Peter Skippen

Clinical practice parameters for hemodynamic support of pediatric and neonatal septic shock: 2007 update from the American College of Critical Care Medicine

Background:The Institute of Medicine calls for the use of clinical guidelines and practice parameters to promote “best practices” and to improve patient outcomes. Objective:2007 update of the 2002 American College of Critical Care Medicine Clinical Guidelines for Hemodynamic Support of Neonates and Children with Septic Shock. Participants:Society of Critical Care Medicine members with special interest in neonatal and pediatric septic shock were identified from general solicitation at the Society of Critical Care Medicine Educational and Scientific Symposia (2001–2006). Methods:The Pubmed/MEDLINE literature database (1966–2006) was searched using the keywords and phrases: sepsis, septicemia, septic shock, endotoxemia, persistent pulmonary hypertension, nitric oxide, extracorporeal membrane oxygenation (ECMO), and American College of Critical Care Medicine guidelines. Best practice centers that reported best outcomes were identified and their practices examined as models of care. Using a modified Delphi method, 30 experts graded new literature. Over 30 additional experts then reviewed the updated recommendations. The document was subsequently modified until there was greater than 90% expert consensus. Results:The 2002 guidelines were widely disseminated, translated into Spanish and Portuguese, and incorporated into Society of Critical Care Medicine and AHA sanctioned recommendations. Centers that implemented the 2002 guidelines reported best practice outcomes (hospital mortality 1%–3% in previously healthy, and 7%–10% in chronically ill children). Early use of 2002 guidelines was associated with improved outcome in the community hospital emergency department (number needed to treat = 3.3) and tertiary pediatric intensive care setting (number needed to treat = 3.6); every hour that went by without guideline adherence was associated with a 1.4-fold increased mortality risk. The updated 2007 guidelines continue to recognize an increased likelihood that children with septic shock, compared with adults, require 1) proportionally larger quantities of fluid, 2) inotrope and vasodilator therapies, 3) hydrocortisone for absolute adrenal insufficiency, and 4) ECMO for refractory shock. The major new recommendation in the 2007 update is earlier use of inotrope support through peripheral access until central access is attained. Conclusion:The 2007 update continues to emphasize early use of age-specific therapies to attain time-sensitive goals, specifically recommending 1) first hour fluid resuscitation and inotrope therapy directed to goals of threshold heart rates, normal blood pressure, and capillary refill ≤2 secs, and 2) subsequent intensive care unit hemodynamic support directed to goals of central venous oxygen saturation >70% and cardiac index 3.3–6.0 L/min/m2.

Long-term Risk of CKD in Children Surviving Episodes of Acute Kidney Injury in the Intensive Care Unit: A Prospective Cohort Study

BACKGROUND The development of standardized acute kidney injury (AKI) definitions has allowed for a better understanding of AKI epidemiology, but the long-term renal outcomes of AKI in the pediatric critical care setting have not been well established. This study was designed to: (1) determine the incidence of chronic kidney disease (CKD) in children 1-3 years after an episode of AKI at a tertiary-care pediatric intensive care unit (ICU), (2) identify the proportion of patients at risk of CKD, and (3) compare ICU admission characteristics in those with and without CKD. DESIGN Prospective cohort study. SETTING & PARTICIPANTS Patients admitted to the British Columbia Childrens Hospital pediatric ICU from 2006-2008 with AKI, as defined by AKI Network (AKIN) criteria. Surviving patients, most with short-term recovery from their AKI, were assessed at 1, 2, or 3 years after AKI. PREDICTORS Severity of AKI as defined by AKIN and several ICU admission characteristics, including demographics, diagnosis, severity of illness, and ventilation data. OUTCOMES & MEASUREMENTS CKD was defined as the presence of albuminuria and/or glomerular filtration rate (GFR) < 60 mL/min/1.73 m2. Being at risk of CKD was defined as having a mildly decreased GFR (60-90 mL/min/1.73 m2), hypertension, and/or hyperfiltration (GFR ≥ 150 mL/min/1.73 m2). RESULTS The proportion of patients with AKI stages 1, 2, and 3 were 44 of 126 (35%), 47 of 126 (37%), and 35 of 126 (28%), respectively. The number of patients with CKD 1-3 years after AKI was 13 of 126 (10.3% overall; 2 of 44 [4.5%] with stage 1, 5 of 47 [10.6%] with stage 2, and 6 of 35 [17.1%] with stage 3; P = 0.2). In addition, 59 of 126 (46.8%) patients were identified as being at risk of CKD. LIMITATIONS Several patients identified with AKI were lost to follow-up, with the potential of underestimating the incidence of CKD. CONCLUSIONS In tertiary-care pediatric ICU patients, ∼10% develop CKD 1-3 years after AKI. The burden of CKD in this population may be higher with further follow-up because several patients were identified as being at risk of CKD. Regardless of the severity of AKI, all pediatric ICU patients should be monitored regularly for long-term kidney damage.

Effect of hyperventilation on regional cerebral blood flow in head-injured children.

