Infectious complications of vascular anomalies treated with sirolimus: A systematic review

BACKGROUND AND OBJECTIVES

Initially developed as immunosuppressive agents, mammalian target of rapamycin (mTOR) inhibitors are currently used widely in the management of vascular malformations and tumors. The incidence of infectious complications in the vascular anomalies (VA) population is not well defined. The goal of this systematic review was to better define the types and severity of reported infectious complications in patients with VAs treated with mTOR inhibition.

METHODS

This was a systematic review conducted following PRISMA guidelines evaluating all research articles focused on infectious complications in patients with VAs treated with sirolimus or everolimus. Thirty articles including 1182 total patients and 316 infections (in 291 unique patients) were ultimately included.

RESULTS

The majority of infections were viral upper respiratory (n = 137, 54%), followed by pneumonia (n = 53, 20%), and cutaneous infections (n = 20, 8%). There were six total infection-related fatalities, which all occurred in patients younger than 2 years. Two cases of Pneumocystis jirovecii pneumonia (PJP) were reported. These were infants with kaposiform hemangioendothelioma (KHE) who were also treated with steroids and did not receive PJP prophylaxis. Almost one-third (n = 96, 32%) of infectious complications were graded 3-4 according to Common Terminology Criteria for Adverse Events (CTCAE) criteria. Details of patient age, subtype of VA, and timing of infection were lacking from many reports.

CONCLUSIONS

Most infectious complications reported in patients with VA on mTOR inhibitors were viral respiratory infections and non-severe. Bacteremia, infectious fatalities, and PJP are exceedingly rare. Future studies are needed to clarify the spectrum of infectious risks in VA patients and to provide guidance for infection prevention.

Factors influencing delayed clearance of high dose methotrexate (HDMTX) in pediatric, adolescent, and young adult oncology patients

Purpose

To identify modifiable risk factors associated with prolonged clearance of methotrexate in pediatric, adolescent, and young adult (AYA) oncology patients receiving high dose methotrexate (HDMTX).

Design/Method

A single institution, retrospective chart review of patients receiving HDMTX between 2010-2017. Patients had a diagnosis of either leukemia or osteosarcoma. Data included demographics, concurrent intravenous (IV) medications, IV fluids (IVF) administered, urine output (UO), and rises in serum creatinine (RSC) reflective of renal toxicity (RT). Outcome measures included 1) delayed targeted MTX clearance (DC), 2) actual time to clearance (TTC) and 3) length of stay (LOS).

Results

Data from 447 HDMTX administrations were analyzed. The sample consisted of 241 (54%) osteosarcoma encounters, and 206 (46%) leukemia encounters, with an average patient age of 12.7 years. Multivariate analysis showed that DC was associated with the diagnosis of leukemia (OR 7.64, p <.0001), and less UO on day 1 (OR 0.76, p=0.005). Increased TTC was associated with increasing age (RR 1.02, p<0.0001), higher 24-hour MTX levels (RR 1.001, p=0.012) and 48-hour MTX levels (RR 1.02, p<0.0001), RT (RR 1.004, p<0.0001), use of IV lorazepam (RR 1.08, p=0.001) and IV metoclopramide (RR 1.08, p<0.001) both on day 3. Like TTC, LOS was affected by MTX levels at 24 (RR 1.001, p=0.025) and 48 hours (RR 1.03, p<0.0001), RT (RR 1.006, p<0.0001), total IV medications on day 3 (RR 1.042, p<0.0001), and the use of leucovorin on day 2 (RR 0.93, p=0.002).

Conclusion

Multiple modifiable risk factors were identified which can be leveraged to improve HDMTX clearance. Subsequent efforts will assess whether acting on such risk factors can improve MTX clearance and shorten LOS.

Eliminating Central Line Associated Bloodstream Infections in Pediatric Oncology Patients: A Quality Improvement Effort

Central Line-Associated Bloodstream Infections (CLABSI) are the largest contributor to harm across the Children's Hospital's Solutions for Patient Safety network. Pediatric hematology/oncology (PHO) patients are at increased risk for CLABSI due to multiple factors. Consequently, traditional CLABSI prevention strategies are insufficient to eliminate CLABSI in this high-risk population.

Methods

Our SMART aim was to reduce the CLABSI rate by 50% from a baseline of 1.89/1000 central line days to less than 0.9/1000 central line days by December 31, 2021. We created a multidisciplinary team being mindful to identify roles and responsibilities upfront. We developed a key driver diagram and designed and implemented interventions to influence our primary outcome.

Results

We implemented interventions and conducted Plan-Do-Study-Act cycles concurrently. We found that performing audits by directly observing tasks rather than auditing documentation resulted in more accurate compliance assessments. As a result, our CLABSI rate improved from 1.89/1000 central line days in 2020 with 11 primary CLABSI to 0.73/1000 central line days in 2021 with four primary CLABSI. Average days between events improved from 30 days in 2020 to 73 days in 2021, and we achieved an unprecedented 542 days CLABSI-free, extending into 2022.

