Feasibility and effectiveness of exercise-based prehabilitation in patients opting for elective abdominal surgeries: A pre-post study

Abbreviations

ACBT: Active Cycle of Breathing Techniques

FC: Functional Capacity

FET: Forced Expiratory Techniques

HR: Heart Rate

IMT: Inspiratory Muscle Training

LOS: Length of Stay

MEP: Maximum Expiratory Pressure

MIP: Maximum Inspiratory Pressure

PEXT: Preoperative Physical Exercise Therapy

PPC: Postoperative Pulmonary Complications

QoL: Quality of Life

RCT: Randomized Control Trials

RPE: Rate of Perceived Exertion

TEE: Thoracic Expansion Exercises

WHOQOL: World Health Organization Quality of life

6MWT: Six-Minute Walk Test

6MWD: Six-Minute Walk Distance

Introduction

Around 235 million major surgical procedures are performed each year globally.¹ This number is constantly growing due to the world’s ageing population, expansion, development of novel surgical methods, and the formation of new surgical facilities across the world.² Despite several ongoing improvements in perioperative care, major abdominal surgeries are associated with postoperative complications and morbidity, and even in the absence of complications, it is seen that there is a reduction in functional capacity (FC).^3–5

Around 35% of patients that endure a major abdominal surgery experience a postoperative complication, with approximately 20-40% reduction in their post-operative physical function.^6,7 A deterioration in quality of life (QoL) is observed even without complications.⁸ It is noted that patients who have experienced complications within 30 days post-surgery have a decreased long-term survival rate.⁹

Postoperative pulmonary complications (PPC) can be caused due to insufficient inspiratory efforts, inadequate sputum expectoration, and a greater respirational demand that produces inspiratory muscle fatigue.¹⁰ The mechanism of PPCs is a decline in lung expansion because of prolonged recumbent positioning, shallow breathing, impaired mucociliary work, diaphragmatic dysfunction, and ineffective coughing.¹¹

Prehabilitation is an umbrella term that includes physical exercises, nutritional support, and stress and anxiety reduction.^12,13 The concept of prehabilitation was initially reported in 1942¹³ and came to light post-2011 after the systematic review published by Valkenet et al.^12,14 It is an intervention of conditioning a patient in the pre-surgical period to cope with the post-surgery stressors.¹⁵ It prepares a patient before major surgery and also, at the same time, aims at reducing postoperative complications, promoting physical activity, and also optimises their psychological wellbeing.^16–18 Prehabilitation before major surgery aims to maintain the normal levels of functionality and attain a faster recovery of the functional status during post-op inactivity.^17–19 Until recently, efforts to improve recovery after major surgery in the post-operative period have been the primary focus.^20,21 However, the emergence of prehabilitation signifies a change from the impairment-driven, reactive model of care toward an active method that allows a patient to become active partakers in their care.²²

Prehabilitation has been found effective in improving postoperative outcomes in studies other than India. There have been improvements in respiratory muscle strength, FC, and QoL, respectively.^5,22,23 Differences in how prehabilitation can work in low and low-middle-income countries like India and how feasible it can be could depend on the socioeconomic inequalities, educational factors, and differences in healthcare setups.

Respiratory muscle strength can be improved by incorporating inspiratory muscle training (IMT), a form of exercise to strengthen the respiratory muscles.²⁴ The decrease in the respiratory muscle can lead to decreasing FC. The six-minute walk test (6MWT) is regularly used to determine FC in patients.²⁵

The World Health Organization Quality Of Life (WHOQOL) groups developed the WHOQOL-BREF assessment to analyse QoL across various populations that could be applicable cross-culturally.²⁶ This scale contains four domains: physical health, psychological, social relationships, and environmental domains.²⁶

Feasibility studies are research done before the main study to answer questions about whether an intervention is appropriate for further testing,²⁷ i.e., they enable researchers to judge whether or not the ideas and findings can be shaped to be relevant for sustainable study.^28,29

Previous studies done in prehabilitation have proved that exercise-based prehabilitation is effective in people who undergo abdominal surgeries in general. However, there is a paucity of literature on whether it is feasible to carry out a pre-operative/prehabilitation exercise program and know its effectiveness in the rehabilitation stage in countries like India.

