Current Ventilator and Oxygen Management during General Anesthesia: A Multicenter, Cross-sectional Observational Study.

BACKGROUND: Intraoperative oxygen management is poorly understood. It was hypothesized that potentially preventable hyperoxemia and substantial oxygen exposure would be common during general anesthesia. METHODS: A multicenter, cross-sectional study was conducted to describe current ventilator management, particularly oxygen management, during general anesthesia in Japan. All adult patients (16 yr old or older) who received general anesthesia over 5 consecutive days in 2015 at 43 participating hospitals were identified. Ventilator settings and vital signs were collected 1 h after the induction of general anesthesia. We determined the prevalence of potentially preventable hyperoxemia (oxygen saturation measured by pulse oximetry of more than 98%, despite fractional inspired oxygen tension of more than 0.21) and the risk factors for potentially substantial oxygen exposure (fractional inspired oxygen tension of more than 0.5, despite oxygen saturation measured by pulse oximetry of more than 92%). RESULTS: A total of 1,786 patients were found eligible, and 1,498 completed the study. Fractional inspired oxygen tension was between 0.31 and 0.6 in 1,385 patients (92%), whereas it was less than or equal to 0.3 in very few patients (1%). Most patients (83%) were exposed to potentially preventable hyperoxemia, and 32% had potentially substantial oxygen exposure. In multivariable analysis, old age, emergency surgery, and one-lung ventilation were independently associated with increased potentially substantial oxygen exposure, whereas use of volume control ventilation and high positive end-expiratory pressure levels were associated with decreased potentially substantial oxygen exposure. One-lung ventilation was particularly a strong risk factor for potentially substantial oxygen exposure (adjusted odds ratio, 13.35; 95% CI, 7.24 to 24.60). CONCLUSIONS: Potentially preventable hyperoxemia and substantial oxygen exposure are common during general anesthesia, especially during one-lung ventilation. Future research should explore the safety and feasibility of a more conservative approach for intraoperative oxygen therapy.

Effect of ethanol on S-warfarin and diclofenac metabolism by recombinant human CYP2C9.1.

The effect of ethanol on the metabolism of S-warfarin and diclofenac by recombinant cytochrome P450 2C9.1 microsomes (CYP2C9.1) was studied. The 7-hydroxylation metabolism of S-warfarin was inhibited by as low as 0.1 vol% (17 mM) ethanol. Ethanol decreased the V(max)/K(m) and V(max) values of S-warfarin metabolism in a concentration-dependent manner, but the K(m) value was unchanged by ethanol. The inhibitory effect of ethanol on the 4'-hydroxylation metabolism of diclofenac was not observed even at 1.0 vol% (170 mM) ethanol. Ethanol at a concentration of 3.0 vol% (510 mM) increased the K(m) value of diclofenac metabolism without changes in the V(max), which indicates that diclofenac 4'-hydroxylation by CYP2C9.1 was competitively inhibited by ethanol. S-Warfarin metabolism by CYP2C9.1 was more sensitive to ethanol than diclofenac metabolism. These results suggest that ethanol inhibits the metabolism by CYP2C9.1 in a substrate-dependent manner.

[Clinical study of 48 cases of viper (Agkistrodon halys blomhoffii "Mamu shi") bite--Does the swelling at the first medical examination reflect the seriousness of the envenomation?].

We have evaluated 48 cases of viper (Agkistrodon halys blomhoffii "Mamushi") bite treated in our hospital from 2001 to 2005. Of all the patients, 21 were bitten in rice field/farm, 10 were in path, 9 were in yard and 8 were in other places. Most cases occurred between July and September. The most frequently bitten regions were fingers and toes. Because swelling reached its maximum at 1.1+/-0.5 day, it was difficult to judge the severity of Mamushi bite by the degree of swelling at the first examination. There was no significant relation between the grade classification of swelling and CPK values. Value of CPK became its peek at 2.0+/-1.1 days after bites. Some reports recommend giving antivenin judging from the grade classification. However we could not estimate the severity of Mamushi bite from the degree of swelling and CPK values at the first examination. The degree of swelling and CPK values at the first examination will not be an index to determine the choice of the treatment including use of the antivenin.

Pharmacological study of modified intermediate-dose cytarabine therapy in patients with acute myeloid leukemia.

BACKGROUND: Instead of the original intermediate dose (0.5 g/m2), a modified intermediate-dose 1-beta-D-arabinofuranosylcytosine (ara-C) therapy (1 g/m2, 1-h intravenous infusion) was pharmacologically studied in 11 leukemic patients. PATIENTS AND METHODS: The concentrations of ara-C and its inactive metabolite, 1-beta-D-arabinofuranosyluracil (ara-U) in the plasma, urine and cerebrospinal fluid were determined using high performance liquid chromatography. RESULTS: The plasma ara-C reached a peak (61.2 +/- 52.7 microM) that far surpassed the saturating level for intracellular activation of the drug. The plasma ara-U reached its peak (139.8 +/- 40.0 microM) and was maintained with a half-life of 277 +/- 76 min. About 60% of the administered drug was recovered, mainly as ara-U in urine within 12 h. In contrast to the original intermediate dose, the therapeutic ara-C levels (above 0.4 microM) persisted in the central nervous system. The therapy salvaged one relapsed leukemia patient with central nervous system involvement. CONCLUSION: Modified intermediate-dose ara-C provides a sufficient plasma ara-C level with a concomitant therapeutic concentration in the cerebrospinal fluid.