Jan Hau Lee

Use of high flow nasal cannula in critically ill infants, children, and adults: a critical review of the literature

BackgroundHigh flow nasal cannula (HFNC) systems utilize higher gas flow rates than standard nasal cannulae. The use of HFNC as a respiratory support modality is increasing in the infant, pediatric, and adult populations as an alternative to non-invasive positive pressure ventilation.ObjectivesThis critical review aims to: (1) appraise available evidence with regard to the utility of HFNC in neonatal, pediatric, and adult patients; (2) review the physiology of HFNC; (3) describe available HFNC systems (online supplement); and (4) review ongoing and planned trials studying the utility of HFNC in various clinical settings.ResultsClinical neonatal studies are limited to premature infants. Only a few pediatric studies have examined the use of HFNC, with most focusing on this modality for viral bronchiolitis. In critically ill adults, most studies have focused on acute respiratory parameters and short-term physiologic outcomes with limited investigations focusing on clinical outcomes such as duration of therapy and need for escalation of ventilatory support. Current evidence demonstrates that HFNC generates positive airway pressure in most circumstances; however, the predominant mechanism of action in relieving respiratory distress is not well established.ConclusionCurrent evidence suggests that HFNC is well tolerated and may be feasible in a subset of patients who require ventilatory support with non-invasive ventilation. However, HFNC has not been demonstrated to be equivalent or superior to non-invasive positive pressure ventilation, and further studies are needed to identify clinical indications for HFNC in patients with moderate to severe respiratory distress.

Risk factors for invasive candidiasis in infants >1500 g birth weight.

Background: We describe the incidence, risk factors and outcomes of invasive candidiasis in infants >1500 g birth weight. Methods: We conducted a retrospective cohort study of infants >1500 g birth weight discharged from 305 neonatal intensive care units in the Pediatrix Medical Group from 2001 to 2010. Using multivariable logistic regression, we identified risk factors for invasive candidiasis. Results: Invasive candidiasis occurred in 330 of the 530,162 (0.06%) infants. These were documented from positive cultures from ≥1 of these sources: blood (n = 323), cerebrospinal fluid (n = 6) or urine from catheterization (n = 19). Risk factors included day of life >7 (odds ratio [OR]: 25.2; 95% confidence interval: 14.6–43.3), vaginal birth (OR: 1.6 [1.2–2.3]), exposure to broad-spectrum antibiotics (OR: 1.6 [1.1–2.4]), central venous line (OR: 1.8 [1.3–2.6]) and platelet count <50,000/mm3 (OR: 3.7 [2.1–6.7]). All risk factors had poor sensitivities, low positive likelihood ratios and low positive predictive values. The combination of broad-spectrum antibiotics and low platelet count had the highest positive likelihood ratio (46.2), but the sensitivity of this combination was only 4%. Infants with invasive candidiasis had increased mortality (OR: 2.2 [1.3–3.6]). Conclusions: Invasive candidiasis is uncommon in infants >1500 g birth weight. Infants at greatest risk are those exposed to broad-spectrum antibiotics and with platelet counts of <50,000/mm3.

Functional Outcomes and Physical Impairments in Pediatric Critical Care Survivors: A Scoping Review.

Objective: Although more children are surviving critical illness, little is known about long-term physical impairment. This scoping review aims to critically appraise existing literature on functional outcome measurement tools, prevalence, and risk factors for physical impairments in pediatric critical care survivors. Data Sources: PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature, using a combination of MeSH terms and keywords (critical illness, intensive care, and functional outcomes/status). Study Selection: All human studies reporting functional outcomes in children 0–18 years old admitted to the PICU. Non-English language, adult and preterm infant studies were excluded. Data Synthesis: Three global assessment tools and eight multidimensional measures were used to measure functional outcome in pediatric survivors of critical illness. Rates of acquired functional impairment in a general pediatric intensive care cohort ranged from 10% to 36% at discharge and 10% to 13% after more than 2 years. Risk factors for acquired functional impairment include illness severity, the presence of organ dysfunction, length of ICU stay, and younger age. There is some evidence that physical impairment may be more severe and persistent than psychosocial components. Conclusions: Functional impairment may be persistent in pediatric survivors of critical care. Unfortunately, studies varied largely in measurement timing and tools used. The lack of differentiation between impairment in different functional domains limited the generalizability of data. Further studies using a combination of standardized measures at various time points of the disease process can help establish more comprehensive rates of physical impairment.