Methods

Results

Participant characteristics

The study has been reported per the Consolidated Standards of Reporting Trials (CONSORT) extension for pilot and feasibility study^32,33 (see Figure 1 and Reporting guidelines⁴⁸).

Figure 1. The Consolidated Standards of Reporting Trials (CONSORT) extension for Pilot and Feasibility Trials.

A total of 170 patients were screened, with 56 participants eligible based on the screening for inclusion criteria. Of these 56 participants, 40 consented to participate in this study, with a mean age of 51.5 years (Table 1). Of the 40 eligible to participate, 25 participants completed the exercise based prehabilitation in this study. Their ages ranged from 37 to 74, with their mean age being 49.8 years (Table 2). The data associated with the participants is available in Underlying data.⁴⁸

Table 1. Demographics of the total participants that agreed to participate.

Variables	Number (N)	Minimum	Maximum	Mean±SD	%
Age (years)	40	37	74	51.5±9.71
Males	15				37.5
Females	25				62.5

Table 2. Demographics of the total participants that completed the study.

Variables	Number (N)	Minimum	Maximum	Mean±SD	%
Age (years)	25	37	74	49.8±9.73
BMI (body mass index)	25	15.06	35.190	22.84±4.50
Males	7				28
Females	18				72

Feasibility characteristics

In this study, feasibility criteria were categorized and measured based on these five criteria:

• 1. Recruitment rate

• 2. Dropout rates

• 3. Adherence to the rehabilitation rate

• 4. Adverse events

• 5. Participants’ level of satisfaction

Recruitment rate

A total of 170 patients were screened, with 56 patients meeting the inclusion criteria (Figure 2) and 114 excluded. These 114 patients were excluded based on the exclusion criteria, i.e., 1. patients undergoing high risk, emergency, laparoscopic surgeries, or 2. having musculoskeletal/neurological impairments. A total of 84% of these 114 patients were received post-operatively, underwent emergency surgeries, and had to be excluded as they had not received prehabilitation. The rest (14%) were excluded as their planned surgery was laparoscopic surgery, and the last 2% were not included since they did not match the age criteria (Figure 3).

Figure 2. Total patients screened.

Figure 3. Reasons for exclusion.

From the 56 patients who met the inclusion criteria, 40 agreed to participate in the study, and 16 denied/did not consent to participate, making the recruitment rate 71% (Figure 4).

Figure 4. Patients meeting inclusion criteria.

Dropout rate

62% patients of the 40 that consented to participate completed the study and the remaining 38% dropped out of the study (Figure 5). The reasons for dropout of patients are explained in Figure 6.

Figure 5. Patients agreeing to participate.

Figure 6. Reasons for patients dropping out.

Adherence

The adherence was reported to be 62%, as the remaining 38% of the patients could not complete the study due to the reasons explained in Figure 6.

Adverse events

The prehabilitation exercise program was given to the patients during the hospital stay from the day of admission to surgery and continued postoperatively. No adverse events were reported during the duration of the exercise protocol.

Participant satisfaction

Lastly, the user satisfaction scale was based on the Likert scale, and above satisfactory scores (3+) were obtained for the questions. A summary of their responses with scoring is given in Table 3.

Table 3. User satisfaction scale.

No	Questions	1. Strongly disagree	2. Disagree	3. Neutral	4. Agree	5. Strongly agree
1	I was willing to participate in the prehabilitation session.			5(20%)	8(32%)	12(48%)
2	I was willing to update my daily treatment through telephonic calls.	-	-	-	-	-
3	The prehabilitation session was easy to understand and participate in.			1(4%)	22(88%)	2(8%)
4	The therapist did not spend time with me.	17(68%)	8(32%)
5	The therapist roughly explained the treatment I will receive.			3(12%)	18(72%)	4(16%)
6	The therapist treated me respectfully.				14(56%)	11(44%)
7	The therapist listened to all my concerns.			2(8%)	15(60%)	8(32%)
8	The Therapist advice on ways I could avoid problems.			3(12%)	19(76%)	3(12%)
9	The therapist advised on ways and gave detailed instruction regarding the future program.				22(88%)	3(12%)
10	I was overall satisfied with the treatment.				15(60%)	10(40%)
11	I would recommend it. For prehabilitation before surgery.			2(8%)	23(92%)

Respiratory muscle strength

The Mean for MIP preoperatively was 30.320 cm H₂O, and the postoperative was 25.360 H₂O (p=0.008). The MEP preoperatively was 30.080 H₂O and postoperatively 25.120 H₂O (p<0.001). Both the MIP and MEP have shown a decline in the postoperative period (Table 4) (Figure 7).

