Airway management of adult epiglottitis: a systematic review and meta-analysis.

Background: Adult epiglottitis is a life-threatening airway emergency where airway protection is the immediate priority. Despite its importance, the optimal approach to airway management remains unclear. We performed a systematic review of the airway management for adult epiglottitis, including meta-analysis of trends over time. Methods: We systematically searched PubMed, Ovid MEDLINE®, and Embase® for adult epiglottitis studies that described the airway management between 1980 and 2020. The primary outcome was the prevalence of airway intervention. Secondary outcomes were prevalence of tracheal intubation, tracheostomy, and failed intubation. A random-effects model meta-analysis was performed with subgroups defined by decade of study publication. Cases that described the specific method of airway intervention and severity of epiglottitis were included in a separate technique summary. Results: Fifty-six studies with 10 630 patients were included in the meta-analysis. The overall rate of airway intervention was 15.6% (95% confidence interval [CI] 12.9-18.8%) but the rate decreased from 20% to 10% between 1980 and 2020. The overall rate of tracheal intubation was 10.2% (95% CI 7.1-13.6%) and that of failed intubation was 4.2% (95% CI 1.4-8.0%). The airway technique summary included 128 cases, of which 75 (58.6%) were performed awake and 53 (41.4%) involved general anaesthesia. We identified 32 cases of primary technique failure. Conclusion: The rate of airway intervention for adult epiglottitis has decreased over four decades to a current level of 10%. Tracheal intubation is a high-risk scenario with a 1 in 25 failure rate. Specific technique selection is most likely influenced by contextual factors including the severity of epiglottitis.

The Effect of High-Flow Nasal Oxygen on Carbon Dioxide Accumulation in Apneic or Spontaneously Breathing Adults During Airway Surgery: A Randomized-Controlled Trial.

BACKGROUND: High-flow nasal oxygen (HFNO) is an emerging technology that has generated interest in tubeless anesthesia for airway surgery. HFNO has been shown to maintain oxygenation and CO2 clearance in spontaneously breathing patients and is an effective approach to apneic oxygenation. Although it has been suggested that HFNO can enhance CO2 clearance during apnea, this has not been established. The true extent of CO2 accumulation and resulting acidosis using HFNO during prolonged tubeless anesthesia remains undefined. METHODS: In a single-center trial, we randomly assigned 20 adults undergoing microlaryngoscopy to apnea or spontaneous ventilation (SV) using HFNO during 30 minutes of tubeless anesthesia. Serial arterial blood gas analysis was performed during preoxygenation and general anesthesia. The primary outcome was the partial pressure of CO2 (Paco2) after 30 minutes of general anesthesia, with each group compared using a Student t test. RESULTS: Nineteen patients completed the study protocol (9 in the SV group and 10 in the apnea group). The mean (standard deviation [SD]) Paco2 was 89.0 mm Hg (16.5 mm Hg) in the apnea group and 55.2 mm Hg (7.2 mm Hg) in the SV group (difference in means, 33.8; 95% confidence interval [CI], 20.6-47.0) after 30 minutes of general anesthesia (P < .001). The average rate of Paco2 rise during 30 minutes of general anesthesia was 1.8 mm Hg/min (SD = 0.5 mm Hg/min) in the apnea group and 0.8 mm Hg/min (SD = 0.3 mm Hg/min) in the SV group. The mean (SD) pH was 7.11 (0.04) in the apnea group and 7.29 (0.06) in the SV group (P < .001) at 30 minutes. Five (55%) of the apneic patients had a pH <7.10, of which the lowest measurement was 7.057. No significant difference in partial pressure of arterial O2 (Pao2) was observed after 30 minutes of general anesthesia. CONCLUSIONS: CO2 accumulation during apnea was more than double that of SV after 30 minutes of tubeless anesthesia using HFNO. The use of robust measurement confirms that apnea with HFNO is limited by CO2 accumulation and the concomitant severe respiratory acidosis, in contrast to SV. This extends previous knowledge and has implications for the safe application of HFNO during prolonged procedures.

