100% Nitrous Oxide in the Oxygen Line: How Could This Happen in a Modern Anesthesia Machine?

The inadvertent crossover between O2 and N2O pipelines has become extremely rare in practice. We describe a case where it was possible to ventilate with 100% N2O instead of the intended 100% O2 on a modern anesthesia delivery system (Dräger Apollo; Drägerwerk AG & Co KgaA, Lübeck, Germany). This was the result of the incorrect assembly of diameter index safety system (DISS) components during preventative maintenance that defeated the DISS failsafe system. To make incorrect assembly easier to avoid, DISS component labeling could be more prominent and color-coded, or the internal construction of the gas manifold could incorporate DISS.

Modified percutaneous tracheostomy in patients with COVID-19.

BACKGROUND: Patients hospitalized with COVID-19 are at risk of developing hypoxic respiratory failure and often require prolonged mechanical ventilation. Indication and timing to perform tracheostomy is controversial in patients with COVID-19. METHODS: This was a single-institution retrospective review of tracheostomies performed on patients admitted for COVID-19 between April 8, 2020 and August 1, 2020 using a modified percutaneous tracheostomy technique to minimize hypoxia and aerosolization. RESULTS: Twelve tracheostomies were performed for COVID-related respiratory failure. Median patient age was 54 years (range: 36-76) and 9 (75%) were male. Median time to tracheostomy was 17 days (range: 10-27), and 5 (42%) patients had failed attempts at extubation prior to tracheostomy. There were no intraprocedural complications, including hypoxia. Post-tracheostomy bleeding was noted in two patients. Eight (67%) patients have been discharged at the time of this study, and there were four patient deaths unrelated to tracheostomy placement. No healthcare worker transmissions resulted from participating in the tracheostomy procedure. CONCLUSIONS: A modified percutaneous tracheostomy is feasible and can be safely performed in patients infected with COVID-19. LEVEL OF EVIDENCE: Level V, case series.

A toolbox of IgG subclass-switched recombinant monoclonal antibodies for enhanced multiplex immunolabeling of brain.

Generating recombinant monoclonal antibodies (R-mAbs) from mAb-producing hybridomas offers numerous advantages that increase the effectiveness, reproducibility, and transparent reporting of research. We report here the generation of a novel resource in the form of a library of recombinant R-mAbs validated for neuroscience research. We cloned immunoglobulin G (IgG) variable domains from cryopreserved hybridoma cells and input them into an integrated pipeline for expression and validation of functional R-mAbs. To improve efficiency over standard protocols, we eliminated aberrant Sp2/0-Ag14 hybridoma-derived variable light transcripts using restriction enzyme treatment. Further, we engineered a plasmid backbone that allows for switching of the IgG subclasses without altering target binding specificity to generate R-mAbs useful in simultaneous multiplex labeling experiments not previously possible. The method was also employed to rescue IgG variable sequences and generate functional R-mAbs from a non-viable cryopreserved hybridoma. All R-mAb sequences and plasmids will be archived and disseminated from open source suppliers.

Epidemiology and Risk Factors for Outpatient-Acquired Catheter-Related Bloodstream Infections in Children Receiving Home Parenteral Nutrition.

BACKGROUND: Few studies have examined the epidemiology and risk factors for the development of outpatient-acquired catheter-related bloodstream infections (CRBSIs) in children receiving home parenteral nutrition. This study aimed to (1) characterize the incidence, clinical presentation, and epidemiology of CRBSIs and (2) identify risk factors for CRBSIs in children receiving home parenteral nutrition. METHODS: A longitudinal database approved by our Institutional Review Board was created to prospectively track CRBSIs in the UCLA pediatric population from January to December 2012. Eligible patients included those < 18 years old receiving home parenteral nutrition. RESULTS: Thirty of 60 patients (50%) were diagnosed with 66 CRBSIs, for an overall CRBSI rate of 3.6 per 1000 catheter days. Of the CRBSIs, 73% were due to single microorganisms and 27% were polymicrobial. There was a significant difference in median (range) time for blood cultures to turn positive depending on type of CRBSIs (p = 0.03), with polymicrobial infections detected at 13.4 (8.7-24.3) hours, gram-negative infections at 16.5 (9-30.8) hours, and gram-positive infections at 18.9 (8.4-37.1) hours. The most common presenting symptom was fever (82%), followed by gastrointestinal symptoms (42%) and chills (29%). The only significant multivariate risk factor for CRBSIs was presence of a feeding tube (2.3-fold increase in CRBSI risk, p = 0.04). DISCUSSION: Outpatient-acquired CRBSIs are common in children receiving home parenteral nutrition. CRBSIs typically present with fever, but are also associated with gastrointestinal and/or respiratory symptoms. The presence of feeding tubes may predispose children on home parenteral nutrition to developing CRBSIs.

