DEFINITION
Sepsis in the newborn or neonatal sepsis is any infection affecting an infant during the first 28 days of life or up to 2 months of life according to some authors. Neonatal sepsis is also known as "sepsis neonatorum." It is an infection that spreads throughout the baby’s body. Sepsis occurs in less than 1 percent of newborns (1 out of every 100), but accounts for up to 30 percent of deaths in the first few weeks of life. Infection is 5-10 times more common in premature newborns and in babies weighing less than 5½ pounds than in normal-weight, full-term newborns.
The infection may be systemic or globally or may be local or limited to just one organ like the lungs, heart,and others. It may be acquired prior to birth (intrauterine sepsis) or after birth (extrauterine sepsis) and maybe due to different causes like Viral (such as herpes, rubella [German measles]), bacterial (such as group B strep) and more rarely fungal (such as Candida). It can either be an early onset sepsis or late onset sepsis depending on the onset of signs and symptoms.
SIGNS AND SYMPTOMS
During pregnancy, it is important to constantly monitor the health of both the pregnant woman and her fetus for any signs or symptoms that might indicate sepsis. There are many indicators that can signal if a potential infection is developing even before delivery. Pregnant Women are screened for infectious diseases ideally on the first pre-natal visit. Some of these include the TORCHS infections like toxoplasmosis, rubella, Chlamydia, herpes, hepatitis B, HIV and syphilis and other sexually transmitted diseases like gonorrhea. Sometimes even immunity to chickenpox is also being checked and between the 35th and 37th week of pregnancy, screening for group B strep is commonly performed.
Some signs and symptoms like a slower than anticipated fetal growth may be a subtle indication of threatened fetal well-being. This can be monitored by measuring the uterine size via the traditional tape measure or ultrasound examination of the uterus, placenta, and fetus. During every prenatal visit, it is important to monitor the actual fetal heart rate at rest as well as the infant's cardiac response to a mild stress like uterine contraction or do a biophysical scoring system for risk assessment which includes taking note of the fetal heart rate, fetal movement and fetal tone. Maternal fever at anytime during her pregnancy should be evaluated and treated if it indicates presence of infection like UTI. The onset of premature labor or premature rupture of the amniotic sac (termed "premature rupture of membranes") may also put a newborn at increased risk of infection.
During labor, several risk factors may indicate the possibility of developing neonatal sepsis. Abnormalities of fetal heart rate, maternal fever, premature separation of the placenta from the uterine wall, or foul smelling/cloudy amniotic fluid all indicate a high-risk labor and delivery. These would require prompt consultation with the pediatrician or neonatologist regarding the potential for delivery and/or postpartum complications.
During labor, several risk factors may indicate the possibility of developing neonatal sepsis. Abnormalities of fetal heart rate, maternal fever, premature separation of the placenta from the uterine wall, or foul smelling/cloudy amniotic fluid all indicate a high-risk labor and delivery. These would require prompt consultation with the pediatrician or neonatologist regarding the potential for delivery and/or postpartum complications.
A neonate who fails to make a smooth transition from intrauterine to extrauterine life should be considered at high risk for sepsis. It is very crucial to closely monitor the vital signs (heart rate, respiratory rate and effort, skin color, temperature, and activity) and see the trending to anticipate such an occurrence.
Early-onset neonatal sepsis occurs within six hours of birth in over half the cases and within 72 hours in the great majority of cases. It is usually due to either prenatal factors as mentioned previously or during labor. Sepsis that begins four or more days after birth is called late-onset sepsis, and is probably an infection acquired in the hospital nursery (a nosocomial infection). In both types of neonatal sepsis, the infection may be only in the bloodstream, or may spread to the lungs (pneumonia), brain (meningitis), bone (osteomyelitis), joints, or other organs in the body.
