The Effect of Foot Reflexology on Physiological Indicators and Mechanical Ventilation Weaning Time among Open-Heart Surgery Patients

Shortening the length of mechanical ventilation (MV) and lowering dose of sedatives among critically ill patients can decrease complications, intensive care length of stay and mortality rate. Therefore, introducing non-pharmacologic interventions such as reflexology became an issue of concern for critical care nurses. The purpose of this study was to investigate the effect of foot reflexology on physiological indicators and mechanical ventilation weaning time in open-heart surgery (OHS) patients. Methods: Quasi-experimental study with a convenience sampling technique was used to recruit 80 patients who underwent open heart operation and admitted to cardiothoracic intensive care unit (ICU) of Mansoura University Hospital. Random assignment was allocated to the intervention group (foot reflexology) and the control group (routine care). Data were collected using participants' physiological indicators and MV weaning time assessment tool. Results: There were statistical significant differences between the foot reflexology group and the control group concerning all physiological indicators (p < 0.05). Statistical significant differences were also noted on shortening the length of weaning time between both groups (p < 0.05). Conclusion: Foot reflexology is an effective method for stabilizing physiological indicators and decreasing ventilator dependence among patients undergoing OHS. Therefore, it can be introduced as an adjunct to daily care of OHS patients in ICU.


Introduction
Cardiovascular diseases (CVDs) are considered to be the first leading cause of death worldwide due to stroke and cardiac arrest. According to the World Health Organization, in 2016, 17.9 million people lost their lives due to CVDs representing 31% of all global deaths [1].
This mortality rate is expected to increase in the following ten years [2]. Surgical interventions still play a critical role in prolonging life and improving patients who experience CVDs quality of life [3]. However, patients undergoing open heart operation may experience physical, psychological and cognitive problems [4].
After operation, OHS patients are transported directly to the cardiothoracic ICU to allow liberation from MV after stabilization of their cardiac and respiratory functions [5]. However, weaning from MV after cardiovascular surgery is still one of the most complex tasks. Moreover, the use of sedatives post cardiac surgery in ICU to improve MV tolerance and reduce metabolic demands during hemodynamic and respiratory instability is very common [6]. However, these agents have several negative consequences on patients' conditions, and may lead to prolongation of MV, over-sedation, delirium, and hemodynamic instability [7].
Prolonged mechanical ventilation (PMV) is a serious complication following cardiovascular surgeries. Although it occurs with a low incidence (3-9.9%), it is associated with increased morbidity, mortality and cost of health care services [8,9]. Furthermore, prolonged ICU length of stay after cardiac operation is associated with increasing cost and resources utilization [6,8]. Therefore, early extubation is considered to be an essential element of 'fast-track' management strategy after cardiac operation and is linked with shorter stay in ICU and lowered health care costs [10].
There are various pharmacological and non-pharmacological methods for reducing patients' stress, pain and anxiety [11]. However, there are several complications related to pharmacological management such as disturbed level of consciousness and increasing the risk of drug dependence [7]. Currently, Nonpharmacological interventions, such as distraction, relaxing music, relaxation techniques, massage therapy and biofeedback are used by nurses as measures for 413 American Journal of Nursing Research reducing patients' anxiety, and enhancing their healing and general health [11,12].
Complementary therapies and non-pharmacological interventions are noninvasive, simple and less expensive, and have less or no adverse effects compared with pharmacological remedies [13]. Foot reflexology massage is one of the non-pharmacological techniques used in ICU. Reflexology is defines as a systematic practice that focuses upon stimulating feet's reflex points that correspond to a specific body part [14]. There are reflex points or zones in the feet correlated with all body parts. These zones form a chart of the body in the feet with the right foot corresponding to the right side of the body and the left foot corresponding to the left side of the body. In other words, the whole body represented in the feet. Hence, when a specific reflex area is excited, the cells of the body comply by creating a reflex effect on the corresponding organs, nerves, tissues, and muscles [15].
Some studies revealed that foot reflexology has immediate effects on reducing heart rate (HR), systolic and diastolic blood pressure (SBP & DBP), and increasing arterial oxygen saturation (SaO2) [16,17,18]. These findings are worthy of getting the attention of critical care nurses as the improvement of vital signs without medications is a significant goal of care. Additionally, foot reflexology can be used to improve physiological indicators in unconscious patients in ICUs.
It had been proven that foot reflexology massage is an efficient technique in decreasing postoperative pain and the use of analgesics, as well as lowering anxiety levels [19]. Additionally, it has been reported that foot reflexology is a useful method for managing incision pain after coronary artery bypass graft surgery [20]. Reflexology is an effective method for improving muscle comfort by enhancing blood flow which stimulates the parasympathetic nervous system [21].
Reflexology was first discovered in Egypt as it was adopted by Egyptians in their daily lives including medical practices. The details of using this technique were detected in the finding of hieroglyphic mural in the pyramid of Saggara [22]. However, currently, the use of reflexology treatment in the Egyptian culture is very limited and unpopular in medical or nursing fields in spite of the proved benefits of this technique.
The effectiveness of foot reflexology on anxiety, pain, stress, fatigue, physiological indices, and sleep quality has been extensively investigated by previous studies in different countries [14,19,23,24,25]. However, research which investigated the effect of this intervention on shortening the length of MV weaning time in patients undergone OHS are scare. Therefore, this study was carried out to address this issue.

