Tamara van Donge

Chapter 3 44 in pediatric intensive care units is 8.2%. 6 Unfortunately, there has been a limited focus on pediatric sepsis and most of the current dosing guidelines for antibiotic treatment are simply extrapolated from adult studies. 7 Further it has been reported that dosing recommendations across intensive care units and international guidelines are highly variable and inconsistent. 8 Characterization of sepsis Diagnosis of sepsis in neonates and infants is complex. Appearances of non-infectious symptoms, which imitate those of sepsis, increase the likelihood of a misdiagnosis. In developed regions the complete sepsis work-up consists of obtaining a blood culture, complete white blood cell count, urine cultures, lumbar puncture and chest radiography. These methods are time consuming, and treatment will have already started before microbiological results are available. In low- and middle-income countries (LMIC), the absence of optimal diagnostic tools together with a high proportion of home births are additional challenging factors. 9 Neonates and infants have unique physiologic characteristics and therefore a distinction between these two populations has been made in terms of diagnostic criteria. Neonatal sepsis can be divided into early and late onset neonatal sepsis (EONS and LONS), which reflects the timing of onset of symptoms, type and virulence of organism and associated pathogenesis. 2 EONS is defined by a life-threatening infection during the first days of life. Hypothermia is more often observed compared to fever, but symptoms such as apnea, grunting and tachypnea can also occur. 3,10-12 In developed countries Group B Streptococcus and Escherichia coli account for most episodes of EONS. 13 Risk factors for EONS are prematurity, premature and prolonged rupture of membranes, intrapartum maternal fever (>38˚C) and maternal Group B Streptococcus colonization. 3,11,12 As expected, neonates with a very low birth weight (VLBW, < 1500 g) are more susceptible to an infection. 11,14 LONS is characterized by the onset of symptoms more than 72 hours after birth. Among VLBW neonates, Gram-positive organisms are most commonly associated with LONS, although it has been shown that the mortality rate is 2-3 times higher in neonates with Gram-negative infections. Prolonged indwelling catheter use and other invasive procedures are potential risk factors. 11 Streptococcus pneumoniae is a major cause of invasive infections during childhood. Because of vaccinations, infections caused by Haemophilus influenzae type b are less common in developed countries compared to resource limited settings. 10 A recent study showed that only 42% of children diagnosed with sepsis, were identified as such by both the physician and the current diagnostic criteria for pediatric sepsis. 15,16 It has been shown that almost half of the pediatric population with sepsis has a comorbid condition, such as congenital heart disease or chronic lung disease, increasing their susceptibility to an infection. 17