Respiratory Physiotherapy: Techniques and Protocols

Introduction to Respiratory Physiotherapy

Respiratory physiotherapy constitutes a major specialty of physical therapy encompassing all manual and instrumental techniques aimed at optimizing ventilatory function, facilitating airway clearance, and improving respiratory capacity in patients with acute or chronic respiratory pathologies. This discipline, born from the need to manage patients with obstructive and restrictive respiratory disorders, has developed considerably over recent decades through evidence-based contributions and deeper understanding of respiratory physiology.

The evolution of respiratory physiotherapy reflects a fundamental paradigm shift: the transition from empirical and often uncomfortable techniques (clapping, traditional chest vibrations) to approaches based on mucociliary clearance physiology and controlled expiration mechanisms. The French-speaking school, notably under the impetus of Guy Postiaux in Belgium and Jacques Chevaillier in France, played a pioneering role in developing augmented expiratory flow (AFE) techniques and autogenic drainage, approaches since validated by international scientific literature.

Today, respiratory physiotherapy addresses a broad therapeutic spectrum: management of infant bronchiolitis, long-term treatment of cystic fibrosis, COPD respiratory rehabilitation, ventilator weaning in intensive care, post-surgical thoracic and abdominal rehabilitation, and management of post-infectious respiratory sequelae. Its efficacy relies on rigorous clinical assessment, technique selection adapted to pathology and patient, and a personalized rehabilitation program integrating therapeutic education.

Physiological Principles

Understanding the physiological mechanisms of mucociliary clearance is fundamental to respiratory physiotherapy practice. Under normal conditions, the bronchial tree produces approximately 100 mL of mucus daily, a viscoelastic gel composed of glycoprotein mucins, water (95%), electrolytes, and antimicrobial proteins. This mucus is mobilized toward the pharynx by the ciliary carpet of bronchial epithelium at approximately 10 mm/minute in large bronchi, constituting the mucociliary escalator.

In respiratory pathologies, several mechanisms alter this physiological clearance: mucus hypersecretion, modification of mucus rheological properties, ciliary dyskinesia, bronchial inflammation with mucosal edema, and bronchospasm. The physiotherapist's role is to compensate for these deficits using techniques that optimize the two physical mechanisms of secretion mobilization: gas-liquid interaction and intraluminal gas compression (equal pressure points).

The equal pressure point (EPP) concept, described by Mead and colleagues in 1967, is central to respiratory physiotherapy. During forced expiration, positive pleural pressure compresses airways from outside. The EPP is where intrabronchial pressure equals pleural pressure; downstream from this point, airways are compressed, accelerating airflow and creating shear forces that detach mucus. By modulating starting lung volume and expiratory flow, the physiotherapist can shift the EPP toward distal bronchi (low lung volume, low flow) or proximal bronchi (high lung volume, high flow), enabling sequential clearance of the entire bronchial tree.

Collateral ventilation also plays an important role. The pores of Kohn and Lambert channels allow ventilation of alveoli whose afferent bronchiole is obstructed by a mucus plug. Slow ventilation techniques exploit this collateral ventilation to reaerate distal lung territories and mobilize trapped secretions.

Clearance Techniques

Augmented expiratory flow (AFE) constitutes the reference technique in French-speaking respiratory physiotherapy. It relies on accelerating expiratory airflow, generating shear forces that mobilize bronchial secretions. AFE comes in two modalities: rapid AFE (high velocity, medium to high lung volumes) targeting proximal secretions, and slow AFE (low velocity, low lung volumes) mobilizing distal secretions. The practitioner performs AFE through thoraco-abdominal manual pressure synchronized with the patient's expiration.

Autogenic drainage (AD), developed by Jean Chevaillier at Antwerp University Hospital in the 1970s, is a self-clearance technique the patient learns to perform autonomously. AD comprises three sequential phases: the "unsticking" phase at low lung volume targeting peripheral secretions; the "collecting" phase at tidal volume gathering secretions in medium-caliber bronchi; and the "evacuating" phase at high lung volume mobilizing secretions toward large bronchi for expectoration.

ELTGOL (slow total expiration with glottis open in lateral decubitus), developed by Guy Postiaux, exploits gravity and pulmonary deflation to mobilize secretions from the dependent lung. The patient is positioned in lateral decubitus with the side to drain in the lower position. They perform slow, prolonged expirations with open glottis to residual volume while the physiotherapist applies manual pressure to optimize lower lung deflation. This technique is particularly recommended for COPD.

Respiratory rhythm drainage (DRR) combines respiratory cycles at different frequencies and amplitudes to optimize mucociliary transport. Instrumental techniques complement the therapeutic arsenal: positive expiratory pressure (PEP), oscillatory PEP (Flutter, Acapella, Aerobika), and mechanical insufflation-exsufflation (Cough Assist) for neuromuscular patients unable to produce effective cough.

Indications and Pathologies

Infant bronchiolitis constitutes the most frequent pediatric indication. RSV causes bronchiolar inflammation with mucosal edema, hypersecretion, and small airway obstruction. Respiratory physiotherapy aims to clear upper airways (rhinopharyngeal clearance), mobilize bronchiolar secretions through adapted slow AFE techniques, and monitor clinical status. The preferred technique in infants is slow augmented expiratory flow (ALFE) combined with rhinopharyngeal clearance using physiological saline instillation and aspiration.

