Comparison of Intracuff Pressure and Postoperative Sore Throat Following Use of Laryngeal Mask Airway Protector With or Without Nitrous Oxide Anesthesia.

PURPOSE: In general anesthesia, the laryngeal mask airway (LMA) is a frequently used effective option. The effect of nitrous oxide on intracuff pressure of the LMA and postoperative sore throat is well known; however, there are no studies related to the second-generation LMA Protector. The purpose of this study was to determine the differences in intracuff pressure and postoperative sore throat, depending on the use of nitrous oxide during general anesthesia using the LMA Protector. DESIGN: This randomized double-blind prospective study was conducted among 88 patients aged 20 to 70 years. METHODS: The cuff pressure started with a baseline of 40 cm H2O and was measured using a digital cuff pressure manometer for 30 minutes. Postoperative sore throat, dysphonia, dysphagia, and numeric rating scale scores were also recorded. FINDINGS: Over time, the intracuff pressure of the nitrous oxide group increased significantly compared with that of the air group. Furthermore, postoperative sore throat and pharyngolaryngeal complications were not significantly different between the two groups. CONCLUSIONS: Intracuff pressure of the LMA Protector increased during anesthesia using nitrous oxide. When the anesthesia time was less than 2 hours, however, there was no difference in postoperative sore throat.

Optimal Cut-Off Value of the Coracohumeral Ligament Area as a Morphological Parameter to Confirm Frozen Shoulder.

BACKGROUND: Thickened coracohumeral ligament (CHL) is one of the important morphological changes of frozen shoulder (FS). Previous research reported that coracohumeral ligament thickness (CHLT) is correlated with anterior glenohumeral instability, rotator interval and eventually FS. However, thickness may change depending on the cutting angle, and measurement point. To reduce measurement mistakes, we devised a new imaging criteria, called the coracohumeral ligament area (CHLA). METHODS: CHL data were collected and analyzed from 52 patients with FS, and from 51 control subjects (no evidence of FS). Shoulder magnetic resonance imaging was performed in all subjects. We investigated the CHLT and CHLA at the maximal thickened view of the CHL using our picture archiving and communications system. The CHLA was measured as the whole area of the CHL including the most hypertrophied part of the MR images on the oblique sagittal plane. The CHLT was measured at the thickest point of the CHL. RESULTS: The average CHLA was 40.88 ± 12.53 mm² in the control group and 67.47 ± 19.88 mm² in the FS group. The mean CHLT was 2.84 ± 0.67 mm in the control group and 4.01 ± 1.11 mm in the FS group. FS patients had significantly higher CHLA (P < 0.01) and CHLT (P < 0.01) than the control group. The receiver operator characteristic analysis showed that the most suitable cut-off score of the CHLA was 50.01 mm², with 76.9% sensitivity, 76.5% specificity, and area under the curve (AUC) of 0.87. The most suitable cut-off value of the CHLT was 3.30 mm, with 71.2% sensitivity, 70.6% specificity, and AUC of 0.81. CONCLUSION: The significantly positive correlation between the CHLA, CHLT and FS was found. We also demonstrate that the CHLA has statistically equivalent power to CHLT. Thus, for diagnosis of FS, the treating physician can refer to CHLA as well as CHLT.