Kazuhide Takeyama

Optimal puncture site of the right internal jugular vein after laryngeal mask airway placement

Background:Puncturing of the internal jugular vein (IJV) after placement of a laryngeal mask airway (LMA) is difficult. Overlapping of the right internal jugular vein (IJV) and common carotid artery (CCA) after placement of an LMA-Classic™ (Laryngeal Mask Company, Henley-on-Thames, United Kingdom) was investigated using an ultrasound scanner. A study was conducted to determine the optimal puncture site in the case of puncturing the right IJV after LMA-Classic™ placement. Methods:The subjects in this study consisted of 114 patients (60 men and 54 women) scheduled to undergo LMA-Classic™ placement (size 4 for men and size 3 for women). Overlapping between the IJV and CCA was investigated at three points (high, middle, and low points) on the right side of the neck after LMA-Classic™ placement. A test puncture was also made at the right low (supraclavicular) point after LMA-Classic™ placement. Results:(1) The degree of overlapping of the right IJV and CCA after LMA-Classic™ placement was clearly greater than before LMA placement. (2) With the exception of some measurements, there were many cases in which the right IJV and CCA were completely overlapping after LMA-Classic™ placement. Furthermore, the CCA was not observed in the vicinity of the right IJV at the right low point. (3) There were no complications (including pneumothorax and accidental arterial puncture) during supraclavicular IJV puncture after LMA-Classic™ placement. Conclusion:After placement of the LMA-Classic™, overlapping of the IJV and CCA increased at the high and middle puncture points of the IJV; however, at the lower puncture point, the position of the vessels remained unaffected. Therefore, during IJV puncture at high or middle points, ultrasound guidance is advisable to avoid CCA puncture.

Anesthetic management for repair of adult Bochdalek hernia by laparoscopic surgery

This report describes anesthetic management of a case (a 64-year-old man) who was originally diagnosed as paraesophageal hernia before surgery and later diagnosed as Bochdalek hernia during laparoscopic surgery. Anesthesia was started with oxygen, nitrous oxide, and sevoflurane, and respiration was managed using controlled mechanical ven-tilation. Although left pneumothorax was noticed during laparoscopic surgery (aeroperitonia pressure: 10 cmH2O), the surgery was performed using the same anesthesia procedure, because hardly any changes were observed on the monitor and vital signs were stable. The surgery was completed without incident. However, postoperative chest X-rays revealed the residual large pneumothorax. A chest drain tube was inserted immediately, after which the pneumothorax was improved. Pneumothorax is considered to be inevitable in cases of laparoscopic repair of Bochdalek hernia. To prevent exacerbation of pneumothorax, anesthetic management should consist of discontinuing the use of nitrous oxide and lowering the aeroperitonia pressure concomitently with the use of positive airway pressure.

The efficiency of beta 2-agonist delivery through tracheal tubes with the metered-dose inhaler: an in vitro study.

AbstractPurpose. To study the delivery efficiency of procaterol aerosols administered through the tracheal tube (ETT) with a metered-dose inhaler (MDI) during apnea. Methods. First, in a normal room air environment (at ambient temperatures of 24° to 26°C), we measured the amount of aerosol delivered through the ETT by comparing the weight of a 2-l bottle before and after firing the MDI directly into the 15-mm adapter of the ETT. The distal half of the ETT was inserted in the bottle. This procedure was repeated using five different ETTs with an internal diameter of 4–8.5 mm. The delivery efficiency was obtained by dividing the amount of aerosol delivered through the ETT by the total aerosol output per MDI puff. Next, we investigated whether the connector attached to the 15-mm ETT adapter could reduce the delivery, by repeating the same procedure with 4-mm and 5-mm ETTs. Finally, we compared the efficiencies of aerosol delivery through the 5-mm ETT and the 7.5-mm ETT in a normal room air environment with results obtained under a humidified condition (100% humid air at 37°C). Results. The percentages of aerosol delivered through the ETTs in a normal room air environment were 40%–60%, except for the 4-mm ETT, for which the percentage was 32.7% ± 6.6% (P < 0.05 vs that with the 5-mm ETT or the 6-mm ETT). A connector attached to the 15-mm ETT adapter significantly decreased the delivery efficiencies (19.0% ± 5.8% vs 32.7% ± 6.6% with the 4-mm ETT, 24.6% ± 11.8% vs 51.7% ± 10.8% in the 5-mm ETT) when compared with those without a connector. The delivery efficiencies under the humidified condition in the 5-mm ETT and the 7.5-mm ETT were 65.5% (P < 0.05) and 89.8% of those in the normal room air environment, respectively. Conclusion. The efficiency of delivery of procaterol aerosol through the ETTs was unexpectedly high (approximately half of the total aerosol output per MDI puff in the 5-mm to 8.5-mm ETTs, and one third of the total aerosol output per MDI puff in the 4-mm ETT). A connector attached to the 15-mm ETT adapter noticeably decreased the delivery efficiency. In the smaller-sized ETT, delivery efficiency was significantly lower under the humidified condition than in the normal room air environment.