Influence of a 30-min break on divided attention and working memory in resident anaesthetists on daily routine

Background. The aim of this study is to test the hypothesisthat a standard 30-min break in a routine 7.5 h period of workmakes a difference in cognitive function. Methods. In a double-blinded, cross-over trial 30 residentsin anaesthesia were randomized to receive or not to receivea 30-min break between the assessment times of 07:30 and 14:00.in a normal working day. After at least 28 days the test wasrepeated with each resident in the opposite group. Primary outcomemeasure was the Test for Attentional Performance with the subtestof working memory and divided attention. Secondary outcomesare the Stanford Sleepiness Scale and the State-Trait AnxietyInventory test. Results. The sleep, caffeine and nicotine habits in both groupswere comparable. There was no difference between the two groupsin the Test for Attentional Performance, Stanford SleepinessScale and the State-Trait Anxiety Inventory. The correlationbetween recovery through sleep and sleep disturbance in thenight before investigation to the Stanford Sleepiness Scale(P<0.001 and P=0.003) and State-Trait Anxiety Inventory (P<0.001and P=0.001) at the 07:30 assessment is significant. For the14:00 assessment the only significant correlation is betweenthe recovery through sleep with the Stanford Sleepiness Scale(P=0.04) and the State-Trait Anxiety Inventory (P=0.05). Conclusion. A 30-min break during a 7.5 h daily routine didnot influence cognitive function tests.