Hiromasa Sekiguchi

Serum and urinary inorganic fluoride concentrations after prolonged inhalation of sevoflurane in humans.

Serum and urinary concentrations of inorganic fluoride were measured before and after sevoflurane anesthesia in 10 patients without renal disease, who were scheduled for surgery lasting 13.4 ± 0.9 h (mean ± se). The mean concentration of serum inorganic fluoride reached a maximal value of 42.5 ± 4.5 μmol/L at the end of anesthesia. However, 5 of 10 patients had serum inorganic fluoride concentrations that exceeded 50 μmol/L (i.e., the nephrotoxic dose). A positive correlation was found between serum inorganic fluoride concentration and anesthetic dose. The largest urinary excretion of inorganic fluoride was 1804 ± 378 μmol/day in the first postoperative day and rapidly decreased thereafter. We concluded that lengthy sevoflurane anesthesia created serum inorganic fluoride concentrations that could influence renal function, although nephrotoxicity was not demonstrated in our biochemical study.

Evaluation of gastric tube with esophageal Thermister (Thermosump

The accuracy and the feasibility of esophageal temperature measured by a new gastric tube. Thermosump®, which is incorporated with a esophageal thermister, was evaluated in anesthetized dogs (n=6) and men (n=59). In dogs, esophageal temperature measured by Thermosump ® was correlated well with the temperatures measured by the conventional esophageal thermister, and also by the pulmonary artery catheter (r=0.98, 0.98, respectively). In anesthetized men, correlation between esophageal temperature by Thermosump® and rectal, or bladder temperature was good during surgery of extremities (r=0.81, 0.80, respectively). But during abdominal surgery, correlation between esophageal and bladder temperature was relatively poor (r=0.50). Insertion of the tube, and suction of gastric fluid through the tube were easy without any complication. This newly developed gastric tube with a esophageal thermister was safe, and useful for measuring esophageal temperature.

Augmentation of Succinylcholine on the Neuromuscular Blocking Effect of Vecuronium in Pediatrics

The administration of succinylcholine enhances subsequent nondepolarizing agent in adult patients(1). However, it was reported that previous succinylcholine administration does not interfere with the recovery rate of twitch height of vecuronium (2), and does not necessitate subsequent alteration in doses of nondepolarizing neuromuscular blockade(3). The purpose of this investigation was to evaluate the effect of succinylcholine on the neuromuscular transmission of subsequently administered vecuronium in pediatrics.

Improved PCO2 monitoring during high frequency jet ventilation

During high frequency jet ventilation (HFJV), it has been shown that PaCO2 can be predicted by capnography when the frequency was temporarily reduced to obtain a steady expiratory2 tension (PETCO2 ) . The influence of the sampling site of expiratory gas in the airway and the driving pressure of the ventilator on the difference between PaCO2 and PETCO2 was investigated in ten adult patients who underwent general anesthesia. During HFJV (frequency; 100 bpm, inspiratory duty cycle; 30%), its frequency was temporarily reduced to 10 bpm in twelve different condition; i.e., 3 different driving pressures (Pd; 20, 30, and 40 psi) at 4 different sampling sites (d; 0, 2, 5, and 10 ern in the endotracheal tube). Both PETCO2 and PaCO2 were measured simultaneously, and their difference was evaluated by using Student’s t-test. The difference between PaCO2 and PmaxCO2 (the maximum PCO2 value in the airway during exhalation) was minimal, when Pd was greater than 30 psi, and d was greater than 5 cm. The present study suggests that better prediction of PaCO2 can be done by PETCO2 during HFJV, when d and Pd were set as large as possible to obtain stable expiratory PCO2 curve.