13.3 Phase I-III Cardiac Rehabilitation & Pulmonary Rehabilitation Protocols
Key Takeaways
- Phase I Inpatient Cardiac Rehabilitation (days 1–3 post-event) focuses on low-level mobility (METs 1.0–3.0) with hemodynamic ceilings of resting HR + 20 bpm (post-MI) or resting HR + 30 bpm (post-CABG/surgery), peak HR ≤120 bpm, and strict sternal precautions (lifting limit 5–10 lbs, 'keep your move in the tube' for 6–8 weeks).
- Phase II Outpatient Monitored Cardiac Rehabilitation (weeks 2–12) utilizes continuous or intermittent ECG telemetry, prescribing aerobic conditioning at 40%–80% HRR or VO2max, RPE 11–14 (Borg 6–20), MET levels 4.0–7.0, and cautious resistance training initiation at 5–8 weeks post-CABG once sternal stability is documented.
- Rate Pressure Product (RPP = HR × SBP) serves as the primary indirect clinical measure of myocardial oxygen consumption (MVO2); therapeutic exercise must be maintained at a workload producing an RPP at least 10 beats/min or 10%–15% below the patient's verified ischemic angina threshold.
- Pulmonary rehabilitation for chronic lung disease (COPD GOLD II–IV, IPF) uses the 6-Minute Walk Test (6MWT, Minimal Clinically Important Difference ~30 meters) to guide aerobic conditioning, upper extremity training (alleviating accessory muscle steal from the rib cage), and supplemental O2 titration to keep SpO2 ≥88%–90%.
- Acute care ICU early progressive mobilization transitions critically ill patients safely through structured stages while maintaining line precautions: arterial line transducers must align at the phlebostatic axis (4th intercostal space, mid-axillary line), chest drainage canisters must remain upright and below chest level (never clamped during walking), and external ventricular drains (EVDs) must be clamped prior to changing bed height or mobilizing.
13.3 Phase I-III Cardiac Rehabilitation & Pulmonary Rehabilitation Protocols
[!NOTE] DHA Licensure Focus: Cardiopulmonary Physical Therapy is one of the ten topics DHA names in its published exam coverage, and rehabilitation protocols with acute-care mobilization are its clinical core. DHA publishes no percentage weight for it, so prepare it to the same depth as every other listed topic. Candidates must understand the precise progression across Phase I, Phase II, and Phase III cardiac rehabilitation, calculate the Rate Pressure Product (RPP) to establish ischemic thresholds, modify exercise intensity for patients on beta-blockers using Borg RPE, manage sternal precautions post-CABG, evaluate functional exercise tolerance via the 6-Minute Walk Test (6MWT), and maintain line precautions (arterial lines, chest tubes, and intracranial pressure monitors) during ICU progressive mobilization.
Cardiopulmonary physical therapy bridges acute inpatient survival with long-term functional recovery, secondary prevention, and community reintegration. Safe progression depends on an understanding of exercise physiology, hemodynamics, and critical care line management.
1. Phase I Inpatient Cardiac Rehabilitation
Phase I Cardiac Rehabilitation begins during the acute inpatient hospital admission, typically within 24 to 48 hours following an uncomplicated acute myocardial infarction (MI), percutaneous coronary intervention (PCI), or open cardiothoracic surgery (coronary artery bypass grafting [CABG] or valve repair/replacement).