OBJECTIVES To study cerebral blood flow and cerebral oxygen consumption in severe head-injured children and also to assess the effect of hyperventilation on regional cerebral blood flow. DESIGN Prospective cohort study. SETTING Pediatric intensive care unit at a tertiary-level university childrens hospital. PATIENTS Twenty-three children with isolated severe brain injury, whose admission Glasgow Coma Scores were <8. INTERVENTIONS PaCO2 was adjusted by altering minute ventilation. Cerebral metabolic measurements were made at three levels of PaCO2 (>35, 25 to 35, and <25 torr [>4.7, 3.3 to 4.7, and <3.3 kPa]) after allowing 15 mins for equilibrium. MEASUREMENTS AND MAIN RESULTS Thirty-eight studies (each study consisting of three sets of measurements at different levels of PaCO2) were performed on 23 patients. At each level of PaCO2, the following measurements were made: xenon-enhanced computed tomography scans; cerebral blood flow; intracranial pressure; jugular venous bulb oxygen saturation; mean arterial pressure; and arterial oxygen saturation. Derived variables included: cerebral oxygen consumption; cerebral perfusion pressure; and oxygen extraction ratio. Cerebral blood flow decreased below normal after head injury (mean 49.6 +/- 14.6 mL/min/100 g). Cerebral oxygen consumption decreased out of proportion to the decrease in cerebral blood flow; cerebral oxygen consumption was only a third of the normal range (mean 1.02 +/- 0.59 mL/min/100 g). Neither cerebral blood flow nor cerebral oxygen consumption showed any relationship to time after injury, Glasgow Coma Score at the time of presentation, or intracranial pressure. The frequency of one or more regions of ischemia (defined as cerebral blood flow of <18 mL/min/100 g) was 28.9% during normocapnia. This value increased to 73.1% for PaCO2 at <25 torr. CONCLUSIONS Severe head injury in children produced a modest decrease in cerebral blood flow but a much larger decrease in cerebral oxygen consumption. Absolute hyperemia was uncommon at any time, but measured cerebral blood flow rates were still above the metabolic requirements of most children. The clear relationship between the frequency of cerebral ischemia and hypocarbia, combined with the rarity of hyperemia, suggests that hyperventilation should be used with caution and monitored carefully in children with severe head injuries.

Critical illness in children with influenza A/pH1N1 2009 infection in Canada*

Objective: To describe characteristics, treatment, and outcomes of critically ill children with influenza A/pandemic influenza A virus (pH1N1) infection in Canada. Design: An observational study of critically ill children with influenza A/pH1N1 infection in pediatric intensive care units (PICUs). Setting: Nine Canadian PICUs. Patients: A total of 57 patients admitted to PICUs between April 16, 2009 and August 15, 2009. Interventions: None. Measurements and Main Results: Characteristics of critically ill children with influenza A/pH1N1 infection were recorded. Confirmed intensive care unit cases were compared with a national surveillance database containing all hospitalized pediatric patients with influenza A/pH1N1 infection. Risk factors were assessed with a Cox proportional hazard model. The PICU cohort and national surveillance data were compared, using chi-square tests. Fifty-seven children were admitted to the PICU for community-acquired influenza A/pH1N1 infection. One or more chronic comorbid illnesses were observed in 70.2% of patients, and 24.6% of patients were aboriginal. Mechanical ventilation was used in 68% of children, 20 children (35.1%) had acute lung injury on the first day of admission, and the median duration of ventilation was 6 days (range, 0–67 days). The PICU mortality rate was 7% (4 of 57 patients). When compared with nonintensive care unit hospitalized children, PICU children were more likely to have a chronic medical condition (relative risk, 1.73); aboriginal ethnicity was not a risk factor of intensive care unit admission. Conclusions: During the first outbreak of influenza A/pH1N1 infection, when the population was naïve to this novel virus, severe illness was common among children with underlying chronic conditions and aboriginal children. Influenza A/pH1N1-related critical illness in children was associated with severe hypoxemic respiratory failure and prolonged mechanical ventilation. However, this higher rate and severity of respiratory illness did not result in an increased mortality when compared with seasonal influenza.

American College of Critical Care Medicine Clinical Practice Parameters for Hemodynamic Support of Pediatric and Neonatal Septic Shock

