Neonatal Sepsis

Written by Dr.Md.Redwanul Huq (Masum)
Monday, 16 January 2012 06:51

Definition:

Neonatal sepsis is defined as a clinical syndrome of bacteremia characterized by systemic signs and symptoms of infection in the first 4 weeks of life.

Classification:

Neonatal sepsis can be classified into two main groups depending on the time of onset of symptoms:

1. Early onset neonatal sepsis
2. Late onset neonatal sepsis

1. Early onset neonatal sepsis:

  • Early onset neonatal sepsis usually presents within first 72 hours of life.
  • The source of infection: The source of infection is generally maternal genital tract.
  • The associated factors for early-onset sepsis include-
  1. low birth weight,
  2. prolonged rupture of membranes,
  3. foul smelling liquor,
  4. multiple per vaginum examinations,
  5. maternal fever,
  6. difficult or prolonged labour
  7. aspiration of meconium.

Late onset neonatal sepsis:

  • Late onset sepsis usually presents after 72 hours of life.
  • The source of infection: The source of infection is in the external environment of the home (community acquired) or the hospital (Nosocomial).
  • The associated factors for late-onset sepsis include-
  1. low birth weight,
  2. lack of breastfeeding,
  3. superficial infections (pyoderma, umbilical sepsis),
  4. aspiration of feeds,
  5. disruption of skin integrity with needle pricks
  6. use of intravenous fluids.
  • Late onset sepsis manifests as septicemia, pneumonia or meningitis.

Risk factors for neonatal sepsis:

Major risk factors for neonatal sepsis–

  • Rupture membrane >24 hrs,
  • Maternal intrapurtum fever >100.4° F/ 38° C,
  • Gestational age <35 wks,
  • Chorioamniontis.

Minor risk factors for neonatal sepsis–

  • Rupture membrane >12 hrs
  • Maternal intrapurtum fever >99.5 F/37.5 C
  • Gestational age <37 wks
  • Low Birth wight <1500 gm
  • Multiple births
  • Foul P/V discharge
  • Low Apgar score (/<5 in 1 min & <7 in 5 min)

(N.B. Infants with one major or two minor risk factors should have a CBC & blood culture & then antibiotics should be started)

Etiology:

  • The microorganisms most commonly associated with early-onset infection include group B Streptococcus (GBS), Escherichia coli, coagulase-negative Staphylococcus, Haemophilus influenzae and Listeria monocytogenes.
  • The microorganisms most commonly associated with late-onset infection in the community are Escherichia coli and Staphylococcus aureus. In hospitals, Klebsiella pneumoniae is also a common organism.

Clinical features:

1. Reduced feeding ability
2. No spontaneous movement (Lethargy)
3. Body temperature >38° C**
4. Prolonged capillary refill time
5. Lower chest wall in drawing*
6. Resp rate > 60/minute (tachypnoea)*
7. Grunting*
8. Cyanosis*
9. H/o of convulsions**
10.Blank look**
11.High pitched cry**
12.Irritability**
13.Neck rigidity**
14.Bulging fontanel**
* Suggestive of pneumonia.
** Suggestive of meningitis.

Investigations for suspected sepsis:

Direct diagnostic method-

Isolation of microorganisms from blood, CSF, urine, pleural fluid or pus is diagnostic.

Indirect diagnostic method-

1. Sepsis screening:
1.Total WBC count: <5000/cmmb)
2.Band – Neutrophil ratio >0.2
3. Micro ESR – >15 mm in the 1st
4.CRP: raised (>10 mg/dl)
5.Haptoglobin – raised
(Note: If all 5 tests are normal probability of no sepsis is 99%,If 3 of 5 tests are positive
probability of sepsis is 90%)
2. Blood culture:
If sepsis is suspected or there is risk factor for sepsis.
3. CSF study:
All late onset sepsis & suspected meningitis (if indicated).
(Indications of CSF study-

  • Late onset sepsis
  • Seizure
  • Bulged fontanel
  • Neck rigidity
  • High pitched cry
  • Iirritability
  • Fever)

CSF study shows increased cells and proteins.
4. X-ray chest:
If respiratory distress (severe chest indrawing, tachypnoea, grunting, cyanosis)
5. Urine for R/M/E & C/S:
(In late onset sepsis) UTI can be diagnosed in presence of one of the following:
a) >10 WBC /cmm in a 10 ml centrifuged urine sample
b) >10 organisms / ml in urine (obtained by catheterization) &
c) any organism in urine (obtained by suprapubic aspiration).
6.  Hb%, Platelet count, Blood sugar,serum electrolytes, X-ray abdomen(If necessary).
7. USG of the brain in all patients to diagnose meningitis.

Treatment of neonatal sepsis:

Supportive care & antibiotics are two equally important components of treatment of neonatal sepsis.

