Dr. Allen Cherer | Neonatal Care & Pediatrics

Dr. Allen Cherer is a neonatal care expert with over 30 years of medical accomplishments to his name.

Category: Research

Noting the Extraordinary Success of Hib Vaccination

August is observed as National Immunization Awareness Month and is a time to highlight the extreme importance and value of vaccination for people of all ages. Vaccination serves as one of the best ways to protect infants, children, and adolescents from sixteen potentially harmful, and even deadly, diseases. Although it is common to think of the vaccines against measles, pertussis, and polio, an astonishingly important vaccine since the end of the 20th century has targeted the bacteria, Haemophilus influenzae type b (Hib).

Haemophilus influenzae is a small, pleomorphic, gram negative coccobacillus. Some strains of H. influenzae possess a polysaccharide capsule, and these strains are serotyped into six different types (a-f) based on their biochemically different capsules.

The H. influenzae strains with no capsule are termed nonencapsulated H. influenzae or nontypable H. influenzae (NTHi). H. influenzae type b is the most virulent, with its polysaccharide capsule being the main factor. Antibody to the capsule is the primary contributor to serum bactericidal activity, and increasing levels of antibody are associated with decreasing risk of invasive H. influenzae disease.

H. influenzae type b most commonly causes pneumonia, bacteremia, meningitis, epiglottitis, and cellulitis. Non-type b encapsulated forms present in a similar manner to type b infections, while non typable strains more commonly cause infections of the respiratory tract, such as pneumonia, otitis media, sinusitis, and conjunctivitis.

Generally, the mode of transmission is person to person by inhalation of respiratory tract droplets or by direct contact with respiratory tract secretions. Pharyngeal colonization by H. influenzae is relatively common, especially with nontypable and non-type b capsular strains.
Before effective Hib conjugate vaccines for infants older than 2 months were available in 1990, Haemophilus influenzae type b was the leading cause of invasive bacterial disease among children in the United States.

One in 200 children developed invasive Hib disease by 5 years of age; approximately 60% of these children had meningitis and 3-6% died from the disease. Of the Hib meningitis survivors, many exhibited permanent sequelae ranging from mild hearing loss to mental retardation.

Sadly, I recall as a Pediatric resident admitting to the hospital at least one infant with H. influenzae type b meningitis almost every night when on call.Remarkably, since the introduction of Hib conjugate vaccines in the United States, the incidence of invasive Hib disease has decreased a stunning 99% to fewer than 1 case/100,000 children younger than 5 years of age, and in 2012, only 30 cases of invasive type b disease were reported in children under 5 years old.

Truly, it has been an amazing accomplishment. Nevertheless, the risk for invasive Hib disease persists among unimmunized and underimmunized children, highlighting the importance of full vaccination with the 2 or 3 injection (depending on the product) series between 2 and 6 months old and a single booster dose given between 12 and 15 months of age.

Certain additional doses may be indicated over 5 years of age depending on medical conditions, such as anatomic or functional asplenia, hematopoietic stem cell transplantation, or HIV infection. The Hib vaccine is very safe. The most common side effects are usually mild and consist of fever and rednesss, swelling, or warmth at the injection site. As with all current vaccines, significant advances and improvement in public health have been witnessed. It is incumbent upon each of us to maintain that success.

Providing Care for Drug-exposed Newborns: Time for the Next Step

During the years 1999-2013, the amount of prescription opioids dispensed in the United States nearly quadrupled, and since 2000, it is estimated that opioid use during pregnancy has tripled. Notably, the tragic consequences of the extreme availability of such drugs include abuse, physical dependence, and increasingly, death through inadvertent overdose.

newborn-boy-sleepingIn addition, for the individual pregnant woman, a minimum of two lives is affected: her own and that of her unborn child. The prevalence of prenatally exposed newborns to one or more illicit drugs approximates 6%. Neonatal Abstinence Syndrome (NAS) refers to the withdrawal symptoms from physical dependence experienced by the newborn exposed during pregnancy generally to illicit drugs, prescribed drugs, or to those opioids employed in medication-assisted treatment of maternal opioid addiction.