Objectives: The American College of Critical Care Medicine provided 2002 and 2007 guidelines for hemodynamic support of newborn and pediatric septic shock. Provide the 2014 update of the 2007 American College of Critical Care Medicine “Clinical Guidelines for Hemodynamic Support of Neonates and Children with Septic Shock.” Design: Society of Critical Care Medicine members were identified from general solicitation at Society of Critical Care Medicine Educational and Scientific Symposia (2006–2014). The PubMed/Medline/Embase literature (2006–14) was searched by the Society of Critical Care Medicine librarian using the keywords: sepsis, septicemia, septic shock, endotoxemia, persistent pulmonary hypertension, nitric oxide, extracorporeal membrane oxygenation, and American College of Critical Care Medicine guidelines in the newborn and pediatric age groups. Measurements and Main Results: The 2002 and 2007 guidelines were widely disseminated, translated into Spanish and Portuguese, and incorporated into Society of Critical Care Medicine and American Heart Association/Pediatric Advanced Life Support sanctioned recommendations. The review of new literature highlights two tertiary pediatric centers that implemented quality improvement initiatives to improve early septic shock recognition and first-hour compliance to these guidelines. Improved compliance reduced hospital mortality from 4% to 2%. Analysis of Global Sepsis Initiative data in resource rich developed and developing nations further showed improved hospital mortality with compliance to first-hour and stabilization guideline recommendations. Conclusions: The major new recommendation in the 2014 update is consideration of institution—specific use of 1) a “recognition bundle” containing a trigger tool for rapid identification of patients with septic shock, 2) a “resuscitation and stabilization bundle” to help adherence to best practice principles, and 3) a “performance bundle” to identify and overcome perceived barriers to the pursuit of best practice principles.

Life-Threatening Human Metapneumovirus Pneumonia Requiring Extracorporeal Membrane Oxygenation in a Preterm Infant

We present the first report in the literature of a child with human metapneumovirus pneumonia who required extracorporeal membrane oxygenation for survival. This was a 3-month-old premature boy from British Columbia, Canada, who developed severe respiratory failure, experienced failure of high-frequency oscillatory mechanical ventilation, and required extracorporeal membrane oxygenation support for 10 days. This case illustrates the importance of including this newly discovered pathogen among the causes of childhood pneumonia.

Ultrasound guidance for central vascular access in the pediatric emergency department.

Central vascular access is sometimes required for hemodynamic monitoring and infusion of fluids and medications in the pediatric emergency department. In many cases, it is attempted after failed peripheral venous and intraosseous access. Some evidence exists demonstrating benefits of ultrasound (US)-guided central vascular cannulation in adults in emergency departments. With appropriate education in its use, US-guided cannulation of central veins in children is likely to be associated with less complications and greater success. In the pediatric emergency department, the femoral vein is the most practical central venous cannulation site. A sound educational and quality assurance program is necessary for US-guided cannulation in the pediatric emergency department.

Correlation of transcutaneous hepatic near-infrared spectroscopy readings with liver surface readings and perfusion parameters in a piglet endotoxemic shock model

Abstract: Purpose: To determine whether transcutaneous liver near‐infrared spectrophotometry (NIRS) measurements correlate with NIRS measurements taken directly from the liver surface, and invasive blood flow measurements.

Evaluation of a pediatric central venous oximetry catheter in critically ill children.

Objective: To compare the readings from a modified pediatric central venous oximetry (Scvo2) catheter with co-oximetry saturations of blood samples from critically ill children. Design: Prospective descriptive study. Intervention: None. Setting: A pediatric intensive care unit at a tertiary care childrens hospital. Measurements and Main Results: Nineteen children, predominantly postcardiac by-pass surgery, were enrolled (mean age, 24.5 mos [range 1 day to 14.3 yrs], mean weight, 9.7 kg [range, 3.2–45 kg]). Measured oxygen saturations were obtained from venous blood samples drawn from the distal port of the catheter and compared with simultaneous values displayed by the oximetry monitor. Sampling was performed every 6 hrs, with the distal port infusions either on, or off, or as clinically indicated. A total of 104 paired samples were obtained. Two subjects were excluded due to the catheter being removed, before the study commenced, to facilitate initiation of extracorporeal support. Regression analysis of the mean oximetry catheter and co-oximetry values showed a correlation of 0.81. The difference between the mean values of both methods was evenly distributed (Bland-Altman analysis) and resulted in a mean percentage difference (oximetry catheter vs. co-oximetry) of 1.09 and a sd of 8.48. There were no device malfunctions or complications. Conclusion: Pediatric central venous oximetry catheters provide accurate trending of continuous Scvo2 within the physiologic range studied.

Potential pediatric intensive care unit demand/capacity mismatch due to novel pH1N1 in Canada.

Objective: To investigate the possibility of pediatric intensive care unit shortfalls, using pandemic models for a range of attack rates and durations. The emergence of the swine origin pH1N1 virus has led to concerns about shortfalls in our ability to provide pediatric ventilation and critical care support. Design: Modeling of pediatric intensive care demand based on pH1N1 predictions using simulation techniques. Setting: Simulation laboratory. Patients: None. Interventions: None. Measurements and Main Results: Data collected during the first wave of the pH1N1 in children in Canada were applied to several second wave pandemic models to explore potential pediatric intensive care unit ventilatory demands for Canada and to investigate the impact of vaccination upon these demands. In almost all cases studied, even for relatively low attack rates of 15%, significant pediatric intensive care unit shortages would be expected to occur. Vaccination strategies targeting 50% of the population significantly reduced demand, but shortages may still be expected. Although shortfalls can occur in all provinces, Ontario and British Columbia may experience the greatest supply-demand difference, even at low attack rates. Conclusion: Reducing the attack rate among children, whether through vaccination or additional measures, such as social distancing, will be critical to ensure sufficient pediatric intensive care unit capacity for continued pediatric care.