+-----------------------------------------------------------------------------------+
| Phase I Inpatient Cardiac Rehab Architecture |
+-----------------------------------------------------------------------------------+
| 1. Primary Objectives: |
| - Prevent complications of prolonged bedrest (deconditioning, atelectasis, DVT)|
| - Hemodynamic evaluation during low-level orthostatic and functional challenges|
| - Safe discharge preparation, family education, and home exercise guidance |
+-----------------------------------------------------------------------------------+
| 2. Energy Demands & Metabolic Levels: |
| - Restricted to Low-Intensity MET Levels: 1.0 to 3.0 METs |
| - Bed mobility, active ankle pumps: 1.0 - 1.5 METs |
| - Supported sitting edge of bed, commode transfers: 1.5 - 2.0 METs |
| - Room ambulation, hallway walking 1.5-2.0 mph: 2.0 - 3.0 METs |
+-----------------------------------------------------------------------------------+
| 3. Hemodynamic Exercise Ceilings (Upper Limits): |
| - Post-Myocardial Infarction: Resting HR + 20 bpm (Peak HR ≤120 bpm) |
| - Post-Cardiac Surgery: Resting HR + 30 bpm (Peak HR ≤120 bpm) |
| - Blood Pressure Ceiling: Systolic BP rise <30 mmHg; Diastolic BP <110 mmHg |
| - Exertional SBP drop >10 mmHg: IMMEDIATE TERMINATION! |
| - RPE Ceiling: Borg 6-20 Scale ≤ 11 to 13 ("Fairly Light" to "Somewhat Hard") |
+-----------------------------------------------------------------------------------+
| 4. Typical Session Structure: |
| - Frequency: 2 to 4 times daily (short-bout interval training) |
| - Duration: 5 to 15 minutes per bout, progressing as tolerated |
+-----------------------------------------------------------------------------------+
Sternal Precautions Following Median Sternotomy
Following median sternotomy for CABG or valve surgery, the divided sternum is re-approximated using stainless steel wires. Complete osseous bone healing requires 6 to 8 weeks:
+-----------------------------------------------------------------------------------+
| Traditional Sternal Precautions |
+-----------------------------------------------------------------------------------+
| - Lifting Limit: Do not lift, push, or pull objects >5 to 10 lbs (weight of a jug)|
| - Range of Motion: Avoid bilateral shoulder flexion and abduction >90° |
| - Bed Mobility / Transfers: Do not push through arms when rising from bed/chair |
| (instruct patient to cross arms over chest, hug a pillow, and use leg drive) |
| - Reaching: Avoid reaching both arms behind the back simultaneously |
| - Driving: Strictly prohibited for 4 to 8 weeks (airbag impact & steering shear) |
| - Coughing: Hug a sternal support pillow firmly to splint the incision |
+-----------------------------------------------------------------------------------+
[!TIP] Contemporary Protocol — "Keep Your Move in the Tube": Recent evidence-based cardiac surgical rehabilitation increasingly employs the "Keep Your Move in the Tube" paradigm. Rather than imposing arbitrary universal restrictions on arm movements, patients are instructed to perform upper body functional tasks while keeping their elbows tucked close to the torso (as if inside an imaginary narrow tube). This biomechanical modification shortens the upper extremity lever arm, minimizing lateral distraction and torsional shear forces across the healing sternum while permitting functional independence.
2. Phase II Outpatient Monitored Cardiac Rehabilitation
Phase II is an outpatient, medically supervised, continuous or intermittently ECG-monitored exercise and risk factor reduction program that typically initiates 2 to 4 weeks post-discharge and spans 6 to 12 weeks (up to 36 total sessions).
+-----------------------------------------------------------------------------------+
| Phase II Outpatient Exercise Prescription Parameters |
+-----------------------------------------------------------------------------------+
| 1. Exercise Frequency: 3 to 5 days per week (supervised center-based sessions) |
+-----------------------------------------------------------------------------------+
| 2. Exercise Duration: 30 to 60 minutes total per session |
| - Warm-up (5-10 min) -> Aerobic Conditioning (20-40 min) -> Cool-down (5-10 min)|
+-----------------------------------------------------------------------------------+
| 3. Aerobic Intensity Targets: |
| - 40% to 80% of Heart Rate Reserve (HRR) or VO2 Peak |
| - Rating of Perceived Exertion (RPE): 11 to 14 on Borg 6-20 scale |
| - Metabolic Equivalent: 4.0 to 7.0 METs (treadmill, cycle ergometer, rower) |
+-----------------------------------------------------------------------------------+
| 4. The Karvonen Target Heart Rate Formula: |
| Target HR = [(HR_max - HR_rest) x % Intensity] + HR_rest |
+-----------------------------------------------------------------------------------+
| 5. Resistance Training Progression: |
| - Post-MI: Initiate after minimum 4-5 weeks post-event (≥2-4 wks aerobic rehab)|
| - Post-CABG: Initiate after minimum 5-8 weeks post-surgery (sternal stability) |
| - Intensity: 30-40% 1RM for upper body; 50-60% 1RM for lower body |
| - Volume: 1-2 sets, 10-15 reps; strictly AVOID the Valsalva maneuver! |
+-----------------------------------------------------------------------------------+
The Beta-Blocker Heart Rate Rule
Beta-adrenergic antagonists (e.g., metoprolol, atenolol, bisoprolol) blunt the normal chronotropic response to exercise, reducing peak and submaximal heart rates by approximately 20% to 30%.
