Neonatal sepsis | |
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Specialty | Pediatrics |
Neonatal sepsis is a type of neonatal infection and specifically refers to the presence in a newborn baby of a bacterial blood stream infection (BSI) (such as meningitis, pneumonia, pyelonephritis, or gastroenteritis) in the setting of fever. Older textbooks may refer to neonatal sepsis as "sepsis neonatorum". Criteria with regards to hemodynamic compromise or respiratory failure are not useful clinically because these symptoms often do not arise in neonates until death is imminent and unpreventable. Neonatal sepsis is divided into two categories: early-onset sepsis (EOS) and late-onset sepsis (LOS). EOS refers to sepsis presenting in the first 7 days of life (although some refer to EOS as within the first 72 hours of life), with LOS referring to presentation of sepsis after 7 days (or 72 hours, depending on the system used). Neonatal sepsis is the single most common cause of neonatal death in hospital as well as community in developing country.
It is difficult to clinically exclude sepsis in newborns less than 90 days old that have fever (defined as a temperature > 38 °C (100.4 °F). Except in the case of obvious acute viral bronchiolitis, the current practice in newborns less than 30 days old is to perform a complete workup including complete blood count with differential, blood culture, urinalysis, urine culture, and cerebrospinal fluid (CSF) studies and CSF culture, admit the newborn to the hospital, and treat empirically for serious bacterial infection for at least 48 hours until cultures are demonstrated to show no growth. Attempts have been made to see whether it is possible to risk stratify newborns in order to decide if a newborn can be safely monitored at home without treatment despite having a fever. One such attempt is the Rochester criteria.
The signs of sepsis are non-specific and include: [1]
A heart rate above 160 can also be an indicator of sepsis, this tachycardia can present up to 24 hours before the onset of other signs.[ citation needed ]
A study performed at Strong Memorial Hospital in Rochester, New York, showed that infants ≤ 60 days old meeting the following criteria were at low-risk for having a serious bacterial illness: [2]
Those meeting these criteria likely do not require a lumbar puncture, and are felt to be safe for discharge home without antibiotic treatment, or with a single dose of intramuscular antibiotics, but will still require close outpatient follow-up.[ citation needed ]
One risk for Group B streptococcal infection (GBS) is preterm rupture of membranes. Screening women for GBS (via vaginal and rectal swabbing) and treating culture positive women with intrapartum chemoprophylaxis is reducing the number of neonatal sepsis caused by GBS.[ citation needed ]
Abnormal heart rate characteristics (HRC) of transient decelerations and reduced baseline variability in heart rate are a risk factor for impending neonatal sepsis. [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [ excessive citations ]
Neonatal sepsis screening:[ citation needed ]
Culturing for microorganisms from a sample of CSF, blood or urine, is the gold standard test for definitive diagnosis of neonatal sepsis. This can give false negatives due to the low sensitivity of culture methods and because of concomitant antibiotic therapy. Lumbar punctures should be done when possible as 10-15% presenting with sepsis also have meningitis, which warrants an antibiotic with a high CSF penetration.[ citation needed ]
CRP is not very accurate in picking up cases. [14]
Molecular assays can give faster result in diagnosis of neonatal sepsis than microbial culture from blood. [15]
Note that, in neonates, sepsis is difficult to diagnose clinically. They may be relatively asymptomatic until hemodynamic and respiratory collapse is imminent, so, if there is even a remote suspicion of sepsis, they are frequently treated with antibiotics empirically until cultures are sufficiently proven to be negative. In addition to fluid resuscitation and supportive care, a common antibiotic regimen in infants with suspected sepsis is a beta-lactam antibiotic (usually ampicillin) in combination with an aminoglycoside (usually gentamicin) or a third-generation cephalosporin (usually cefotaxime—ceftriaxone is generally avoided in neonates due to the theoretical risk of kernicterus.) The organisms which are targeted are species that predominate in the female genitourinary tract and to which neonates are especially vulnerable to, specifically Group B Streptococcus, Escherichia coli , and Listeria monocytogenes (This is the main rationale for using ampicillin versus other beta-lactams.) Of course, neonates are also vulnerable to other common pathogens that can cause meningitis and bacteremia such as Streptococcus pneumoniae and Neisseria meningitidis . Although uncommon, if anaerobic species are suspected (such as in cases where necrotizing enterocolitis or intestinal perforation is a concern, clindamycin is often added.[ citation needed ]