Typical symptoms of a newborn with sepsis include: CRAFTS
CARDIAC symptoms (bradycardia, tachycardia)
unusual RASHES
poor ACTIVITY or listlessness (a very sleepy baby)
poor FEEDING
a high OR low TEMPERATURE jaundiced SKIN
unusual RASHES
poor ACTIVITY or listlessness (a very sleepy baby)
poor FEEDING
a high OR low TEMPERATURE jaundiced SKIN
Other symptoms include: GIJRS
GASTROINTESTINAL symptoms (repeated vomiting, projectile vomiting, diarrhea, abdominal distention)
excessive JITTERINESS
RESPIRATORY symptoms (difficulty of breathing, rapid breathing, apnea or when the baby stops breathing)
SEIZURES
excessive JITTERINESS
RESPIRATORY symptoms (difficulty of breathing, rapid breathing, apnea or when the baby stops breathing)
SEIZURES
DIAGNOSIS
To arrive at a diagnosis of neonatal sepsis, it is important to take a complete history (including pregnancy, labor, and delivery) and perform a thorough physical examination. Various laboratory tests are also requested annd done which include:
Blood tests:
CBC (Complete blood count) with White Blood Cell Count and Differential, platelet count, toxic granules
When an infant is fighting an infection, their white blood cell count may increase, as the infant’s body produces more infection-fighting cells, or it might also decrease if the infant has used up all of their white blood cells fighting the infection and can no longer keep up with their production of white cells. Another change that is seen when an infant is fighting an infection is an increase in the percentage of immature white cells. This is due to the increased production rate of white blood cells, such that more immature white blood cells are being released into the blood stream. This higher percentage of immature white cells is sometimes referred to as a “left-shift,” and is one of the things that can tell the doctors that the infant has an infection. The presence of toxic granules may also indicate infection.
CRP (C-Reactive Protein)
This is a laboratory test that measures a protein that is a non-specific marker for inflammation and therefore infection. If the infant has two normal CRP levels measured 24 hours apart, then there is a 99% chance that the infant does not have an infection. Therefore, this test is most useful in ruling out an infection.
Blood chemistries (blood sugar, kidney- and liver-function tests, CPKMB)
A random blood sugar (RBS) or Hemoglucose test (Hgt) that is below normal may indicate infection. Increased levels of renal function test with urinary tract infection may signify acute renal failure and give a bad prognosis. An elevated liver function test levels may indicate the need to decrease dosages of the antibiotics and sometimes may require a more invasive approach to treatment like exchange transfusion if coupled with marked jaundice unresponsive to the usual regimen. Sometimes, persistent bradycardia despite adequate antibitoic therapy may warrant a request for CPKMB.
Cultures of body fluids (blood, urine, CSF [cerebrospinal fluid])
Positive cultures will help identify the cause of sepsis in the neonate as well as guide the antibiotic therapy. Only small samples of blood and other body fluids are taken so that sometimes no organism is found. However, the infant may still be treated if other laboratory studies or the infant’s clinical appearance strongly suggest an infection.
A spinal tap, or lumbar puncture will be performed if meningitis is suspected, especially more common if something has grown in the baby’s blood culture. It allows the doctor to obtain a small amount of cerebrospinal fluid (CSF), which is the protective fluid that surrounds the brain and the spinal cord. The CSF can then be cultured to determine if the bacteria has spread to the nervous system.
Radiological studies (chest and abdominal X-rays, ultrasound studies)
Two-dimensional echocardiography (2D echo), if with elevated CPKMB levels
Two-dimensional echocardiography (2D echo), if with elevated CPKMB levels
PROGNOSIS AND TREATMENT
Neonatal sepsis is treated with antibiotics given intravenously. Antibiotics are often started ideally after all the necessary blood work ups are requested and done and even before laboratory and culture results are available. The empiric choice of antibiotics depends on the prevailing or common cause of neonatal infection. The doctor may then shift to a different antibiotic that is more specific to the baby’s infection once the results of laboratory tests are back. The duration of antibiotic treatment varies depending on the infant’s clinical status, laboratory test results, and kind of infection. If blood cultures and other laboratory tests are all negative, antibiotics may be discontinued after 48 hours of treatment. If the cultures are positive, or if the laboratory tests and clinical status are suggestive of infection, the treatment with antibiotics may range between 7-14 days. When appropriately treated with antibiotics and cared for in the intensive care unit, the great majority of newborns with sepsis live without any long-term sequelae.
The treatment of sepsis in the newborn involves correcting any abnormal vital signs as well as directed antibiotic therapy. A very sick infant will commonly need IV fluids and may require medications to support blood pressure and heart function. Since many of these infants are very weak and too sick to feed, nutritional support will commonly involve administration of either breast milk/formula via a tube passed through the oropharynx into the stomach or rely solely on IV mixtures of proteins, carbohydrates, and fats. For some critically ill neonates, assisted ventilation (via a tube passed into the larynx) may be necessary.
Prevention of sepsis in the newborn is still the key to a good neonatal outcome. It requires a timely and focused prenatal care, close observation during labor and delivery and detailed monitoring of the newborn after birth in the nursery and even at home after discharge.
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