Anticoagulation during extracorporeal membrane oxygenation: A narrative review

Extracorporeal Membrane Oxygenation (ECMO) is a technology that offers organ support for critically ill patients with respiratory and/or cardiac failure. Despite improvements in recent years in technology and the biocompatibility of circuits, patients on ECMO remain at high risk of hematologic complications, such as bleeding or thrombosis. Anticoagulation is required in most cases to limit the risk of clotting, but questions persist regarding the optimal anticoagulation strategy. More precisely, there is still debate around the best anticoagulation agent and monitoring tools as well as on the transfusion thresholds and appropriate corrective measures when faced with complications. This narrative review provides an overview of hemostasis on ECMO and the impact of circuit size and coating. The benefits and downsides of unfractionated heparin (UHF) and Direct Thrombin Inhibitors (DTIs) as anticoagulation agents are reviewed. Finally, commonly available coagulation tests (activated clotting time, activated partial thrombin time, anti-Xa, and viscoelastic tests) and their limitations are addressed. In conclusion, future research is needed to determine the best anticoagulation strategy for patients on ECMO.

Iron Deficiency in Anemic Children Surviving Critical Illness: Post Hoc Analysis of a Single-Center Prospective Cohort in Canada, 2019-2022

OBJECTIVES

Many children leave the PICU with anemia. The mechanisms of post-PICU anemia are poorly investigated, and treatment of anemia, other than blood, is rarely started during PICU. We aimed to characterize the contributions of iron depletion (ID) and/or inflammation in the development of post-PICU anemia and to explore the utility of hepcidin (a novel iron marker) at detecting ID during inflammation.

DESIGN

Post hoc analysis of a single-center prospective study (November 2019 to September 2022).

SETTING

PICU, quaternary center, Canada.

PATIENTS

Children admitted to PICU with greater than or equal to 48 hours of invasive or greater than or equal to 96 hours of noninvasive ventilation. We excluded patients with preexisting conditions causing anemia or those admitted after cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Hematological and iron profiles were performed at PICU discharge on 56 participants of which 37 (37/56) were diagnosed with anemia. Thirty-three children (33/56; 59%) were younger than 2 years. Median Pediatric Logistic Organ Dysfunction score was 11 (interquartile range, 6-16). Twenty-four of the 37 anemic patients had repeat bloodwork 2 months post-PICU. Of those, four (4/24; 16%) remained anemic. Hematologic profiles were categorized as: anemia of inflammation (AI), iron deficiency anemia (IDA), IDA with inflammation, and ID (low iron stores without anemia). Seven (7/47; 15%) had AI at discharge, and one had persistent AI post-PICU. Three patients (3/47; 6%) had IDA at discharge; of which one was lost to follow-up and the other two were no longer anemic but had ID post-PICU. Eleven additional patients developed ID post-PICU. In the exploratory analysis, we identified a diagnostic cutoff value for ID during inflammation from the receiver operating characteristic curve for hepcidin of 31.9 pg/mL. This cutoff would increase the detection of ID at discharge from 6% to 34%.

CONCLUSIONS

The burden of ID in children post-PICU is high and better management strategies are required. Hepcidin may increase the diagnostic yield of ID in patients with inflammation.

Two months outcomes following delirium in the pediatric intensive care unit

The lasting consequences of delirium in children are not well characterized. This study aimed to compare the two-month outcomes in pediatric intensive care unit (PICU) survivors according to the presence of delirium. Post-hoc analysis of a single-center prospective study of mechanically ventilated (invasive ventilation or non-invasive ventilation) children followed at the CHU Sainte-Justine PICU follow-up clinic two months after PICU discharge, between October 2018 and August 2022. Delirium was defined as one or more Cornell Assessment of Pediatric Delirium (CAPD) scores ≥ 9. Primary outcome was survivors' quality of life and secondary outcomes were sleep and posttraumatic stress and anxiety and depression in parents. Multivariable linear and logistic regression models assessed the independent associations between delirium and outcomes while adjusting for age, sex, comorbidity, diagnosis, severity of illness, PICU length of stay, and invasive mechanical ventilation. Of the 179 children included over a 47 month-period, 117 (65.4%) had delirium. Children with delirium were more commonly intubated (91.5% vs. 30.7%, p < 0.001) and had higher PELOD-2 scores (10 vs. 4, p < 0.001). On multivariable analysis, delirium was associated with a decreased quality of life at 2.3 months post discharge (p = 0.03). The severity of the delirium episode (higher scores of CAPD) was associated with a higher likelihood of sleep disturbances (OR 1.13, p = 0.01) and parental anxiety (OR 1.16, p = 0.01), in addition to lower quality of life (p = 0.03).Conclusions: Two months following their PICU stay, children with delirium had a lower quality of life, suggesting a lasting effect of delirium on children and their families.