Nutrition Deficiencies in Children With Intestinal Failure Receiving Chronic Parenteral Nutrition.

BACKGROUND: Home parenteral nutrition (PN) is a lifesaving therapy for children with intestinal failure (IF). Our aims were to describe the prevalence of micronutrient deficiencies (vitamin D, zinc, copper, iron, selenium) in a diverse population of children with IF receiving PN and to identify and characterize risk factors associated with micronutrient deficiencies, including hematologic abnormalities. METHODS: Data were collected on 60 eligible patients through retrospective chart review between May 2012 and February 2015. Descriptive statistics included frequencies, medians, interquartile ranges (IQRs), and odds ratios (ORs). Statistical analyses included χ2 , Fisher's exact, t tests, and logistic, univariate, and multivariate regressions. RESULTS: Patients were primarily young (median age, 3.3 years; IQR, 0.7-8.4), Latino (62%), and male (56%), with short bowel syndrome (70%). Of 60 study patients, 88% had ≥1 deficiency and 90% were anemic for age. Of 51 patients who had all 5 markers checked, 59% had multiple deficiencies (defined as ≥3). Multivariate analysis shows multiple deficiencies were associated with nonwhite race (OR, 9.4; P = .012) and higher body mass index z score (OR, 2.2; P = .016). Children with severe anemia (hemoglobin <8.5 g/dL) made up 50% of the cohort. Nonwhite race (OR, 6.6; P = .037) and zinc deficiency (OR, 11; P = .003) were multivariate predictors of severe anemia. CONCLUSIONS: Micronutrient deficiency and anemia are overwhelmingly prevalent in children with IF using chronic PN. This emphasizes the importance of universal surveillance and supplementation to potentially improve quality of life and developmental outcomes. Future research should investigate how racial disparities might contribute to nutrition outcomes for children using chronic PN.

Vitamin D deficiency in children with intestinal failure receiving home parenteral nutrition.

BACKGROUND: Vitamin D plays important roles in both skeletal and nonskeletal health. Limited data suggest that patients with intestinal failure (IF) receiving home parenteral nutrition (PN) are at risk for vitamin D deficiency due to inadequate oral intake, poor absorption, and chronic illness. The purpose of this study was to document vitamin D status in pediatric patients with IF receiving home PN. MATERIALS AND METHODS: We performed a 2-year retrospective review of children with IF followed at our center who had been on home PN for ≥6 months and had ≥1 serum 25-hydroxyvitamin D (25-OHD) level checked as part of routine clinical care. Patients were then categorized as deficient (<20 ng/mL), insufficient (20-29 ng/mL), or normal (≥30 ng/mL) based on their lowest vitamin D level. Demographic data and clinical characteristics were also assessed. RESULTS: Eleven of 27 children (41%) had ≥1 insufficient 25-OHD level, including one child with vitamin D deficiency. Diagnosis of short bowel syndrome (compared with dysmotility or malabsorption syndromes) was associated with decreased likelihood of suboptimal vitamin D status, with an odds ratio of 0.12 (95% confidence interval, 0.02-0.8, P = .028). Osteopenia was noted in 59% of the cohort. There was a trend toward higher risk for osteopenia in patients with low 25-OHD levels compared with those with normal 25-OHD levels (82% vs 44%, P = .109). CONCLUSION: Suboptimal 25-OHD levels are common in children with IF on home PN. This emphasizes the critical importance of routine surveillance of serum vitamin D levels and consideration of enteral supplementation when indicated.