Bacterial Sepsis
Neal J. Thomas
Robert F. Tamburro
Surender Rajasekaran
Julie C. Fitzgerald
Scott L. Weiss
Mark W. Hall
KEY POINTS
The International Consensus Conference on Pediatric Sepsis and Organ Dysfunction was convened to develop pediatric-specific definitions for systemic inflammatory response syndrome, sepsis, severe sepsis, and septic shock. These definitions provide the framework for the evaluation and analysis of sepsis across patient and study populations.
This overall prevalence of pediatric sepsis is 0.89 per 1000 children, with a national estimate of prevalence of severe sepsis of >75,000 cases. The greatest prevalence is in newborns (9.70 per 1000) and decreases to a low of 0.23 per 1000 in children 10-14 years of age.
While many viruses may cause the sepsis syndrome in isolation, the presence of bacterial coinfections, particularly methicillin-resistant Staphylococcus aureus, should be suspected in patients with a viral syndrome and severe sepsis.
An ever-growing body of literature suggests that the genetic composition of an individual influences the risk of developing sepsis and the outcome from that septic process. In fact, data suggest that death from infection has a stronger heritable component than death from cancer or cardiovascular disease.
The presence of a comorbid condition predisposes significantly to both the incidence and outcome of pediatric sepsis.
Any device that breaches the skin barrier and remains in place creates the potential for contamination of the device and subsequent bacteremia. Most endemic transmission follows the route of nose to hand to device from either the patient or the healthcare worker. Healthcare-associated infections are a large source of morbidity and have a high cost, making them a prime target for quality improvement initiatives.
Septic shock is commonly a combination of distributive, hypovolemic, and cardiogenic shock. Septic shock requires manifestations of decreased organ perfusion by definition.
Sepsis in children is much different than in adults. While some children, especially those in whom sepsis is recognized early in the course of infection, can present with the classic adult picture of “warm,” vasodilated shock signified by an increase in cardiac output and a decrease in systemic vascular resistance, most children will present with “cold” shock, with an increase in systemic vascular resistance and a decrease in cardiac output, requiring inotropic support as opposed to a vasopressor. Children often change sepsis phenotype during their course, and therapies that may have been appropriate on one day may not be beneficial, or may even be harmful, on another.
A critical part of the evaluation of the patient with suspected sepsis is the identification of an infectious source. Current guidelines recommend obtaining cultures and administering empiric broad-spectrum antibiotics within 1 hour of presentation.
The first hours following the diagnosis of severe sepsis represent an important opportunity for intervention to reverse shock and prevent or attenuate organ dysfunction.
The American College of Critical Care Medicine revised their clinical practice parameters for hemodynamic support of pediatric and neonatal patients in septic shock in 2009 (1). These parameters were also briefly reviewed in 2012 in a revision of the adult sepsis guidelines (2). These important documents were based upon review of the medical evidence and consensus expert opinion and fulfill an essential role in the standardization of pediatric sepsis treatment.
Goals of therapy for the initial management of pediatric septic shock include prompt recognition of decreased perfusion based on the clinical exam, administration of up to 60 mL/kg of crystalloid or colloid, initiation of antibiotics within 15 minutes of recognition of decreased perfusion, and initiation of inotropic agents for fluid-refractory shock within 60 minutes of shock recognition.
In bacterial sepsis, early diagnosis and intervention will result in improved outcomes. Compromised systemic perfusion can often be diagnosed clinically by poor skin perfusion and signs of decreased organ function. The use of hemodynamic monitoring may complement the clinical detection of compromised perfusion as well as assist in clinical decision making.
Healthcare-associated infections (HAIs) contribute significantly to hospital-associated morbidity, mortality, and costs. Critically ill children have an increased risk of sepsis related to HAIs due to a high rate of comorbid conditions, depressed immune function, and the presence of indwelling catheters and tubes.
The case-fatality rate from pediatric sepsis in 2005 was 8.9%, not significantly changed from 2000, but decreased from 1995. In the United States, there were 75,255 pediatric hospitalizations in 2005 involving severe sepsis, with an associated cost of $4.8 billion.INTRODUCTION AND DEFINITION
Brief Overview
Bacterial sepsis is a major cause of morbidity and mortality in children and a common reason for children to require pediatric intensive care unit (PICU) resources. Worldwide, sepsis is the most common cause of deaths in infants, as it can occur secondary to pneumonia, diarrhea, malaria, and other invasive bacterial diseases. Conversely, in developed countries, great progress has been made in the treatment of this heterogeneous, infectious condition, with the vast majority of children surviving sepsis. This chapter will serve to identify the epidemiology, etiology, pathophysiology, clinical presentation, clinical management, quality indicators, outcomes, and future directions of bacterial sepsis in children.
Definitions
The sepsis syndrome represents the systemic inflammatory response to suspected or proven infection. The associated signs and symptoms can include fever, tachycardia, tachypnea, abnormal peripheral white blood cell count, and evidence of organ dysfunction, but a practical framework for diagnostic criteria was lacking until the 2001 International Sepsis Definitions Conference (3). The definitions that resulted, including systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, and septic shock, were specific to adults. Thus, an International Consensus Conference on Pediatric Sepsis 
and Organ Dysfunction was convened to develop pediatricspecific definitions for SIRS, sepsis, severe sepsis, and septic shock, which were published in 2005 (4,5) (Table 87.1). To date, these definitions provide the framework for the evaluation and analysis of sepsis in children.
and Organ Dysfunction was convened to develop pediatricspecific definitions for SIRS, sepsis, severe sepsis, and septic shock, which were published in 2005 (4,5) (Table 87.1). To date, these definitions provide the framework for the evaluation and analysis of sepsis in children.TABLE 87.1 DEFINITIONS OF SYSTEMIC INFLAMMATORY RESPONSE SYNDROME, INFECTION, SEPSIS, SEVERE SEPSIS, AND SEPTIC SHOCK IN CHILDREN | |
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