Withdrawal symptoms can vary markedly in terms of time of onset and severity but typically manifest as tremulousness, agitation, sleeplessness, and poor feeding. NAS increased threefold from 2000-2009 and frequently requires prolonged newborn hospitalization. It has been reported that aggregate hospital charges for NAS increased from 732 million dollars to 1.5 billion dollars with approximately 80% attributed to state Medicaid programs in 2012. Clearly, NAS is a costly public health problem resulting in significant human suffering and expense.

Traditionally, infants who are known to be at risk for NAS have been monitored in the postpartum unit after birth for at least 96 hours and withdrawal symptoms scored based on the Finnegan Scale developed in the mid 1970’s. Typically, if the scores exceed certain values, the newborn is admitted to a Special Care Unit where pharmacologic treatment is frequently started. As withdrawal symptoms subside, dosing is gradually tapered and ultimately stopped. The newborn is observed off medication and monitored for recurrence of disabling withdrawal symptoms. The entire process can generally result in a prolonged Special Care Unit hospital stay of 2-10 weeks.

With the seemingly overnight explosion in the number of newborns demonstrating withdrawal symptoms in the early 2000’s, medical caregivers and hospitals were caught off-guard. On short notice, staff addiction education, medication and weaning protocols, general care policies, and hospital space allocation were required. After a number of years of concerted, collaborative work, much has been learned and achieved in improving the care of the substance-exposed infant.

Nevertheless, pharmacologic treatment continues to require prolonged hospital stays, often in costly Special Care Units. In addition, it effectively excludes full participation by the eventual sole primary caregivers, ideally the parents. It is with these disturbing issues in mind that it is refreshing to note the work and studies over the past several years to further optimize the care provided to infants with NAS and their families.

One of the earlier studies to suggest the therapeutic benefits of a different approach to caring for the drug-exposed infant was that of Abrahams et al. published in the Canadian Family Physician in 2007. During the same period of frenzy involving inpatient hospital transfers, guaranteeing interobserver scoring reliability, pharmacologic treatment protocols, and nursing care directives, the Canadian group with extensive previous experience in addiction medicine reported in a retrospective cohort study the benefits of a rooming-in policy whereby infants remained with their mothers as primary caretakers.

They noted that infants who roomed-in were less likely to require pharmacologic therapy for withdrawal and more likely to be discharged to mother’s care compared to infant’s who received standard nursery care. Subsequently, other retrospective cohort studies both in Europe and the United States demonstrated equally beneficial effects of rooming-in regarding decreased requirement for pharmacologic therapy and decreased duration of hospital stay.

Most recently, the results of a quality collaborative project from the Children’s Hospital at Dartmouth Hitchcock were described in the May, 2016 Pediatrics and demonstrated the beneficial effects of combined standardized protocols and family-centered care in the management of the drug-exposed infant. Over time, the project safely reduced the number of infants requiring pharmacologic therapy, average length of stay, and overall hospital costs.

Among others, key drivers to success were prenatal education of family caregivers including expressed expectation that they would provide meaningful rooming-in care, baby-centered NAS scoring including on demand feeding schedules, pharmacologic therapy when necessary with dosing adjustment based on overall infant condition rather than solely Finnegan score and determined by a consistent team, and an infant “snuggler” volunteer program to assist families when times required their absence.

Overall, the project demonstrated that despite many practical obstacles to providing high quality care for drug-exposed newborns and their families in the hospital setting, where there’s a will, there’s a way.

Antenatal Corticosteroid Use for Late Preterm Delivery

In 1972, Drs. Liggins and Howie published their landmark study demonstrating that antenatal corticosteroids administered to women 24-36 weeks of gestation reduced the incidence of respiratory distress syndrome and  neonatal mortality. Liggins had previously noted that lambs, treated with intrafetal  ACTH, cortisol, or dexamethasone, delivered prematurely, and sacrificed, demonstrated partially expanded  lungs.

Such alveolar stability was not typically noted until later in gestation. It suggested to Liggins that glucocorticoids might cause premature liberation of surfactant into the alveoli and served as the basis for his study. In the trial, the most significant difference in the incidence of respiratory distress syndrome among those treated vs. not treated with corticosteroids occurred in those gestations  less than 32 weeks.

