Study of the intensive care unit activity scale in the early rehabilitation of patients after direct cardiac surgery

Abstract

BACKGROUND

Direct cardiac surgery often necessitates intensive post-operative care, and the intensive care unit (ICU) activity scale represents a crucial metric in assessing and guiding early rehabilitation efforts to enhance patient recovery.

AIM

To clarify the clinical application value of the ICU activity scale in the early recovery of patients after cardiac surgery.

METHODS

One hundred and twenty patients who underwent cardiac surgery between September 2020 and October 2021 were selected and divided into two groups using the random number table method. The observation group was rated using the ICU activity scale and the corresponding graded rehabilitation interventions were conducted based on the ICU activity scale. The control group was assessed in accordance with the routine rehabilitation activities, and the postoperative rehabilitation indexes of the patients in both groups were compared (time of tracheal intubation, time of ICU admission, occurrence of complications, and activity scores before ICU transfer). The two groups were compared according to postoperative rehabilitation indicators (time of tracheal intubation, length of ICU stay, and occurrence of complications) and activity scores before ICU transfer.

RESULTS

In the observation group, tracheal intubation time lasted for 18.30 ± 3.28 h and ICU admission time was 4.04 ± 0.83 d, which were significantly shorter than the control group (t-values: 2.97 and 2.038, respectively, P < 0.05). The observation group also had a significantly lower number of complications and adverse events compared to the control group (P < 0.05). Before ICU transfer, the observation group (6.7%) had few complications and adverse events than the control group (30.0 %), and this difference was statistically significant (P < 0.05). Additionally, the activity score was significantly higher in the observation (26.89 ± 0.97) compared to the control groups (22.63 ± 1.12 points) (t-value; -17.83, P < 0.05).

CONCLUSION

Implementation of early goal-directed activities in patients who underwent cardiac surgery using the ICU activity scale can promote the recovery of cardiac function.

Key Words: Early recovery activities; Goal orientated; ICU mobility scale; Intensive care unit; Cardiac surgery

Core Tip: Intensive care unit (ICU) activity scale-guided graded rehabilitation interventions significantly shortened the tracheal intubation time and ICU stay, lower complication rates, and improved the activity scores of patients undergoing cardiac surgery. This suggests that the ICU Activity Scale has a positive clinical application value in promoting early recovery after cardiac surgery.

INTRODUCTION

Direct-vision intracardiac surgery involves correcting defects or removing lesions, installing valves, vascular bypass, and other operations performed by opening the patient’s heart in case of cardiac arrest or non-stop beating[1]. Various complications, such as pulmonary infection, neuromuscular atrophy, lower extremity venous thrombosis, and intensive care unit (ICU)-acquired debilitation, often occur in patients after direct cardiac surgery, which can easily affect the recovery of body function and increase the patient’s economic burden. Recently, early rehabilitation activities have been considered effective and safe. With the in-depth study of early rehabilitation activities, they have become an important part of postoperative cardiac surgery care[2]. Studies have shown that the current early rehabilitation activities do not result in the highest level of patient mobility while ensuring safety, and there are no standardized criteria for the optimal mode, intensity, and duration of activities[3]. Early goal-directed activities are needed for ICU patients who require early rehabilitation activities. The team (physicians, nurses, and physiotherapists) sets a goal based on progressive, feasible, and safe activities and proceeds according to the goal, so that the patient’s mobility can reach the highest level[4] and the patient can receive precise and individualized rehabilitation treatment. Based on multidisciplinary teamwork, ICU activity scale ratings were performed on patients who underwent direct cardiac surgery, early rehabilitation activity interventions were performed based on ICU activity scale ratings using goal orientation, and their effects on postoperative cardiac rehabilitation were observed. The remainder of this paper is organized as follows.

MATERIALS AND METHODS

Information and methods

General information: Postoperative cardiac surgery patients admitted to the ICU between September 2020 and October 2021 were selected and divided into two groups using the random number table method. Sample size estimation used the formula N1 = N2 = 2[(tα/2 + tβ/2)S/δ]2 to estimate the mean of two samples in the experimental study, combined with the pre-test results of the tracheal intubation time to obtain δ = 15.58, S = 20.36, bilateral α = 0.05, β = 0.1, and examined the table to obtain tα/2 = 1.96, tβ/2 = 1.282, and substituting into the formula to obtain the samples needed in each of the two groups. Considering sample shedding, the sample size was expanded by 20%, that is, at least 48 cases were needed in each of the two groups. Both groups included 60 cases. Inclusion criteria: (1) Age ≥ 18 years; (2) Coronary artery bypass grafting, aortic replacement, and valve replacement surgery; (3) Postoperative hemodynamic stability, no angina attack, no acute myocarditis or pericarditis, no peripheral vascular thrombosis or embolism, no cerebrovascular accidents, good glycemic control, and no new electrocardiographic ischemic changes; (4) Basic verbal communication skills; and (5) The patients and their family members signed an informed consent form. Exclusion criteria: (1) Mental, cognitive, and consciousness disorders; (2) Lower limb mobility disorders or self-care ability defects; (3) Combined serious respiratory, hepatic, renal and systemic diseases; and (4) Combined with chest trauma or tumor. This study was approved by the Ethics Committee of Dongyang People’s Hospital.