Cystic fibrosis represents the quintessential chronic indication. Patients produce abnormally viscous mucus due to CFTR channel dysfunction, leading to chronic bronchial obstruction, recurrent infections, and progressive pulmonary function deterioration. Daily respiratory physiotherapy (one to three sessions daily) is a treatment pillar, with age-adapted techniques: passive AFE in infants, autogenic drainage learned from age 8-10, oscillatory PEP as complementary self-clearance.

COPD benefits from two-level respiratory physiotherapy management. Bronchial clearance, when clinically significant (expectoration exceeding 30 mL/day), preferentially uses ELTGOL and autogenic drainage. Pulmonary rehabilitation, recommended at all stages of symptomatic COPD, combines exercise training (endurance and peripheral muscle strengthening), therapeutic education, and psychosocial support. Six to twelve-week rehabilitation programs have demonstrated significant improvement in exercise capacity, quality of life, and reduced hospitalizations.

The post-operative period after thoracic and abdominal surgery represents a prevention indication. Surgery causes transient diaphragmatic dysfunction, reduced functional residual capacity, and increased risk of atelectasis and nosocomial pneumonia. Pre and post-operative respiratory physiotherapy significantly reduces pulmonary complication incidence.

Course of a Session

The respiratory physiotherapy session begins with a systematic clinical assessment. The physiotherapist evaluates respiratory rate, oxygen saturation (pulse oximetry), ventilatory pattern, signs of respiratory distress, and performs pulmonary auscultation identifying secretion location and nature (inspiratory crackles = distal secretions, expiratory rhonchi = proximal secretions, wheezes = bronchospasm).

Rhinopharyngeal clearance (DRP) constitutes the first step in infants and children. DRP through physiological saline instillation followed by gentle aspiration clears upper airways before bronchial clearance.

Bronchial clearance follows sequential logic: distal secretion mobilization (slow AFE, AD phase 1, ELTGOL), collection in medium-caliber bronchi (moderate AFE, AD phase 2), then evacuation through expectoration (rapid AFE, directed cough, AD phase 3). The physiotherapist continuously adapts techniques based on auscultatory feedback, patient response, and oxygen saturation.

In adults with COPD, rehabilitation sessions combine clearance (if needed) with exercise training. The program typically includes 5-10 minute warm-up, 20-45 minute endurance training at 60-80% maximum aerobic power, and peripheral muscle strengthening at 50-70% maximal voluntary force. Monitoring includes heart rate, oxygen saturation, dyspnea (modified Borg scale), and muscle fatigue.

The session concludes with comparative assessment, control auscultation, and self-management instructions for the patient and/or parents: self-drainage techniques, drainage positions, warning signs requiring urgent medical consultation, and home exercise program.

Variants and Complementary Techniques

Non-invasive ventilation (NIV) techniques complement the therapeutic arsenal. Intermittent positive pressure ventilation increases inspiratory volumes in patients with reduced inspiratory capacity. Therapeutic CPAP can recruit atelectatic lung territories before drainage. Nebulization of mucoactive substances may be combined: hypertonic saline (3-7%) for mucus hydration, dornase alpha (Pulmozyme) to reduce purulent mucus viscosity, and inhaled mannitol (Bronchitol) for periciliary fluid hydration.

Home-based pulmonary rehabilitation, facilitated by telemedicine technologies and connected devices, represents a major evolution. Remotely supervised programs using digital platforms for physical activity tracking, oxygen saturation monitoring, and video consultations have demonstrated results comparable to hospital programs.

Diaphragmatic rehabilitation techniques aim to restore optimal diaphragmatic breathing patterns. Controlled diaphragmatic breathing, directed ventilation, respiratory biofeedback, and thoracic mobility exercises improve ventilatory efficiency and reduce breathing work. Associated postural rehabilitation corrects acquired thoracic deformities limiting lung expansion.

Aerosol therapy integration optimizes the combined effects of medication delivery and airway clearance. The physiotherapist ensures optimal timing of bronchodilator administration before clearance techniques, and positions the patient appropriately to maximize aerosol deposition in targeted lung regions.

Contraindications and Precautions

Absolute contraindications are rare but must be strictly respected. Active massive hemoptysis constitutes a formal contraindication to bronchial clearance. Undrained pneumothorax contraindicates any positive pressure technique. Hemodynamically unstable state requires prior stabilization before any respiratory maneuver.

Relative contraindications require technique adaptation rather than complete abstention. Acute bronchospasm mandates prior bronchodilator treatment and exclusive use of low-flow techniques. Severe acute respiratory decompensation requires priority medical management.

In infants, specific precautions apply. Neonatal thoracic fragility mandates minimal manual pressure and abandonment of traditional percussion techniques (clapping), now considered iatrogenic in infants. Continuous oxygen saturation monitoring is mandatory during sessions. Signs of intolerance (persistent desaturation below 92%, bradycardia, apnea, cyanosis) mandate immediate technique cessation.

Patient fatigue constitutes an important limit. Clearance techniques are energy-intensive and may worsen respiratory fatigue. The physiotherapist must fractionate sessions, alternate active techniques with rest phases, and monitor respiratory fatigue signs. Asepsis is paramount for immunocompromised or cystic fibrosis patients, preventing cross-transmission of pathogens.