Yield and Energy Modeling for Biochar and Bio-Oil Using Pyrolysis Temperature and Biomass Constituents.

Pyrolysis offers a sustainable and efficient approach to resource utilization and waste management, transforming organic materials into valuable products. The quality and distribution of the pyrolysis products highly depend on the constituents' properties and set process parameters. This research aims to investigate and model this dependency, offering decision-makers a tool to guide them when designing the process for a particular application. Experimental data on the pyrolysis of various types of feedstocks processed at a wide range of pyrolysis temperatures (350-650 °C) are utilized to develop the prediction models. Four variables are modeled: the yield and energy content for both the biochar and bio-oil as a function of the pyrolysis temperature and feedstock characteristics. The models developed had very good prediction power with the coefficient of determination above 90%. The results highlight the advantages of food waste (leftover) as a suitable feedstock to produce biochar at the pyrolysis temperature within the range of 450-550 °C. Furthermore, the biofuels produced from food waste are found to be of good quality, with the bio-oil exceptionally high in energy content (HHV = 34.6 MJ/kg), which is almost 80% of that of diesel. The developed models provide a tool for predicting the biofuel yield and quality based on the feedstock selection and process temperature.

Multi-institutional search for patient factors associated with adverse events following tracheotomy.

BACKGROUND: Tracheotomy is a common procedure for otolaryngologists. The risk of complications is difficult to predict. This study aims to identify measurable preoperative indicators associated with adverse events following tracheotomy. METHODS: The charts of adults undergoing tracheotomy for respiratory failure at one of four university-affiliated hospitals between 1/2012 and 8/2018 were reviewed. Complications were analyzed in the context of demographics, physiologic parameters, and comorbidities. RESULTS: Among 507 tracheotomies performed, the most common complications included infection, bleeding, and cardiac arrest. Mortality was 39 % in patients with pulmonary hypertension, 42 % in those with ejection fraction ≤ 40 and 32 % in those with abnormal right ventricular function, double the rates in patients without each of these findings. CONCLUSION: Many critically ill tracheotomy patients experience significant rates of adverse events. Risk factors for mortality include ejection fraction ≤ 40, pulmonary hypertension, and abnormal ventricular function. These should be considered for use in preoperative counseling.

Tracheostomy protocols during COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has resulted in the implementation of rapidly changing protocols and guidelines related to the indications and perioperative precautions and protocols for tracheostomy. The purpose of this study was to evaluate current guidelines for tracheostomy during the COVID-19 pandemic to provide a framework for health systems to prepare as the science evolves over the upcoming months and years. METHODS: Literature review was performed. Articles reporting clinical practice guidelines for tracheostomy in the context of COVID-19 were included. RESULTS: A total of 13 tracheotomy guidelines were identified. Two were available via PubMed, five in society or organization websites, and six identified via health system websites or other sources. Five were from Otolaryngology-Head and Neck Surgery specialties, six from Anesthesiology and one from Pulmonary/Critical Care. All (100%) studies recommended postponing elective OR cases in COVID-19 positive patients, while seven recommended reducing team members to only essential staff and three recommended forming a designated tracheostomy team. Recommendations with supporting references are summarized in the article. CONCLUSIONS: Tracheostomy guidelines during the COVID-19 pandemic vary by physician groups and specialty, hospital systems, and supply-chain/resource availability. This summary is provided as a point-in-time current state of the guidelines for tracheotomy management in April 2020 and is expected to change in coming weeks and months as the COVID-19 pandemic, virus testing and antibody testing evolves.

Intraoperative and postanesthesia care unit fluid administration as risk factors for postoperative complications in patients with head and neck cancer undergoing free tissue transfer.

BACKGROUND: This study aims to evaluate the impact of perioperative fluid administration, defined as fluid delivered intraoperatively and in the postanesthesia care unit, on postoperative outcomes. METHODS: Medical records of 102 patients with oral cavity squamous cell carcinoma undergoing free flap reconstruction between January 2011 and December 2015 were reviewed. The primary endpoint was development of a postoperative complication according to the Clavien-Dindo classification. Perioperative factors recorded were Washington University Head and Neck Comorbidity Index, operating time, vasopressor use, blood loss, intraoperative fluid, and perioperative fluid. RESULTS: Greater perioperative fluid administration was independently associated with surgical complications, flap complications, overall incidence of any complication, and increased length of stay. Greater intraoperative fluid administration was independently associated with higher rates of surgical complications. Intraoperative delivery of vasopressors was not associated with flap or surgical complications. CONCLUSION: Receiving less perioperative fluid was associated with fewer complications and decreased length of stay.

Nasal Obstruction Considerations in Sleep Apnea.

Obstructive sleep apnea (OSA) is a highly prevalent condition in the context of the global obesity epidemic with significant medical comorbidities and psychosocial implications. The first-line treatment of OSA is continuous positive airway pressure (CPAP). There is evidence to demonstrate an association between nasal obstruction and OSA. Therefore, medications and surgical interventions to address nasal obstruction may play a role in the treatment of OSA. In addition, surgical correction of nasal obstruction has been shown to improve CPAP tolerance and compliance.