Early Hyperglycemia in Pediatric Traumatic Brain Injury Predicts for Mortality, Prolonged Duration of Mechanical Ventilation, and Intensive Care Stay

We aim to study the association between hyperglycemia and in-hospital outcomes among children with moderate and severe traumatic brain injury (TBI). This retrospective cohort study was conducted in a tertiary pediatric hospital between 2003 and 2013. All patients < 16 years old who presented to the Emergency Department within 24 hours of head injury with a Glasgow Coma Scale (GCS) ≤ 13 were included. Our outcomes of interest were death, 14 ventilation-free, 14 pediatric intensive care unit- (PICU-) free, and 28 hospital-free days. Hyperglycemia was defined as glucose > 200 mg/dL (11.1 mmol/L). Among the 44 patients analyzed, the median age was 8.6 years (interquartile range (IQR) 5.0–11.0). Median GCS and pediatric trauma scores were 7 (IQR 4–10) and 4 (IQR 3–6), respectively. Initial hyperglycemia was associated with death (37% in the hyperglycemia group versus 8% in the normoglycemia group, p = 0.019), reduced median PICU-free days (6 days versus 11 days, p = 0.006), and reduced median ventilation-free days (8 days versus 12 days, p = 0.008). This association was however not significant in the stratified analysis of patients with GCS ≤ 8. Conclusion. Our findings demonstrate that early hyperglycemia is associated with increased mortality, prolonged duration of mechanical ventilation, and PICU stay in children with TBI.

Protocol-Driven Enteral Nutrition in Critically Ill Children A Systematic Review

Enteral nutrition (EN) protocols are thought to improve clinical outcomes in the pediatric intensive care unit (PICU); however, critical evaluation of their efficacy is limited. We conducted a systematic review with the aim of assessing the effect of EN protocols on important clinical outcomes in these children. We searched MEDLINE, Cochrane Database for Reviews, Embase, and CINAHL using predetermined keywords and MESH terms. We included randomized controlled trials (RCTs) and observational studies that involved EN protocols in children admitted to the PICU for >24 hours. We included studies that reported at least 1 of our outcomes of interest. Studies that exclusively studied premature neonates or adults were excluded. Primary outcomes were PICU or hospital mortality, PICU or hospital length of stay (LOS), duration of mechanical ventilation, gastrointestinal (GI) complications, and infective complications. Secondary outcomes were time to initiate feeds and time to achieve goal feeds. In total, we included 9 studies (total 1564 children) in our systematic review (1 RCT, 4 before-and-after studies, 1 single-arm cohort study, 1 prospective descriptive study, and 2 audits). There is low-level evidence that the use of EN protocols is associated with a reduction in GI and infective complications and improved timeliness of feed initiation and achievement of goal feeds. Current medical literature does not have compelling data on the effects of an EN protocol on clinical outcomes among critically ill children. Future clinical trials should look into using standardized interventions and outcome measures to strengthen the existing evidence.

Epidemiology of pediatric acute respiratory distress syndrome in singapore: risk factors and predictive respiratory indices for mortality.

