Videolaryngoscopy vs. direct Macintosh laryngoscopy in tracheal intubation in adults: a ranking systematic review and network meta-analysis.

Videolaryngoscopes are thought to improve glottic view and facilitate tracheal intubation compared with the Macintosh direct laryngoscope. However, we currently do not know which one would be the best choice in most patients undergoing anaesthesia. We designed this systematic review with network meta-analyses to rank the different videolaryngoscopes and the Macintosh direct laryngoscope. We conducted searches in PubMed and a further five databases on 11 January 2021. We included randomised clinical trials with patients aged ≥16 years, comparing different videolaryngoscopes, or videolaryngoscopes with the Macintosh direct laryngoscope for the outcomes: failed intubation; failed first intubation attempt; failed intubation within two attempts; difficult intubation; percentage of glottic opening seen; difficult laryngoscopy; and time needed for intubation. We assessed the quality of evidence according to GRADE recommendations and included 179 studies in the meta-analyses. The C-MAC and C-MAC D-Blade were top ranked for avoiding failed intubation, but we did not find statistically significant differences between any two distinct videolaryngoscopes for this outcome. Further, the C-MAC D-Blade performed significantly better than the C-MAC Macintosh blade for difficult laryngoscopy. We found statistically significant differences between the laryngoscopes for time to intubation, but these differences were not considered clinically relevant. The evidence was judged as of low or very low quality overall. In conclusion, different videolaryngoscopes have differential intubation performance and some may be currently preferred among the available devices. Furthermore, videolaryngoscopes and the Macintosh direct laryngoscope may be considered clinically equivalent for the time taken for tracheal intubation. However, despite the rankings from our analyses, the current available evidence is not sufficient to ensure significant superiority of one device or a small set of them over the others for our intubation-related outcomes.

Pre-operative voice evaluation as a hypothetical predictor of difficult laryngoscopy

We examined the potential for voice sounds to predict a difficult airway as compared with prediction by the modified Mallampati test. A total of 453 patients scheduled for elective surgery under general anaesthesia with tracheal intubation were studied. Five phonemes were recorded and their formants analysed. Difficult laryngoscopy was defined as the Cormack-Lehane grade 3 or 4. Univariate and multivariate logistic regression were used to examine the association between some variables (mouth opening, sternomental distance, modified Mallampati and formants) and difficult laryngoscopy. Difficult laryngoscopy was reported in 29/453 (6.4%) patients. Among five regression models evaluated, the model achieving better performance to predict difficult laryngoscopy, after a variable selection criteria (stepwise, multivariate) and included a modified Mallampati classification (OR 2.920; 95%CI 1.992-4.279; p < 0.001), first formant of /i/(iF1) (OR 1.003; 95%CI 1.002-1.04; p < 0.001), and second formant of /i/(iF2) (OR 0.998; 95%CI 0.997-0.998; p < 0.001). The receiver operating curve for a regression model that included both formants and Mallampati showed an area under curve of 0.918, higher than formants alone (area under curve 0.761) and modified Mallampati alone (area under curve 0.874). Voice presented a significant association with difficult laryngoscopy during general anaesthesia showing a 76.1% probability of correctly classifying a randomly selected patient. (AU)

Pre-operative voice evaluation as a hypothetical predictor of difficult laryngoscopy.