Spontaneous Respiration Using Intravenous Anesthesia and High-Flow Nasal Oxygen (STRIVE Hi) Management of Acute Adult Epiglottitis: A Case Report.

High-flow nasal oxygen (HFNO) is a potentially life-saving adjunct in the emergency management of the obstructed airway. HFNO has multiple beneficial applications in critical care and respiratory support, but its use in emergency-obstructed airway management has not been defined. This case report describes spontaneous respiration using intravenous anesthesia and high-flow nasal oxygen to successfully manage acute adult epiglottitis with rapidly progressing airway obstruction. Oxygenation, carbon dioxide levels, and airway patency were maintained, which facilitated endotracheal intubation while the patient was spontaneously breathing during general anesthesia. The application of HFNO can be extended to emergency airway obstruction.

The S.T.A.B. trial-standardized testing of artificial blood: a comparative study of various products that may be used as artificial blood for high fidelity simulation training in the critical care setting.

AIM: In the current climate of medical education, there is an ever-increasing demand for and emphasis on simulation as both a teaching and training tool. The objective of our study was to compare the realism and practicality of a number of artificial blood products that could be used for high-fidelity simulation. METHOD: A literature and internet search was performed and 15 artificial blood products were identified from a variety of sources. One product was excluded due to its potential toxicity risks. Five observers, blinded to the products, performed two assessments on each product using an evaluation tool with 14 predefined criteria including color, consistency, clotting, and staining potential to manikin skin and clothing. Each criterion was rated using a five-point Likert scale. The products were left for 24 hours, both refrigerated and at room temperature, and then reassessed. Statistical analysis was performed to identify the most suitable products, and both inter- and intra-rater variability were examined. RESULTS: Three products scored consistently well with all five assessors, with one product in particular scoring well in almost every criterion. This highest-rated product had a mean rating of 3.6 of 5.0 (95% posterior Interval 3.4-3.7). Inter-rater variability was minor with average ratings varying from 3.0 to 3.4 between the highest and lowest scorer. Intrarater variability was negligible with good agreement between first and second rating as per weighted kappa scores (K = 0.67). CONCLUSION: The most realistic and practical form of artificial blood identified was a commercial product called KD151 Flowing Blood Syrup. It was found to be not only realistic in appearance but practical in terms of storage and stain removal.

Should we follow ATLS guidelines for the management of traumatic pulmonary contusion: the role of non-invasive ventilatory support.

OBJECTIVE: To assess the management of patients with blunt traumatic pulmonary contusion admitted to our hospital. To identify the role of early blood gas analysis, non-invasive ventilation and to assess the validity of the current Advanced Trauma Life Support manual statement that "Patients with significant hypoxia, i.e. PaO(2)<65 mm Hg or 8.6 kPa on room air, SaO(2)<90%, should be intubated and ventilated within the first hour after injury". SETTING: A 24 bed Intensive Care Unit in a major Trauma Centre situated in South Western Sydney, Australia. METHODS: Retrospective review of adults with blunt traumatic pulmonary contusion identified from the trauma registry. RESULTS: A total of 75 patients with an age range of 16-81 years were identified over a 2-year period. Arterial blood gas measurement was available for 32 patients during the immediate resuscitative period (<1 h from admission). All patients received supplemental oxygen and a PaO(2)/FiO(2) ratio was calculated. Seven patients had significant pulmonary contusion, indicated by an initial PaO(2)/FiO(2) ratio of <300, and were treated successfully with non-invasive ventilatory support. A further five patients without arterial blood gas (ABG) analysis on admission but with PaO(2)/FiO(2) ratio of <300 in the ICU were also managed with non-invasive ventilatory support. Multi-modal analgesia was commonly used. CONCLUSIONS: All major trauma patients admitted to our hospital received supplemental oxygen. Interpretation of ABG breathing room air was not used as an indicator for intubation. Most decisions to intubate early were based on clinical need. Patients with significant pulmonary contusion required intubation for reasons other than respiratory failure. Patients with significant pulmonary contusion were managed safely with non-invasive ventilatory support. Further investigation will determine the role of non-invasive ventilatory support in the management of these patients.