Videolaryngoscopes in the Morbidly Obese

This study will evaluate four videolaryngoscopes used for intubation of extremely obese(class 3 obesity) patients scheduled for bariatric surgery. One hundred adult patientswill be scheduled for an elective sleeve gastrectomy at the Mazowiecki SzpitalSpecjalistyczny in Radom, Poland. All patients will receive premedication with 300 mgpregabalin 30 minutes before the start of anaesthesia. An extended monitoring will beapplied. This consists of ECG, IBP (invasive blood pressure), SpO2, TOF (train‐of‐four),entropy and volatile anaesthetic concentration. All patients will be placed in a rampedposition (HELP ‐ Head‐elevated Laryngoscopy Position) and will be pre‐oxygenated withFiO2 1.0 for three minutes prior to induction. A standardised local protocol ofopioid‐free anaesthesia for bariatric patients will be utilised. Prior to properinduction of anaesthesia, IV infusions of 1% lidocaine and dexmedetomidine 10 µg ml‐1will be started. This will be followed by induction with IV propofol (200 mg) andketamine (50 mg). Rocuronium (100 mg) will be used as a neuromuscular blocking agent.Adequate neuromuscular block will be confirmed and controlled throughout the procedurewith TOF Watch (Organon, Dublin, Ireland). A cuffed, size 8.0 tracheal tube with stylet(Sumi, Sulejówek, Poland) will be used for intubation. A single‐use hyperangulated bladewill be used in all studied devices. Correct placement of the tracheal tube will beconfirmed by videolaryngoscopy, capnography and chest auscultation. All patients will beanaesthetised by experienced consultant anaesthetists with over 10 years of clinicalpractice after completion of specialist training. Furthermore, all anaesthetistsparticipating in the study will be trained with all VLs used until they feel competent.Only two intubation attempts with a studied videolaryngoscope will be allowed. A singleattempt will be limited to 60 seconds. A failure is defined as an attempt which lastedmore than 60 seconds, when saturation dropped below 90%, after two unsuccessful attempts,when airway injury or bronchospasm occurred. A single‐digit number will be allocated toeach of the studied videolaryngoscopes: 1 for the C‐MAC PM, 2 for the McGrath MAC, 3 forthe VisionPro and 4 for the AceScope. A single sheet of paper containing printed numberwill be placed in an opaque envelope. Then they will be assigned to the participatinganaesthetist by computer‐generated randomization. The SPSS 29.0 software (IBM, Armonk,NY, USA) will be used for allocation. Furthermore, patients will be blinded torandomization.Collected data will be analysed using Statistica 14.0 (TIBCO Software, Palo Alto, CA,USA) and Microsoft Office Excel 2021 spreadsheet (Microsoft, Redmond, WA, USA). TheWilcoxon signed‐rank test and the paired Student t‐test will be used for data analysis.Continuous variables will be presented either as mean ± SD (standard deviation) or median(IQR ‐ interquartile range) for non‐normally distributed data. The Kolmogorov‐Smirnovtest determines whether the analysed variables match the characteristics of a normaldistribution. The investigators assumed that the overall success rate of intubation inobese patients would be 90% (α = 0.05, 2‐sided, β = 0.1, 95% CI). The calculated samplesize requires 95 participants and the final adjusted sample size will be 100 patients tocompensate for dropouts. A p‐value of less than 0.05 (p < 0.05) is consideredstatistically significant.