A) Supportive care:

Supportive care of a septic neonate-
1. Providing warmth, ensuring consistently normal temperature,
2. Infusing intravenous fluid if indicated(described later).
3. Infusing normal saline 10 ml/kg over 5-10 minutes, if perfusion is poor as evidenced by
capillary refill time (CRT) of> 3 seconds.The same dose should be repeated  1-2 times over
the next 30-45 minutes, if perfusion continues to be poor.
4. Infusing glucose (10 percent) 2 ml/kg stat.
5. Inj. Vitamin K 1 mg intramuscularly.
6. Oxygen therapy, if the neonate is cyanosed or grunting or have severe chest indrawing.
7. Providing gentle physical stimulation, if the neonate is apneic.
8. Providing bag and mask ventilation with oxygen if breathing is inadequate.
9. Avoidance of enteral feeding if very sick, giving maintenance IV fluids.
10. Use of dopamine if perfusion is persistently poor.
11.Blood transfusion if indicated(described later).
12.Transfusion of Fresh frozen plasma – for bleeding.
13.Exchange transfusion if indicated.

Indications of I/V infusion:

1. Birth weight <1.2kg
2. Gestational age <30 weeks
3. Severe perinatal asphyxia
4. Severe respiratory distress (severe chest indrawing, tachypnoea, gasping, grunting, cyanosis )
5. Apnoea
6. Recurrent seizure
7. NEC(Necrotizing EnteroColitis)/ Intestinal obstruction
8. Absent bowel sound
9. Feeding intolerance (poor sucking, choking, vomiting, abdominal distension, gastric stasis, blood in the stool.)

Indication of Blood transfusion:

In mobile transfusion – [20 ml/Kg] [17 ml blood + 3 ml CPD]
1. Hb – <12 gm / dl (in neonatal sepsis)
2. Sclerema
3. NEC(Necrotizing EnteroColitis)
4. Hb – <10 gm in a symptomatic baby (poor weight gain, poor feeding,tachycardia )
5. Hb – <8 gm in a asymptomatic baby
6. Acute blood loss
7. Heart failure due to anaemia.

B) Antibiotics:

If any of the culture yields any organism, antibiotics should be continued for 14 & 21 days for gm positive & gm negative organisms respectively. In culture negative cases, if the sepsis screen is positive & / or the patient is clinically suggestive then antibiotics should be continued for 7 days. For culture and sepsis screen negative cases and the patients who are also clinically not suggestive of having infection, antibiotics can be discontinued. Babies in the hospital and those younger than 4 weeks old are started on antibiotics before lab results are back(Lab results may take 24-72 hours). Antibiotic therapy should cover the common causative bacteria, namely,Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. A combination of ampicillin and gentamicin is recommended for treatment of sepsis and pneumonia. In cases of suspected meningitis, cefotaxime should be used along with an aminoglycoside. Detailed guidelines about antibiotic therapy in neonatal sepsis is given bellow:

Recommended Antibiotics for suspected sepsis:

1st line Antibiotics:
Inj. Ampicillin (200 mg/kg/day) plus Inj. Gentamycin (5 mg/kg/day)
2nd line Antibiotics:
Inj. Ceftriaxone (100 mg/kg/day)/Inj. Cefotaxime (100 mg/kg/day)/Inj. Ceftazidime (100 mg/kg/day)
plus Inj. Amikacin (15-25 mg/kg/day)
3rd line Antibiotics:
Inj. Ciprofloxacin (20-30 mg/kg/day) or Inj. Meropenum /Inj. Imipenum(20-40 mg/kg/day).
[N.B.:If NEC or intestinal pathology is suspected Inj. Metronidazole – 1.5 ml/kg/dose 8 hourly divided doses should be added. When nosocomial infection is suspected Inj. Cloxacillin(100 mg/kg/day) should be added.If the infection is caused by MRSA Inj.vancomycin (30 mg/kg/day) should be used.]

Complications of neonatal sepsis:

  •  Disability
  • Death

Prevention of neonatal sepsis:

  •  A good antenatal care-

* All mothers should be immunized against tetanus.

* All types of infections should be diagnosed early and treated vigorously in pregnant mothers.

  • Preventative antibiotics may be given to pregnant women who have chorioamnionitis, Group B strep, or who have previously given birth to an infant with sepsis due to the bacteria.
  • Preventing and treating infections in mothers.
  • Providing a clean birth environment, and delivering the baby within 24 hours of rupture of membranes where possible.
  • Babies should be fed early and exclusively with expressed breast milk (or breastfed) without any prelacteal feeds.
  • Cord should be kept clean and dry.
  • Unnecessary interventions should be avoided.
  • All persons taking care of the baby should strictly follow hand washing policies before touching any baby. The sleeves should be rolled above the elbows. Rings, watches and jewellery should be removed.
  • The nursery environment should be clean and dry with 24 hour water supply and electricity. There should be adequate ventilation and lighting. The nursery temperature should be maintained between 30+2°C. Overcrowding should be avoided. All procedures should be performed after wearing mask and gloves. Every baby must have separate thermometer & stethoscope and all barrier nursing measures must be followed.

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