Yet another favorable report, page-43

The levels increased, but not significantly.
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The cumulative probabilities from months 1–24 exhibited increased levels of serum fluoride from month 0 (baseline) results (Fig. 1). For any given serum fluoride level, this finding indicates an increased likelihood of this level or less being identified in month 0 compared with subsequent months. Therefore, this finding implies serum fluoride results may have been elevated above baseline after introduction of methoxyflurane in month 0. However, this finding was not statistically significant: a two-sample two-sided Kolmogorov–Smirnov test comparing month 0 data with months 1–24 found a non-significant result (P=0.9995). A power analysis determined the sample size n=12 was needed to observe a difference of 1 μmol L−1 to be significant with 80% power. The rightward shift seen in Fig. 1 is generally less than 1 μmol L−1.
This cumulative distribution analysis suggests serum fluoride levels of ambulance officers occupationally exposed to methoxyflurane do not increase significantly. Even if statistical significance was achieved in identifying an increase, the serum fluoride values determined in this study suggest it might be clinically unimportant.
Delays in obtaining ethical approval resulted in serum fluoride results taken within the initial month of methoxyflurane availability rather than before. This delay potentially raised baseline levels, and obscured observation of early initial increases in serum fluoride. Nonetheless, the serum fluoride values determined by this study provide some reassurance of safety from renal toxicity in ambulance officers occupationally exposed while administering methoxyflurane analgesia. However, this result might depend on use of the activated carbon filter, as occurred in this ambulance service, and on exposure frequency and duration consistent with this ambulance service's clinical practice, as well as on the environment in which methoxyflurane is administered. Therefore, these results may not be applicable to other services utilising methoxyflurane more frequently, or in less-ventilated environments.