Effectiveness of the Multi-Modal Sensory Stimulation on the Level of Consciousness Among Unconscious Patients

INTRODUCTION

Around the world, being unconscious is a major factor in morbidity, mortality, disability, and intensive care unit (ICU) hospitalisation. Patients with brain injuries who are unconscious may live for days or even months, but they frequently have a lower quality of life. The damage to the brain caused by a disruption in its blood supply is dealt with in cerebral vascular accidents, a medical emergency.^[1] One of the most perilous consequences of trauma or cerebral haemorrhage is acute, severe brain injury. The three main causes are systemic pathology-induced diffuse neuronal disorders, cerebral structural tumours, and irregular psychological factors. The structural causes include cerebrovascular accident (CVA), traumatic brain injury (TBI), intracranial, epidural, and subdural haemorrhages. Fluid and electrolyte imbalances, seizures, systemic infections (sepsis), meningitis, and encephalitis are some of the systemic causes. Conversion disorders and severe depression are two psychiatric causes.^[2]

An estimated 1.5-2 million people in India suffer traumatic brain injuries each year, and 1 million people pass away. ¹ Strokes are the third-leading cause of disability around the world and the second-most common cause of death. By 2030, it is predicted that there will be 23,000,000 stroke cases per year if population growth and effective interventions are not implemented. According to the most recent statistics, there were 64,362 TBI-related deaths in 2020 and about 2,23,135 hospitalizations related to traumatic brain injuries in 2019.^[3]

The goal of sensory stimulation is to increase arousal and recovery by systematically revealing a comatose or partially conscious patient to various environmental stimuli (visual, auditory, tactile, olfactory, and kinaesthetic). Multimodal sensory stimulation involves increasing arousal, awareness, and behavioural responses in each sense’s physiology. Olfactory stimulation, as accomplished by aromatherapy, can aid in the release of G-protein, which raises antibodies and enhances blood flow. Meanwhile, auditory techniques can activate brain nerve cells. The blood flow system that returns blood to the cortical circulation system is improved by tactile stimulation therapy, effectively making up for blockages that could lead to stroke. Finally, by simultaneously focusing on several senses, certain measures can target the ascending reticular activating system (ARAS), which can improve patient consciousness and reduce the risk of ischaemic damage to brain cells. The sympathetic nervous system can become more active when stimulated by perception and the sense of taste.^[4] The use of a sensory stimulation programme for an unconscious participant has turned out to be a workable, non-invasive, non-pharmacologic, and cost-effective intervention that improves medical care.^[5] The ICU can be made less unfamiliar and less stressful by using sensory stimulations administered by family members under the direction of nurses. Each stimulation increased their O₂ saturation and vital signs.^[6] It has also been found to significantly reduce distress, tension, restlessness, negative moods, and anxiety.^[7]

The Glasgow coma scale (GCS) and coma recovery scale-revised (CRS-R) are the standardized clinical tools used to objectively describe the extent of impaired consciousness in all types of acute medical and trauma patients. The scores from each section of the scale are useful for describing disruptions in nervous system function and help providers track changes. It’s the most widely used tool for measuring comas and decreases in consciousness.^[8,9]

Hence, nurses are in a unique position to influence targeted sensory stimulation. They should feel empowered to calm the agitation of TBI patients hospitalised in ICUs because they are keen observers during the care process. The researcher also imparts nursing intervention skills to the patient’s families on how to care for brain injury patients with diminished consciousness. To develop and improve targeted stimulation strategies and eventually make the lead goal a reality, nurses must continue to collaborate with other hospital professionals and family members. This study was carried out with the intention of examining the outcome of multimodal sensory input on patients’ levels of perception and awareness among unconscious participants.

MATERIAL AND METHODS

A randomised control trial study was conducted among 40 unconscious patients, 20 of them in each experimental and control group, diagnosed with TBI and CVA cases with a GCS Score between 3-8 in a selected hospital, Mangalore. The patients were selected by random sampling from various ICUs and were assigned to experimental and control groups. Patients who had blindness and deafness before the comatose state and those under septic shock were the exclusion criteria of the study. It includes two tools that were designed by the researcher in the English language after reviewing the related literature. These tools comprised the following parts.

