Humans can sense light by sight. Light is strongly related with the secretion of melatonin, which plays an important role in the regulation of sleep-wake cycles and is produced in the pineal gland generally during night time, when light cannot be sensed. Nocturnal light levels in the ICU may interrupt sleep pattern. In fact, the light levels in the ICU have been documented to be over 1000 lux [2]. Nocturnal light levels as low as 100 to 500 lux can affect melatonin secretion, and those between 300 to 500 lux may disrupt the circadian cycles [3]. Although nocturnal light levels have been associated with sleep disorder, getting enough bright light in the morning and in the daytime is important to maintain the circadian rhythm [4].

The visual field of patients in the ICU is occasionally obstructed or limited because of immobilization. Interruption of sight was suggested to cause a loss of approximately 80% of information input [5]. We empirically noticed that color vision has psychological effects. Based on general opinion, such as that in pseudoscience, red gets people excited and increases body temperature and inflammation; blue leads to calm and relaxation and reduces inflammation; and green inhibits extreme excitation and balances emotional harmony. In the scientific aspect, perception of red color was likewise suggested to be associated with higher testosterone concentration. In fact, high intensity exercise while wearing red-colored lenses was reported to increase testosterone secretion [6]. In the 2004 Olympic Games, the contestants in all four combat sports of boxing, Taekwondo, Greco-Roman wrestling, and freestyle wrestling were observed to have consistent and significant patterns of winning more fights when wearing red. Even in cases of similar effects among the weight classes in each sport, 60% had more red winners and only 40% had more blue winners [7].

Noise has several negative effects on health. It is an unwanted sound that is judged to be unpleasant, loud, or disruptive to hearing, although these perceptions may be subjective. For example, rock and roll music may be perceived as unpleasure by some but not by others. Therefore, qualitative assessment of noise is difficult. Most researches on noise have been conducted based on the degree of loudness. Noise is recognized as one of the sensory nuisances and has been suggested to be associated with cardiovascular risks, such as hypertension and ischemic heart disease [8].

For the ICU, the World Health Organization recommended that sound levels should not exceed 35 dB on the average and 40 dB all throughout the night; however, one study reported that sound levels in the ICU exceeded 45 dB on the average and 85 dB at a moment [9]. Moreover, such large noise was said to have occurred and persisted for about 10 minutes every hour. Around 80 dB is equivalent to the noise from heavy city traffic [9] [10]. Most of the ICU noise that is more than 80 dB are likely from alarm activities and electronic sounds, which are more arousing, compared with human voices; therefore, these likely caused the continuous disruption of the patients’ sleep [9]. Noise exposure impairs sleep quality and is associated with negative physical changes on the cardiovascular, respiratory, immune, and neurocirculatory systems [11].

On the other hand, some sounds can reduce the stress response, and these include music that is comfortable based on individual preference. However, as mentioned before, a kind of music can be a noise for someone. Another option is provision of sounds with 1/f fluctuation characteristics; examples of these are the various natural phenomena, such as breeze, streams, candle flames, and the luminous patterns of fireflies [12]. In general, listening to 1/f sounds has been previously demonstrated to effectively reduce stress response, although this remains a matter of debate [13].

Bad smell is one of things that can have negative effects on people. Although the definition of bad smell strongly depends on individual preferences, perception of a bad or nasty smell becomes a kind of pollution for the individual and can induce a stress response. Instinctively, humans perceive an uncomfortable smell as unpleasure, which may decrease the probability of survival and cause an individual to avoid or escape from such smell. Animals were reported to show stress response and escape behavior against the odors of predators and putrefaction odors [14]. A previous research suggested that overall, olfactory-evoked memory were more intense and vivid, compared with the memories evoked by the primary sensory systems of sight and hearing [15].

In the ICU, an uncomfortable memory evoked by a nasty odor is a concern. On the other hand, in aromatherapy, smell has a healing effect. In fact, aromatherapy using lavender essential oil has been reported to significantly contribute to improve mood, perceived levels of anxiety, and sleep quality [16] [17]. Although the influence of smell variations on the healing effects of aromatherapy remains conclusive, some have reported different healing effects of various aromas other than lavender.

Different kinds of tactile sensations, such as those from frequent painful interventions or treatment, may affect patients in the ICU physically and mentally. After ICU discharge, more than half of patients were reported to recall an experience of discomfort during ICU stay. The presence of an endotracheal tube was the most frequently reported source of discomfort [18]. Moreover, one study showed that care interactions were provided at a mean number of 42.6 per night and were most frequent at midnight; moreover, only 6% had uninterrupted sleep periods of 2 to 3 hours during the study period [19]. Indeed, the previously reported sleep disturbance in 68% of patients in the ICU is very convincing [20].

On the other hand, stimulating tactile sensation can sometimes alleviate hard symptoms. Touch therapy is popular in the field of palliative care. A systematic review showed that touch therapy may have a modest effect on pain relief [21]. In addition, alleviation of pain by rubbing the sore site is a common observation. The gate control theory, which describes how non-painful sensations can override and reduce painful sensations, may explain this phenomenon [22]. Aromatherapy massage, which is often shortened to aroma massage, is a combined therapy of touch and smell. Aroma massage with plant-derived oil substances may be beneficial as a complementary therapy or relaxing technique for the symptomatic management of various conditions, mainly psychological and pain-related disturbances, and palliative care conditions [23].