Although many antibiotics are used in neonatal sepsis, it is unknown which antibiotics is better than others for neonatal sepsis management. [16] [17] [18]
Granulocyte-macrophage colony stimulating factor (GM-CSF) is sometimes used in neonatal sepsis. However, a 2009 study found that GM-CSF corrects neutropenia if present but it has no effect on reducing sepsis or improving survival. [19]
In cases of suspected Early Onset Sepsis (EOS) one of the treatments is empirical antibiotics. [20] The strategy of clinicians utilizing antibiotics as a course of treatment for EOS has resulted in the overtreatment of antibiotics to infants suspected of having signs of EOS. There are several consequences to the overtreatment of antibiotics in newborns including "microbiome alterations, which are linked to the development of asthma, food allergies, and childhood obesity". [21] Another risk in the early introduction of antibiotics in infants is the increase in the development of antibiotic-resistant strains of infectious disease. [22] Current methods of treatment for EOS are often implemented before a positive sepsis blood culture is found. In the last two decades (2000-2020), the use of intrapartum antibiotics has reduced the incidence of EOS. [22] The current challenge faced by clinicians is mainly weighing the risk and benefits of the possibility of antibiotic overtreatment vs. the effects of sepsis. [20]
Since the 1990s early-onset sepsis has declined because of screening of group B streptococcus. The cause of early-onset neonatal sepsis are pathogens that contaminate the placenta, vaginal canal, cervix, or amniotic fluid, and these pathogens can affect the baby either in the womb or during labor. [23] Early-onset neonatal sepsis is found to be 0.77 to 1 per 100,000 live births in the U.S. In premature babies, the incidence and mortality rates are higher due to the weakness of their immune system. For infants with low birth weight, cases of early-onset sepsis is found to be about 26 per 1,000 and 8 per 1,000 live births. Certain populations of babies are at more risk as well. Mothers who have poor healthcare, low socioeconomic status, substance abuse, or are African American have higher rates of neonatal sepsis. In fact, African American preterm babies have the highest rate of infection and mortality. 5.14 of every 1,000 live births and 24.4% case fatality ratio, respectively. [24] The mother is not the only one who can contract the bacteria that contributes to sepsis. The child can contribute to the onset of sepsis through multiple factors. Mothers contribute to the risk through a variety of ways like diets during pregnancy and potential intake of foods that are contaminated, through invasive procedures like amniocentesis and cervical cerclage, or contamination of bacteria in the vaginal canal. Infants can contribute to early-onset sepsis through prematurity, congenital anomalies, complicated birth or instrument assisted birth, and low APGAR scores. [24] Testing for neonatal sepsis is done because of how little it physically presents itself in babies. Infants showing no signs of neonatal sepsis will have a sepsis workup done only if concerning factors are shown. Only a small percentage of infants will have a sepsis workup done. Of this small population only 3% to 8% will show positive cultures. [23]
Trials of probiotics for prevention of neonatal sepsis have generally been too small and statistically underpowered to detect any benefit, [25] but a randomized controlled trial that enrolled 4,556 neonates in India reported that probiotics significantly reduced the risk of developing sepsis. [26] The probiotic used in the trial was Lactobacillus plantarum .[ citation needed ]
