Aerosol Retention Characteristics of Barrier Devices.

BACKGROUND: Disease severity in coronavirus disease 2019 (COVID-19) may be associated with inoculation dose. This has triggered interest in intubation barrier devices to block droplet exposure; however, aerosol protection with these devices is not known. This study hypothesized that barrier devices reduce aerosol outside of the barrier. METHODS: Aerosol containment in closed, semiclosed, semiopen, and open barrier devices was investigated: (1) "glove box" sealed with gloves and caudal drape, (2) "drape tent" with a drape placed over a frame, (3) "slit box" with armholes and caudal end covered by vinyl slit diaphragms, (4) original "aerosol box," (5) collapsible "interlocking box," (6) "simple drape" over the patient, and (7) "no barrier." Containment was investigated by (1) vapor instillation at manikin's right arm with video-assisted visual evaluation and (2) submicrometer ammonium sulfate aerosol particles ejected through the manikin's mouth with ventilation and coughs. Samples were taken from standardized locations inside and around the barriers using a particle counter and a mass spectrometer. Aerosol evacuation from the devices was measured using standard hospital suction, a surgical smoke evacuator, and a Shop-Vac. RESULTS: Vapor experiments demonstrated leakage via arm holes and edges. Only closed and semiclosed devices and the aerosol box reduced aerosol particle counts (median [25th, 75th percentile]) at the operator's mouth compared to no barrier (combined median 29 [-11, 56], n = 5 vs. 157 [151, 166], n = 5). The other barrier devices provided less reduction in particle counts (133 [128, 137], n = 5). Aerosol evacuation to baseline required 15 min with standard suction and the Shop-Vac and 5 min with a smoke evacuator. CONCLUSIONS: Barrier devices may reduce exposure to droplets and aerosol. With meticulous tucking, the glove box and drape tent can retain aerosol during airway management. Devices that are not fully enclosed may direct aerosol toward the laryngoscopist. Aerosol evacuation reduces aerosol content inside fully enclosed devices. Barrier devices must be used in conjunction with body-worn personal protective equipment.

Understanding heart rate alarm adjustment in the intensive care units through an analytical approach.

BACKGROUND: Heart rate (HR) alarms are prevalent in ICU, and these parameters are configurable. Not much is known about nursing behavior associated with tailoring HR alarm parameters to individual patients to reduce clinical alarm fatigue. OBJECTIVES: To understand the relationship between heart rate (HR) alarms and adjustments to reduce unnecessary heart rate alarms. METHODS: Retrospective, quantitative analysis of an adjudicated database using analytical approaches to understand behaviors surrounding parameter HR alarm adjustments. Patients were sampled from five adult ICUs (77 beds) over one month at a quaternary care university medical center. A total of 337 of 461 ICU patients had HR alarms with 53.7% male, mean age 60.3 years, and 39% non-Caucasian. Default HR alarm parameters were 50 and 130 beats per minute (bpm). The occurrence of each alarm, vital signs, and physiologic waveforms was stored in a relational database (SQL server). RESULTS: There were 23,624 HR alarms for analysis, with 65.4% exceeding the upper heart rate limit. Only 51% of patients with HR alarms had parameters adjusted, with a median upper limit change of +5 bpm and -1 bpm lower limit. The median time to first HR parameter adjustment was 17.9 hours, without reduction in alarms occurrence (p = 0.57). CONCLUSIONS: HR alarms are prevalent in ICU, and half of HR alarm settings remain at default. There is a long delay between HR alarms and parameters changes, with insufficient changes to decrease HR alarms. Increasing frequency of HR alarms shortens the time to first adjustment. Best practice guidelines for HR alarm limits are needed to reduce alarm fatigue and improve monitoring precision.

Simulation Manikin Modifications for High-Fidelity Training of Advanced Airway Procedures.

Thoracic anesthesia procedures are challenging to master during anesthesia training. A Laerdal ALS Simulator® manikin was modified by adding a bronchial tree module to create fidelity to the fourth generation. After modification, placement of endotracheal tubes up to 8.0 mm is possible by direct laryngoscopy, video laryngoscopy, and fiberoptically; in addition, it allows fiberoptically guided insertion of endobronchial blockers. Insertion of left and right 35-Fr double-lumen tubes permits double- and single-lung ventilation with continuous positive airway pressure and positive end-expiratory pressure. This anatomical modification created a high-fidelity training tool for thoracic anesthesia that has been incorporated into educational curricula for anesthesia.

Easy-to-implement oral cavity modification to expand simulation-based training in airway management.

INTRODUCTION: Injuries to the oral cavity and teeth can occur during routine intubation and general anesthesia but often occur in emergency situations when the priority of securing the airway supersedes preanesthetic evaluation. This study demonstrates the feasibility of modifying the oral cavity to increase the dental fidelity during emergency airway management. METHODS: A Laerdal Manikin was used to manipulate the preexisting Polyester (hard) and the Vinyl (flexible) dentition sets that are interchangeable among the Laerdal family of manikins. Items easily available in a dental laboratory such as dental acrylic and dental impression material were used to create modifications. RESULTS: Laerdal dentition sets were altered to simulate common dental (tooth-related) trauma encountered during intubation such as a fracture, luxation, or avulsion injuries. Anatomic variations such as carious (decayed) teeth, loose teeth, and class II malocclusion (overbite) were also fabricated. Tooth luxation was engineered to occur with pressure by a laryngoscope, and bleeding teeth were also created to demonstrate excessive pressure applied during direct laryngoscopy. It is feasible to improve the realism of the Laerdal family of manikins with simple modifications. CONCLUSIONS: This project proves the concept of feasibly fabricating anatomic variations to increase the fidelity of existing simulation manikins. Other anatomic variations present challenges to airway management, and future research will aim at creating additional modifications. In addition, future research will seek to quantify the improvement in airway management skills by anesthesia and emergency medicine providers by training on manikins with variable oral cavity anatomy.