Outcomes of patients supported by mechanical ventilation and their families two months after discharge from pediatric intensive care unit

Introduction

The outcomes of children undergoing mechanical ventilation (MV) in a Pediatric Intensive Care Unit (PICU) remain poorly characterized and increasing knowledge in this area may lead to strategies that improve care. In this study, we reported the outcomes of children receiving invasive mechanical ventilation (IMV) and/or non-invasive ventilation (NIV), 2 months after PICU discharge.

Methods

This is a post-hoc analysis of a single-center prospective study of PICU children followed at the PICU follow-up clinic at CHU Sainte-Justine. Eligible children were admitted to the PICU with ≥2 days of IMV or ≥4 days of NIV. Two months after PICU discharge, patients and families were evaluated by physicians and filled out questionnaires assessing Quality of life (Pediatric Quality of Life Inventory™), development milestones (Ages and Stages Questionnaire), and parental anxiety and depression (Hospital Anxiety and Depression Scale).

Results

One hundred and fifty patients were included from October 2018 to December 2021; 106 patients received IMV (±NIV), and 44 patients received NIV exclusively. Admission diagnoses differed between groups, with 30.2% of patients in the IMV group admitted for a respiratory illness vs. 79.5% in the NIV group. For the entire cohort, QoL scores were 78.1% for the physical domain and 80.1% for the psychological domain, and were similar between groups. Children with a respiratory illness exhibited similar symptoms at follow-up whether they were supported by IMV vs. NIV. For developmental outcomes, only 22.2% of pre-school children had normal scores in all ASQ domains. In the entire cohort, symptoms of anxiety were reported in 29.9% and depression in 24.6 of patients.

Conclusions

PICU survivors undergoing mechanical ventilation, and their families, experienced significant morbidities 2 months after their critical illness, whether they received IMV or NIV. Children with respiratory illness exhibited a higher prevalence of persistent respiratory difficulties post PICU, whether they underwent IMV or NIV. Patients' quality of life and parental symptoms of anxiety and depression did not differ according to the type of respiratory support. These findings justify the inclusion of patients receiving NIV in the PICU in follow-up assessments as well as those receiving IMV.

Prevalence and determinants of anemia at discharge in pediatric intensive care survivors

BACKGROUND

Restrictive transfusion practices are increasingly being followed in pediatric intensive care units (PICU); consequently, more patients are discharged anemic from PICU. Given the possible impact of anemia on long-term neurodevelopmental outcomes, we aim to describe the epidemiology of anemia at PICU discharge in a mixed (pediatric and cardiac) cohort of PICU survivors and to characterize risk factors for anemia.

STUDY DESIGN AND METHODS

We performed a retrospective cohort study in the PICU of a multidisciplinary tertiary-care university-affiliated center. All consecutive PICU survivors for whom a hemoglobin level was available at PICU discharge were included. Baseline characteristics and hemoglobin levels were extracted from an electronic medical records database.

RESULTS

From January 2013 to January 2018, 4750 patients were admitted to the PICU (97.1% survival); discharge hemoglobin levels were available for 4124 patients. Overall, 50.9% (n = 2100) were anemic at PICU discharge. Anemia at PICU discharge was also common in the cardiac surgery population (53.3%), mainly in acyanotic patients; only 24.6% of cyanotic patients were anemic according to standard definitions of anemia. Cardiac surgery patients were transfused more often and at higher hemoglobin levels than medical and non-cardiac surgery patients. Anemia at admission was the strongest predictor of anemia at discharge (odds ratios (OR): 6.51, 95% confidence interval (CI:5.40;7.85)).

DISCUSSION

Half of PICU survivors are anemic at discharge. Further studies are required to determine the course of anemia after discharge and to ascertain whether anemia is associated with adverse long-term outcomes.

Impact of the Covid-19 Pandemic on Children and Families in PICU Follow-Up Clinic

The novel coronavirus disease 2019 (COVID-19) pandemic disrupted the lives of many families, especially those of children with chronic health problems. Little is known about the impact of this pandemic on the health and well-being of critically ill children and their families after their discharge from pediatric intensive care unit (PICU) hospitalization. This study describes the repercussions of the COVID-19-related lockdown on the physical and psychological wellbeing, quality of life, and access to resources of PICU survivors and their families. This was a prospective cohort study of children and families followed at the Centre Hospitalier Universitaire Ste-Justine PICU follow-up clinic from October 2018 to February 2020. Families were contacted by phone to complete validated questionnaires (Pediatric Quality of Life Inventory, Hospital Anxiety and Depression Scale) and to evaluate the impact of the COVID-19 pandemic on their access to medical care and extrafamilial support. Fifty-five families were contacted between November and December 2020. Quality of life scores were 88.1 ± 16.9 and 83.8 ± 13.9 for physical and psychosocial aspects, respectively. Symptoms of anxiety and depression were detected in 23.6 and 3.6% of respondent parents, respectively. A significant proportion of families reported canceled or delayed health care appointments (65.5%) and difficulty with medication access (12.7%). Twenty-five families (45.5%) reported a significant decrease in income. We could not identify any statistically significant predictors for lower quality of life scores. Difficulty accessing medical care was associated with higher symptoms of anxiety and/or depression in parents on multivariate analysis (p = 0.02). In conclusion, the COVID-19 pandemic has had a significant negative impact on PICU survivors' access to medical resources and extrafamilial support.