A very large meta-analysis investigated the effect of probiotics on preventing late-onset sepsis (LOS) in neonates. [27] Probiotics were found to reduce the risk of LOS, but only in babies who were fed human milk exclusively. [27] It is difficult to distinguish if the prevention was a result of the probiotic supplementation or if it was a result of the properties of human milk. [27] It is also still unclear if probiotic administration reduces LOS risk in extremely low birth weight infants due to the limited number of studies that investigated it. [27] Out of the 37 studies included in this systematic review, none indicated any safety problems related to the probiotics. [27] It would be beneficial to clarify the relationship between probiotic supplementation and human milk for future studies in order to prevent late onset sepsis in neonates. [27]
In a randomized controlled trial of 3,003 very low birth weight (VLBW) infants, Heart Rate Characteristics (HRC) monitoring reduced all-cause mortality by 22%, [28] mortality after infection by 40%, [29] reduced length of stay in the NICU after controlling for improved survival, [30] and reduced mortality as well as mortality-or-severe-cerebral-palsy at 18–22 months corrected age among the extremely low birth weight (ELBW) patients. [31]
From 1993 to 2007, doctors at Kaiser Permanente Medical Care Program hospitals, Brigham Women's Hospital, and Beth Israel-Deaconess Medical Center conducted a nested case-control study in an effort to create a better quantitative method for determining risk factors for neonatal early-onset sepsis. [32] The study examined over 600,000 live births of infants born less than or equal to 34 weeks gestation. The study used measures of health available at the time of birth such as highest intrapartum maternal temperature, rupture of membranes, whether or not the mother has group b streptococcus, and if the mother was given any intrapartum antibiotics. [20] Intrapartum prophylaxis is a strategy for "the secondary prevention of early-onset GBS disease in newborns" that could lead to EOS. [33] The Sepsis Risk Calculator (SRS) is meant to be another clinical measure that physicians can use in conjunction with physical examination. [22]
An evaluation of the SRS was done in an independent retrospective cohort study by doctors at a University Hospital in Greece. [34] The study aimed to "compare our clinical practice based on risk-factor guidance with that projected through the application of the SRC". [34] The study incorporated 2,084 infants and found that "The adoption of SRC would have significantly reduced antibiotic usage; however, a significant portion of cases with clinical EOS would have been missed". [34] Another study evaluated the impact of Integrating the SRC into the electronic health record in order to "improve compliance and accuracy through automation". [35] The study concluded that the integration of the EOS into the electronic health record system "significantly increased calculator accuracy". [35]
Neutropenia is an abnormally low concentration of neutrophils in the blood. Neutrophils make up the majority of circulating white blood cells and serve as the primary defense against infections by destroying bacteria, bacterial fragments and immunoglobulin-bound viruses in the blood. People with neutropenia are more susceptible to bacterial infections and, without prompt medical attention, the condition may become life-threatening.
Preterm birth, also known as premature birth, is the birth of a baby at fewer than 37 weeks gestational age, as opposed to full-term delivery at approximately 40 weeks. Extreme preterm is less than 28 weeks, very early preterm birth is between 28 and 32 weeks, early preterm birth occurs between 32 and 34 weeks, late preterm birth is between 34 and 36 weeks' gestation. These babies are also known as premature babies or colloquially preemies or premmies. Symptoms of preterm labor include uterine contractions which occur more often than every ten minutes and/or the leaking of fluid from the vagina before 37 weeks. Premature infants are at greater risk for cerebral palsy, delays in development, hearing problems and problems with their vision. The earlier a baby is born, the greater these risks will be.
Cardiotocography (CTG) is a technique used to monitor the fetal heartbeat and uterine contractions during pregnancy and labour. The machine used to perform the monitoring is called a cardiotocograph.
Infantile respiratory distress syndrome (IRDS), also called respiratory distress syndrome of newborn, or increasingly surfactant deficiency disorder (SDD), and previously called hyaline membrane disease (HMD), is a syndrome in premature infants caused by developmental insufficiency of pulmonary surfactant production and structural immaturity in the lungs. It can also be a consequence of neonatal infection and can result from a genetic problem with the production of surfactant-associated proteins.