Impact of elective neck dissection on the outcome of oral squamous cell carcinomas arising in the maxillary alveolus and hard palate.

BACKGROUND: Whether elective lymph neck dissection (ELND) is associated with improved survival in oral squamous cell carcinomas (SCC) of the maxillary alveolus/hard palate is not known. METHODS: One hundred ninety-nine patients presenting de novo and receiving treatment for clinically node negative SCC of the maxillary alveolus/hard palate at 2 cancer centers between 1985 and 2011 were analyzed. RESULTS: Forty-two patients (21%) received ELND. Occult nodal metastases were present in 29% of the dissected necks. The ELND group had more T3 to T4 status tumors (62% vs 34%; p < .001) and positive-margin resections (59% vs 38%; p = .019). Patients undergoing ELND experienced lower rates of neck recurrence (6% vs 21%; p = .031), superior 5-year recurrence-free survival (68% vs 45%; p = .026), and overall survival (86% vs 62%; p = .043). ELND was associated with a 2-fold decrease in risk of recurrence in multivariable analysis. CONCLUSION: ELND was associated with lower rates of recurrence and improved survival in SCC of the maxillary alveolus/hard palate. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1688-E1694, 2016.

Individualized Risk Estimation for Postoperative Complications After Surgery for Oral Cavity Cancer.

IMPORTANCE: Postoperative complications after head and neck surgery carry the potential for significant morbidity. Estimating the risk of complications in an individual patient is challenging. OBJECTIVE: To develop a statistical tool capable of predicting an individual patient's risk of developing a major complication after surgery for oral cavity squamous cell carcinoma. DESIGN, SETTING, AND PARTICIPANTS: Retrospective case series derived from an institutional clinical oncologic database, augmented by medical record abstraction, at an academic tertiary care cancer center. Participants were 506 previously untreated adult patients with biopsy-proven oral cavity squamous cell carcinoma who underwent surgery between January 1, 2007, and December 31, 2012. MAIN OUTCOMES AND MEASURES: The primary end point was a major postoperative complication requiring invasive intervention (Clavien-Dindo classification grades III-V). Patients treated between January 1, 2007, and December 31, 2008 (354 of 506 [70.0%]) comprised the modeling cohort and were used to develop a nomogram to predict the risk of developing the primary end point. Univariable analysis and correlation analysis were used to prescreen 36 potential predictors for incorporation in the subsequent multivariable logistic regression analysis. The variables with the highest predictive value were identified with the step-down model reduction method and included in the nomogram. Patients treated between January 1, 2007, and December 31, 2008 (152 of 506 [30.0%]) were used to validate the nomogram. RESULTS: Clinical characteristics were similar between the 2 cohorts for most comparisons. Thirty-six patients in the modeling cohort (10.2%) and 16 patients in the validation cohort (10.5%) developed a major postoperative complication. The 6 preoperative variables with the highest individual predictive value were incorporated within the nomogram, including body mass index, comorbidity status, preoperative white blood cell count, preoperative hematocrit, planned neck dissection, and planned tracheotomy. The nomogram predicted a major complication with a validated concordance index of 0.79. Inclusion of surgical operative variables in the nomogram maintained predictive accuracy (concordance index, 0.77). CONCLUSIONS AND RELEVANCE: A statistical tool was developed that accurately estimates an individual patient's risk of developing a major complication after surgery for oral cavity squamous cell carcinoma.

Defining value-driven care in head and neck oncology.

In the USA, increasing attention is being paid to adopting a value-based framework for measuring and ultimately improving health care delivery. Value is defined as the benefit achieved relative to costs. The numerator of the value equation includes quality of care and outcomes achieved. The denominator includes costs, both financial costs and harms of treatment. Herein, we describe these elements of value as they pertain to head and neck cancer. A particular focus is to identify areas of the value equation where physicians have some control. We examine quality in each of three dimensions: structure, process, and outcomes. We also adopt Porter's three-tiered hierarchy of outcomes model, with specific outcomes relevant to patients with head and neck and thyroid cancer. Finally, we review issues related to costs and harms. We believe these findings can serve as a framework for further efforts to drive value-based delivery of head and neck cancer care.

Accuracy of administrative and clinical registry data in reporting postoperative complications after surgery for oral cavity squamous cell carcinoma.

BACKGROUND: The purpose of this study was to describe and compare how postoperative complications after oral cavity squamous cell carcinoma (SCC) surgery are reported in medical records, institutional billing claims, and national clinical registries. METHODS: The medical records of 355 previously untreated patients who underwent surgery for oral cavity SCC at our institution were retrospectively reviewed for postoperative complications. Information was compared with claims and National Surgical Quality Improvement Program (NSQIP) data. RESULTS: We identified 219 patients (62%) experiencing 544 complications (10% major). Billing claims identified 29% of these patients, 36% of overall complications, and 98% of major complications. Of overlapping patients, NSQIP identified 27% of patients, 33% of overall complications, and 100% of major complications noted on chart abstraction. CONCLUSION: The incidence of minor postoperative complications after oral cavity SCC surgery is relatively high. Both claims data and NSQIP accurately recorded major complications, but were suboptimal compared to chart abstraction in capturing minor complications.