Table 4. Comparisons of outcomes preoperatively and postoperatively.

Variables	Preoperative (Mean±SD)	Postoperative (Mean±SD)	t-values	p-values
MIP	30.3±17.7	25.4±12.6	2.902	0.008
MEP	30.1±14.0	25.1±11.0	4.165	<0.001
6MWD	307±128	213±107	5.600	<0.001
WHOQOL BREF D1	55.9±13.5	56.1±13.5	-0.440	0.664
WHOQOL BREF D2	56.1±14.3	56.4±14.4	-0.629	0.536
WHOQOL BREF D3	62.8±11.6	62.8±11.6	-	-
WHOQOL BREF D4	69.2±11.4	69.9±10.7	-1.000	0.327

Figure 7. Comparison of maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) preoperatively and postoperatively.

Functional capacity

The FC was measured using the 6-minute walk test (meters), and the distance was compared preoperatively and postoperatively. The mean distance was 306.712 meters preoperatively, and 213.080 meters postoperatively (p<0.001), which showed a significant decrease in the preoperative and postoperative distance walked by the patients (Table 4) (Figure 8).

Figure 8. Comparison of 6MWD (Six-Minute Walk Distance) preoperatively and postoperatively.

Quality of life

QoL was measured using the WHO-QOL BREF scale. The WHOQOL BREF is a shorter form of the WHOQOL. This scale includes scoring based on four domains: physical health, psychological health, social relationships, and environmental aspects. The results showed that there was no statistically significant improvement seen (Table 4 and Figure 9).

Figure 9. Comparison of quality of life scores preoperatively and postoperative (WHOQOL-BREF=World Health Organization Quality of life-BREF Scale).

Discussion

The goal of this study was to determine the feasibility and efficacy of prehabilitation as part of a routine rehabilitation programme in patients undergoing elective abdominal surgeries. The current study focused on four key outcomes of feasibility, respiratory muscle strength, FC, and QoL.

Feasibility in terms of research refers to how people who carry out a study or intervention can practically do so in the actual world.³⁵ Feasibility may focus on developmental research, as in developing a feasibility study.³⁶ Feasibility studies are pieces of research done before the main study to answer whether a study can be done or not.³⁵ It estimates the critical parameters needed to construct the main study.^27,37–39 Feasibility studies can be conducted for four primary purposes, i.e., process assessment, resource assessment, management, and scientific basis to plan RCT.²⁷ In line with the aforementioned purposes, alongside outcomes mentioned by El-Kotob R et al.,³⁵ our study had five outcomes: recruitment rate, dropout rates, adherence to the rehabilitation rate, adverse events, and user satisfaction scale.

The recruitment rate is defined as the number of eligible patients who consented to participate in study.³⁵ A total of 170 patients were screened over the duration of 12 months, with 56 meeting the inclusion criteria and 40 agreeing to participate in the study. According to these results, around 71% of the eligible patients were willing to begin an exercise program prior to elective abdominal surgeries. Other comparable trials showed mixed results, some reporting a recruitment rate of 85%,⁴⁰ some 45%,⁴¹ and some as low as 20%.⁴²

Dropout rates are those who agreed to participate in the study but were unable to complete it owing to a variety of circumstances. 38% of the individuals in our study dropped out due to unavoidable reasons. Surgery cancellation accounts for 60% of dropouts, scheduled surgery being modified by 20%, and 7% of included individuals being diagnosed with coronavirus disease 2019 (COVID-19), ultimately leading to cancelled surgery and increasing the dropout rate. The outcomes of our study are consistent with the findings of Martin et al., who determined that the reasons for patients dropping out were unavoidable circumstances.⁴¹