Congenital syphilis is syphilis that occurs when a mother with untreated syphilis passes the infection to her baby during pregnancy or at birth. It may present in the unborn baby, newborn baby or later. Clinical features vary and differ between early onset, that is presentation before age 2-years of age, and late onset, presentation after age 2-years. Infection in the unborn baby may present as poor growth, non-immune hydrops leading to premature birth or loss of the baby, or no signs. Affected newborns mostly initially have no clinical signs. They may be small and irritable. Characteristic features include a rash, fever, large liver and spleen, a runny and congested nose, and inflammation around bone or cartilage. There may be jaundice, large glands, pneumonia, meningitis, warty bumps on genitals, deafness or blindness. Untreated babies that survive the early phase may develop skeletal deformities including deformity of the nose, lower legs, forehead, collar bone, jaw, and cheek bone. There may be a perforated or high arched palate, and recurrent joint disease. Other late signs include linear perioral tears, intellectual disability, hydrocephalus, and juvenile general paresis. Seizures and cranial nerve palsies may first occur in both early and late phases. Eighth nerve palsy, interstitial keratitis and small notched teeth may appear individually or together; known as Hutchinson's triad.
Necrotizing enterocolitis (NEC) is a devastating intestinal disease that affects premature or very low birth weight infants. Symptoms may include poor feeding, bloating, decreased activity, blood in the stool, vomiting of bile, bowel death, multiorgan failure, and even death.
Omphalitis of newborn is the medical term for inflammation of the umbilical cord stump in the neonatal newborn period, most commonly attributed to a bacterial infection. Typically immediately after an infant is born, the umbilical cord is cut with a small remnant left behind. Normally the stump separates from the skin within 3–45 days after birth. A small amount of pus-like material is commonly seen at the base of the stump and can be controlled by keeping the stump open to air to dry. Certain bacteria can grow and infect the stump during this process and as a result significant redness and swelling may develop, and in some cases the infection can then spread through the umbilical vessels to the rest of the body. While currently an uncommon anatomical location for infection in the newborn in the United States, it has caused significant morbidity and mortality both historically and in areas where health care is less readily available. In general, when this type of infection is suspected or diagnosed, antibiotic treatment is given, and in cases of serious complications surgical management may be appropriate.
Streptococcus agalactiae is a gram-positive coccus with a tendency to form chains. It is a beta-hemolytic, catalase-negative, and facultative anaerobe.
Group B streptococcal infection, also known as Group B streptococcal disease or just Group B strep, is the infection caused by the bacterium Streptococcus agalactiae. GBS infection can cause serious illness and sometimes death, especially in newborns, the elderly, and people with compromised immune systems.
Bronchopulmonary dysplasia is a chronic lung disease in which premature infants, usually those who were treated with supplemental oxygen, require long-term oxygen. The alveoli that are present tend to not be mature enough to function normally. It is more common in infants with low birth weight (LBW) and those who receive prolonged mechanical ventilation to treat respiratory distress syndrome (RDS). It results in significant morbidity and mortality. The definition of BPD has continued to evolve primarily due to changes in the population, such as more survivors at earlier gestational ages, and improved neonatal management including surfactant, antenatal glucocorticoid therapy, and less aggressive mechanical ventilation.
Chorioamnionitis, also known as intra-amniotic infection (IAI), is inflammation of the fetal membranes, usually due to bacterial infection. In 2015, a National Institute of Child Health and Human Development Workshop expert panel recommended use of the term "triple I" to address the heterogeneity of this disorder. The term triple I refers to intrauterine infection or inflammation or both and is defined by strict diagnostic criteria, but this terminology has not been commonly adopted although the criteria are used.
Perinatal mortality (PNM) is the death of a fetus or neonate and is the basis to calculate the perinatal mortality rate. Perinatal means "relating to the period starting a few weeks before birth and including the birth and a few weeks after birth."