We examined the potential for voice sounds to predict a difficult airway as compared with prediction by the modified Mallampati test. A total of 453 patients scheduled for elective surgery under general anaesthesia with tracheal intubation were studied. Five phonemes were recorded and their formants analysed. Difficult laryngoscopy was defined as the Cormack-Lehane grade 3 or 4. Univariate and multivariate logistic regression were used to examine the association between some variables (mouth opening, sternomental distance, modified Mallampati and formants) and difficult laryngoscopy. Difficult laryngoscopy was reported in 29/453 (6.4%) patients. Among five regression models evaluated, the model achieving better performance to predict difficult laryngoscopy, after a variable selection criteria (stepwise, multivariate) and included a modified Mallampati classification (OR 2.920; 95%CI 1.992-4.279; p < 0.001), first formant of /i/(iF1) (OR 1.003; 95%CI 1.002-1.04; p < 0.001), and second formant of /i/(iF2) (OR 0.998; 95%CI 0.997-0.998; p < 0.001). The receiver operating curve for a regression model that included both formants and Mallampati showed an area under curve of 0.918, higher than formants alone (area under curve 0.761) and modified Mallampati alone (area under curve 0.874). Voice presented a significant association with difficult laryngoscopy during general anaesthesia showing a 76.1% probability of correctly classifying a randomly selected patient.

Evaluation of Frozen and Paraffin Sections Using the Maryland Aggregate Pathology Index Score in Donor Kidney Biopsy Specimens of a Brazilian Cohort.

The Maryland aggregate pathology index (MAPI) score is an important tool developed to help pathologists in evaluating potential organs for transplantation. It is based on analysis of five variables (present or absent): arteriolar hyalinosis (4 points), periglomerular fibrosis (2 points), arterial wall-lumen ratio superior to 0.5 (2 points), global glomerulosclerosis in more than 15% of glomeruli (2 points), and interstitial scar (3 points). Kidneys with a MAPI score >7 points are considered inadequate for donation. This study aimed to evaluate pathology agreement between frozen sections (FS) and paraffin sections (PS) using the MAPI score in a cohort of 262 biopsy specimens obtained at the General Hospital of Fortaleza, Brazil. We performed a retrospective review of pathological reports of FS (signed out by an on-call pathologist) and their corresponding PS (authorized by a specialist in renal pathology). Agreement was calculated using the Kappa test. Kappa values ranging from 0.29 to 0.51 were obtained when MAPI parameters were separately evaluated. When the score was used, the coefficient was 0.59. Fourteen of 262 kidneys were classified as inadequate for donation using PS and 8 cases were diagnosed using FS. There were no differences between wedge-shaped and filiform samples, apart from the mean number of glomeruli. Discordant cases had no statistical difference from concordant ones when clinical and macroscopic pathological parameters were analyzed. The MAPI score can be useful to minimize disagreements between FS and PS, but more effort should be made to standardize criteria and enable pathologists to recognize chronic lesions in FS samples.

Behaviour of Mycobacterium sp. NRRL B-3805 whole cells in aqueous, organic-aqueous and organic media studied by fluorescence microscopy.

The present work aimed at quantifying the viability and morphological changes occurring during the time course of the side-chain cleavage of beta-sitosterol, in aqueous, two-phase organic-aqueous and organic media by free resting cells of Mycobacterium sp. NRRL B-3805. The solvent used was bis(2-ethylhexyl) phthalate (BEHP). A 66.3% reduction in cell viability was observed after 24 h when the cells were incubated in phosphate buffer only, but the percentage of viable cells was constant thereafter. In biphasic systems with BEHP, cell viability was maintained at higher values in the first 48 h, during which complete degradation of substrate was achieved. The availability of oxygen, which should be higher in the biphasic system than in the aqueous system, and of a carbon and energy source, thus seem important for the cells to retain their viability. In biphasic systems, cells tended to shrink and decrease their surface roughness, i.e. to decrease their surface area, possibly as a way to protect themselves from mechanical stress due to the presence of organic-aqueous interfacial forces, which resulted in disaggregation of cell clusters. A method used to visualise BEHP droplets with a standard optical microscope showed that the cells adhered to the surface of the solvent droplets, but no cells were observed inside these. In pure BEHP medium, cells retained their viability level for at least 150 h, independently of a pre-incubation period, which did not seem to induce any adaptation effect. Solvent biocompatibility, higher oxygen availability and reduced interfacial stress could have contributed to this maintenance of viability.