Background Nasal intubation is indispensable for some cases that require intraoral surgical access, and the fiberoptic bronchoscope is the best tool for difficult airways. However, fiberoptic bronchoscopy is not always possible in cases with altered pharyngeal anatomy. Case presentation In this report, we introduce a novel technique for retrograde endotracheal oral-to-nasal conversion with an ordinary endotracheal tube exchange catheter. A 49-year-old male with a fractured mandible angle and symphysis was scheduled to undergo mandible reconstruction. Secondly, a 45-year-old male who had a bone defect in the mandible angle and ramus was scheduled for mandible and oral cavity reconstruction. We chose to intubate orally first and successfully converted the endotracheal tube from oral to nasal retrogressively using a tube exchange catheter. Conclusions Our simple and safe technique, which use a tube exchange catheter retrogressively, provides an alternative method for a difficult airway in which the fiberscope is not helpful.

Background: Appropriate blood component transfusion might differ between intraoperative massive bleeding and traumatic massive bleeding in the emergency department because trauma patients initially bleed undiluted blood and replacement typically lags behind blood loss. We compared these two blood loss scenarios, intraoperative and traumatic, using a computer simulation.Methods: We modified the multi-compartment dynamic model developed by Hirshberg and implemented it using STELLA 9.0. In this model, blood pressure changes as blood volume fluctuates as bleeding rate and transcapillary refill rate are controlled by blood pressure. Using this simulation, we compared the intraoperative bleeding scenario with the traumatic bleeding scenario. In both scenarios, patients started to bleed at a rate of 50 ml/min. In the intraoperative bleeding scenario, fluid was administered to maintain isovolemic status; however, in the traumatic bleeding scenario, no fluid was supplied for up to 30 min and no blood was supplied for up to 50 min. Each unit of packed red blood cells (PRBC) was given when the hematocrit decreased to 27%, fresh frozen plasma (FFP) was transfused when plasma was diluted to 30%, and platelet concentrate (PC) was transfused when platelet count became 50,000/ml.Results: In both scenarios, the appropriate ratio of PRBC:FFP was 1:0.47 before PC transfusion, and the ratio of PRBC:FFP:platelets was 1:0.35:0.39 after initiation of PC transfusion.Conclusion: The ratio of transfused blood component did not differ between the intraoperative bleeding and traumatic bleeding scenarios.

Masseter muscle rigidity can be seen following administration of opioids, succinylcholine, and nondepolarizing muscle relaxants. We report a case of a 56-year-old male patient in a “Cannot Intubate Cannot Ventilate Situation” due to masseter muscle rigidity after initiating monitored anaesthesia care (MAC) with remifentanil and propofol using target-controlled infusion in procedural cardiology. For rapid effect and equilibrium between plasma-concentration and effect site-concentration using target-controlled infusion, remifentanil overdose is possible during the induction period of MAC. Moreover, the presence of propofol could result in a significantly greater remifentanil concentration. To manage masseter muscle rigidity, muscle relaxants and emergent ventilation systems should be prepared to secure airway maintenance. In addition, alternative airway management devices and techniques should be on hand even if no airway difficulties are expected.