Purpose
The purpose of this study was to investigate the effect of foot reflexology on physiological indicators and the length of mechanical ventilation weaning time in patients undergone open-heart surgery.

Research Hypotheses
There were two research hypotheses for this study including: 1) Open-heart surgery patients who receive foot reflexology intervention will have better physiological indicators than those who do not receive this intervention. 2) Open-heart surgery patients who receive foot reflexology intervention will have shorter mechanical ventilation weaning time than those who do not receive this intervention.

Study Design and Setting
This study has a quasi-experimental design. Participants' recruitment and data collection occurred at the cardio-thoracic ICU of Mansoura University Hospital, Egypt. This ICU includes 5 beds and it is well equipped with advanced technology and manpower needed for patient care. The nurse-patient ratio in this unit is nearly 1:1.

Subjects
The study involved a convenience sample of OHS patients who were admitted to the cardiothoracic surgery department and were subjected to OHS during the study period.

Inclusion Criteria
The inclusion criteria for eligible participants were patients in the age group ranged from 18 to 75 years old, HR of more than 60 b/m, a SBP of greater than 90 mmHg and partial thromboplastin time of > 60 seconds.

Exclusion Criteria
The exclusion criteria were patients who were subjected to emergency OHS, patients with foot related medical issue (like corn, callus, neuropathy, fungal skin infection or past scars) and those who received more than one inotropic drugs after operation. Patients who had pace-maker or intra-aortic balloon pump, patients who needed prolonged MV more than 24 hours, patients with disturbed conscious level and those who received sedatives before intervention were also excluded from the study.

Sample Size
Based on year 2016 census report of patients' admission to the cardio-thoracic surgery department (Mansoura University Hospital Census, 2017), the total number of subjects assigned to perform OHS was 400. Steve thompon equation was used to calculate the sample size, at 5% ∞ error (95.0% significance) and 20.0 β error (80.0% power of the study) [26].
Where: N= Population size (400), Z= degree of standardization for 95.0% significance, it is equal to 1.96, d= Error percentage (0.05), P= Percentage of occurrence of event or not, it is 0.5.
Accordingly, the sample size was determined to be 39.99. Totally, 80 patients were enrolled and randomly assigned to two groups (40 patients in each group):  Reflexology group who received foot reflexology intervention 60 minutes after being admitted to the cardio-thoracic ICU.  Control group who was given the ordinary care without foot massage.

