Neonatal Sepsis - Preg Med

What is neonatal sepsis?

Neonatal sepsis, also known as sepsis neonatorum and neonatal septicemia, is a bacterial blood infection found in newborn infants younger than 3 months ^[1]. It can be a life threatening condition unless treated at an early stage.

Neonatal Sepsis Types

Early-onset neonatal sepsis: Occurring within 24 hours to one week of birth ^[2]
Late-onset neonatal sepsis: Occurring in newborns aged between one week and 3 months ^[3]

What are the causes of neonatal sepsis?

Early-onset neonatal sepsis

Different kinds of bacteria, including Listeria, E.coli (Escherichia coli), Group B Streptococcus, Haemophilus influenza and Klebsiella pneumonia are generally responsible for this infection. Risk factors include:

Preterm delivery
Group B streptococcus (GBS) infection during pregnancy ^[4]
Rupture of membranes (water breaking) that last for over 24 hours before delivery
Chorioamnionitis (infection of the amniotic fluid and placenta tissues) ^[5]
Maternal fever at the time of labor ^[6]

Late-onset neonatal sepsis

Caused by different organisms like Coagulase-negative Staphylococcus, Staphylococcus aureus, E.coli and GBS, risk factors for late-onset neonatal sepsis include:

Extended use of catheter during pregnancy ^[7]
Extended hospital stay after the baby is born ^[8]

Neonatal Sepsis Pathophysiology

Neonates are highly vulnerable to bacterial infection due to their low non-specific and specific immunity, such as chemotaxis response delay, low phagocytosis, low or no IgA (immunoglobulin A) and IgM (immunoglobulin M) and low complement levels (a type of blood protein that functions alongside antibodies during immune responses) ^[9].

The early-onset type of the infection is usually obtained from the blood stream of the mother or by aspiration or ingestion of contaminated amniotic fluid. In late onset sepsis, bacterial invasion generally occurs through the gated umbilical stump, nose, skin, mucus membranes of the eyes, ear, pharynxes as well as internal systems like the respiratory, urinary, gastrointestinal and nervous systems. Babies may also get contaminated from other babies, adults (parents, caregivers) and objects.

What are the signs and symptoms of neonatal sepsis?

Abnormally high (100.4 °F) or low body temperatures ^[10]
Diarrhea
Slow heart rate
Respiratory distress (often presents as tachypnea and mild nasal flaring) ^[11]
Poor feeding or sucking ^[4]
Low blood sugar
Swelling of the belly area
Jaundice or changes in skin color (skin turning pale or bluish) ^[10]
Vomiting
Seizures ^[8]
Irritability
Lethargy and extreme sleepiness
Skin rash
Decreased urine output ^[12]
Cold, clammy skin ^[13]
Reduced movements

Neonatal Sepsis Prevention

A swab test performed between the 35th week and the 37th week can determine whether the mother is carrying the GBS bacteria. Women with a positive swab test result are given intravenous antibiotics around 4 hours before delivery so that the infection does not transmit to the baby ^[14].

A fever when in labor, a premature rupture of membranes or a history of having children with sepsis (or any other GBS infection) increases the chances of carrying the bacteria. So, women with these risk factors are given IV antibiotics in labor to reduce the risk of infection in the newborn. Delivering the baby within 24 hours of labor and providing a clean birth environment can also help with the prevention ^[4].

Preventive measures for the late-onset form include:

Vaccination against Haemophilus influenzae type b and specific strains of pneumococcus ^[15]
Washing your hands properly
Making sure no sick or infected person comes near your baby
Children in need for long term use of medical devices like IV lines and catheters should be given extra care for keeping the devices and the surrounding environment clean and hygienic

Neonatal Sepsis Diagnosis

Most diagnostic tests involve checking for bacteria in the baby’s body.

Blood tests (e.g. complete blood count) and blood cultures ^[4] for detecting traces of bacteria in the blood as well as for determining that organs like the liver and kidneys are working properly. An abnormal WBC count, low platelet count or a high I:T ratio (ratio between the number of immature WBC and total WBC) helps to confirm the diagnosis ^[11]
Urine culture
X-rays, especially chest x-rays to rule out pneumonia (it is generally performed on babies having breathing difficulty) ^[4]
Lumbar puncture or spinal tap for detecting the infection and differentiating it from other conditions like meningitis (it depends on age and overall health of the baby)
Ultrasound studies ^[16]
Culture of skin lesions^[13]
Bowel obstruction in the infant ^[17]
Congenital pneumonia
Congestive heart failure
Newborn hemolytic disease
Congenital diaphragmatic hernia
Respiratory distress syndrome
Necrotizing enterocolitis
Bacterial pericarditis ^[17]
Meconium aspiration syndrome
Pulmonary hypoplasia

Neonatal Sepsis Differential Diagnosis

Bowel obstruction in the infant ^[17]
Congenital pneumonia
Congestive heart failure
Newborn hemolytic disease
Congenital diaphragmatic hernia
Respiratory distress syndrome
Necrotizing enterocolitis
Bacterial pericarditis ^[17]
Meconium aspiration syndrome
Pulmonary hypoplasia

Neonatal Sepsis Treatment and Management

The treatment depends on the type, severity and location of the infection. It may continue for 7 to 21 days after the diagnosis is confirmed by a culture test ^[13]. Neonates suspected to have sepsis at birth are immediately given empirical antibiotic treatment, before a confirmed diagnosis ^[18]. Ampicillin is an antibiotic medication commonly used for this purpose^[19]. Doctors may also employ the following treatment options:

Medications that help to maintain the blood pressure and proper heart functioning
IV fluids for keeping the patient hydrated
Correction of abnormal vital signs
Nutritional support involving administration of formula, breast milk or a mixture of carbohydrates proteins and fats ^[13]
Assisted ventilation (in severe cases) ^[16]

Mild cases of late-onset sepsis can be treated without antibiotics [4]. Instead, the affected babies are closely monitored on an outpatient basis.

Neonatal sepsis associated with meningitis, extracorporeal membrane oxygenation therapy, prolonged hypoxia and brain abscess generally need long-term follow-up treatment (continuing several years) for assessing proper neurodevelopment ^[20].

What is the prognosis for neonatal sepsis?

Failing to address the infection early can lead to organ damage, disability and even death. Studies show neonatal sepsis to be one of the main causes of infant death. However, proper early treatment can cure the problem completely with no side effects or complications ^[4].

Are there any possible complications of neonatal sepsis?

Sepsis associated with meningitis may lead to the following complications ^[21]:

Cerebral palsy
Developmental delay
Hearing loss
Seizures

Neonatal Sepsis Incidence Statistics

It is considered an uncommon condition, occurring in 2 to 4 out of every 1000 live births ^[22].

What are the ICD-9 and ICD-10 Codes for neonatal sepsis?

The ICD-9 code used for indicating neonatal sepsis is 771.81 ^[23] while its ICD-10 code is P36 ^[24].

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