Procalcitonin in the Early Course Post Pediatric Cardiac Surgery.

OBJECTIVE: Procalcitonin has emerged as a promising infection marker, but previous reports from small-sized studies suggest nonspecific elevation of procalcitonin after pediatric heart surgery. As procalcitonin is increasingly used as a marker for infection in the PICU, the aim of this study was to identify factors associated with postoperative procalcitonin elevation and to investigate the role of procalcitonin as an early marker of outcome after cardiac surgery. DESIGN: Prospective observational study. SETTING: Single, tertiary referral PICU. PATIENTS: Patients aged 0-16 years following cardiac surgery with or without cardiopulmonary bypass. INTERVENTIONS: Procalcitonin was measured in all patients at admission to PICU, and on postoperative day 1 and 2. Outcome variables included major adverse event, length of stay in PICU, postoperative renal failure requiring temporary dialysis, duration of mechanical ventilation and duration of inotropic support. A major adverse event was defined as cardiac arrest, need for postoperative extracorporeal life support or death within 3 months of cardiac surgery. MEASUREMENTS AND MAIN RESULTS: In 221 included patients who underwent 232 operations, procalcitonin at admission to PICU was significantly associated with mechanical ventilation prior to surgery (p = 0.001), preoperative myocardial dysfunction (p = 0.002), duration of cardiopulmonary bypass (p < 0.001), intraoperative cross-clamp time (p = 0.015), and serum lactate at admission (p < 0.001). Patients suffering a major adverse event and patients with postoperative renal failure had significantly higher procalcitonin levels at admission to PICU (p = 0.04 and 0.01, respectively). Furthermore, procalcitonin levels at admission correlated significantly with the length of stay in the PICU (p = 0.005), time on mechanical ventilation (p = 0.03), and duration of inotropic support (p = 0.02). CONCLUSIONS: Elevated levels of procalcitonin in the early phase after pediatric cardiac surgery are a marker for increased risk for major adverse events and postoperative renal failure and increased postoperative morbidity.

The effect of high flow nasal cannula therapy on the work of breathing in infants with bronchiolitis.

The main physiological impact of high flow nasal cannula (HFNC) therapy is presumed to be a decrease in work of breathing (WOB). To assess this, diaphragmatic electrical activity and esophageal pressure changes were measured off then on HFNC delivered at 2 L/kg/min, in 14 infants with bronchiolitis and 14 cardiac infants. Electrical activity of the diaphragm (Edi) was measured using an Edi catheter with calculations of signal peak (EdiMAX ) and amplitude (EdiAMPL ). Pressure-rate and pressure-time products (PRP, PTP) were calculated from analyses of esophageal pressure. Changes in end-expiratory lung volume were measured using respiratory inductance plethysmography (RIPEEL ). The EdiMAX and EdiAMPL were significantly higher in infants with bronchiolitis than in cardiac infants (P < 0.05). Within the bronchiolitis group, both were significantly reduced between HFNC states from 27.9 µV [20.4, 35.4] to 21.0 µV [14.8, 27.2] and from 25.1 µV [18.0, 32.2] to 19.2 µV [13.3, 25.1], respectively (mean, 95% CI, P < 0.05). A less prominent offload of the diaphragm was observed in cardiac infants (P < 0.05). WOB decreased in both groups with a significant reduction of PRP and PTP (P < 0.05). RIPEEL increased significantly in bronchiolitis only (P < 0.05). HFNC offloads the diaphragm and reduces the WOB in bronchiolitis. A similar effect was demonstrated in cardiac infants, a group without signs of airway-obstruction.

High-flow nasal cannula therapy for respiratory support in children.

BACKGROUND: Respiratory support is a central component of the management of critically ill children. It can be delivered invasively via an endotracheal tube or non-invasively via face mask, nasal mask, nasal cannula or oxygen hood/tent. Invasive ventilation can be damaging to the lungs, and the tendency to use non-invasive forms is growing. However, non-invasive delivery is often poorly tolerated by children. High-flow nasal cannula (HFNC) oxygen delivery is a relatively new therapy that shows the potential to reduce the need for intubation and be better tolerated by children than other non-invasive forms of support. HFNC therapy differs from other non-invasive forms of treatment in that it delivers heated, humidified and blended air/oxygen via nasal cannula at rates > 2 L/kg/min. This allows the user to deliver high concentrations of oxygen and to potentially deliver continuous distending pressure; this treatment often is better tolerated by the child. OBJECTIVES: To determine whether HFNC therapy is more effective than other forms of non-invasive therapy in paediatric patients who require respiratory support. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 4); MEDLINE via PubMed (January 1966 to April 2013); EMBASE (January 1980 to April 2013); CINAHL (1982 to April 2013); and LILACS (1982 to April 2013). Abstracts from conference proceedings, theses and dissertations and bibliographical references to relevant studies were also searched. We applied no restriction on language. SELECTION CRITERIA: We planned to included randomized controlled trials (RCTs) and quas-randomized trials comparing HFNC therapy with other forms of non-invasive respiratory support for children. Non-invasive support encompassed cot, hood or tent oxygen; low-flow nasal cannulae (flow rates ≤ 2 L/min); and continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) delivered via facial or nasal mask/cannula. Treatment failure was defined by the need for additional respiratory support. We excluded children with a diagnosis of bronchiolitis. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed all studies for selection and data extraction. We used standard methodological procedures expected by The Cochrane Collaboration. MAIN RESULTS: Our search yielded 922 records. A total of 109 relevant records were retrieved with reference to our search criteria. After duplicates and irrelevant studies were removed, 69 studies were further scrutinized. Of these, 11 studies involved children. No study matched our inclusion criteria. AUTHORS' CONCLUSIONS: Based on the results of this review, no evidence is available to allow determination of the safety or effectiveness of HFNC as a form of respiratory support in children.