Methods

This was a double-blinded randomized clinical trial that was conducted on 46 unconscious patients with a GCS score of 3-8 and diagnosed with TBI and CVAs. The sample size was calculated using the results reported by a study where the mean scores in their groups were 6.6 and 11.9. So far, with a confidence level of 95% and a 10% attrition rate, we concluded that 23 patients were needed for each study group. Eligible patients were randomly assigned to two groups of experimental and control, using a table of random numbers [Figure 1]. The investigator explained the purpose of the study to the family members and obtained their consent prior to conducting the research. Ethical Approval was obtained. Researchers provided information about the importance of family involvement in providing sensory stimulation and the consent form was obtained through them. The qualified nurses who were blinded to both the groups were trained in recording the GCS and CRS-R scores. For the experimental group, the investigator will provide sensory stimulation for all five sensory modalities for 5 minutes each. Auditory Stimulation was carried out by speaking directly to the client for 5 minutes at a distance of 10 cm from both ear canals. Visual Stimulation was carried out by holding and focusing the pen torch 12 to 15 inches from the client and slowly moving forward to the client’s eye from the periphery to the central aspects of the vision. The light is shined into each eye separately, the right eye, and then the left eye, for 10 seconds, three times. Olfactory stimulation was applied with the help of mild bath soap at a distance of 3 cm from the nostril. Tactile Stimulation was carried out using 5 steps of back care massage along with combing of hair. Gustatory stimulation included gum massage, along with brushing the teeth and tongue with a soft brush for 5 minutes. The total duration of the stimulation was 25 to 30 minutes, which was carried out twice a day, in the morning and afternoon, for seven consecutive days in the experimental group, along with routine care.

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Figure 1:

CONSORT: Consolidated standards of report trails where n represents number of patients involved in the study.

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For the control group, routine care such as sponge bath, medication administration, Ryles tube feeding, positioning, maintaining the lighting, and noises of the equipment in the ICU were carried out by the staff nurses. Post-test was recorded in the morning and afternoon by the qualified nurse for 7 consecutive days.^[10] The data were analysed with the help of an independent t-test and a two-way factor of analysis of variance.

RESULTS

Patients (6, 30%) with the highest percentage were in the age group of 30-45 and 65-75 years. The majority (12, 60%) of patients were males, and 16 (80%) of them were married. In the control group, the highest percentage (8, 40%) of patients belonged to the age group of 46-60 years, most (17, 85%) of whom were males, and 18(90%) were married. The Chi-square test showed no significant difference between the groups according to demographic variables (p<0.05), indicating the homogeneity of the groups.

In both experimental and control groups, 50% (10) of the patients were hospitalised due to CVA, followed by road traffic accident (40%). Half (10, 50%) of patients in the control group suffered from TBI, seven (35%) in the experimental group suffered from haemorrhagic injury. Whereas the least percentage of the patients in the experimental group (3, 15%) and none in the control group suffered from anoxic injury. Majority of the patients in experimental group 12 (60%) and half of the patients in control group 10 (50%) group had duration of unconsciousness less than 5 days and least percentage of the patients in the experimental group 1 (5%) and none of the patients in the control group had duration of unconsciousness more than 15 days. In the experimental and control groups, the majority (8, 40%) of patients had the temporal lobe as the site of brain injury, and the least percentage (1, 5%) of them had the occipital and cerebellum as the site of brain injury. The majority of the patients in the experimental (13, 65%) and control groups (15, 75%) have not undergone any surgery. Whereas few patients in the experimental group (1, 5%) and none in the control group were eligible for surgery. A greater proportion of patients in the experimental group (10, 50%) had no comorbidities. Whereas many patients in the control group (10, 50%) had a history of cardiovascular disorder. The Chi-square test showed no significant difference between the groups according to clinical variables (p<0.05), indicating the homogeneity of the groups.

Mean GCS scores of patients in the experimental and control groups were 5.3 (1.6) and 4.74 (1.8), respectively. To assess the homogeneity of outcome variables at baseline, an independent t-test was used. The t-test revealed that patients in both groups didn’t differ at baseline measurement (p>0.05). Hence, the two groups were considered equal.