Data Collection Instruments
Data were collected using participants' physiological indicators and MV weaning time assessment tool. It was developed by the primary investigator based upon relevant literature [16,24,27,28,29]. It consists of two parts:

Part I: Participants' Demographic and Health Profile data
This part collected participants' demographic data including age, sex, marital status, occupation and educational level. It also covered participants' health profile including admission date, medical diagnosis, surgery type, past medical and surgical history, smoking status, cardiac ejection fraction (EF) and pharmacological treatment.

Part II: Physiological Indicators and MV Weaning Time Observation Checklist
This part involved patients' physiological indicators including HR, RR, SBP, DBP, MAP, and SpO2 which were monitored six times. The six measurement time-points included monitoring the physiological indicators immediately after admission to cardio-thoracic ICU, one hour after being admitted to the ICU, immediately after reflexology, 10 minutes after reflexology, immediately after extubation and 60 minutes after extubation by using an electronic monitor. The MV weaning time was defined as the duration between admission to the cardio-thoracic ICU and extubation. This time was calculated by minutes.

Validity and Reliability of the Tool
The content validity of the tool was assessed by seven experts from Critical Care and Emergency Nursing, and Medicine fields. Modifications were made accordingly. The reliability of the tool was tested using Cronbach's alpha test and found to be 91% which indicates high reliability tool.

Pilot Study
A pilot study was carried out to check the clarity, feasibility, and applicability of the data collection tool. It involved 8 patients (10% of the total sample) who were not included in the study sample.

Ethical Considerations
An ethical approval was gained from the Ethics Committee of Faculty of Nursing (No. 108/2017). Informed consent was obtained from participants one day before the surgery after providing them with comprehensive information about the study including the aim, benefits, risks, procedure and duration. The voluntariness nature of participation was emphasized to all eligible patients. They were also informed that they had the right to discontinue at any stage without responsibility. Furthermore, confidentiality of participants' personal information was maintained.

Preparation
An official permission to conduct the study was obtained from the administrative authorities of Mansoura University Hospital. Before commencing the study, the primary investigator received practical training on how to apply foot reflexology by a reflexology specialist from 'The Egyptian Academy of Complementary Medicine in Cairo' in February 2018. The primary investigator interviewed patients who met the inclusion criteria one day before surgery to explain to them the nature of the research and to invite them to participate in the study. Patients who accepted to take part in this research were enrolled in the study. Patients' demographic data were obtained from their medical records. Allocation of participants was done the day before surgery by using lottery randomization technique through choosing one of two cards labeled group A (foot reflexology group) and group B (control group).

Selected Points
Based on the claim of reflexologists, the points on the planter surface of the foot which may be responsible for stabilization of physiological indicators and reduction of ventilation dependence were chosen. These points included diaphragm, solar plexus, heart, and lung. Diaphragm reflex point runs along the horizontal crease just below the ball of the foot and involved in respiration. Solar plexus point (relaxation point) located at the midline below the ball of both feet. This point communicates with the whole nervous system and can trigger a major relaxing effect as well as diminish both of anxiety and stress. Heart reflex point is located on the bottom of the big toe of the planter aspect of both feet. This point regulates blood circulation and improves the function of the heart. Lung reflex point regulates breathing and oxygen level and keeps the chest and lungs open [16,30,31,32].

Applying Foot Reflexology Technique
The reflexology procedure was performed by the primary investigator. The steps of foot reflexology technique were adopted from Kunz and Kunz [31]. Reflexology group received foot reflexology intervention 60 minutes after being admitted to the cardio-thoracic ICU while the other group received the usual care of the unit without foot massage. In the reflexology group, the patient was assisted to lie down in supine position with raising the head of the bed to 30 degrees. First, the primary investigator removed any metal object (e.g. ring), washed and warmed her hands, and lubricated them with nontherapeutic baby oil to facilitate massaging. Then, she administered general foot massage and reflexology massage to the participant. The investigator put four fingers on the dorsal aspect of the patient's foot and utilized the thumb to make rotational pressure on lung and heart area of the sole. Reflexology massage for every foot lasted from 15 to 20 minutes. Thirty minutes session can provide therapeutic and relaxation benefits [18,33,34]. Data collection extended over a period of seven months between April and October 2018.

