Caffeine Accelerates Emergence from Isoflurane Anesthesia in Humans

Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background There are currently no drugs clinically available to reverse general anesthesia. We previously reported that caffeine is able to accelerate emergence from anesthesia in rodents. This study was carried out to test the hypothesis that caffeine accelerates emergence from anesthesia in humans. Methods We conducted a single-center, randomized, double-blind crossover study with eight healthy males. Each subject was anesthetized twice with 1.2% isoflurane for 1 h. During the final 10 min of each session, participants received an IV infusion of either caffeine citrate (15 mg/kg, equivalent to 7.5 mg/kg of caffeine base) or saline placebo. The primary outcome was the average difference in time to emergence after isoflurane discontinuation between caffeine and saline sessions. Secondary outcomes included the end-tidal isoflurane concentration at emergence, vital signs, and Bispectral Index values measured throughout anesthesia and emergence. Additional endpoints related to data gathered from postanesthesia psychomotor testing. Results All randomized participants were included in the analysis. The mean time to emergence with saline was 16.5 ± 3.9 (SD) min compared to 9.6 ± 5.1 (SD) min with caffeine (P = 0.002), a difference of 6.9 min (99% CI, 1.8 to 12), a 42% reduction. Participants emerged at a higher expired isoflurane concentration, manifested more rapid return to baseline Bispectral Index values, and were able to participate in psychomotor testing sooner when receiving caffeine. There were no statistically significant differences in vital signs with caffeine administration and caffeine-related adverse events. Conclusions Intravenous caffeine is able to accelerate emergence from isoflurane anesthesia in healthy males without any apparent adverse effects.

Introduction to the Rasch Poisson Counts Model: An R Tutorial

The Rasch Poisson Counts Model is the oldest Rasch model developed by the Danish mathematician Georg Rasch in 1952. Nevertheless, the model has had limited applications in psychoeducational assessment. With the rise of neurocognitive and psychomotor testing, there is more room for new applications of the model where other item response theory models cannot be applied. In this paper, we give a general introduction to the Rasch Poisson Counts Model and then using data of an attention test walk the reader through how to use the “lme4” package in R to estimate the model and interpret the outputs.

Scientific rationale for changing lower water temperature limits for triathlon racing to 12°C with wetsuits and 16°C without wetsuits

ObjectivesTo provide a scientific rationale for lower water temperature and wetsuit rules for elite and subelite triathletes.Methods11 lean, competitive triathletes completed a 20 min flume swim, technical transition including bike control and psychomotor testing and a cycle across five different wetsuit and water temperature conditions: with wetsuit: 10°C, 12°C and 14°C; without wetsuit (skins): 14°C and 16°C. Deep body (rectal) temperature (Tre), psychomotor performance and the ability to complete a technical bike course after the swim were measured, as well as swimming and cycling performance.ResultsIn skins conditions, only 4 out of 11 athletes could complete the condition in 14°C water, with two becoming hypothermic (Tre<35°C) after a 20 min swim. All 11 athletes completed the condition in 16°C. Tre fell further following 14°C (mean 1.12°C) than 16°C (mean 0.59°C) skins swim (p=0.01). In wetsuit conditions, cold shock prevented most athletes (4 out of 7) from completing the swim in 10°C. In 12°C and 14°C almost all athletes completed the condition (17 out of 18). There was no difference in temperature or performance variables between conditions following wetsuit swims at 12°C and 14°C.ConclusionThe minimum recommended water temperature for racing is 12°C in wetsuits and 16°C without wetsuits. International Triathlon Union rules for racing were changed accordingly (January 2017).

Quantifying Instructional Interventions in Pediatric Physical therapy with the Motor Teaching Strategies Coding Instrument (MTSCI-1): A Pilot Study

Purpose: This paper presents the development and preliminary psychomotor testing of a new instrument, the Motor Teaching Strategies Coding Instrument (MTSCI-1), designed to quantitatively assess motor-teaching strategies used by physical therapists during therapeutic interventions with children. Method: The MTSCI-1 was developed to evaluate the use of strategies grounded in motor learning theories and concepts. The items were generated from a review of the literature. To evaluate reliability, two physical therapists used the MTSCI-1 to code videotaped treatment sessions of pediatric physical therapists. Kappa was calculated. Validation was examined by comparing scores of physical therapists with different years of experience. Results: The resulting instrument had two main sections: (a) task/movement characteristics, and (b) before-, during- and after-task strategies. Each activity trial was analyzed and frequency of strategies used was determined. Percentage of agreement and preliminary inter- and intra-rater reliability (κ=.66-.94) as well as content and construct validation were established. The instrument differentiated the use of some strategies among groups of physical therapists with varied years of experience. Conclusions: The MTSCI-1 may be considered in research studies to document the motor-teaching strategies of physical therapists. The MTSCI-1 may also facilitate the learning and training of therapists from various fields in the application of motor learning to maximize clients’ outcomes from their motor-teaching activities.