Pediatric sepsis is currently defined as the systemic inflammatory response syndrome (SIRS), which includes either an abnormal temperature or leukocyte count along with tachycardia/bradycardia and/or tachypnea, in the presence of a confirmed or suspected invasive infection Severe sepsis is defined as sepsis plus (1) cardiovascular dysfunction, (2) acute respiratory distress syndrome, or (3) ≥2 organ system dysfunctions Septic shock refers to the subset of patients with cardiovascular dysfunction In 2005, approximately 75,000 children were hospitalized with severe sepsis in the United States at $4.8 billion in health care costs and an estimated mortality of 8.9% Although many patients who appear to have sepsis, severe sepsis, or septic shock have negative cultures, exposure to microbial components (e.g., endotoxin, lipoteichoic acid, viral proteins) is believed to trigger a cascade of inflammatory, coagulation, and vascular mediators that result in severe capillary leak (causing hypovolemia), myocardial depression, and vasomotor instability Although classic septic shock results in hyperdynamic cardiac function and low SVR that manifest as “warm” shock, more than half of children with septic shock exhibit low cardiac output and elevated SVR, or “cold” shock In 2016, Sepsis-3 updated the definition and operational criteria for sepsis and septic shock for adults with sepsis defined as life-threatening organ dysfunction caused by a dysregulated host response to infection and septic shock defined as the subset of sepsis with profound circulatory, cellular, and metabolic abnormalities associated with a greater risk of mortality than sepsis alone These updates acknowledge that SIRS is not always present in sepsis and that cellular/metabolic abnormalities are key components of septic shock Similar revisions to the definition/criteria for pediatric sepsis and septic shock have been proposed but not yet finalized In anaphylaxis, the sudden release of preformed histamine, proteases (tryptase, chymase), and proteoglycans (heparin) in mast cells followed by prostaglandins and leukotrienes leads to the classic symptoms of the skin (urticarial) and respiratory tract (edema, wheezing), as well as a profound vasodilatory response resulting in a low SVR state along with capillary leak causing hypovolemia The resulting neurohumoral response leads to an increase in heart rate and contractility that raise cardiac output (see Chapter 85 Allergic Emergencies ) Neurogenic Shock Neurogenic shock is a special cause of distributive shock resulting from the sudden disruption of sympathetic nerve stimulation to the vascular smooth vessel leading to a profound decrease in SVR Unlike other types of shock, the unopposed vagal activity classically results in bradycardia or, at least, absence of the usual tachycardic response to hypotension Neurogenic shock can be seen following severe traumatic brain or cervical spine injury (see Chapter 112 Neck Trauma ) Dissociative Shock Dissociative shock is a special category of shock that occurs as a consequence to a toxic metabolite or drug that severely impairs cellular oxygen delivery or utilization despite sustained or supranormal tissue perfusion Examples include severe anemia, methemoglobinemia, and carbon monoxide poisoning (see Chapter 102 Toxicologic Emergencies ) CLINICAL CONSIDERATIONS IN SHOCK RECOGNITION The early recognition of children with compensated shock is an important clinical challenge We focus here primarily on early septic shock recognition, but these principles can be applied to multiple shock types Vital Signs Important vital sign abnormalities, including fever or hypothermia, tachycardia, and tachypnea may signal developing septic shock Because hypotension is a late finding in pediatric shock, children often present in compensated shock with tachycardia and abnormal perfusion, but normal blood pressure However, given the high prevalence of SIRS in the pediatric emergency setting in patients without sepsis, as well as the overall rarity of sepsis in children with infectious illness, use of these vital sign–based criteria alone has proven insufficient to recognize sepsis The challenge of identifying the pediatric patient with compensated septic shock is often described as “finding a needle in a haystack.” As such, there is increasing interest from hospitals, professional medical societies, and legislative bodies to put systems in place to improve sepsis recognition Automated sepsis alert systems embedded in the electronic medical record are one such mechanism Although there is evidence that such alerts, which utilize differing combinations of history, vital signs, and nursing assessments, can improve the sensitivity of sepsis recognition, the specificity of such alerts can be substantially increased by a prompt physician evaluation at the bedside to assess for other clinical signs of shock In addition, the impact of these electronic alerts