Key Concepts for Clinical Practical Exam of the Respiratory System
For a clinical practical exam focusing on the respiratory system, you should master comprehensive assessment techniques including history taking, physical examination, pulmonary function testing, and exercise testing protocols that directly impact patient morbidity and mortality.
Respiratory Assessment Framework
History Taking
- Focus on respiratory symptoms including:
- Recurrent chest infections
- Sleep-disordered breathing
- Ability to clear secretions
- Dyspnea patterns
- Ambulatory status 1
Physical Examination
- Systematic approach including:
- Inspection: Observe breathing pattern, chest wall movement, use of accessory muscles
- Palpation: Assess chest expansion, tactile fremitus, identify abnormal masses
- Percussion: Determine underlying tissue density (normal resonance vs. dullness/hyperresonance)
- Auscultation: Listen for breath sounds, adventitious sounds (wheezes, crackles, rubs) 1
Pulmonary Function Testing
Spirometry
- Key measurements:
Test Protocol Standards
- Incremental cycle ergometry:
- Start with 3-min rest phase
- Follow with 3-min unloaded pedaling
- Increase intensity by 5-25W per minute until exhaustion 1
- Constant work rate test:
- Performed at 70% of peak work rate from incremental test
- Measures endurance time to exhaustion 1
Field Walking Tests
6-Minute Walk Test (6MWT)
- Protocol:
- Requires 30m hallway
- Standardized instructions and encouragement
- Measures distance walked in 6 minutes
- Document oxygen saturation, heart rate, dyspnea and leg fatigue (Borg scale) before and after 1
- Clinical value: Better reflects functional exercise capacity for daily activities than maximal tests 1
Incremental Shuttle Walking Test (ISWT)
- Uses audio signals to pace walking speed on 10m course
- Speed increases each minute until patient cannot reach turnaround point
- Similar to maximal incremental treadmill testing 1
Respiratory Pressure Measurements
Mechanics Assessment
- Understand respiratory system equation of motion:
- Pappl = (1/C)V + RV
- Where C = compliance, R = resistance, V = volume, V̇ = flow 1
- Recognize how endotracheal tubes affect resistance measurements in ventilated patients 1
Quality Control and Technical Standards
Equipment Standards
- Technicians should:
- Understand calibration procedures
- Maintain documentation of daily instrument calibration
- Record anomalous events and corrective actions 1
- Training requirements:
- At least 2 years of college education with health sciences emphasis
- Formal classroom training plus hands-on experience
- Refresher training every 3-5 years 1
Special Considerations
Medication Effects
- Recognize respiratory depressant effects:
- Opiates should be carefully prescribed, especially when FVC <80%
- Some cough medications can reduce secretion clearance 1
- Understand bronchodilator therapy:
- Recognize paradoxical bronchospasm risk with inhaled medications
- Monitor for cardiovascular effects (tachycardia, hypertension) 2
Red Flags in Assessment
- Asynchronous rib cage-abdominal motion may indicate respiratory muscle fatigue
- Abdominal paradox and respiratory alternans may predict ventilatory failure 1
- Progressive upper limb weakness (inability to raise hand to mouth) correlates with respiratory impairment 1
Practical Tips for Exam Success
- Record patient position during all pulmonary function tests for accurate serial comparison 1
- Monitor for sleep-disordered breathing symptoms regardless of patient age or ambulatory status 1
- Remember that daytime SpO2 is often not informative for diagnosing ventilatory failure 1
- Ensure proper cleaning of testing equipment to prevent infection transmission and maintain accuracy 2
By mastering these key concepts, you'll be well-prepared to demonstrate competence in respiratory system assessment during your clinical practical exam, focusing on elements that directly impact patient outcomes.