Conclusions

Through a multimodal approach and utilizing characteristics of high-reliability organizations, we significantly reduced primary CLABSI, approaching zero in our PHO population and doubling the average days between events. Future efforts will focus on the sustained engagement of all stakeholders and improving our safety culture.

Mortality in pediatric oncology and stem cell transplant patients with bloodstream infections

Background

Bloodstream infections (BSI) continue to represent a significant source of morbidity for pediatric oncology patients, however less is known regarding this population's risk of death. We sought to evaluate the risk of BSI and death at a large pediatric cancer center.

Methods

We retrospectively collected inpatient data from pediatric oncology and hematopoietic stem cell transplant (HSCT) patients over a 9-year period. We performed univariate and multivariable modeling to assess risk of BSI and mortality examining the following variables: demographics, underlying malignancy, history of HSCT, central line type, and febrile neutropenia (FN).

Results

During the study period, 6763 admissions from 952 patients met inclusion criteria. BSI occurred in 367 admissions (5.4%) from 231 unique individuals. Risk factors for BSI include younger age, diagnoses of hemophagocytic lymphohistiocytosis or acute myeloid leukemia, ethnicity, and history of HSCT. Mortality for those with BSI was 6.5%, compared to 0.7% without (OR 7.2, CI 4.1 - 12.7, p<0.0001). In patients with BSI, admissions with FN were associated with reduced mortality compared to admissions without FN (OR 0.21, CI 0.05 - 0.94, p=0.04). In both univariate and multivariable analysis, no other risk factor was significantly associated with mortality in patients with BSI.

Conclusion

BSI is a significant source of mortality in pediatric oncology and HSCT patients. While demographic variables contribute to the risk of BSI, they did not influence mortality. These findings highlight the importance of BSI prevention to reduce the risk of death in pediatric oncology patients. Future studies should focus on comprehensive BSI prevention.

Failure modes and effects analysis of pediatric I-131 MIBG therapy: Program design and potential pitfalls

BACKGROUND

There is growing interest among pediatric institutions for implementing iodine-131 (I-131) meta-iodobenzylguanidine (MIBG) therapy for treating children with high-risk neuroblastoma. Due to regulations on the medical use of radioactive material (RAM), and the complexity and safety risks associated with the procedure, a multidisciplinary team involving radiation therapy/safety experts is required. Here, we describe methods for implementing pediatric I-131 MIBG therapy and evaluate our program's robustness via failure modes and effects analysis (FMEA).

METHODS

We formed a multidisciplinary team, involving pediatric oncology, radiation oncology, and radiation safety staff. To evaluate the robustness of the therapy workflow and quantitatively assess potential safety risks, an FMEA was performed. Failure modes were scored (1-10) for their risk of occurrence (O), severity (S), and being undetected (D). Risk priority number (RPN) was calculated from a product of these scores and used to identify high-risk failure modes.

RESULTS

A total of 176 failure modes were identified and scored. The majority (94%) of failure modes scored low (RPN <100). The highest risk failure modes were related to training and to drug-infusion procedures, with the highest S scores being (a) caregivers did not understand radiation safety training (O = 5.5, S = 7, D = 5.5, RPN = 212); (b) infusion training of staff was inadequate (O = 5, S = 8, D = 5, RPN = 200); and (c) air in intravenous lines/not monitoring for air in lines (O = 4.5, S = 8, D = 5, RPN = 180).

CONCLUSION

Through use of FMEA methodology, we successfully identified multiple potential points of failure that have allowed us to proactively mitigate risks when implementing a pediatric MIBG program.

Clostridioides difficile Infections in Inpatient Pediatric Oncology Patients: A Cohort Study Evaluating Risk Factors and Associated Outcomes

BACKGROUND

Clostridioides difficile infection (CDI) is a significant source of morbidity in pediatric cancer patients. Few reports to date have evaluated risk factors and short-term outcomes for this population.

METHODS

We retrospectively evaluated pediatric oncology admissions at St Louis Children's Hospital from 2009 to 2018. All inpatient cases of diagnosed initial CDI were identified. We aimed to investigate the prevalence of CDI and associated risk factors, including coadmission with another patient with CDI, and to evaluate short-term outcomes including length of stay and delays in subsequent scheduled chemotherapy.

