Participants and Sampling: In this quasi-experimental study, the research population included all the patients who underwent open heart surgery at Kosar Hospital (Fars Heart Foundation), Shiraz, Iran in February to November 2019. The participants were selected through convenience sampling and in case they fulfilled the inclusion criteria of the study and signed written informed consents, they were recruited into the study. Considering the significance level of 5.0% and power of 80.0%, a 96-subject sample size was determined for the study (48 subjects in each group). The demographic information questionnaire was completed by all the participants and then, they were divided into a control and an intervention group. Since two similar research environments were not available simultaneously and the interventions caused environmental changes as well as changes in the process of patients’ caretaking, first 48 individuals from the control group and then, the 48 ones from the intervention group underwent investigation. The inclusion criteria of the study were aging below 65 years, not suffering from and not having the history of debilitating mental illness and neurological diseases, obtaining minimum Mini-Mental State Examination (MMSE) score of 25.0, not being addicted to drugs and alcohol, and having the ability to communicate. On the other hand, the exclusion criteria of the study were mechanical ventilation for more than 12 hours, heart and lung bypass for more than 90 minutes, and repeated heart surgery for any reason, such as bleeding and tamponade.
Measurement instruments: The applied instruments in this study were as follows
1- Demographic information form, which was prepared based on review of the literature and experts’ opinions. This form included sex, age, place of residence, education level, occupation, history of underlying diseases, and type of surgery.
2- MMSE, which contained 11 questions with a total score between 0 and 30. This scale evaluated cognitive defects and changes over time and could be completed within only 5–10 minutes.20 In order to investigate the psychometric properties of this instrument in Iranian society, Cronbachʼs alpha coefficient method (0.87) and split-half technique (0.71) were used. In addition, the validity of MMSE was assessed by concurrent criterion method, revealing a significant inverse relationship between the score of this test and the score produced from the Global Deterioration Scale (GDS) (p = 0.0001). The sensitivity and specificity of the questionnaire were also determined as 0.90 and 0.84, respectively .21
3- Delirium Observation Screening (DOS) scale, which consisted of 13 items. The maximum total score of this scale was 13, with scores equal to or more than 3 representing the incidence of delirium. DOS scale was used in this study because it is allocated to nurses, can be completed in less than 5 minutes, and provides the possibility to determine the severity of delirium. The ability to assess the severity of delirium is yet another strong point of this instrument.22 In this study, DOS scale was scored three times a day by nurses via observation and the final score was computed as the mean of the three scores. The validity of DOS scale was surveyed by Delirium Rating Scale-Revised-98 (DRS-R-98) and was estimated to be 0.67. Additionally, its reliability was assessed by Inter Class Correlation (ICC) and was reported to be 0.99.22,23 In order to assess the psychometric properties of DOS scale in Iranian society, this instrument was firstly translated into Persian by an expert translator. Thereafter, in order to determine its content validity, 11 experts were required to express their opinions regarding the relevancy, clarity, and simplicity of the items using Waltz and Bausell validity index. Face validity of the instrument was also assessed by 6 occupied nurses at ICU of heart surgery ward and nursing experts. Moreover, the reliability of DOS scale was evaluated using inter-rater reliability method. In doing so, the instrument was completed for 13 heart surgery patients by the researcher and an educated nursing expert. Then, the correlation between the scores produced by the two observers was calculated, and the results indicated acceptable reliability (r = 0.83).
Intervention: The multi-component intervention consisted of three parts, namely training the nursing personnel, training the patients, and environmental interventions. Training the personnel of heart surgery ICU was carried by the researcher in form of a two-hour session. Considering the personnel’s rotational shifts and the necessity of their presence, this class was repeated for three times. In this way, training the personnel regarding delirium and its importance, methods of prevention and treatment of delirium, correct way of communicating with such patients, and orienting patients about time, place, and person was carried out at least twice in each shift. The educational content was presented through lecture and discussion. Moreover, the presented materials were installed as a poster at the nursing station, so as to increase the personnel’s exposure to the subjects.
Pre-surgery training of the patients was carried out by the researcher at least 24 hours before the open heart surgery. This was done via individual face-to-face conversations along with some pictures from ICU for a period of at least 15 minutes. During this conversation, in addition to education, the patients’ questions and ambiguities were answered. The preoperative educational content consisted of type and process of the disease, surgery method, time of transfer to the ICU after surgery, environment and equipment of ICU, possible limitations such as inability to talk or drink water due to the existence of Endo Tracheal Tube (ETT) and complete rest on the bed, approximate length of ICU stay, limitations related to visiting one’s family at the ICU, reassuring the patients regarding pain monitoring and control by the personnel, independence from analgesic drugs, and all the therapeutic and nursing measures that were going to be carried out during the days after the surgery.
In addition to training the personnel and patients, environmental interventions were also conducted in this study. These interventions consisted of light adjustment, using calendar and clock, and providing the patients with the possibility to visit their families at the ICU for 10 minutes once a day and making phone calls to their family members at least once at each shift. Using communication aids, such as glasses, hearing aids, and dentures, for the patients who were using such equipment before the surgery, rapidly sending the patients out of bed, and preventing dehydration by assessing tongue mucus and skin turgor, as one of the risk factors of postoperative delirium, were among the other interventions carried out for the patients.
Design: Due to the fact that the physical environment of ICU can influence the study results, it was necessary to carry out the investigation on both control and intervention groups at one ward in order to make a similar research environment. Therefore, both control and intervention groups went under study at a single ward, but at two different times. Moreover, since the interventions could cause environmental changes as well as changes in the process of patients’ caretaking, first the control group and then the intervention group underwent investigation.
The patients in the control group received the routine care at the post open heart surgery wards of Shiraz Kosar Hospital and were assessed concerning the incidence, severity, and duration of delirium once at the end of each shift until the end of the fourth day after surgery. It should be mentioned that the incidence and severity of delirium was assessed using DOS scale by some fixed in-charges at the ward because at least one of them was present at each shift. Additionally, since they did not play any direct roles in the patients’ caretaking and doing postoperative interventions, they had no knowledge about the control and intervention groups. Before completing the DOS scale, the necessary information about using this instrument was given to the nurses in a one-hour session. Thereafter, their ability in using the instrument was evaluated by putting them at a similar position; i.e., patient’s bedside. After making sure about their knowledge and ability in using the DOS scale, they assessed the incidence and severity of delirium. In the control group, the incidence, severity, and duration of delirium were evaluated by the researcher and trained nurses using the DOS scale after the patients’ coming into consciousness and extubation thrice a day at the end of each shift (8 A.M., 2 P.M., and 8 P.M.) until the end of the fourth day after the surgery.
After completion of sampling in the control group, the other group of participants who met the inclusion criteria and signed written informed consents were entered into the intervention group. Then, the systematic interventions, including training the nursing personnel, training the patients, and environmental interventions, were performed. In this group also, the incidence, severity, and duration of delirium were evaluated as in the control group.
After all, the collected data were entered into the SPSS statistical software, version 20 and were analyzed using independent t-test, chi-square test, one-way ANOVA, and Pearson’s correlation coefficient.