Tomoko Goto’s scientific contributions

PurposeNumerous techniques have been used to reduce epistaxis during nasotracheal intubation. Rhinometry can assess nasal patency in preoperative conditions. However, the possible role of rhinometry in routine nasotracheal intubation has not been studied. Methods One hundred and one patients undergoing dental and maxillofacial surgery that required general anesthesia and nasotracheal intubation were enrolled. We examined whether symmetry or any asymmetry in bilateral airflow patterns by condensation of the expiration, assessed by preoperative rhinometry on seated position, increased the incidence of epistaxis and the need for a nasogastric catheter to guide the endotracheal tube into the oropharynx. We also compared the incidence of changing the site of nasal intubation between the assessment by rhinometry and by cone-beam computed tomography analysis of nasal airspace in the inferior meatus. ResultsPatients with any asymmetry in bilateral airflow patterns were 18 % (n = 18), the remaining 82 % (n = 83) had symmetric bilateral nasal cavities. Patients with any asymmetry were more likely to need a guiding nasogastric catheter than patients with symmetry (22 vs. 3.6 %, p = 0.018). The incidence of epistaxis was higher in patients with any asymmetry (39 %) than those with symmetry (16 %), but there was no significant difference between groups (p = 0.055). The site of intubation was changed more frequently based on cone-beam computed tomography analysis than by rhinometry (38 vs. 11 %, p = 0.043). Conclusion Preoperative rhinometry may be a valuable objective tool to assess nasal patency for nasotracheal intubation in patients who undergo dental and maxillofacial surgery.

The airway scope (AWS) improves views of the larynx during orotracheal intubation. However, the role of the AWS in routine nasotracheal intubation has not been studied adequately. One hundred and three patients undergoing dental and maxillofacial surgery that required general anesthesia and nasotracheal intubation were enrolled. The study was approved by our Institution Review Board, and written informed consent was obtained from all patients. We evaluated the success rate of AWS intubation and the incidence of difficult nasotracheal intubation using a modified intubation difficulty scale (IDS) to examine preoperative characteristics and intubation profiles. Categories were difficult intubation (IDS ≥5), mildly difficult (IDS = 1-4), and intubation without difficulty (IDS = 0). We also assessed the incidence of the use of Magill forceps or cuff inflation (the cuff of endotracheal tube is inflated with 10-15 ml air) to guide the endotracheal tube into the glottis. AWS nasotracheal intubation was 100 % successful. The cuff inflation technique was used in 37 patients. Neither Magill forceps nor other devices were needed for any patient during AWS use. The incidence of difficult nasotracheal intubation was 10 % (n = 10). Of the patients, 61 % (n = 63) had mildly difficult intubation and 29 % (n = 30) had no difficulty. Patients with difficult intubation were more likely to be male and to have a larger tongue and a higher Cormack grade than in the other two groups. Complications, involving minor soft tissue injury, were observed in only 1 patient (1 %). The AWS achieves a high success rate for nasotracheal intubation with cuff inflation in patients undergoing dental and maxillofacial surgery.