RESULTS

Review of 6567 admissions from 952 patients revealed 109 CDI cases (11.4% of patients). Patients with leukemia or lymphoma, compared to those with solid tumors, were more likely to have CDI (odds ratio [OR], 3 [95% CI, 1.4-6.6], and 3 [95% CI, 1.3-6.8], respectively). Autologous hematopoietic stem cell transplant (HSCT) was also a risk factor (OR, 3.5 [95% CI, 1.7-7.4]). Prior antibiotic exposure independently increased the risk for CDI (OR, 3.0 [95% CI, 1.8-4.8]). Concurrent admission with another patient with CDI also significantly increased the risk (OR, 84.7 [95% CI, 10.5-681.8]). In contrast to previous reports, exposure to acid-suppressing medications decreased the risk for CDI (OR, 0.5 [95% CI, .3-.7]). CDI was associated with increased length of stay (mean difference, 8 days [95% CI, 4.6-11.4]) and prolonged delays for subsequent chemotherapy (mean difference, 1.4 days [95% CI, .1-2.7]).

CONCLUSIONS

CDI in pediatric oncology patients significantly prolongs hospitalization and delays chemotherapy treatment plans. Interventions to control CDI will improve the care of pediatric oncology patients.

Toxicity of gutkha, a smokeless tobacco product gone global: is there more to the toxicity than nicotine?

The popularity of smokeless tobacco (ST) is growing rapidly and its prevalence of use is rising globally. Consumption of Gutkha, an addictive form of ST, is particularly common amongst South Asian communities throughout the World. This includes within the US, following large-scale immigration into the country. However, there exists a lack of knowledge concerning these alternative tobacco products. To this end, a study was carried out to determine the toxicity of gutkha, and what role, if any, nicotine contributes to the effects. Adult male mice were treated daily for 3-week (5 day/week, once/day), via the oral mucosa, with equal volumes (50 μL) of either sterile water (control), a solution of nicotine dissolved in water (0.24 mg of nicotine), or a solution of lyophilized guthka dissolved in water (21 mg lyophilized gutkha). Serum cotinine, measured weekly, was 36 and 48 ng/mL in gutkha- and nicotine-treated mice, respectively. Results demonstrated that exposure to nicotine and gutkha reduced heart weight, while exposure to gutkha, but not nicotine, decreased liver weight, body weight, and serum testosterone levels (compared to controls). These findings suggest that short-term guhtka use adversely impacts growth and circulating testosterone levels, and that gutkha toxicity may be driven by components other than nicotine. As use of guthka increases worldwide, future studies are needed to further delineate toxicological implications such that appropriate policy decisions can be made.

Menthol attenuates respiratory irritation responses to multiple cigarette smoke irritants

Menthol, the cooling agent in peppermint, is added to almost all commercially available cigarettes. Menthol stimulates olfactory sensations, and interacts with transient receptor potential melastatin 8 (TRPM8) ion channels in cold-sensitive sensory neurons, and transient receptor potential ankyrin 1 (TRPA1), an irritant-sensing channel. It is highly controversial whether menthol in cigarette smoke exerts pharmacological actions affecting smoking behavior. Using plethysmography, we investigated the effects of menthol on the respiratory sensory irritation response in mice elicited by smoke irritants (acrolein, acetic acid, and cyclohexanone). Menthol, at a concentration (16 ppm) lower than in smoke of mentholated cigarettes, immediately abolished the irritation response to acrolein, an agonist of TRPA1, as did eucalyptol (460 ppm), another TRPM8 agonist. Menthol's effects were reversed by a TRPM8 antagonist, AMTB. Menthol's effects were not specific to acrolein, as menthol also attenuated irritation responses to acetic acid, and cyclohexanone, an agonist of the capsaicin receptor, TRPV1. Menthol was efficiently absorbed in the respiratory tract, reaching local concentrations sufficient for activation of sensory TRP channels. These experiments demonstrate that menthol and eucalyptol, through activation of TRPM8, act as potent counterirritants against a broad spectrum of smoke constituents. Through suppression of respiratory irritation, menthol may facilitate smoke inhalation and promote nicotine addiction and smoking-related morbidities.

Role of metabolic activation and the TRPA1 receptor in the sensory irritation response to styrene and naphthalene

The current study was aimed at examining the role of cytochrome P450 (CYP450) activation and the electrophile-sensitive transient receptor potential ankyrin 1 receptor (TRPA1) in mediating the sensory irritation response to styrene and naphthalene. Toward this end, the sensory irritation to these vapors was measured in female C57Bl/6J mice during 15-min exposure via plethysmographic measurement of the duration of braking at the onset of each expiration. The sensory irritation response to 75 ppm styrene and 7 ppm naphthalene was diminished threefold or more in animals pretreated with the CYP450 inhibitor metyrapone, providing evidence of the role of metabolic activation in the response to these vapors. The sensory irritation response to styrene (75 ppm) and naphthalene (7.6 ppm) was virtually absent in TRPA1-/- knockout mice, indicating the critical role of this receptor in mediating the response. Thus, these results support the hypothesis that styrene and naphthalene vapors initiate the sensory irritation response through TRPA1 detection of their CYP450 metabolites.