Pulmonary mechanics are further disturbed after cardiothoracic surgery that manifests like restrictive pathology, which may persist for weeks to months postoperatively. This experimental aimed to investigate the efficacy of a positive end-expiratory pressure device on maximum expiratory pressure, maximum voluntary ventilation, and dyspnea index in patients who underwent valve surgery.

Thirty male and female adolescent patients who underwent valve surgery aged 12-18 years old, recruited from the national heart institute enrolled in this experimental. They were assigned into two matched groups: Experimental group consisted of 15 patients, received positive end-expiratory pressure (PEEP) with a mouthpiece in addition to routine chest physiotherapy (postural drainage, percussion, vibration, and deep breathing exercises). Control group consisted of 15 patients, received routine chest physiotherapy alone. The program continued for four weeks.

Inclusion Criteria:

• Male patients
• underwent valve surgery (repair or replacement) for mitral valve stenosis;
• hemodynamically stable,
• ages ranged from 12 to 18 years old-
• BMI ranges from 18.5 to 24.9
• reduced MEP, MVV and complaining from shortness of breath with exertion.

Exclusion Criteria:

• Patients with previous cardiac surgery
• congenital heart disease
• neurological disorders
• type1 diabetes mellitus
• smoker
• pacemaker implantation
• atrial fibrillation
• utilization of mechanical ventilation longer than 24 hours.