Is abdominal muscle training prior to surgery effective in reducing the occurrence of postoperative pulmonary complications in postoperative cardiac surgery patients compared to usual care?

Study setting - This study will be conducted at the National Hospital of Sri Lanka.

Method of randomization- A computer-generated randomization table will be used for simple randomization. Randomization will be done by an independent investigator who will not be involved in the recruitment, treatment or assessment of patients

Intervention- The intervention is a pre-operative abdominal muscle training program. Three exercises will be used for the pre-operative abdominal muscle training program. The training will commence two weeks prior to the scheduled date of surgery and conducted for two weeks prior to the surgery.
The training will be conducted under supervision of a physiotherapist. Exercises of the program will be resistance exercises with body weight and/or free weights and conducted for three days per week with at least 48 hours separating the exercise training sessions. The FITT-VP (Frequency, Intensity, Time, Type, Volume, and Progression) principle will be used to describe the exercises for abdominal muscle training for patients with cardiac conditions. The description of the exercise program based on the FITT-VP principle is as follows. Frequency - The resistance exercises of the training can be performed on three non-consecutive days per week. Intensity - the resistance exercises can initially be performed 10-15 repetitions with initial RPE 11-13 on 6-20 Borg scale; performing 10-15 repetitions or 40%-60% of one-repetition maximum (1RM). RPE (Rating of Perceived Exertion) is a way of measuring physical activity intensity level. Borg RPE scale is used for rating exertion and breathlessness during physical activity; that is, how hard the activity is as shown by high heart and respiration rate, profuse perspiration and muscle exertion. 1-RM is the greatest resistance/weight that can be moved through the full range of motion for a single repetition in a controlled manner with good posture. Time - Each resistant exercise of the training can be conducted for 1-3 sets with a rest interval of 2–3 min between each set. Type - resistance exercises can be conducted with body weight and/or free weights. Exercised will be commenced with body weight, and free weights will be introduced according to the progression of individual patients. Volume - exercise volume is the product of Frequency, Intensity, and Time (duration) of exercise. In this resistance training program, the volume should be considered in the progression of the training. Progression - resistance exercises can be progressed by increasing training volume in 2%–10% increments when an individual patient can comfortably complete one to two sets over the desired number of repetitions on two consecutive training days.

Usual Care - patients waiting for cardiac surgery receive incentive spirometer exercises, deep breathing exercises and advice on sternal precautions and postoperative physiotherapy, 1-2 weeks prior to the scheduled surgery date. They will be instructed to perform incentive spirometer exercises, deep breathing exercises 3 times a day.

The outcome assessment will be done by independent investigator who will not involve in the recruitment, randomization or treatment of patients.

Adult male and female patients (age >=18), scheduled for any type of elective cardiac surgery.

1. Patients who have lesser than two weeks of waiting time for the date of surgery,
2. Patients who have a history of stroke,
3. Patients who have used immunosuppressive medication for 30 days before surgery.
4. Patients with neuromuscular disorders.
5. Patients suffering with low back pain and abdominal muscle strains
6. Patients who have an aneurysm or aortic dissection.
7. Patients who have severe heart failure (New York Heart Association Class IV) or unstable angina (Canadian Cardiovascular Society Class IV) symptoms.
   
8. Patients who have uncontrolled hypertension (systolic blood pressure >= 160 mm Hg and/or diastolic blood pressure >=100 mm Hg)
9. Patients who have uncontrolled atrial or ventricular arrhythmias or uncontrolled sinus tachycardia (>120 beats min?1)
10. Patients who have low ejection fraction pre-op (<40%).
11. Patients who have a recent history of congestive heart failure that has not been evaluated and effectively treated.
12. Patients who have severe aortic or mitral stenotic or regurgitate valvular disease ( severe aortic or mitral stenosis - aortic or mitral valve area < 1.0 cm2 or mean gradient > 40 or >10 mmHg respectively),
13. Patients with severe asthma (asthma that remains ‘uncontrolled’ despite optimized treatment with high dose– Inhaled corticosteroids (ICS) - Long acting beta2 agonist (LABA), or that requires high dose ICS- LABA to prevent it becoming ‘uncontrolled') and on bronchodilators.
14. Patients who have hypertrophic cardiomyopathy.
15. Patients undergoing combined procedures.
16. Patients who have a recent history of congestive heart failure that has not been evaluated and effectively treated.
17. Patients who have active pericarditis or myocarditis.
18. Patients who had recent embolism (pulmonary or systemic).
19. Patients who have acute thrombophlebitis.
20. Patients who have cognitive deficits that would preclude participation to the exercise program.
21. Patients who have physical limitations that would preclude participation to the exercise program.
22. Patients who are unable to attend the exercise program.