lead to a change inmanagement.

Article page 134<

Long-term effects ofsevere lower

respiratory tractinfections in

early childhood— Robert W. Wilmott, MD

A lthough it is widely believed that severe lower respiratory tract infection (LRTI) inearly childhood is associated with later onset of chronic respiratory disease, the

data are not conclusive. This is partly because it is possible that severe LRTI andchronic respiratory disease share common antecedents. In addition, even thoughearlier studies have shown an association, they have been based on relatively smallpopulations. In this issue of The Journal, a longitudinal population-based study is re-ported by Szabo et al. They have used patient-level administrative data from publicdatabases, which cover almost all of the population of Quebec. The cohort includedall children born in 1996 and 1997, and the children with acute lower respiratory tractinfections were identified from International Classification of Diseases, Ninth editioncodes. A total of more than 145 000 children comprised the birth cohort; 5.7% wereborn preterm, 2.2%were diagnosed with congenital heart disease, and 0.2%were diag-nosed with bronchopulmonary dysplasia (BPD) during the first two years of life. Themost common severe LRTIs were acute bronchitis and bronchiolitis. Over 8 years offollow-up, children from the LRTI and respiratory syncytial virus (RSV) cohorts hadalmost twice the risk of developing chronic respiratory morbidity compared with thenonhospitalized comparison group. The population attributable risk of childhoodchronic respiratory morbidity due to severe LRTI was almost 25% over the 8 yearperiod. Most of the chronic respiratory morbidity was due to asthma. Multivariableanalysis showed that male sex, prematurity, diagnosis of congenital heart disease, orBPD/chronic lung disease prior to 2 years of age and hospitalization for LRTI before2 years of age were significantly associated with chronic respiratory morbidity. The au-thors concluded that the findings from this study are useful for quantifying the contri-bution of severe LRTIs, including RSV, to the burden of childhood chronic respiratoryconditions and helps highlight the clinical burden due to severe LRTI hospitalizationsbeyond the first two years of life. Asthma and other chronic respiratory conditionsremain an important source of childhood morbidity.

Article page 123<

3