- Standard age-predicted maximal heart rate equations (220 - age) are completely invalid in patients taking beta-blockers!
- If a graded symptom-limited exercise stress test is unavailable, the physical therapist must prescribe exercise intensity based strictly on the Rating of Perceived Exertion (Borg 6–20 scale, target 11–14) rather than heart rate.
3. Phase III & Phase IV Cardiac Rehabilitation
- Phase III (Maintenance / Community-Based): Outpatient maintenance program situated in hospital wellness centers or community fitness facilities. Patients are clinically stable, have completed Phase II, and no longer require continuous telemetry monitoring. Exercise intensity is maintained at 60% to 85% HRR or RPE 12 to 16, incorporating resistance training (up to 60–70% 1RM) and long-term independent lifestyle modification.
- Phase IV (Long-Term Fitness): Unsupervised, lifelong self-sustained community fitness and wellness maintenance.
4. Rate Pressure Product (RPP) & Angina Threshold
The Rate Pressure Product (RPP), also known as the Double Product, provides an accurate, non-invasive indirect measure of myocardial oxygen consumption (MVO2) and coronary workload.
Clinical Example: 140 bpm × 150 mmHg = 21,000 (or 210 × 10²)
+-----------------------------------------------------------------------------------+
| Clinical Utility of the RPP Angina Threshold |
+-----------------------------------------------------------------------------------+
| 1. Individual Ischemic Threshold: |
| - In patients with fixed coronary artery stenosis, myocardial ischemia |
| (manifesting as angina pectoris or ST-segment depression ≥1 mm) occurs at |
| a remarkably reproducible RPP level during incremental exercise. |
+-----------------------------------------------------------------------------------+
| 2. Exercise Prescription Rule: |
| - To train safely without precipitating myocardial ischemia, the physical |
| therapist must set the target exercise workload to maintain the patient's |
| operating heart rate at least 10 bpm (or 10% to 15%) BELOW the HR at which |
| angina or ischemic ECG changes were triggered during testing! |
+-----------------------------------------------------------------------------------+
| 3. Aerobic Training Adaptation: |
| - Longitudinal aerobic conditioning lowers resting and submaximal HR and SBP. |
| - Consequently, at any given external workload (e.g., 4 mph walk), the RPP is |
| significantly lower, allowing the patient to achieve higher functional MET |
| levels before reaching their ischemic threshold. |
+-----------------------------------------------------------------------------------+
5. Pulmonary Rehabilitation Protocols
Pulmonary rehabilitation is an evidence-based multidisciplinary intervention for patients with symptomatic chronic respiratory disease (COPD GOLD stages II–IV, Idiopathic Pulmonary Fibrosis, cystic fibrosis, bronchiectasis, and pre-/post-lung transplantation).
Functional Capacity Assessment: The 6-Minute Walk Test (6MWT)
- Standardized Protocol: Administered along a flat, straight, enclosed 30-meter indoor walking corridor marked at 3-meter intervals. The patient is instructed to walk as far as possible in 6 minutes at their own pace. Standardized verbal encouragement is delivered every 60 seconds using neutral phrases (e.g., "You are doing well, you have 4 minutes to go"). The patient may pause or lean against the wall to rest, but the stopwatch continues running.
- Outcome Measures: Total distance walked in meters, pre- and post-test SpO2, heart rate, blood pressure, and Borg Dyspnea / Leg Fatigue score (Borg CR10 scale).
- Minimal Clinically Important Difference (MCID): ~30 meters (range 25 to 35 meters). A change ≥ 30 meters signifies a clinically meaningful functional improvement following pulmonary rehabilitation.
Aerobic Conditioning & Upper vs. Lower Extremity Work
- Lower Extremity Training: Continuous or interval treadmill walking or cycle ergometry performed at 60% to 80% of peak work rate obtained from baseline testing, or titrated to a dyspnea score of 3 to 5 on the Borg CR10 scale ("moderate" to "severe"), for 20 to 30 minutes, 3 to 5 days/week.