High-flow nasal cannula oxygen therapy for infants with bronchiolitis: pilot study.

AIM: To obtain data on the safety and clinical impact of managing infants with bronchiolitis on the ward with high-flow nasal cannula (HFNC) treatment. METHODS: A prospective pilot study was conducted of 61 infants aged <12 months with bronchiolitis and oxygen requirement presenting to the emergency department. HFNC was commenced at 2 L/kg/min, and fraction of inspired oxygen was titrated to oxygen saturation > 94%. A standard-treatment group (n = 33) managed with standard low-flow subnasal oxygen during the same time period was retrospectively identified. RESULTS: Admission demographics, heart rate (HR) and respiratory rate (RR) were similar in test and standard-treatment groups. Responders and non-responders to HFNC were identified within 60 min of treatment. Non-responders to HFNC requiring paediatric intensive care unit (PICU) admission showed no change in HR and RR, whereas responders showed decreases in HR and RR (P < 0.02). Patients receiving HFNC were four times less likely to need PICU admission than the standard treatment group (OR 4.086, 95%CI 1.0-8.2; P = 0.043). No adverse events such as pneumothorax, bradycardia, bradypnoea, emergency intubation or cardiopulmonary resuscitation were observed. No patients admitted to the PICU required intubation. CONCLUSIONS: HFNC treatment in the paediatric ward is safe. Non-responders requiring PICU admission can be identified within the first hour of HFNC treatment by monitoring HR and RR. It is feasible to undertake a randomised controlled trial based on this pilot with the aim of decreasing PICU admissions.

High-flow nasal cannula (HFNC) support in interhospital transport of critically ill children.

PURPOSE: Optimal respiratory support for interhospital transport of critically ill children is challenging and has been scarcely investigated. High-flow nasal cannula (HFNC) therapy has emerged as a promising support mode in the paediatric intensive care unit (PICU), but no data are available on HFNC used during interhospital transport. We aimed to assess the safety of HFNC during retrievals of critically ill children and its impact on the need for invasive ventilation (IV). METHODS: This was a retrospective, single-centre study of children under 2 years old transported by a specialized paediatric retrieval team to PICU. We compared IV rates before (2005-2008) and after introduction of HFNC therapy (2009-2012). RESULTS: A total of 793 infants were transported. The mean transport duration was 1.4 h (range 0.25-8), with a mean distance of 205 km (2-2,856). Before introduction of HFNC, 7 % (n = 23) were retrieved on non-invasive ventilation (NIV) and 49 % (n = 163) on IV. After introduction of HFNC, 33 % (n = 150) were retrieved on HFNC, 2 % (n = 10) on NIV, whereas IV decreased to 35 % (n = 162, p < 0.001). No patients retrieved on HFNC required intubation during retrieval, or developed pneumothorax or cardiac arrest. Using HFNC was associated with a significant reduction in IV initiated by the retrieval team (multivariate OR 0.51; 95 % CI 0.27-0.95; p = 0.032). CONCLUSIONS: We report on a major change of practice in transport of critically ill children in our retrieval system. HFNC therapy was increasingly used and was not inferior to low-flow oxygen or NIV. Randomized trials are needed to assess whether HFNC can reduce the need for IV in interhospital transport of critically ill children.

A case series of paediatric high flow nasal cannula therapy.

INTRODUCTION: High flow nasal cannula is an emerging treatment option in Paediatric Intensive Care Units for paediatric patients in acute respiratory distress. Yet there is a paucity of literature describing its clinical application in various presenting pathophysiologies. AIM: To describe three cases with differing underlying pathophysiologies and their response to high flow nasal cannula oxygen therapy. METHOD: Patients admitted to the Paediatric Intensive Care Unit with bronchiolitis, asthma and cardiomyopathy, and treated with high flow nasal cannula therapy were searched in the Paediatric Intensive Care database. The most representative cases were chosen to review. RESULTS: One infant and two children were reviewed. All were commenced on high flow nasal cannula therapy in the Paediatric Intensive Care Unit and all demonstrated an improvement in their work of breathing. There was also a substantial improvement in their haemodynamic status. No patient required escalation to other forms of respiratory therapy. CONCLUSION: High flow nasal cannula therapy is a viable treatment option for a range of patients presenting to the Paediatric Intensive Care Unit with acute respiratory distress. More invasive methods of respiratory support may be avoided by the use of high flow nasal cannula therapy.

Multiple processes in prospective memory retrieval: factors determining monitoring versus spontaneous retrieval.

Theoretically, prospective memory retrieval can be accomplished either by controlled monitoring of the environment for a target event or by a more reflexive process that spontaneously responds to the presence of a target event. These views were evaluated in Experiments 1-4 by examining whether performing a prospective memory task produced costs on the speed of performing the ongoing task. In Experiment 5, the authors directly tested for the existence of spontaneous retrieval. The results supported the multiprocess theory (M. A. McDaniel & G. O. Einstein, 2000) predictions that (a) spontaneous retrieval can occur and can support good prospective memory and (b) depending on task demands and individual differences, people rely to different degrees on monitoring versus spontaneous retrieval for prospective remembering.