There was an improvement in the mean GCS scores from day 1 (5.3 ± 1.6) to day 7 (13.04 ± 1.5) in the experimental group. In the control group, there was not much improvement in mean GCS scores from day 1 (4.74 ± 1.8) to day 7 (5.87 ± 2.8). On day 7, the mean GCS of the experimental group (13.04± 1.5) was more than that of the control group (5.87± 2.8), thus stating that multimodal sensory stimulation had improved the GCS mean scores of patients in the experimental group [Table 1].

There was an improvement in the mean total CRS-R scores from day 1 (4.87 ± 3.58) to day 7 (19± 2.7) in the experimental group. In the control group, there was minimal improvement in mean total CRS-R scores from day 1 (3.3 ± 3.75) to day 7 (6.83 ± 5.8). On day 7, the mean total CRS-R of the experimental group (19± 2.7) was more than the mean total CRS-R of the control group (6.83 ± 5.8). There was an improvement in the area-wise mean CRS-R scores in the experimental group on day 7. On day 7, the area wise mean CRS-R of experimental group (auditory 3.5±0.5), (visual 4.3±0.8), (motor 4.7±0.), (communication 1.7±0.5), (verbal 2.1±0.5), (arousal 2.6±0.6) were more than the area wise mean CRS-R of control group (auditory 1.39±1.23), (visual 1.7±1.72), (motor 1.52±1.34), (communication 0.74±0.62), (verbal 0.65±0.78), (arousal 0.83±0.94), which shows that multimodal sensory stimulation was effective in refining the total and area wise CRS-R mean scores of patients in experimental group [Table 2].

There was a significant difference between pretest (Day 1) and post-test (Day 7) scores in the experimental group (p<0.001), which showed that multimodal sensory stimulation had an impact on improving GCS and CRS-R scores among unconscious patients in the experimental group.

There was a significant difference between pretest (Day 1) and post-test (Day 7) area-wise CRS-R scores in the experimental group (p<0.001), which indicates that multimodal sensory stimulation had an effect in improving the area-wise level of conscious scores among unconscious patients in the experimental group.

There was no significant difference in GCS scores on days 1 and 2, as well as CRS-R scores on days 1, 2, and 3. However, there was a high significant difference seen in GCS and CRS-R scores from day 4 to day 7 (p=<0.001), which revealed that multimodal sensory stimulation was effective in improving the GCS and CRS-R level of conscious scores among unconscious patients in the experimental group.

The mean CRS-R scores in the experimental group were more than the mean CRS-R scores in the control group in all areas of the CRS-R scale. There was a significant difference in all areas of the CRS-R scale between the experimental and control groups on day 7 (p=<0.001), which inferred that multimodal sensory stimulation had an impact in improving the level of conscious among unconscious patients in the experimental group.

There was a high significant difference in the level of consciousness among unconscious patients between the experimental and control group, which revealed that multimodal sensory stimulation had an impact in improving the level of conscious scores among unconscious patients in the experimental group [Table 3].

There was high significant difference in the level of consciousness among the unconscious patients in the experimental and control groups, thus stating that the multimodal sensory stimulation was effective in improving the level of conscious among unconscious patients in the experimental group [Table 4].

DISCUSSION

The results of the current study revealed that most patients in the experimental group (12, 60%) were in the age group of 30-45 and 66-75 years, whereas in the control group, 8 (40%) patients were in the age group of 46-60 years. Most (12, 60%) of the patients in the experimental group and most (5, 83.3%) of those in the control group were males. Most of the patients in the experimental group (16, 80%) and the control group (18, 90%) were married. The findings of this study are similar to those of other studies, in which the majority of subjects were married males in the 35-80 year age group.^[1,11-15]

The present study results also revealed that in the experimental and control groups half (10, 50%) of the patients were hospitalised due to CVA and suffered a traumatic type of brain injury. Data also reveals that 8 (40%) patients in the experimental and control groups had the temporal lobe as the most affected anatomical site. The results of the present study contradict the study of effects of sensory stimulation programme on recovery in unconscious patients with TBI, where results showed that 6 (30%), had the bilateral fronto-temporal lobe as the most affected anatomical site in both experimental and control groups. Other studies demonstrated that the highest percentage of patients in the experimental and control groups were hospitalised due to CVA and suffered TBI along with fronto-parietal lobe as the most affected site of brain injury.^[16,17]

