Auditory stimuli as a contributor to consciousness while under general anesthesia.

BACKGROUND: The incidence of intraoperative awareness under general anesthesia approaches 1% in high-risk patients. Anesthesiologists commonly utilize processed electroencephalograms (EEG) in order to monitor "depth" of anesthesia, the most common of which is the Bispectral Index (BIS). The B-aware and B-Unaware trials, which were designed to test the efficacy of the BIS monitor, noted an auditory component in 16 of 17 confirmed cases of intraoperative awareness. Implicit auditory memory formation has been documented under general anesthesia. Small studies have documented a significant effect of noise on BIS scores during monitored anesthesia care. METHODS: Twenty-two patients undergoing general anesthesia received earplugs after the induction of anesthesia. Every ten minutes the earplugs were reinserted or removed. Noise levels were recorded every 0.125 s and both average and maximal BIS scores were recorded every minute. Non-parametric analysis of both populations (with and without earplugs) was performed. A mixed effects model with one degree of freedom (with and without earplugs) was generated to take into account the effect of anesthetic agents on BIS scores. RESULTS: 3009 min of data were recorded. The median and range (25-75%) BIS scores were 39 (29-46) and 39 (28-44) with and without earplugs in place, respectively. Earplugs were associated with lower BIS scores (p=0.0183). The mixed effects model confirmed this relationship (p<0.001). Subgroup analysis of BIS scores in which the potential for awareness existed (maximum BIS>60 in any one minute epoch) showed a 32% reduction in the incidence of maximal BIS scores exceeding 60 (p=0.0012). There was no relationship between ambient noise level and average maximal BIS score (R(2)=0.003). CONCLUSIONS: Our study suggests that earplugs may reduce the incidence of BIS scores >60 in patients undergoing total intravenous anesthesia and that auditory stimuli may affect EEG interpretation. Because of the low cost and safety of noise reduction, as well as the catastrophic implications of intraoperative awareness, further studies to explore the effects of auditory stimuli on awareness and anesthesia are warranted.

Acitretin in dermatology: a review.

INTRODUCTION: Acitretin is a systemic retinoid drug used in the treatment of severe psoriasis. It has also been used for a spectrum of other difficult-to-treat dermatoses, including hyperkeratotic and inflammatory dermatoses and non-melanoma skin cancers. Here we review the available data regarding both FDA-approved and off-label uses of acitretin, clinically relevant adverse events, precautions and monitoring. METHODS: A PubMed literature search was conducted utilizing the search term "acitretin," which yielded 714 hits. Results were further limited to English language clinical trials in human subjects. Of 78 articles evaluated for relevance, 60 were included for review. RESULTS: Acitretin is effective as monotherapy and in multidrug therapeutic regimens for the treatment of psoriasis and other hyperkeratotic and inflammatory disorders, as well as for malignancy chemoprevention. Its use is limited by its teratogenic potential and other adverse effects, including mucocutaneous effects and hepatotoxicity. Potential adverse effects may be reduced or avoided by using lower doses of acitretin or in combination with other therapies. LIMITATIONS: The reviewed studies include many small trials and case reports of the use of acitretin for psoriasis. Studies of acitretin therapy for the treatment of other cutaneous disorders are limited. CONCLUSION: Acitretin is a beneficial treatment for psoriasis, and should be considered when not contraindicated. Particularly when used in combination with ultraviolet (UV) phototherapy, is a safe and cost effective therapeutic strategy.