David Tellez

An ovine model of maternal iron poisoning in pregnancy

An ovine model of maternal iron poisoning in pregnancy was used to examine the placental transport of deferoxamine and ferrioxamine and to follow maternal and fetal serum iron concentrations when maternal serum iron levels exceeded total iron-binding capacity. Ewes in the third stage of gestation underwent hysterotomy and delivery of the fetal head through an abdominal incision while under ketamine and halothane anesthesia. The fetal external jugular vein was catheterized for sampling of venous blood while the fetus remained in utero. Administration of deferoxamine mesylate or ferrioxamine mesylate IV to ewes was not accompanied by measurable deferoxamine or ferrioxamine in fetal blood. In a final experiment, four gravid ewes in a control group received 2 mg/kg maternal body wt iron IV over 60 minutes. An experimental group comprising another four ewes received similar doses of iron but then received 50 mg/kg deferoxamine mesylate IV over 15 minutes. Control and deferoxamine ewes reached similar peak maternal serum iron concentrations (2,479 +/- 266 and 2,121 +/- 343 micrograms/dL, respectively). The markedly elevated maternal serum iron concentrations were not accompanied by meaningful elevations in fetal serum iron levels over baseline values. Maternal deferoxamine infusion resulted in a more rapid fall in maternal serum iron concentrations but had no effect on fetal serum iron levels. The ovine fetus appears to be protected from elevated maternal serum iron concentrations in the last trimester of pregnancy. It could not be demonstrated that meaningful quantities of deferoxamine or ferrioxamine cross the placenta in the last trimester.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Direct Fluorescent-Antibody Testing Followed by Culture for Diagnosis of 2009 H1N1 Influenza A

ABSTRACT During the 2009 H1N1 influenza A outbreak, 773 children were tested for influenza by direct fluorescent-antibody testing with PCR confirmation. Direct fluorescent-antibody testing has a specificity of 99.6% but a sensitivity of only 65.0%. Physicians should recognize diagnostic limitations of direct fluorescent-antibody testing, which missed one-third of infected individuals.

Vancomycin Monotherapy May Be Insufficient to Treat Methicillin-resistant Staphylococcus aureus Coinfection in Children With Influenza-related Critical Illness

Abstract Background Coinfection with influenza virus and methicillin-resistant Staphylococcus aureus (MRSA) causes life-threatening necrotizing pneumonia in children. Sporadic incidence precludes evaluation of antimicrobial efficacy. We assessed the clinical characteristics and outcomes of critically ill children with influenza–MRSA pneumonia and evaluated antibiotic use. Methods We enrolled children (<18 years) with influenza infection and respiratory failure across 34 pediatric intensive care units 11/2008–5/2016. We compared baseline characteristics, clinical courses, and therapies in children with MRSA coinfection, non-MRSA bacterial coinfection, and no bacterial coinfection. Results We enrolled 170 children (127 influenza A, 43 influenza B). Children with influenza–MRSA pneumonia (N = 30, 87% previously healthy) were older than those with non-MRSA (N = 61) or no (N = 79) bacterial coinfections. Influenza–MRSA was associated with increased leukopenia, acute lung injury, vasopressor use, extracorporeal life support, and mortality than either group (P ≤ .0001). Influenza-related mortality was 40% with MRSA compared to 4.3% without (relative risk [RR], 9.3; 95% confidence interval [CI], 3.8–22.9). Of 29/30 children with MRSA who received vancomycin within the first 24 hours of hospitalization, mortality was 12.5% (N = 2/16) if treatment also included a second anti-MRSA antibiotic compared to 69.2% (N = 9/13) with vancomycin monotherapy (RR, 5.5; 95% CI, 1.4, 21.3; P = .003). Vancomycin dosing did not influence initial trough levels; 78% were <10 µg/mL. Conclusions Influenza–MRSA coinfection is associated with high fatality in critically ill children. These data support early addition of a second anti-MRSA antibiotic to vancomycin in suspected severe cases.

Effect of Location on Tracheal Intubation Safety in Cardiac Disease—Are Cardiac ICUs Safer?

Objectives: Evaluate differences in tracheal intubation–associated events and process variances (i.e., multiple intubation attempts and oxygen desaturation) between pediatric cardiac ICUs and noncardiac PICUs in children with underlying cardiac disease. Design: Retrospective cohort study using a multicenter tracheal intubation quality improvement database (National Emergency Airway Registry for Children). Setting: Thirty-six PICUs (five cardiac ICUs, 31 noncardiac ICUs) from July 2012 to March 2016. Patients: Children with medical or surgical cardiac disease who underwent intubation in an ICU. Interventions: None. Measurements and Main Results: Our primary outcome was the rate of any adverse tracheal intubation–associated event. Secondary outcomes were severe tracheal intubation–associated events, multiple tracheal intubation attempt rates, and oxygen desaturation. There were 1,502 tracheal intubations in children with underlying cardiac disease (751 in cardiac ICUs, 751 in noncardiac ICUs) reported. Cardiac ICUs and noncardiac ICUs had similar proportions of patients with surgical cardiac disease. Patients undergoing intubation in cardiac ICUs were younger (median age, 1 mo [interquartile range, 0–6 mo]) compared with noncardiac ICUs (median 3 mo [interquartile range, 1–11 mo]; p < 0.001). Tracheal intubation–associated event rates were not different between cardiac ICUs and noncardiac ICUs (16% vs 19%; adjusted odds ratio, 0.74; 95% CI, 0.54–1.02; p = 0.069). However, in a sensitivity analysis comparing cardiac ICUs with mixed ICUs (i.e., ICUs caring for children with either general pediatric or cardiac diseases), cardiac ICUs had decreased odds of adverse events (adjusted odds ratio, 0.71; 95% CI, 0.52–0.97; p = 0.033). Rates of severe tracheal intubation–associated events and multiple attempts were similar. Desaturations occurred more often during intubation in cardiac ICUs (adjusted odds ratio, 1.61; 95% CI, 1.04–1.15; p = 0.002). Conclusions: In children with underlying cardiac disease, rates of adverse tracheal intubation–associated events were not lower in cardiac ICUs as compared to noncardiac ICUs, even after adjusting for differences in patient characteristics and care models.