Gray baby syndrome is a rare but serious, even fatal, side effect that occurs in newborn infants following the accumulation of the antibiotic chloramphenicol. Chloramphenicol is a broad-spectrum antibiotic that has been used to treat a variety of bacteria infections like Streptococcus pneumoniae as well as typhoid fever, meningococcal sepsis, cholera, and eye infections. Chloramphenicol works by binding to ribosomal subunits which blocks transfer ribonucleic acid (RNA) and prevents the synthesis of bacterial proteins. Chloramphenicol has also been used to treat neonates born before 37 weeks of the gestational period for prophylactic purposes. In 1958, newborns born prematurely due to rupture of the amniotic sac were given chloramphenicol to prevent possible infections, and it was noticed that these newborns had a higher mortality rate compared with those who were not treated with the antibiotic. Over the years, chloramphenicol has been used less in clinical practice due to the risks of toxicity not only to neonates, but also to adults due to the risk of aplastic anemia. Chloramphenicol is now reserved to treat certain severe bacteria infections that were not successfully treated with other antibiotic medications.
Intraventricular hemorrhage (IVH), also known as intraventricular bleeding, is a bleeding into the brain's ventricular system, where the cerebrospinal fluid is produced and circulates through towards the subarachnoid space. It can result from physical trauma or from hemorrhagic stroke.
Neonatal encephalopathy (NE), previously known as neonatal hypoxic-ischemic encephalopathy, is defined as a encephalopathy syndrome with signs and symptoms of abnormal neurological function, in the first few days of life in an infant born after 35 weeks of gestation. In this condition there is difficulty initiating and maintaining respirations, a subnormal level of consciousness, and associated depression of tone, reflexes, and possibly seizures. Encephalopathy is a nonspecific response of the brain to injury which may occur via multiple methods, but is commonly caused by birth asphyxia, leading to cerebral hypoxia.
Neonatal withdrawal or neonatal abstinence syndrome (NAS) or neonatal opioid withdrawal syndrome (NOWS) is a withdrawal syndrome of infants after birth caused by in utero exposure to drugs of dependence, most commonly opioids. Common signs and symptoms include tremors, irritability, vomiting, diarrhea, and fever. NAS is primarily diagnosed with a detailed medication history and scoring systems. First-line treatment should begin with non-medication interventions to support neonate growth, though medication interventions may be used in certain situations.
Neonatal meningitis is a serious medical condition in infants that is rapidly fatal if untreated. Meningitis is an inflammation of the meninges, the protective membranes of the central nervous system, is more common in the neonatal period than any other time in life, and is an important cause of morbidity and mortality globally. Mortality is roughly half in developing countries and ranges from 8%-12.5% in developed countries.
Neonatal hypoglycemia occurs when the neonate's blood glucose level is less than the newborn's body requirements for factors such as cellular energy and metabolism. There is inconsistency internationally for diagnostic thresholds. In the US, hypoglycemia is when the blood glucose level is below 30 mg/dL within the first 24 hours of life and below 45 mg/dL thereafter. In the UK, however, lower and more variable thresholds are used. The neonate's gestational age, birth weight, metabolic needs, and wellness state of the newborn has a substantial impact on the neonates blood glucose level. There are known risk factors that can be both maternal and neonatal. This is a treatable condition. Its treatment depends on the cause of the hypoglycemia. Though it is treatable, it can be fatal if gone undetected. Hypoglycemia is the most common metabolic problem in newborns.
Neonatal resuscitation, also known as newborn resuscitation, is an emergency procedure focused on supporting approximately 10% of newborn children who do not readily begin breathing, putting them at risk of irreversible organ injury and death. Through positive airway pressure, and in severe cases chest compressions, medical personnel certified in neonatal resuscitation can often stimulate neonates to begin breathing on their own, with attendant normalization of heart rate.
Neonatal infections are infections of the neonate (newborn) acquired during prenatal development or within the first four weeks of life. Neonatal infections may be contracted by mother to child transmission, in the birth canal during childbirth, or after birth. Neonatal infections may present soon after delivery, or take several weeks to show symptoms. Some neonatal infections such as HIV, hepatitis B, and malaria do not become apparent until much later. Signs and symptoms of infection may include respiratory distress, temperature instability, irritability, poor feeding, failure to thrive, persistent crying and skin rashes.