on sepsis overidentification, antibiotic overuse, and other balancing measures in the emergency department (ED) needs to be fully evaluated History and Physical Examination Findings In addition to vital signs, there are elements of history and physical examination that should be assessed to recognize compensated and decompensated shock In general, alteration in mental status, extremity perfusion, and oliguria are early indicators of shock Bedside point of care ultrasound (POCUS) is a helpful adjunctive tool to assess intravascular volume status, myocardial function, and other clues about the underlying etiology of shock (e.g., pericardial effusion, pneumothorax) that may be readily available in the ED setting Findings on POCUS may help to optimize interventions to correct shock and can be used to assess patient response to treatment Hemorrhagic Shock Determine by history whether there was possible trauma, and if so whether it was blunt or penetrating The provider should also determine whether any source of bleeding was recognized prior to arrival (e.g., hematemesis, hemoptysis, vaginal bleeding, hematochezia) The emergency provider also needs to have a high index of suspicion for nonaccidental trauma in a child presenting in shock with no other preceding symptoms Trauma or suspected trauma patients should undergo a full trauma evaluation including the primary and secondary surveys as detailed in Chapter A General Approach to the Ill or Injured Child Careful evaluation for evidence of bleeding including assessment of open fontanelles, all orifices, and thorough abdominal examination POCUS findings: The focused assessment with sonography in trauma (FAST) examination may identify areas of internal bleeding (e.g., abdominal, pericardial) Hypovolemic Shock Determine if volume loss may be due to decreased intake or increased output (vomiting, diarrhea) On physical examination, one should assess the following: Mental status/level of activity Sunken fontanelle and/or eyes Skin turgor Capillary refill Urine output POCUS findings: Ratio of inferior vena cava to aorta (IVC/Ao) 50% respiratory variation (nonintubated patients) and >20% respiratory variation in the IVC diameter on longitudinal view Repeat POCUS examinations during volume resuscitation can be used to evaluate for changes to the above parameters to determine if hypovolemia is improved A decrease in the IVC respiratory variation may indicate that the patient may not respond to further fluid resuscitation An IVC/Ao ratio of to 1.4 is indicative of euvolemia, and >1.4 is indicative of hypervolemia It is important to note that positive pressure ventilation may distend the IVC and limit the evaluation of fluid status using the IVC/Ao ratio Cardiogenic Shock Cardiogenic shock is often difficult to distinguish from other shock states, as a prolonged history of worsening symptoms is less common in children as compared to adult heart failure Historical information should be obtained regarding chest pain, syncope, known cardiac abnormalities, and cardiac medications On physical examination, one should assess the following: Neck: Jugular venous distention Cardiac: Murmur, gallop, perfusion abnormalities including delayed capillary refill, diminished or bounding pulses Respiratory: Respiratory distress, rales to suggest pulmonary edema Abdomen: Hepatomegaly Extremities: Peripheral edema, delayed capillary refill POCUS findings: Distended IVC, right and/or left ventricular or biventricular dysfunction, possible ventricular dilation, pulmonary edema may be seen on lung ultrasound Obstructive Shock On physical examination, one should assess the following: Neck: Jugular venous distention Cardiac: Murmur, gallop Respiratory: Unilateral decreased breath sounds suspicious for tension pneumothorax Abdomen: Hepatomegaly Extremities/skin: Poor perfusion, cyanosis in unrepaired congenital heart disease including differential perfusion, and cyanosis between the upper and lower extremities to indicate interrupted aortic arch or critical aortic coarctation Beck triad in cardiac tamponade: Distended neck veins, hypotension, diminished heart sounds POCUS findings: Distended IVC, possible right ventricular dilation and systolic dysfunction in pulmonary embolism or tension pneumothorax, possible pericardial effusion in cardiac tamponade  ... in pediatric shock, children often present in compensated shock with tachycardia and abnormal perfusion, but normal blood pressure However, given the high prevalence of SIRS in the pediatric emergency. .. sign–based criteria alone has proven insufficient to recognize sepsis The challenge of identifying the pediatric patient with compensated septic shock is often described as “finding a needle in a haystack.”... electronic alerts on sepsis overidentification, antibiotic overuse, and other balancing measures in the emergency department (ED) needs to be fully evaluated History and Physical Examination Findings