- The Biomechanical Dilemma of Upper Extremity Conditioning:
THE ACCESSORY MUSCLE PARADOX IN COPD UPPER BODY TASKS
[ FLATTENED, MECHANICALLY DISADVANTAGED DIAPHRAGM ]
│
▼
Ventilation Heavily Dependent on Accessory Inspiratory Muscles:
- Pectoralis Major & Minor - Latissimus Dorsi - Scalenes / Trapezius
│
▼
UNSUPPORTED UPPER EXTREMITY EXERCISE
(Brushing hair, lifting groceries, arm ergometer)
│
▼
Accessory Muscles Diverted to POSTURAL STABILIZATION of Arm / Scapula
│
▼
ROBBED OF THEIR INSPIRATORY CONTRIBUTION TO RIB CAGE ELEVATION
│
▼
Acute Diaphragmatic Overload ───> SEVERE DYSPNEA & THORACOABDOMINAL
DYSSYNCHRONY AT LOW WORKLOADS!
- Clinical Solution: Supported arm training and progressive upper extremity resistance and endurance training (arm ergometer, light resistance bands, overhead dowel reaches) are essential. Conditioning improves the metabolic efficiency of the shoulder girdle, reducing accessory muscle oxygen demand and alleviating dyspnea during activities of daily living (dressing, cooking, carrying items).
Supplemental Oxygen Titration
During exercise training, supplemental oxygen must be titrated to maintain SpO2 ≥ 88% to 90% under physician standing protocol. If saturation drops below 88%, the therapist must pause exercise, increase O2 flow rate as authorized, and allow recovery.
6. ICU / Acute Care Progressive Mobility & Line Precautions
Early progressive mobilization in the Intensive Care Unit (ICU) prevents intensive care unit-acquired weakness (ICUAW), critical illness polyneuropathy/myopathy, deep vein thrombosis, and prolonged mechanical ventilation.
+-----------------------------------------------------------------------------------+
| ICU Progressive Mobility Clinical Protocol |
+-----------------------------------------------------------------------------------+
| Level 1: Passive/Active-Assisted ROM, therapeutic turning every 2 hours, |
| head of bed elevation to 30-45°. |
+-----------------------------------------------------------------------------------+
| Level 2: Active bed exercises, bridging, bed mobility, edge-of-bed (EOB) sitting |
| with therapist trunk support, static sitting balance. |
+-----------------------------------------------------------------------------------+
| Level 3: Dynamic sitting balance at EOB, active sit-to-stand transfers, pre-gait |
| stepping in place, transfer to bedside cardiac armchair. |
+-----------------------------------------------------------------------------------+
| Level 4: Progressive ambulation in patient room and ICU corridor with walker, |
| portable ventilator / oxygen, and multi-disciplinary nursing support. |
+-----------------------------------------------------------------------------------+
Invasive Lines, Tubes, and Monitoring Precautions Matrix
| Medical Line / Device | Anatomical / Clinical Function | Mandatory Physical Therapy Precautions & Safety Rules |
|---|---|---|
| Arterial Line (A-line) | Continuous real-time arterial blood pressure monitoring and arterial blood gas sampling. | Transducer alignment is critical: The pressure transducer must be positioned at the level of the right atrium, defined as the phlebostatic axis (4th intercostal space at the mid-axillary line). If transducer is placed too high above axis → falsely low BP readings; if too low → falsely high readings. If radial line, avoid wrist hyperflexion. Accidental dislodgement causes rapid arterial hemorrhage: apply immediate, continuous direct manual pressure over the site! |
| Chest Tube (Thoracostomy) | Evacuates air (pneumothorax) or fluid/blood (pleural effusion, hemothorax) from pleural space. | Golden Rule 1: Drainage canister must ALWAYS remain upright and BELOW the level of the patient's chest to prevent gravity backflow of fluid or air into the pleural space. Golden Rule 2: NEVER clamp a chest tube during transfers or ambulation! Clamping traps accumulating air/fluid, rapidly precipitating a life-threatening tension pneumothorax. If accidentally pulled out of canister, submerge distal tube end in sterile water to restore underwater seal. |
| Endotracheal Tube (ETT) | Invasive mechanical ventilation for acute respiratory failure. | Note the centimeter depth mark at the patient's incisor teeth/lip before and after mobility. Avoid neck rotation and cervical extension. Ensure sufficient tubing slack and support ventilator circuit to prevent accidental extubation. Have an Ambu bag (Bag-Valve-Mask) immediately accessible at bedside. |