Aim: Acute respiratory distress syndrome (ARDS) represents the most severe form of acute lung injury. The aim of our study is to describe the epidemiology of pediatric ARDS in Singapore and compare the outcomes of ARDS using the following respiratory indices: PaO2/FiO2 ratio (P/F ratio), SpO2/FiO2 ratio (S/F ratio), oxygenation index (OI), and oxygen saturation index (OSI). Methods: We examined medical records of patients admitted to the Children’s Intensive Care Unit in KK Women’s and Children’s Hospital from 2009 to 2012. Those who fulfilled criteria for the American-European Consensus Conference definition for ARDS were identified. Demographic, clinical, and radiographic information were extracted and analyzed. Results: We identified 70 patients with ARDS. Median age (interquartile range) was 6.2 (1.4, 10.4) years. The most common risk factor was pneumonia [50 (71%)]. Overall mortality was 44 (63%) patients. Thirty-two (56%) patients had an underlying chronic comorbidity; 18 (46%) were hematology–oncology conditions. Fifty-six (80%) patients had multiorgan dysfunction. Adjunct therapies used in our patients included inhaled nitric oxide [5 (7%)], prone position [22 (31%)], steroids [26 (37%)], and neuromuscular blockade [26 (37%)]. A high OI and low PF ratio after 24 h of diagnosis of ARDS were associated with mortality. From day 3 onward, all four respiratory indices appropriately differentiated survivors from non-survivors. Severity based on the S/F ratio and OSI demonstrated association with decreased ventilator free days and ICU free days. Conclusion: Risk factors for mortality included having an underlying comorbidity, multiorgan dysfunction, a low PF ratio, and high OI at 24 h of ARDS. Abnormal SpO2-based measurements were reliable markers of poor outcomes in pediatric ARDS.

Nutrition Delivery Affects Outcomes in Pediatric Acute Respiratory Distress Syndrome

Background: Malnutrition is prevalent in critically ill children. We aim to describe nutrition received by children with acute respiratory distress syndrome (ARDS) and to determine whether provision of adequate nutrition is associated with improved clinical outcomes. Materials and Methods: We studied characteristics and outcomes of 2 groups of patients: (1) those who received adequate calories (defined as ≥80% of predicted resting energy expenditure) and (2) those who received adequate protein (defined as ≥1.5g/kg/d of protein). Outcomes of interest were mortality, ventilator-free days (VFDs), intensive care unit (ICU)–free days, multiorgan dysfunction, and need for extracorporeal membrane oxygenation. Categorical variables were analyzed using the Fisher exact test, and continuous variables were analyzed using the Mann-Whitney U test. Univariate and multivariate logistic regression models were used to identify associated risk factors related to these outcomes of interest. Results: In total, 107 patients with ARDS were identified. There was a reduction in ICU mortality in patients who received adequate calories (34.6% vs 60.5%, P = .025) and adequate protein (14.3% vs 60.2%, P = .002) compared with those that did not. Patients with adequate protein intake also had more VFDs (median [interquartile range], 12 [3.0–19.0] vs 0 [0.0–14.8] days; P = .005). After adjusting for severity of illness, adequate protein remained significantly associated with decreased mortality (adjusted odds ratio [95% confidence interval], 0.09 [0.01–0.94]; P = .044). Conclusion: Our study demonstrated that adequate nutrition delivery in children with ARDS was associated with improved clinical outcomes. Protein delivery may have potentially more impact than overall caloric delivery.

Neonatal Extracorporeal Membrane Oxygenation: Update on Management Strategies and Long-Term Outcomes.

BACKGROUND Extracorporeal membrane oxygenation (ECMO) can be deployed to support patients with severe cardiorespiratory failure unresponsive to conventional medical interventions. Neonatal trials have demonstrated that ECMO is an effective treatment of severe respiratory failure, with acceptable cognitive and functional outcomes. Technological advances in ECMO have resulted in improved safety and accessibility, contributing to decreased morbidity and improved survival of increasingly complex patients requiring ECMO support. PURPOSE This review aims to describe the innovations in ECMO technology and management in the neonatal population in the last decade. The long-term outcomes of neonatal patients requiring ECMO support will be discussed. SEARCH STRATEGY Relevant clinical trials from MEDLINE and the Cochrane Library were identified. The following key words were used: ECMO, infant, neonate, and outcomes. FINDINGS Challenges still remain in supporting the premature and/or low-birth-weight infant with severe respiratory failure, as well as infants with congenital diaphragmatic hernia. Neonatal ECMO survivors can present with neurodevelopmental and respiratory problems, which become more prominent with time. IMPLICATIONS FOR PRACTICE While newer technologies have led to fewer neonates with respiratory failure progressing to ECMO, it remains an important tool to in those who have failed conventional therapies. Given the presence of neurodevelopmental problems in neonatal ECMO survivors, multidisciplinary follow-up targeting motor performance, exercise capacity, behavior, and subtle learning deficits is warranted. IMPLICATIONS FOR RESEARCH With the overall decreasing use of neonatal ECMO, ECMO centers must find ways to maintain their expertise in the light of lower patient volumes amidst complex patient physiology.