Statistical Analysis
Statistical Package for Social Sciences (SPSS) program version 22 and Medcalc statistical analysis software version 15.8 were used to analyze the collected data. Descriptive statistics were used to analyze the sample with 95% confident interval. Qualitative data were expressed as frequency and percentage. Quantitative data were initially tested for normality using Kolmogorov-Smirnov and Shapiro-Wilk's test with data being normally distributed if p >0.050. Quantitative data (HR, RR, SBP, DBP, MAP, SPO2 & MV weaning time) were expressed as mean ± standard deviation (SD) if normally distributed or median and interquartile range (IQR) if not normally distributed. Chi-Square test or Fisher's exact test was used to assess the similarity between the two groups in terms of demographic characteristics. The non-parametric alternative Mann-Whitney U test was used to compare MV weaning time between the groups. The repeated measures of analysis of variance (RM-ANOVA) test were also used to examine the differences between the two groups concerning variations of physiological parameters across the six measurement time points. The statistical significance level P value was set at less than 0.05.

Participants' Demographic Data and
Baseline Characteristics Table 1 illustrated that 55% of the participants were males and 45% were females. The range of the patients' age was 18 to 75 years, with 36.3% were in age group of 51-60 years. Overall, the majority (81.25%) were married, 43.7% had achieved a high school level of education, 36.2% were house wife and 36.2% were smokers. The majority of the participants (80 %) had a good ejection fraction ≥50%. The results show that 31.2% of the participants had diabetes mellitus and 42.5% had hypertension. There were no statistical significant differences between the reflexology and the control groups regarding demographic data (p>0.05) which indicates similarity between the study groups before intervention.  Table 2 compares between the physiological indicators of the study groups.

HR
A statistically significant decrease in the HR (p<0.0005) was detected in foot reflexology group compared with the control group. Additionally, the mean HR was statistically significant between the two groups (p<0.0005).

RR
The participants in foot reflexology group showed significantly lower RR than participants in the control group (p<0.0005). Also, the mean RR was statistically significant between the two groups (p<0.0005).

SBP
A statistical significant reduction in the SBP was noted in foot reflexology group (p<0.0005). Moreover, the mean SBP was statistically significant between the two groups (p<0.0005).

DBP
The DBP was statistically significant lower in foot reflexology group compared with the control group (p<0.0005). As well, there was a statistically significant difference between the two groups regarding the mean DBP (p<0.0005).

MAP
There was a statistically significant drop in the MAP (p<0.0005) in the reflexology group compared with the control group. Besides, the mean MAP was statistically significant between the two groups (p<0.0005).

SPO2
A statistical significant elevation in the SPO2 was found in the reflexology group compared with the control group (p<0.0005). The mean SPO2 was also statistically significant between the two groups (p<0.0005).

Variable Group
On admission One hour after admission Immediately after reflexology 10 minutes after reflexology After extubation One hour after extubation RM-ANOVA Between Groups x : Mean, SD: Standard Deviation, *Statistically significant P ≤0.05.  Table 3 showed that the median of MV weaning time in the reflexology group was 270 minutes while in the control group was 435 minutes. There was a statistically significant shorter weaning time in the reflexology group as compared to the control group (Z value = -7.230, p <0.0005).