The results of the present study also show that in the experimental group, a majority (14, 70%) of the patients had not undergone surgery, and half (10, 50%) of the patients had no co-morbidities. Whereas in the control group, the majority (15, 75%) of the patients have not undergone surgery, and half (10, 50%) had a co-morbid history of cardiovascular disorder. In other similar studies majority of the patients in the experimental and control groups have not undergone any surgery and had a co-morbid history of cardiovascular disorder.^[18,19]

The current study’s findings showed an improvement in mean GCS scores from Day 1 (5.3 ± 1.6) to Day 7 (13.04 ± 1.5). On day 7, the mean GCS scores of the experimental group (13.04±1.5) were more than the mean GCS scores of the control group (5.87 ± 2.8) at 14 measurement time points. Additional research using a quasi-experimental study corroborates similar findings that during post-test, the mean GCS scores of the experimental group were more than the mean GCS scores of the control group at different measurement time points. The results showed that patients in the intervention group had increased GCS scores after the application of sensory stimulation, which had an impact on improving consciousness level in comatose patients.^[12,18,19]

The current study findings show that in the experimental group, there was an improvement in mean total CRS-R scores from Day 1 (4.87±3.58) to Day 7 (19±2.7). On day 7, the mean total CRS-R scores of the experimental group (19±2.7) were more than the mean total CRS-R scores of the control group (6.83±5.8). Additional research using a randomized control trial corroborates the findings that on day 7, the mean total CRS-R scores of the experimental group were more than the mean total CRS-R scores of the control group at seven measurement time point.^[1,20] The results determined that the patients in the experimental group had an improvement in the CRS-R scores compared to the control group after commencing the application of sensory stimulation at various points during the measurement process.^[20]

The current study’s findings show that the calculated two-way repeated measures of ANOVA f-values for GCS and CRS were f = 41.288, p <, and f = 60.923, p < 0.001, respectively. This indicates a highly significant difference in the level of consciousness among unconscious patients in the experimental and control groups.

Similar study findings showed the results of the repeated measures ANOVA, where statistically significant difference was observed among the groups with respect to the mean GCS scores across the seven measurement time points.^[21-23] The repeated measures ANOVA also indicated significant differences among the groups regarding the variations of CRS-R scores across the seven measurement time points. The results are contradictory to a pre-post experimental study, which showed that after commencing sensory stimulation, there was no significant improvement seen among the comatose patients in the experimental group.^[21-23]

The results of the current study show the two-way repeated measures of ANOVA where the calculated f value of GCS and CRS are f=33.404, p<0.001 and f=44.855, p<0.001 respectively, which shows that there was high significant difference in the level of consciousness among the unconscious patients between experimental and control group which inferred that the multimodal sensory stimulation was effective in improving the level of conscious among unconscious patients in the experimental group.

Similar study findings showed the results of the repeated measures ANOVA, where statistically significant difference was observed among the groups with respect to the mean GCS scores across the seven measurement time points. However, the differences between the groups were statistically significant from day 4 to day 7. The repeated measures ANOVA indicated a significant difference among the groups regarding the variations of CRS-R scores across the seven measurement time points. The results are contradictory to the quasi-experimental study, which showed that after applying sensory stimulation to adults with TBI, there was no significant improvement in sensory function among the adults in the experimental group.^[21-23]

However, the results of the present study illustrated that multimodal sensory stimulation was effective in improving the level of consciousness among unconscious patients with traumatic and cerebrovascular brain injuries.

CONCLUSION

Based on the results of the present study, it can be concluded that the application of sensory stimulation had an impact on improving the level of consciousness. Nurses can incorporate sensory stimulation into existing interventions, especially for patients with decreased consciousness. Both independently performed nursing interventions and collaborative efforts with patient’s family members must make use of sensory stimulation. Additionally, it is advised that this application must be incorporated into the nursing curriculum and regular care plans for comatose patients in ICUs.