It’s 3 am in the morning; you are covering too many wards. Nurses are paging you for a patient with high fever from 3C while you are busy formulating good questions for a phone consult with the consultant who told you “not to ring me unless you have a good reason to get me coming in”. You are too busy to take a break although your adrenaline level is keeping you high anyway. When you can finally come off duty after a grueling night shift and handover at 7:30 am, you don’t realize how exhausted you are until you almost doze off at the traffic lights driving home.
Delivering optimal patient care requires absolute attentiveness, emotional readiness, technical and clinical skills. This can hardly be achieved when you are sleep deprived and exhausted – body and mind. The deleterious effects of long working hours are well-documented and include impairment of mood, memory, physical dexterity and cognitive function [1-3]. Even worse, a recent study found that sleep deprivation adversely affects the recognition of subtle facial cues of the emotions that are most relevant to highly evolved prosocial interactions including empathy [4].
Yes…yes ….you say, we know all that; but what can we DO about it?? Well, we have searched the literature for helpful stuff and have come up with some ideas about napping that may be of practical help.
In recognition of the grueling hours traditionally worked by junior doctors, and the negative effects this has on not only the young doctor but on patient safety, the U.S. Accreditation Council for Graduate Medical Education published new guidelines in 2010. In these guidelines “strategic napping” during long shifts was strongly encouraged! At the time it was considered pretty amazing that the organisation that sets the standards for training programs for young doctors in the U.S. has endorsed napping, albeit carefully qualified as being of the strategic kind [5]. Nevertheless, this move reflects an increasing awareness that napping can actually be good for you.
Napping is undoubtedly beneficial to your health, performance and overall wellbeing [6-11]. The trick seems to be in the timing of the nap; here ‘less is more’ as the saying goes.
People often think that the longer the nap, the more benefits can be gained from it. This is not so. The secret of taking a high-quality nap is in preventing yourself from entering or waking up during deep or slow-wave sleep as this is likely to induce sleep inertia. Shorter naps (10-20 minutes) mostly consist of stage 1 or 2 (light) sleeps, while deep (slow-wave) sleep sets in after 30 to 45 minutes under normal conditions. Thus, taking a longer than 30-minute nap can result in sleep inertia, a transient period of feeling drowsy and groggy with impaired alertness, labile mood and cognitive function [11, 12].
So, to put power in your nap, keep it short.
As with everything in life, we need to keep in mind that ‘we are all individuals’; so the perfect nap timing and context may differ from person to person. There is nothing like finding out your best power nap parameters by trial and error!
…and lets stick with the term ‘power nap’ as the often-used moniker ‘cat nap’ is clearly a misnomer. Cats basically sleep all the time, up to 20 hours a day. We hope to maximise the benefits from the minimal sleep, napping like a cat would bring in more harm than good to a human.
A lot of famous people and high-achievers were fierce proponents of the power nap.
Instead of lying flat on a cosy bed supported by a memory foam-filled mattress, try napping in an armchair. The “slumber with a key” method is also an interesting way to prevent entering deep sleep as the artist Salvador Dali wrote in 50 secrets of Magic Craftsmanship [13]. This method involves placing a plate upside down on the floor and hanging a key in between fingers, so the key would clang the plate when one has fallen asleep deeply.
Afternoon naps have been shown to produce the best immediate effects and better performance outcomes. During night shifts, the best time to take a nap is when the highest level of sleepiness (or greatest sleep debt) is felt – mostly around 2 to 6 am. It was found that a 10-minute nap right before the end of a night shift led to sleep inertia, and it did not improve performance [11].
Have a cup of coffee before napping as it takes effect towards the end of the nap (a.k.a. controlled recovery period), however, beware of your caffeine intake as it should be no more than 400 mg daily. British researchers Horne and Reyner [14] found that caffeine and a 15-minute nap significantly improved cognitive performance, subjective sleepiness, and EEG activity indicating drowsiness compared to just napping. Nappuccinos that included “non-sleep dozing” (i.e. if you cannot actually fall asleep properly) also were effective.
More and more institutions around the world have recognised the benefits of napping and have built nap rooms for their employees/students. Such nap zones incorporate chairs with recliner options, cots or giant beanbags. In Brazil, there is a Power Nap Center accommodating twenty soundproofed cabins with “nappers-friendly” designs, including blue lighting and relaxing music. Some universities and teaching hospital also have “sleeping pods” equipped with white noise machines and disposable pillowcases to boost students’ productivity [15,16]. Positive feedback with reduced sleepiness was reported from a pilot study that had implemented formal breaks for nursing staff [17], though there were some barriers in gaining approval from the nursing manager…!
May the power of a well-timed snooze be with you!