Intravenous Immunoglobulin Use In Critically Ill Children

Purpose: The use of intravenous immunoglobulins (IVIG) has increased significantly in the last decade causing challenges for blood suppliers to respond to the demand. Indications for which IVIG infusion should be given to critically ill children remain unclear. The objective of this study is to characterize the epidemiology of IVIG use in this population. Methods: We performed a single-center retrospective cohort study of all patients aged between 3 days and 18 years who received at least one IVIG infusion while hospitalized in the pediatric intensive care unit of the Centre hospitalier universitaire (CHU) Sainte-Justine, Montréal Quebec (Canada) between January 1, 2013 and December 31, 2018. Results: One hundred and seventy-two patients received a total of 342 IVIG infusions over the study period. Most common indications for IVIG infusions were staphylococcal or streptococcal toxic shock syndrome (n=53/342, 15.5%), immunoglobulin replacement in chylothorax (n=37/342, 10.9%), prophylaxis following bone marrow transplantation (n=31/342, 9.1%), myocarditis (n=25/342, 7.3%) and post-solid organ transplant complications (n=21/342, 6.1%). The median dose of IVIG per infusion was 0.95 g/kg (IQR 0.5-1.0) and median number of IVIG infusions per patient was one (IQR: 1-2). Seventy-nine percent of IVIG infusions given were administrated for off-label indications with regards to Health Canada recommendations. Conclusion: This study identified the most common indications for IVIG infusion in critically ill children in a tertiary care pediatric intensive care unit. Given the costs, the known adverse events associated with IVIG and the pressure that blood suppliers are facing to meet the demands, clinical trials are needed to evaluate the efficacy and safety of IVIG in conditions where use is significant.

Anemia after Pediatric Congenital Heart Surgery

The postoperative course of infants following congenital heart surgery is associated with significant blood loss and anemia. Optimal transfusion thresholds for cardiac surgery patients while in pediatric intensive care unit (PICU) remain a subject of debate. The goal of this study is to describe the epidemiology of anemia and the transfusion practices during the PICU stay of infants undergoing congenital heart surgery. A retrospective cohort study was performed in a PICU of a tertiary university-affiliated center. Infants undergoing surgery for congenital heart disease (CDH) before 6 weeks of age between February 2013 and June 2019 and who were subsequently admitted to the PICU were included. We identified 119 eligible patients. Mean age at surgery was 11 ± 7 days. Most common cardiac diagnoses were d-Transposition of the Great Arteries (55%), coarctation of the aorta (12.6%), and tetralogy of Fallot (11.8%). Mean hemoglobin level was 14.3 g/dL prior to surgery versus 12.1 g/dL at the PICU admission. Hemoglobin prior to surgery was systematically higher than hemoglobin at the PICU entry, except in infants with Hypoplastic Left Heart Syndrome. The average hemoglobin at PICU discharge was 11.7 ± 1.9 g/dL. Thirty-three (27.7%) patients were anemic at PICU discharge. Fifty-eight percent of patients received at least one red blood cell (RBC) transfusion during PICU stay. This study is the first to describe the epidemiology of anemia at PICU discharge in infants following cardiac surgery. Blood management of this distinctive and vulnerable population requires further investigation as anemia is a known risk factor for adverse neurodevelopment delays in otherwise healthy young children.

Inhaled Antibiotics for the Prevention of Respiratory Tract Infections in Children With a Tracheostomy

Objective: To describe the use of prophylactic inhaled antibiotics in children with a tracheostomy and assess if its use is associated with a reduction in exposition to broad-spectrum antibiotics and a lower risk of acquired respiratory tract infections. Methods: A case series study was performed in a tertiary care university affiliated hospital. All consecutive children (<18 years old) with a tracheostomy, hospitalized between January 2004 and November 2016, and treated with prophylactic inhaled antibiotics were identified. We analyzed the 3 month- period before and after initiation of prophylactic inhaled antibiotics and described exposure to broad spectrum antibiotics, the number of respiratory tract infections and the associated adverse events. Results: Six children (median age: 11 months, range: 8-100) were included. One received colimycin, 3 received tobramycin and 2 were treated with both antibiotics in alternance. The median duration of treatment was 74 days (22-173) with one patient still being treated at the end of the study. Patients were exposed to systemic antibiotics for 18 days (2-49) in the 3 months preceding the treatment vs. 2 days (0-15) in the 3 months following the treatment initiation (p = 0.115). The number of respiratory tract infections went from median of 2 (0-3) to 1 (0-1) during the same periods (p = 0.07). Adverse events most commonly reported were cough (n = 2) and increased respiratory secretions post-inhalation (n = 4). Only one new bacterial resistance was observed. Conclusions: This series of consecutive cases underlines the need for future studies evaluating the potential benefit of prophylactic inhaled antibiotics in children with a tracheostomy.