The Effect of Foot Reflexology on Physiological Indicators
Our study focused on investigating the effect of foot reflexology on physiological indicators and the length of MV weaning time in patients undergone OHS. The findings of this study support the hypothesis that foot reflexology positively affects the stabilization of physiological indicators (HR, RR, SBP, DBP, MAP and SPO2) of critically ill patients and decreases ventilation dependence as compared with patients who did not receive foot massage. This improvement may be due to the presence of nearly 15000 nerves in the feet that enervate all body parts. Therefore, when applying reflexology technique it causes calmness for the nervous system [34]. Additionally, massaging reflexology areas of the lung on foot positively influences pulmonary function which in turn reduces ventilation dependence and facilitates liberation from MV. Moreover, massaging heart reflex point increases blood supply to the heart which enables the heart to pump the oxygen-rich blood around the body and improves oxygenation [31].
Our results are consistent with preceding studies which demonstrated the efficiency of foot reflexology technique in improving physiological indicators including HR, RR, SBP, DBP and SPO2 among various patient categories and in different settings [17,18,24,32,35,36]. Similarly, a study conducted by Khaledifar et al., [37] illustrated that there was a significant improvement in some of vital parameters including DBP, HR and RR in patients undergoing coronary angiography after reflexotherapy. However, they reported that the change in SBP was not significant. Also, Abbaszadeh et al., [16] reported that foot reflexology technique had a statistically significant influence on physiological parameters (SBP, DBP, MAP, RR and SPO2) except the HR. This could be because the investigators performed reflexology massage for heart reflex point only on the left foot. On the same line, our findings are consistent with other studies which obtained evidence that foot reflexology decreases SBP and DBP [30,38]. Additionally, Khalili et al., [39] revealed that foot reflexology has a positive effect on reducing SBP and DBP, but no significant effect was noted on HR or RR. Another study carried out by Azami et al., [40] found that foot reflexology reduces MAP among neurosurgical patients in ICUs. On the contrary, many research studies did not reveal the positive effect of foot reflexology on physiological parameters. This inconsistency could be due to many factors such as applying foot massage by two different individuals [28], recruiting small sample size [41,42] and variations in the number and duration of reflexology sessions [29].
Interestingly, one study investigated the cardiovascular effects of reflexology in healthy people illustrated that foot reflexology could increase BP and HR [43]. The investigators interpreted this finding as a positive outcome because reflexology co-activates two branches of autonomic nervous system which could be useful in enhancing hemostasis and healing process.

The Effect of Foot Reflexology on MV Weaning Time
The results of our study illustrated the effectiveness of reflexology treatment on shortening the length of MV weaning time. There is a paucity of studies which examined the effect of this intervention on the weaning time from MV. Ebadi et al., [28] investigated the effectiveness of reflexology on physiological parameters and MV weaning time in patients undergoing OHS in Iran. Similar to our results, they reported that the means of weaning time in the reflexology and the control groups were 283.43 ± 96.26 and 322.54 ± 70.95 minutes, respectively which indicates that the weaning time in the reflexology group was shorter than the control group. Similarly, our findings are supported by other previous studies which reported that reflexotherapy is an effective procedure in reducing the required level of sedation and analgesia for patients receiving MV [27,35]. This can lead to decrease the length of stay on MV and accelerate weaning process [44].
On the contrary, our study findings are contradicted with a previous study conducted by Ismail [45] who evaluated the effect of reflexology on physiological outcomes among mechanically ventilated patients in ICUs at Cairo University Hospitals. The investigator demonstrated that the mean duration of stay on MV in the reflexology group was 18.98±9.905 while in the control group was 19.78±11.696 with no significant differences detected between groups regarding stay on MV (t=0.75, p= 0.46). The researcher referred these findings to participants' medical diagnosis, chronic illness and co-morbidities

Limitations
There are two limitations for this study. First, the study was conducted in one cardiothoracic ICU in one teaching hospital. Second, the study involved a small sample size (80 patients). These two factors limit the generalizability of the research findings.

Conclusion and Recommendations
Based on the results of our study, we conclude that foot reflexology massage can significantly enhance the physiological indicators, and shorten MV weaning time in patients undergone OHS. Therefore, foot reflexology massage can be incorporated into daily patient care in cardiothoracic ICU. Training programs on applying foot reflexology for critical care nurses are needed. Future large scale studies on different patient population are also required in order to obtain a strong evidence to support this approach and enrich the body of knowledge in this area.