| External Ventricular Drain (EVD / ICP Monitor) | Measures Intracranial Pressure (normal 0–15 mmHg; pathological >20 mmHg) and drains CSF. | Mandatory Action: The EVD must be clamped by the ICU nurse prior to changing bed height, head-of-bed elevation, or mobilizing the patient out of bed! Moving the patient with an unclamped drain can cause catastrophic intracranial CSF overdrainage, ventricular collapse, or tonsillar brain herniation. Level transducer at the external auditory meatus (foramen of Monro) once stationary. |
| Central Venous Line / PICC Line | Administers vasoactive infusions, hyperalimentation (TPN), and measures Central Venous Pressure (CVP). | Avoid shoulder flexion and abduction >90° on the ipsilateral side of subclavian/internal jugular lines. Check insertion site integrity and ensure line is securely taped before transfer. |
7. Clinical Scenarios & DHA Exam Traps
Clinical Scenario: Post-CABG Inpatient Mobilization
A 64-year-old female is seen on post-operative day 2 following a triple CABG. Her resting heart rate is 76 bpm (in normal sinus rhythm), blood pressure is 122/74 mmHg, and SpO2 is 96% on 2 L/min nasal cannula. She has a right radial arterial line and a midline sternotomy incision closed with surgical staples. The therapist plans an initial hallway ambulation trial.
- Hemodynamic Ceiling: Post-cardiac surgery Phase I guidelines permit an exercise heart rate increase of up to resting HR + 30 bpm, without exceeding 120 bpm. Her heart rate ceiling is 76 + 30 = 106 bpm.
- Sternal Protection: The therapist instructs the patient to cross her arms and hug a sternal pillow when transitioning from supine to sitting, avoiding any pushing through her arms on the bed mattress. During ambulation, the radial arterial line transducer is kept secured at the phlebostatic axis, and the patient is monitored for lightheadedness or SBP drop.
DHA Exam Traps to Avoid
- Trap 1: Clamping Chest Tubes During Ambulation: Exam scenarios often suggest clamping the chest tube with hemostats before walking the patient down the hall to prevent fluid leaks. This is completely wrong and lethal! Clamping a chest tube in a patient with an active air leak creates a closed thoracic space, causing rapid development of a fatal tension pneumothorax. The tube must remain unclamped, connected to the drainage unit below the chest.
- Trap 2: Beta-Blocker Target Heart Rates: When an exam question provides an age-predicted target heart rate calculation for a patient taking a beta-blocker, recognizing the trap is essential. Beta-blockers blunt the heart rate response; therapists cannot rely on target heart rate formulas and must instead use the Borg Rating of Perceived Exertion (RPE 11–14).
- Trap 3: Arterial Line Transducer Positioning: Candidates often confuse what happens when an arterial line transducer is moved. If the transducer falls below the bed and rests near the floor, it measures the added hydrostatic column of fluid and produces a falsely high blood pressure reading. If it is elevated above the patient, it produces a falsely low reading. It must always be aligned at the phlebostatic axis (4th intercostal space, mid-axillary line).
A 61-year-old male who underwent coronary artery bypass graft (CABG) surgery 3 days ago is participating in Phase I inpatient cardiac rehabilitation. His resting heart rate is 74 bpm, resting blood pressure is 118/76 mmHg, and his medication regimen includes metoprolol. According to standard Phase I cardiac rehabilitation guidelines, what is the maximal allowable exercise heart rate ceiling and the most appropriate lifting restriction for this patient during acute hospital care?
A physical therapist in the intensive care unit is preparing to mobilize an alert, critically ill 56-year-old patient who has a left-sided thoracostomy chest tube draining a resolving pleural effusion and a right radial arterial line for continuous blood pressure monitoring. Which combination of clinical precautions is mandatory during out-of-bed progressive mobility?
During a pulmonary rehabilitation intake evaluation, a 67-year-old female with severe chronic obstructive pulmonary disease (COPD, GOLD Stage III) reports that she can walk on flat ground for 10 minutes with mild dyspnea, but experiences disabling shortness of breath and extreme fatigue within 90 seconds of brushing her hair or folding laundry. What physiological mechanism explains this profound discrepancy between lower extremity and upper extremity exercise tolerance?