Taste can affect patients in the ICU physically or mentally. Patients in the ICU seem to rarely have an opportunity to taste something, because they are rarely on oral intake. Although there is insufficient evidence on the topic, sweet tasting was suggested to alleviate pain [24] and had been found to reduce needle-related pain in infants during immunization. If this treatment can be substantially promising for adult patients, sweet tasting may possibly alleviate the physical and mental burden in the ICU. However, the perception of pleasurable or unpleasurable taste depends on individual preferences. This kind of treatment might be difficult to apply universally, because taste preference differs from person to person. Aside from sweet tasting, quenching of thirst is important, especially for patients in the ICU. In fact, thirst was reported to be the second most prevalent symptom among patients in the ICU [25]. Effective interventions to relieve this distressing sensation are important, because thirst is closely related with the activation of the rennin-angiotensin aldosterone system [26].

After institutional review board approval and obtaining a written informed consent from each patient, we investigated the effects of aromatherapy massage at an ornamental hospital room in the ICU on the stress response of patients during ICU stay. Stress response was objectively evaluated by measurement of salivary amylase and heart rate variability before and after the aromatherapy massage. In addition, the degree of burden or distress was subjectively evaluated using a visual analog scale (VAS) before and after aromatherapy massage. The patients received the same specialized aromatherapy massage on the arms, hands, and upper legs for 20 - 30 minutes by skilled therapists. Lavender, rose, or eucalyptus essential oil was used, according to the patient’s preference.

Salivary amylase, which has been widely used as a noninvasive biomarker of the sympathetic nervous system in response to stress [27], was supposed to reflect the degree of comfort or discomfort of the patients in the ICU. We used a salivary amylase biosensor (Nipro Corporation Cocoro Meter, Osaka, Japan), which is commercially available, was easy to operate, and produced results fast.

By far, a total of 40 patients have experienced aromatherapy massage, and the results of the interim analysis of these patients (Table 1 and Table 2) have been reported in a local Japanese journal [28]. After the intervention, the mean arterial pressure, heart rate, and respiratory rate; VAS; and level of salivary amylase significantly decreased. Based on these results, we supposed that both the objective and subjective stress responses were reduced by the aromatherapy massage.

In addition, we notice some effects of the aromatherapy massage on heart rate variability. The time interval between heartbeats is not consistent and varies from 10% to 30%, even at a constant heart rate; this physiologic phenomenon is called heart rate variability [29]. In general, after frequency domain analysis, heart rate variability can be divided into the high frequency band (HF), which represents 0.15 - 0.4 Hz, and the low frequency band (LF), which represents 0.04 - 0.15 Hz. However, the study designs for heart rate variability have been complicated because of the different HF and LF standards adopted by several researchers [29]. HF is recognized as an index of parasympathetic activity, whereas LF is considered as an index of both sympathetic and parasympathetic activities. Therefore, LF or HF may be used as an index of sympathetic activity; however, these definitions remain controversial [29]. Previously, we found that LF/HF showed insignificant changes before, during, and after aromatherapy massage (Figure 1). This finding suggested that a pleasant feeling may not always suppress sympathetic activity or that aromatherapy massage may not always give a pleasant feeling.

APACHE II: acute physiology and chronic health evaluation II score; GCS: Glasgow coma scale.

VAS; Visual analog scale for stress; Shaded cells show parameters, which significantly changed by the intervention.

A false window is an artificial frame that can display a range of different outdoor scenes, such as a specific landscape from the hospital, superb views from all over the world, and world heritage sites. At our hospital, the false window usually displayed a real-time landscape view from a web camera that was set on the roof of the hospital and was connected to the display through the intranet (Figure 2). This was introduced with the cooperation of Professor Mitsunnori Miki, the Faculty of Science and Engineering, Doshisha University. False windows using a liquid crystal display were reported to be effective in providing psychological effects that were equivalent with those provided by real windows in the working space without windows [30]. Interestingly, one study reported that patients who had a window view of nature had relatively short postoperative hospital stay, received few negative comments from nurses, took moderate and strong analgesic doses less frequently, and had slightly low scores on minor postsurgical complications [31]. In the ICU environment, a false window view may be given similar promising and positive effects on patients. However, our prototype false window is not available commercially and lacks versatility, because its real-time landscape view is provided only through the intranet. On the other hand, there is a commercially available false window (Atmoph Window, Atmoph Inc., Kyoto), which can display real-time landscape views from 1000 web cameras set at all over the world and can be connected to the display through the internet (Figure 3).

A room in the ICU was remodeled with fantastic emblems to break through the commonly held image of ICUs or hospitals (Figure 4). In addition, the room is

colored with a lot of vitamin colors. It should be noted that the term “vitamin color” is an English word coined in Japan, and the nearest word for vitamin color is vivid color or bright color but different. It is believed that vitamin colors affect us positively and bravely as well as vividly and brightly. To facilitate this concept, the ICU staff started to wear fantastic emblems on their sleeves and scrub suit tops after the room was created (Figure 5). Although acceptance of this design by all patients was a concern, we thought that the ornamental hospital room concept gave an opportunity to start a conversation and helped improve the communication among the healthcare providers, patients, and the patients’ families. We previously conducted the survey that asked patients and their family about the false window and ornamental hospital room in an intensive care unit [32]. Majority of answers positively supported these innovations; however, there was still room for improvement in the remodeled room. The remodeled room at that time was as shown in Figure 6. Based on the results of the survey, the current ornamental hospital room was remodeled.