Another component analysed in feasibility was adherence, which according to the WHO, was defined as “the degree to which the person’s behaviour corresponds with the agreed recommendations from a health care provider”.⁴³ Any therapeutic intervention’s effectiveness relies on the patient’s ability to keep up with the prescribed therapy.⁴³ In this study, adherence was analysed through the exercise protocol administered in a supervised environment by a physiotherapist in the hospital-based setup. All the patients recruited for the prehabilitation program were admitted to the hospital prior to the surgery. 62% of the participants who completed the study adhered to the program compared to the rest of the 38% who did not adhere. According to a previous study, patients who were given prehabilitation activities face-to-face had a higher adherence rate of 93%, compared to 64% for those given prehabilitation exercises as unsupervised home exercises.⁴⁰ Lack of social support from family and friends and the patient’s lack of belief in the merits of the exercises have been identified as plausible factors for low adherence in prior trials when prehabilitation was available.⁴¹

Adverse events were not reported in our study. Only one of the trials by Martin et al. reported short-term adverse events during the cardiopulmonary exercise testing during the assessment.⁴¹

Another variable assessed in feasibility was the level of satisfaction among patients who finished the exercise-based prehabilitation. The user satisfaction scale addressed three distinct factors, namely, 1. their willingness to participate, 2. the patient-therapist interaction, and 3. their overall satisfaction with the treatment. The scoring was based on the Likert scale and was adapted from a similar study.³⁴ The scoring for the 11 questions was 3+ above 48% of participants strongly agreed that they were willing to participate in exercises preoperatively, and 88% agreed that the exercises were easy to understand and follow. Above satisfactory scorings in the questions that assess the therapist-patient relationship parameters were noted. The third criteria presented that 60% of the participants were satisfied and 40% extremely satisfied with the preoperative exercises, and 92% of them would thoroughly recommend the program.

The secondary outcomes of our studies were to assess the effectiveness of the exercise-based prehabilitation post-surgery. One of the secondary outcomes included respiratory muscle strength, measured using global measures of MIP and MEP. These significant pressures can be achieved during maximal inspiration and expiration against an obstructed airway, respectively.^24,44 The MIP measures inspiratory muscular strength created by a sub-atmospheric pressure, whereas the MEP is a supra-atmospheric pressure developed by abdominal and intercostal muscle effort.^44,45 In our study, the mean MIP preoperatively is 30.3 cm H₂O and postoperative is 25.4 cm H₂O and MEP preoperatively is 30.1 cm H₂O and postoperatively is 25.1 cm H₂O which shows that there is a decline in the preoperative and postoperative values.

Six min walk test was used to analyse FC. The 6MWT is a submaximal exercise test that measures aerobic capacity and endurance. The distance covered in 6 minutes is utilized as the outcome to compare improvements in performance capability.⁴⁶ In our study FC was computed through the 6MWD that showed a mean of 307 meters preoperatively and 213 meters postoperatively.

Reduced respiratory muscle strength, pain caused postoperatively due to surgery, or even the fact that patients received treatment for less than two weeks preoperatively, i.e., patients could not be admitted/received early preoperatively for an average of four days, could be the possible reasons for the decline in postoperative outcomes. In a previous study conducted by Kulkarni et al., they found that IMT is effective and has significant improvement when compared preoperatively and postoperatively.¹⁰ Prehabilitation exercise programs were planned and administered to patients who had more than two weeks until their procedures in this study.^10,40,41 Many participants were eliminated from Martin et al.’s study because of these criteria.⁴¹ Because there was no established criterion for how many days before prehabilitation patients should be included in our trial, we included all participants who had been referred to us prior to surgery.

The WHOQOL-BREF scale, a condensed version of the WHOQOL-100, was used to assess QoL. The WHOQOL-BREF scale consists of 26 questions and contains four domains: physical health, psychological, social relationships, and environment.^26,47 There was no significant statistical improvement seen.

Conclusions

It can be concluded that exercise-based prehabilitation is feasible and can effectively be delivered to patients scheduled for elective abdominal surgery. All the feasibility criteria taken into consideration have been met (>50%). With the recruitment rate of the patients that were approached being 71%, it can be stated that patients that were eligible were willing to participate. However, in order to establish the prehabilitation programs efficacy, a future study must be conducted with a homogenous group and a larger sample size, taking into account the hurdles encountered.

Data availability

Reporting guidelines

Open Science Framework: CONSORT extension for Pilot and Feasibility Trials Checklist and flow diagram for: ‘Feasibility and effectiveness of exercise-based prehabilitation in patients opting for elective abdominal surgeries: a pre-post study’. https://doi.org/10.17605/OSF.IO/FH8XB.⁴⁸

Data are available under the terms of the Creative Commons Attribution 4.0 International license (CC-BY 4.0).