Although those gestations treated between 32 and 37 weeks exhibited a decreased incidence of respiratory distress, the number did not reach statistical significance. Nevertheless, even at that time, Liggins postulated that mechanisms in addition to enhanced surfactant production and release might be responsible for the improved pulmonary function noted in more advanced gestations treated with antenatal corticosteroids.  

Interestingly, despite the findings of the initial study and similar results in multiple subsequent studies , the 1994 NIH Consensus report on the effect of corticosteroids for fetal maturation on perinatal outcomes found that only 20% of women who delivered newborns  501-1500 grams received the benefit of antenatal steroids. After a thorough review of available evidence, including  12 year neurodevelopmental follow up showing no adverse outcomes, the Consensus Panel felt  the benefits of antenatal administration of corticosteroids vastly outweigh the risks and all fetuses between 24 and 34 weeks gestation at risk of preterm delivery should be considered candidates for antenatal  treatment.

Only in those few pregnancies where corticosteroids would have an adverse effect on the mother or delivery was imminent  should steroid treatment be withheld. In addition, although Grade 1 evidence existed at the time to support the use of antenatal corticosteroids for gestations greater than 34 weeks, it was judged insufficient to recommend their use.

Since the Consensus statement, the use of antenatal corticosteroid use has become common and has resulted in considerable reduction in mortality and morbidity, as well as total health care costs. In addition, further neurodevelopmental follow up, including the original Auckland steroid trial participants, continues to demonstrate no adverse effects on psychological functioning and health-related quality of life. Other studies have demonstrated a decrease in overall respiratory disease in infants born beyond 34 weeks who had previously been exposed to antenatal corticosteroids when compared to unexposed infants born at similar gestations.

More than 300,000 pregnancies deliver in the late preterm period (34 0/7 – 36 6/7 weeks gestation) each year in the United States. Seventy per cent of Intensive Care Nursery admissions are late preterm newborns. Their increasing numbers and the broad range and severity of respiratory disorders with which they present beg for a re-evaluation of antenatal corticosteroid use in this range of gestations. This is especially appropriate with a better understanding of the multiple actions of corticosteroids as gestation approaches term.

A recent study, titled Antenatal Late Preterm Steroids (ALPS), a Randomized Trial to Reduce Neonatal Respiratory Morbidity, was published in The New England Journal of Medicine in April, 2016. The study enrolled over 2800 women with singleton pregnancies at high risk for late preterm delivery.

The participants were randomized to receive antenatal betamethasone by injection or a matching placebo. Greater than 80% of women in the trial delivered prior to 37 weeks gestation. The primary outcome was a neonatal composite of treatment in the first 72 hours (CPAP or High Flow Nasal Cannula for at least 2 hours, supplemental oxygen with fraction of inspired oxygen of at least 0.3 for at least 4 hours, mechanical ventilation, or ECMO) or stillbirth or neonatal death within 72 hours of birth.

The study found a significant decrease in neonatal respiratory complications in the group given the steroid treatment (11.6% vs. 14.4%). In addition, severe respiratory complications occurred significantly less frequently in the betamethasone group. The incidence of neonatal hypoglycemia  was increased in those treated with betamethasone (24% vs. 14.9%), but no other adverse neonatal outcomes were noted between the groups.

The study is authoritative due to its size, generalizability, and methodologic rigor. Although the issue of long term follow up cannot be specifically addressed, follow up studies of similar treatment in earlier gestations are reassuring. Late preterm births comprise a high risk group for hypoglycemia regardless of maternal antenatal steroid treatment and warrant vigilant monitoring during the newborn period.  In sum, the findings of the Antental Late Preterm Steroids study are consistent with other randomized controlled trials of antenatal corticosteroids administered at gestations less than 34 weeks.

Both the American College of Obstetrics and Gynecology with an endorsement by the American Academy of Pediatrics and the Society for Maternal-Fetal Medicine have addressed and published recommendations based on the study’s findings. Although the recommendations do not establish exclusive standards of care, the organizations approve the use of antenatal corticosteroids in certain defined late preterm pregnancies.  It is only with thoughtful application of the recommendations and further studies that the efficacy and safety of antenatal steroids in the late preterm pregnancy will be realized. It is a significant start.

Powered by WordPress & Theme by Anders Norén