Protocol for Usability Testing and Validation of the ISO Draft International Standard 19223 for Lung Ventilators.

BACKGROUND: Clinicians, such as respiratory therapists and physicians, are often required to set up pieces of medical equipment that use inconsistent terminology. Current lung ventilator terminology that is used by different manufacturers contributes to the risk of usage errors, and in turn the risk of ventilator-associated lung injuries and other conditions. Human factors and communication issues are often associated with ventilator-related sentinel events, and inconsistent ventilator terminology compounds these issues. This paper describes our proposed protocol, which will be implemented at the University of Waterloo, Canada when this project is externally funded. OBJECTIVE: We propose to determine whether a standardized vocabulary improves the ease of use, safety, and utility as it relates to the usability of medical devices, compared to legacy medical devices from multiple manufacturers, which use different terms. METHODS: We hypothesize that usage errors by clinicians will be lower when standardization is consistently applied by all manufacturers. The proposed study will experimentally examine the impact of standardized nomenclature on performance declines in the use of an unfamiliar ventilator product in clinically relevant scenarios. Participants will be respiratory therapy practitioners and trainees, and we propose studying approximately 60 participants. RESULTS: The work reported here is in the proposal phase. Once the protocol is implemented, we will report the results in a follow-up paper. CONCLUSIONS: The proposed study will help us better understand the effects of standardization on medical device usability. The study will also help identify any terms in the International Organization for Standardization (ISO) Draft International Standard (DIS) 19223 that may be associated with recurrent errors. Amendments to the standard will be proposed if recurrent errors are identified. This report contributes a protocol that can be used to assess the effect of standardization in any given domain that involves equipment, multiple manufacturers, inconsistent vocabulary, symbology, audio tones, or patterns in interface navigation. Second, the protocol can be used to experimentally evaluate the ISO DIS 19223 for its effectiveness, as researchers around the world may wish to conduct such tests and compare results.

Technical communication: the effect of the double mask on anesthetic waste gas levels during pediatric mask inductions in dental offices.

A significant portion of office-based general anesthesia for pediatric patients is performed in dental offices and involves mask inductions with inhaled drugs. This can lead to significant pollution with waste gases. We assessed occupational exposure to anesthetic drugs during pediatric general anesthesia in dental offices and assessed the effectiveness of the "double mask." Nine freestanding dental offices had measurements of anesthetic waste gas levels taken before and immediately after implementation of a double-mask system. Levels of nitrous oxide decreased from a median of 40.0 parts per million (ppm; interquartile range [IQR] = 23.0-46.0 ppm, n = 9) to 3.0 ppm, (IQR = 2.3-4.7 ppm, n = 9, P = 0.0055) and exceeded 25 ppm in 0% of the 9 offices (upper 95% confidence limit 34%) when using the double mask. Levels of sevoflurane decreased from a median of 4.60 ppm (IQR = 3.10-7.00 ppm, n = 9) to 0 ppm (IQR = 0-0.39 ppm, n = 9, P = 0.0024) and exceeded 2 ppm in 0% of the 9 offices (upper 95% confidence limit 34%) when using the double mask. We demonstrated in our study that the double-mask system, when used with dental "high-volumes" suctions (high-volume evacuators producing approximately 12 m(3)/h) in freestanding dental offices, was sufficient to decrease the exposure to anesthetic waste gas during pediatric mask induction in at least two thirds of offices when compared with the traditional mask.

Home noninvasive ventilation: what does the anesthesiologist need to know?

Treatment of chronic respiratory failure with noninvasive ventilation (NIV) is standard pediatric practice, and NIV systems are commonly used in the home setting. Although practice guidelines on the perioperative management of children supported with home NIV systems have yet to be published, increasingly these patients are referred for consultation regarding perioperative management. Just as knowledge of pharmacology underlies the safe prescription of medication, so too knowledge of biomedical design is necessary for the safe prescription of NIV therapy. The medical device design requirements developed by the Organization for International Standardization provide a framework to rationalize the safe prescription of NIV for hospitalized patients supported at home with NIV systems. This review article provides an overview of the indications for home NIV therapy, an overview of the medical devices currently available to deliver it, and a specific discussion of the management conundrums confronting anesthesiologists.

Morbidity in patients with or at high risk for obstructive sleep apnea after ambulatory laparoscopic gastric banding.

Considerable controversy exists about the perioperative management of patients at high risk for obstructive sleep apnea (OSA) in free-standing clinics. Eighty-eight percent of an American Society of Anesthesiologists expert panel felt that upper abdominal laparoscopic surgery could not be performed safely on an outpatient basis. We sought to review the incidence of major adverse events after outpatient laparoscopic adjustable gastric banding (LAGB) in a high risk population for OSA at a free-standing facility. Research Ethics Board approval was obtained and charts were reviewed retrospectively for 2,370 LAGB performed at a free-standing clinic between 2005 and 2009. In this observational cohort study, patients were classified as high risk for OSA if they received continuous positive airway pressure (CPAP) treatment for OSA pre-operatively or had a history of at least three STOP-BANG criteria. Follow-up was verified and adverse events reviewed, including death, unanticipated transfer or admission to hospital within 30 days. A total of 746 of the 2,370 patients (31%) met criteria for or were at high risk for OSA (357 received CPAP for OSA and 389 by STOP-BANG criteria). The incidence of transient desaturation to less than 93% was 39.5%. There were no deaths and no cases of respiratory failure or re-intubation. The 30-day mortality was zero and the 30-day anesthesia related morbidity was less than 0.5%. For patients at high risk for OSA after LAGB, the significance of transient oxygen desaturation and the need to develop monitoring and admission standards remain to be determined.

Consensus statement: minimal criteria for reporting the systemic inflammatory response to cardiopulmonary bypass.

The lack of established cause and effect between putative mediators of inflammation and adverse clinical outcomes has been responsible for many failed anti-inflammatory interventions in cardiopulmonary bypass (CPB). Candidate interventions that impress in preclinical trials by suppressing a given inflammation marker might fail at the clinical trial stage because the marker of interest is not linked causally to an adverse outcome. Alternatively, there exist examples in which pharmaceutical agents or other interventions improve clinical outcomes but for which we are uncertain of any antiinflammatory mechanism. The Outcomes consensus panel made 3 recommendations in 2009 for the conduct of clinical trials focused on the systemic inflammatory response. This panel was tasked with updating, as well as simplifying, a previous consensus statement. The present recommendations for investigators are the following: (1) Measure at least 1 inflammation marker, defined in broad terms; (2) measure at least 1clinical end point, drawn from a list of practical yet clinically meaningful end points suggested by the consensus panel; and(3) report a core set of CPB and perfusion criteria that maybe linked to outcomes. Our collective belief is that adhering to these simple consensus recommendations will help define the influence of CPB practice on the systemic inflammatory response, advance our understanding of causal inflammatory mechanisms, and standardize the reporting of research findings in the peer-reviewed literature.