Sub-100 W picosecond output from a phase-conjugate Nd:YVO4 bounce amplifier.

We demonstrated >80 W picosecond output at a pulse repetition frequency of 100 MHz from a dual Nd:YVO(4) amplifier laser system consisting of a phase-conjugate Nd:YVO(4) bounce amplifier combined with a second diode-side-pumped Nd:YVO(4) bounce amplifier. The output exhibited high quality spatial form with M(2) < 1.8 and a pulse duration (FWHM) of 9.2 ps. A peak power of >7.4 MW with an average power of 78.5 W was also achieved at a pulse repetition frequency of 1.0 MHz.

Power scaling of a pico-second Nd:YVO(4) master-oscillator power amplifier with a phase-conjugate mirror.

We investigated design issues for the power scaling of a pico-second Nd:YVO(4) master-oscillator power amplifier system with a photorefractive phase-conjugate mirror by using standard beam propagation analysis. We also demonstrated a 25 W diffraction-limited pico-second output. A corresponding extraction efficiency of 31 % was achieved.

In vivo spin-trap study on anaerobic dehalogenation of halothane.

Radical formation in vivo by anaerobic dehalogenation of halothane is described in this paper. The radicals were stabilized by spin-trapping and assayed by electron spin resonance spectrometry. The radical adducts were formed by inhalation of halothane in vivo and increased with decrease in inspired oxygen concentration. Following administration of the spin-trap, the expired concentration of CF2CHCl and CF3CH2Cl which are the anaerobic metabolites of halothane decreased, but bilious trifluoroacetate which are aerobic did not change. These results strongly suggest that radical intermediates are produced in anaerobic dehalogenation of halothane to CF2CHCl and CF3CH2Cl.

A prospective multicenter trial to determine the incidence of transient neurologic symptoms after spinal anesthesia with phenylephrine added to 0.5% tetracaine.

The addition of vasoconstrictors for spinal anesthesia is controversial, since an increase in the incidence of transient neurologic symptoms (TNS) has been reported. A multicenter, randomized, double-blind study was conducted to assess the effectiveness of spinal anesthesia with phenylephrine in addition to tetracaine as well as the incidence of neurological complications. We studied 64 patients with comparable demographic characteristics who were scheduled for elective surgery for a lower limb, or a gynecological or urological procedure. The patients were allocated randomly into 2 groups. Group P (n = 34) received 0.5% tetracaine in 10% glucose with 0.025% phenylephrine, while group C (n = 30) received 0.5% tetracaine in 10% glucose. Our results showed that only 2 patients (6.7%) in group C experienced TNS, and their symptoms disappeared within 72 hr after anesthesia, while none of the patients (0%) in group P complained of symptoms. The incidence of TNS was thus not significantly different between the two groups. Six hours after the sensory block, group P patients demonstrated sensory disturbance, with the median spinal dermatome corresponding to the L1 segment. Moreover, systolic blood pressure in group P was significantly higher than that in group C, 5 min, 15 min, and 20 min after injection. The incidence of TNS in the present study does not seem to be greater after surgery with spinal anesthesia using 0.5% hyperbaric tetracaine and 0.5 mg phenylephrine than without phenylephrine. Randomized, double-blind, cross-over trials with a larger sample size would be required in the future to obtain more reliable results.

[General anesthesia for expandable endotracheobronchial metal stent insertion].

We experienced eight cases of general anesthesia for endotracheobronchial expandable metal stent insertion. Awake intubation was performed following NLA induction. Anesthesia was maintained by inhalational anesthetics and fentanyl was added under spontaneous breathing assisted manually. Two patients showed a marked hemodynamic change and hypoxia due to endotracheobronchial bleeding and suction. Six patients received EMS insertion with no trouble. We conclude that endotracheobronchial bleeding is an important factor to be watched for during anesthetic management for EMS insertion.

Does lidocaine provoke clinically significant vasospasm?

Two cases with peripheral vasoconstriction possibly caused by topical application of lidocaine were reported. A potential risk of vasospasm provoked by lidocaine may be a pitfall for anesthesiologists because lidocaine is commonly considered a vasodilator.

Intraoperative changes in blood coagulation and the effectiveness of ulinastatin during liver resection.

The blood coagulation status of 16 patients undergoing liver resection was monitored by thrombelastograph (TEG). Coagulation test by TEG was performed at three different times: before and one hour after induction of anesthesia and after liver resection. The four variables such as r (reaction time), k (coagulation velocity), ma (maximum amplitude) and me (maximum elasticity) were measured. In 8 patients, Ulinastatin was not administered during the operation and FFP was transfused after the second measurement of TEG (group I). The other 8 patients were administered totally 300,000 units of Ulinastatin after induction until the second measurement of TEG, thereafter FFP was transfused (group II). The TEG showed poor preoperative coagulation state in both groups. In group I, TEG variables showed coagulopathy was exacerbated significantly during liver resection. In group II TEG variables showed no significant changes during operation. Between the two groups there were statistical differences in the TEG variables during the operation. The TEG was useful for monitoring coagulation function during liver resection. It was impossible to improve TEG data by only replacement of FFP. Ulinastatin was useful in normalizing the coagulation function and in preventing the changes in TEG measurements during liver resection.