Hyperoxia and Antioxidants for Myocardial Injury in Noncardiac Surgery: A 2 × 2 Factorial, Blinded, Randomized Clinical Trial.

BACKGROUND: Hyperoxia and oxidative stress may be associated with increased risk of myocardial injury. The authors hypothesized that a perioperative inspiratory oxygen fraction of 0.80 versus 0.30 would increase the degree of myocardial injury within the first 3 days of surgery, and that an antioxidant intervention would reduce degree of myocardial injury versus placebo. METHODS: A 2 × 2 factorial, randomized, blinded, multicenter trial enrolled patients older than 45 yr who had cardiovascular risk factors undergoing major noncardiac surgery. Factorial randomization allocated patients to one of two oxygen interventions from intubation and at 2 h after surgery, as well as antioxidant intervention or matching placebo. Antioxidants were 3 g IV vitamin C and 100 mg/kg N-acetylcysteine. The primary outcome was the degree of myocardial injury assessed by the area under the curve for high-sensitive troponin within the first 3 postoperative days. RESULTS: The authors randomized 600 participants from April 2018 to January 2020 and analyzed 576 patients for the primary outcome. Baseline and intraoperative characteristics did not differ between groups. The primary outcome was 35 ng · day/l (19 to 58) in the 80% oxygen group; 35 ng · day/l (17 to 56) in the 30% oxygen group; 35 ng · day/l (19 to 54) in the antioxidants group; and 33 ng · day/l (18 to 57) in the placebo group. The median difference between oxygen groups was 1.5 ng · day/l (95% CI, -2.5 to 5.3; P = 0.202) and -0.5 ng · day/l (95% CI, -4.5 to 3.0; P = 0.228) between antioxidant groups. Mortality at 30 days occurred in 9 of 576 patients (1.6%; odds ratio, 2.01 [95% CI, 0.50 to 8.1]; P = 0.329 for the 80% vs. 30% oxygen groups; and odds ratio, 0.79 [95% CI, 0.214 to 2.99]; P = 0.732 for the antioxidants vs. placebo groups). CONCLUSIONS: Perioperative interventions with high inspiratory oxygen fraction and antioxidants did not change the degree of myocardial injury within the first 3 days of surgery. This implies safety with 80% oxygen and no cardiovascular benefits of vitamin C and N-acetylcysteine in major noncardiac surgery.

Tube tip in pharynx-a conduit for awake oral intubation in patients with extremely restricted mouth opening.

PURPOSE: Awake flexible bronchoscope-guided intubation is challenging in patients with extremely limited mouth opening (when there is inadequate space for an oropharyngeal airway), especially when nasal access is unavailable. Alternatives include awake front of neck access, which is an invasive procedure and not suitable for elective surgery. We present a novel technique to facilitate flexible bronchoscope-guided oral intubation in these patients. CLINICAL FEATURES: Tube tip in pharynx (TTIP) is a technique for establishing a patent airway if ventilation is difficult or has failed using a face mask, supraglottic airway, or endotracheal tube. The technique involves placing the tip of the endotracheal tube in the pharynx, 10-14 cm past the teeth, filling the cuff with air, closing the mouth and nose of the patient, and then initiating ventilation. The TTIP method thus combines the function of an oropharyngeal airway and a face mask akin to a supraglottic airway device, but is more flexible with regard to insertion depth and cuff inflation and demands only minimal mouth opening. We have adapted the TTIP technique for awake flexible bronchoscope-guided oral intubation and report the technique illustrated with three cases where mouth opening was so restricted that it precluded insertion of an oropharyngeal airway. CONCLUSION: By placing an endotracheal tube with the tip in the pharynx, TTIP can establish a conduit for awake oral flexible bronchoscope-guided intubation in patients with extremely limited mouth opening and unavailable nasal access. This technique requires equipment that is readily available and may help avoid unnecessary awake tracheostomy.

RéSUMé: OBJECTIF: L'intubation éveillée guidée par bronchoscope flexible est un défi chez les patients présentant une ouverture buccale extrêmement restreinte (lorsqu'il n'y a pas suffisamment d'espace pour une canule oropharyngée), et tout particulièrement lorsqu'un accès nasal est non disponible. Les alternatives incluent l'accès antérieur du cou chez patient éveillé, une procédure invasive qui ne convient pas pour la chirurgie élective. Nous présentons une technique innovante pour faciliter l'intubation orale guidée par bronchoscope flexible chez ces patients. CARACTéRISTIQUES CLINIQUES: La technique TTIP (de l'anglais Tube Tip In Pharynx) permet d'établir un accès aux voies aériennes si la ventilation est difficile ou a échoué à l'aide d'un masque, d'un dispositif supraglottique ou d'un tube endotrachéal. La technique consiste à placer l'extrémité du tube endotrachéal dans le pharynx, à 10-14 cm au-delà des dents, à remplir le ballonnet d'air, à fermer la bouche et le nez du patient, puis à amorcer la ventilation. La méthode TTIP combine ainsi la fonction d'une canule oropharyngée et d'un masque facial, de façon similaire à un dispositif supraglottique, mais est plus flexible en ce qui concerne la profondeur d'insertion et le gonflage du ballonnet et ne nécessite qu'une ouverture minimale de la bouche. Nous avons adapté la technique TTIP pour l'intubation orale éveillée guidée par bronchoscope flexible et rapportons la technique en l'illustrant par trois cas où l'ouverture de la bouche était si restreinte qu'elle empêchait l'insertion d'une canule oropharyngée. CONCLUSION: En plaçant l'extrémité d'un tube endotrachéal dans le pharynx, la technique TTIP peut établir un passage pour l'intubation orale éveillée guidée par bronchoscope flexible chez les patients ayant une ouverture de la bouche extrêmement limitée et un accès nasal indisponible. Cette technique nécessite du matériel facilement disponible et peut contribuer à éviter une trachéotomie non nécessaire chez patient éveillé.