Structured clinical reasoning for exercise prescription in patients with comorbidity

Figures & data

Figure 1. Evidence-based practice model for clinical decisions [8].

Figure 2. The adapted i3-S strategy for tailored exercise therapy in an individual patient with any index disease and comorbidity.

Table 1. Case description: adapting an exercise program for an individual with knee OA-related symptoms and activity limitations to the presence of comorbid conditions, following the i3-S strategy.

Case knee osteoarthritis
64 years old woman
Clinically and radiographically diagnosed knee osteoarthritis (OA)
Symptoms of pain and stiffness in right knee; knee symptoms limit daily activities (walking, stair climbing, rising from a chair)
Some experience with exercising and glycemic control
Personal goals: increase in walking distance to 5 km, being able to climb stairs at daughters house, less difficulty in rising up or down from a chair
Regular exercise program for knee OA, according to best available evidence and personal goals
Supervised program: 12 weeks, two sessions/week, 60 minutes per session Aerobic exercise (e.g., walking, cycling, rowing): 50–80% of VO2max/HRR/HRmax/maximal workload, Borg score 12–16, 20–30 minutes of continuous exercise Resistance exercise of lower limb muscles: at least two sets of 8–12 reps at 60–80% of 1 RM (the selected resistance should permit the completion of 8–12 reps per set, or the number needed to induce muscle fatigue but not exhaustion) Functional exercise related to personal goals Warm-up and cool down periods (5–10 min), and gradual increase in exercise intensity to avoid increase in joint pain Home-based program: daily flexibility exercises and encouragement to meet the recommendations on physical activity for health
Comorbid conditions
i3-S step 1 – inventory of health status
Comorbidity	Clinical factors
1. Diabetes Mellitus Type II (since 8 years)	Insulin dependent HbA1c reported by patient: 65 mmol/ml (indicating moderate/poor regulation) Infrequent hypoglycemia Reduced sensibility metatarsophalangeal joint 1 both sides Impaired wound healing
2. Obesity	Body weight 88 kg, length 1.55 m (BMI 36.6) Motivated to lose weight, but does not know how
3. Hypertension	Blood pressure 160/95 mmHg Uses metoprolol (beta-blocker)
i3-S step 2 – inventory of contraindications and restrictions and step 3 – inventory of exercise adaptations
Medical clearance necessary → Yes → CPET: no contra-indications
Restrictions	Adaptations
DM II
Use of insulin	Monitor blood glucose levels before and after the exercise session and in the evening. Induced hypoglycemia during exercise and up to 48 hours afterwards or 72 hours after intense strength training may occur. Postpone exercise training in case of blood glucose values ≤5 and ≥15 mmol/L or signs of hypoglycemia. Regulation of blood glucose level is necessary. Use of medication diary can be helpful.
Moderately poorly regulated diabetes with high HbA1c and infrequent hypoglycemia	Ensure adequate hydration and carbohydrate intake before exercise session Start with two weeks of aerobic training at 40–50% of VO2max then gradually increase training intensity from 50% to 80% of VO2max. When continuous exercise is too strenuous or leads to hypoglycemia, start with interval training and progress to continuous exercise when possible.
Sensory deficits	Be careful with exercises that require tactile feedback (e.g., balance) and consider providing exercises on machines (patient can have difficulties feeling where, for example, dumbbells are in hands, with the risk of dropping them). Advise patient to wear good fitting, stable footwear with good grip under surface (fall prevention).
Impaired wound healing	Check regularly for wounds. Avoid weight bearing exercises when wounds at the feet are present and refer for foot care when required.
Obesity
Be aware of increased stress and pressure that may cause pain in weight bearing joint	Stimulate weight reduction (in addition to referral to dietician) Reduce weight bearing exercises if increased stress on joints causes joint pain
Be aware of poor thermoregulation during exertion	Reduce training intensity in warm climatic conditions because of poor thermoregulation during exertion
Hypertension
Blood pressure still elevated, despite anti-hypertensive medication	Avoid high intensity strength training. Start with two weeks of strength training at 40–50% of 1 RM Check blood pressure before the start of every training session and increase strength training intensity when possible Contraindication for exercise participation: resting systolic blood pressure of >180 mmHg or diastolic blood pressure of >110 mmHg. Refer to physician.
Use of beta-blocker	Be aware that medication to lower blood pressure, like beta blockers, can reduce maximal exercise tolerance and attenuate heart rate response to exercise
i3-S step 4 – synthesis: prescribe tailored exercise program

VO2max: maximum oxygen uptake; HRR: heart rate reserve; HRmax: maximum heart rate: 1 RM: 1-repetion maximum; reps: repetitions; HbA1c: hemoglobin A1c (glycated hemoglobin); BMI: body mass index; CPET: cardiopulmonary exercise testing.

Haynes RB, Devereaux PJ, Guyatt GH. Clinical expertise in the era of evidence-based medicine and patient choice. ACP J Club. 2002;136:A11–A14.

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