Research tool: In 2014, the ICU mobility scale (IMS) was developed by Australian researchers Hodgson et al[5] to assess the optimal level of activity of ICU patients, which is divided into 11 grades, of which inactivity is grade 0, and active activity in bed to independent walking is divided into 10 grades, with a reliability of 0.69–0.83. Liu et al[6] conducted Chinese translation and reliability and validity tests of the IMS, resulting in a weighted Kappa value of 0.84 and validity of 0.872. In the reliability and validity test, the results of the IMS had good reliability and internal consistency; the weighted Kappa value was 0.84 and validity was 0.872.

Perme et al[7] developed the Perme Critical Patient Mobility Score (The Perme Intensive Care Unit Mobility Score, Perme score) in 2014 at Houston Hospital, United States, and is suitable for assessing critically ill patients with any diagnosis. Wilches Luna et al[8] developed a Chinese version of the Perme Score and conducted a reliability analysis, with a Cronbach’s α coefficient of 0.853, the scale has 13 entries in four dimensions, with a score of 30. The higher the score, the better the patient’s mobility.

Research methods: (1) Observation group; After the MDT discussion based on the IMS rating of post-cardiac surgery patients, the patients were instructed to perform corresponding early activities; and (2) The control group included patients who underwent routine early activities.

Evaluation indexes

Postoperative recovery indices of the two patient groups: (1) The responsible nurse recorded the time of tracheal intubation, time of ICU admission, and related complications (Table 1); and (2) Revised Pelme Critical Patient Activity Score.

Table 1 Intensive care unit mobility scale rating scale.

IMS	Activity content
Grade 0	Perform the first step, physical activity (goal; twice daily), including PROM at least 10 times daily, and train and encourage family members to perform PROM on the patient for 15–30 min, if the patient can tolerate it
Grade 1	Perform step 2 and step 3. If not tolerated, perform step 3 first and step 2 again. Step 2, elevate the head of the bed > 45° for > 1 h (goal: Twice daily). Step 3, adjust the bed to a chair position, elevate the head of the bed > 60° for > 1 h, and repeat every 2 h if tolerated by the patient
Grade 2	Perform step 4, adjusting the bed into a heart failure chair position for > 1 h, and if the patient tolerates it, repeat the above every 2 h for > 4 h at a time. Steps 2 to 4 require checking the patient’s tolerance level at least twice every 30 min
Grade 3	Perform step 5, sit at the edge of the bed (target; 20 min) or help the patient to sit at the edge of the bed with minimal assistance, this step requires at least one staff member to help the patient sit and assist the patient to move their lower limbs
Grade 4	Perform step 6, stand at the edge of the bed for > 2 min (goal; twice daily). If possible, try to walk at the edge of the bed for 10 s
Grades 5–6	Perform step 7, move the patient to sit on a chair for > 60 min (goal; 2–3 times daily) and adjust the patient’s sitting position every 1 h, if the patient is unstable during this process, support the patient to the chair with assistance and do not continue to step 8
Grades 7–10	Perform step 8, walking tolerance training (goal; 2-3 times daily), recording the distance the patient walks and assistive devices used

IMS: Intensive care unit mobility scale; PROM: Passive physical activity.

Statistical analysis

The researcher established a database based on the collected information and two-person entry ensured entry accuracy. SPSS 22.0 statistical analysis software was used for the analysis and processing. Measurement data were expressed as mean ± SD, t-test was used to measure normally distributed data, and rank-sum test was used to measure non-normally distributed data; count data were expressed as frequency and rate and compared using the χ² test for comparison. Statistical significance was defined as P < 0.05 indicated significant differences.

RESULTS

Comparison of general demographic data of patients in both groups

There were no statistically significant differences between the two groups concerning general demographic data, such as sex, age, occupation, acute physiology and chronic health status score II (APACHE-II), diagnosis, and operative style (P > 0.05) (Table 2).

Table 2 Comparison of general demographic and clinical data of post cardiac surgery patients in the two groups.

Factors	Observation, n = 60	Control, n = 60	χ2	P value
Sex
Men	40	31	2.794	0.095
Women	20	29
Age
18–30	0	1	2.588	0.662
31–50	11	11
51–60	23	17
61–70	16	21
70 above	10	10
Occupation
Farmer	54	54	1.612	0.816
Laborer	1	3
Retired	2	1
Other	3	2
APACHE-II
1–10	16	19	3.088	0.244
11–20	37	39
21–30	7	2
Diagnosis
Heart valve disease	34	34	0	1
Coronary heart disease	18	18
Aortic dissection	8	8
Surgical procedure
Heart valve replacement + plasty	21	26	2.037	0.361
Coronary bypass	18	20
Aortic replacement + plasty	21	14

APACHE-II scores: Acute Physiology and Chronic Health Status Score II.

