Difficult airway management practice changes after introduction of the GlideScope videolaryngoscope: A retrospective cohort study.

BACKGROUND: Introduction of the GlideScope videolaryngoscope caused a change in use of other devices for difficult airway management. OBJECTIVE: The influence of the GlideScope videolaryngoscope on changes in the indications for and the frequency of use of flexible fibreoptic-assisted intubation and other difficult airway management techniques. DESIGN: Retrospective cohort study. SETTING: Tertiary care referral centre. METHODS: Two periods of equal length (647 days each) before and after introducing the GlideScope were compared. Information about patients who were intubated using nondirect laryngoscopic techniques were analysed. Data were retrieved from the anaesthesia and hospital information management systems. RESULTS: Difficult airway management techniques were used in 235/8306 (2.8%) patients before and in 480/8517 (5.6%) (P < 0.0001) patients after the introduction of the GlideScope. There was an overall 44.4% reduction in use of flexible fibreoptic bronchoscopy after GlideScope introduction [before 149/8306 (1.8%); after 85/8517 (1.0%), P < 0.0001]. The GlideScope replaced flexible fibreoptic bronchoscopy in most cases with expected and unexpected difficult intubation. In patients with limited mouth opening, flexible fibreoptic bronchoscopy was still mostly the first choice after the introduction of the GlideScope. There was a 70% reduction in the use of other difficult intubation techniques after the introduction of the GlideScope [before 84/8306 (1.0%); after 22/8517 (0.3%), P < 0.0001)]. CONCLUSION: The GlideScope videolaryngoscope replaced flexible fibreoptic bronchoscopy for most patients with expected and unexpected difficult intubation. In the case of limited mouth opening, flexible fibreoptic bronchoscopy was still the first choice after the introduction of the GlideScope. The reduced use of flexible fibreoptic bronchoscopy raises concerns that residents may not be adequately trained in this essential airway management technique. GlideScope use was disproportionately greater than the reduction in the use of flexible fibreoptic bronchoscopy and other difficult intubation techniques. This may be attributed to resident teaching and use in patients with low-to-moderate suspicion of difficult intubation.

Prospective observational investigation of body habitus measurements and relationship to epidural depth in term pregnant women.

BACKGROUND: High body mass index (BMI) can predict difficult neuraxial block; however, fat distribution may also be important. The primary study aim was to identify body habitus and fat distribution measurements that correlated with ultrasound measured epidural depth. We hypothesized that measurements such as midarm and subscapular fatpad thicknesses and length of cervical spine may correlate better with ultrasound measured epidural depth than a global measure of BMI. METHODS: Prospective IRB approved study of term pregnant women requiring neuraxial block. We measured height, weight (BMI, kg/m2 ), subscapular, midarm fatpad thickness (digital caliper, mm), vertebral column length (C7 to sacral hiatus, cm) and epidural depth (ultrasound, mm). Four experts assessed photographs to assign anticipated difficult neuraxial block in sitting and lateral positions (5-point Likert scale, 1 = very easy, 5 = very difficult). RESULTS: In all, 131 women completed body habitus measurements. Measured mean (standard deviation) BMI was 30.3 (5.4) kg/m2 . Measured BMI, subscapular fatpad and midarm fatpad thickness were significantly correlated with ultrasound depth to epidural space (R2 0.733, 0.626 and 0.633, respectively, P < .0001) but vertebral column length was not. The experts had a high level of agreement (Cronbach's alpha >0.7) for assessment of anticipated difficult block in the sitting and lateral positions; however, anticipated difficult block was not correlated with epidural depth measured by ultrasound for sitting position, R2  = -0.015, P = .87; and lateral position, R2  = -0.087, P = .33. CONCLUSIONS: Measurements of body habitus and fat distribution were no better than measured BMI to anticipate greater ultrasound measured depth to epidural space. Clinical trial number: Non-interventional observational study, not registered.

Bioluminescent liquid light guide pad biosensor for indoor air toxicity monitoring.

Indoor air pollution became a recent concern found to be oftentimes worse than outdoor air quality. We developed a tool that is cheap and simple and enables continuous monitoring of air toxicity. It is a biosensor with both a nondisposable (monitor) and disposable (calcium alginate pads with immobilized bacteria) elements. Various parameters to enhance its signal have been tested (including the effect of the pad's orientation, it's exposure to either temperature or time with the air toxicant analyte, and various concentrations thereof). Lastly, the sensor has demonstrated its ability to sense the presence of chemicals in a real, indoor environment. This is the first step in the creation of a sensitive and simple operative tool that may be used in different indoor environments.