A review of the use of adjunctive therapies in severe acute asthma exacerbation in critically ill children

Asthma is a common and potentially life threatening childhood condition. Asthma involves not only chronic airway remodeling, but may also include frequent exacerbations resulting from bronchospasm, edema, and mucus production. In children with severe exacerbations, standard therapy with β2-agonists, anti-cholinergic agents, oxygen, and systemic steroids may fail to reverse the severe airflow obstruction and necessitate use of adjunctive therapies. These therapies include intravenous or inhaled magnesium, inhaled helium-oxygen mixtures, intravenous methylxanthines, intravenous β2-agonists, and intravenous ketamine. Rarely, these measures are not successful and following the initiation of invasive mechanical ventilation, inhaled anesthetics or extracorporeal life support may be required. In this review, we discuss the mechanisms and evidence for adjunctive therapies in the setting of severe acute asthma exacerbations in children.

Relationship Between Adverse Tracheal Intubation Associated Events and PICU Outcomes

Objective: Tracheal intubation in PICUs is a common procedure often associated with adverse events. The aim of this study is to evaluate the association between immediate events such as tracheal intubation associated events or desaturation and ICU outcomes: length of stay, duration of mechanical ventilation, and mortality. Study Design: Prospective cohort study with 35 PICUs using a multicenter tracheal intubation quality improvement database (National Emergency Airway Registry for Children: NEAR4KIDS) from January 2013 to June 2015. Desaturation defined as Spo2 less than 80%. Setting: PICUs participating in NEAR4KIDS. Patients: All patients less than18 years of age undergoing primary tracheal intubations with ICU outcome data were analyzed. Measurements and Main Results: Five thousand five hundred four tracheal intubation encounters with median 108 (interquartile range, 58–229) tracheal intubations per site. At least one tracheal intubation associated event was reported in 892 (16%), with 364 (6.6%) severe tracheal intubation associated events. Infants had a higher frequency of tracheal intubation associated event or desaturation than older patients (48% infants vs 34% for 1–7 yr and 18% for 8–17 yr). In univariate analysis, the occurrence of tracheal intubation associated event or desaturation was associated with a longer mechanical ventilation (5 vs 3 d; p < 0.001) and longer PICU stay (14 vs 11 d; p < 0.001) but not with PICU mortality. The occurrence of severe tracheal intubation associated events was associated with longer mechanical ventilation (5 vs 4 d; p < 0.003), longer PICU stay (15 vs 12 d; p < 0.035), and PICU mortality (19.9% vs 9.6%; p < 0.0001). In multivariable analyses, the occurrence of tracheal intubation associated event or desaturation was significantly associated with longer mechanical ventilation (+12%; 95% CI, 4–21%; p = 0.004), and severe tracheal intubation associated events were independently associated with increased PICU mortality (OR = 1.80; 95% CI, 1.24–2.60; p = 0.002), after adjusted for patient confounders. Conclusions: Adverse tracheal intubation associated events and desaturations are common and associated with longer mechanical ventilation in critically ill children. Severe tracheal intubation associated events are associated with higher ICU mortality. Potential interventions to decrease tracheal intubation associated events and oxygen desaturation, such as tracheal intubation checklist, use of apneic oxygenation, and video laryngoscopy, may need to be considered to improve ICU outcomes.