Comparison of activity scores of critically ill patients in both groups

The activity scores of the observation group were significantly higher than that of the control group, and the difference was statistically significant (P < 0.05, Table 3).

Table 3 Comparison of the revised pelme critical patient activity score between the two groups of postoperative cardiac patients.

Group	Cases	PermeScore	Of them
			Activity upon request	Impaired mobility	Bed mobility	Underbed mobility
Observation	60	25.98 ± 0.97	7	1.1	5.8	12.1
Control	60	22.63 ± 1.08	7	1	5.35	9.2
t	-17.83
P value	P < 0.005

PermeScore: The Perme Intensive Care Unit Mobility Score.

Comparison of routine rehabilitation indicators between both groups

The mechanical ventilation time and ICU hospitalization time of the observation group were significantly better than those of the control group, with statistically significant differences (P < 0.05, Table 4), and the incidence of complications or adverse reactions was lower than that of the control group, with statistically significant differences (P < 0.05, Table 5).

Table 4 Comparison of rehabilitation indexes between two groups of postoperative cardiac patients (mean ± SD).

Group	Cases	Duration of mechanical ventilation (h)	Length of ICU stay (d)
Observation	60	18.30 ± 3.28	4.04 ± 0.83
Control	60	21.59 ± 7.93	4.66 ± 2.19
t		2.97	2.038
P value		P < 0.05	P < 0.05

ICU: Intensive care unit.

Table 5 Comparison of the incidence of complications or adverse events between the two groups of postoperative cardiac patients (cases), n (%).

Group	Cases	Number of cases	pulmonary atelectasis	arrhythmia	Poor incision healing	Pipe Slip	Total
Observation	60	2	1	1	0	0	4 (6.7)
Control	60	9	4	3	1	1	18 (30.0)
χ2	4.904
P value	P < 0.05

DISCUSSION

Some foreign experts[4] used the IMS ratings to guide patients in performing early rehabilitation activities of different intensities, such as turning, sitting, standing, and walking, increasing exercise duration and physical mobility[8]. This study showed that early activities guided by IMS ratings for postoperative cardiac patients were beneficial for early rehabilitation, shortened the duration of tracheal intubation retention and ICU admission time, and reduced the occurrence of related complications. Consistent with the results of Gaweda et al[9], this study was better than ours regarding the index of tracheal intubation retention time in post-cardiac surgery patients. To analyze the reasons, because of the complexity and high risk of cardiac surgery, patients have more postoperative complications[10], and to reduce the work of the heart, postoperative cardiac patients mostly need ventilator-assisted respiration, which may cause Ventilator-associated pneumonia, ventilator-associated diaphragmatic insufficiency, and respiratory muscle wasting atrophy[11]. In this study, the IMS was used to assess the patient’s mobility, and the corresponding early rehabilitation activities were implemented according to the grades assessed, so that the patient’s physical mobility could reach the highest level under the premise of ensuring safety, while the time of tracheal intubation retention, ICU admission time, and related complications were significantly less in the observation group than in the control group.

Early rehabilitation activities guided by IMS ratings for postoperative cardiac patients are conducive to improving patient mobility, shortening ICU admission time, reducing hospitalization costs, and reducing hospitalization burden. This study showed that goal-directed activities after implementation of IMS ratings for postoperative cardiac patients can improve physical mobility, and the observation group was better than the control group by comparing the Revised Pelme Critical Patient Activity Score. This finding is consistent with the results of a large-sample study by Schaller et al[12]. For analysis, postoperative cardiac patients often suffer from various complications, which may affect the recovery of body functions and prolong hospital stay[13]. Early rehabilitation interventions are considered safe and beneficial to improve patients’ muscle strength and physical function and reduce complications; thus, improving their care outcomes and reducing healthcare costs and ICU stay[14,15].

While the results of this study indicate that ICU activity-guided graded rehabilitation interventions can promote early recovery after cardiac surgery, several limitations should be acknowledged. Firstly, the study was conducted at a single center, limiting the generalizability of the findings across institutions with varying patient populations and surgical protocols. Second, the sample size of 120 patients may not have been sufficient to capture all potential variations in patient outcomes. Larger multicenter studies are required to provide more robust evidence. Additionally, the long-term effects of ICU activity scale-guided rehabilitation on patient outcomes, such as quality of life or mortality rates, were not assessed. Therefore, future studies should consider including these longer-term outcomes to fully evaluate the clinical value of this approach. Finally, the observational nature of the study did not account for the potential impact of other factors, such as patient comorbidities or surgical complexity, on the outcomes. Further research is required to investigate the optimal ICU activity scale for different patient populations.

CONCLUSION

Overall, early rehabilitation activities guided by the IMS ratings for postoperative cardiac patients shortened the time of tracheal intubation retention and ICU admission, reduced the occurrence of related complications, and allowed patients to reach the highest level of physical activity they could tolerate. This study provides a scientific and targeted activity program for postoperative cardiac patients with team assistance. One hospital was selected for this study because of time and geographical constraints. A multicenter, large-sample trial will be conducted subsequently to further explore the effectiveness of this program for post-cardiac surgery patients.