Effect of Positioning and ACBT on Pulmonary Complications After Cardiac Surgery

This quasi-experimental, non-equivalent control group study is designed to evaluate the clinical impact of position management, the Active Cycle of Breathing Techniques (ACBT), and their combined application on reducing postoperative pulmonary complications (PPCs) among adult patients undergoing elective cardiac surgery via median sternotomy.

Study Phases and Flow:

• Preparatory Phase: Official administrative approvals will be secured from the director of the cardiothoracic care unit (CTCU) at Assiut University Heart Hospital. The data collection tools will be validated by a jury panel of five experts in medical-surgical nursing and cardiothoracic surgery.

Internal consistency will be evaluated using Cronbach's Alpha. A pilot study involving 10% of the sample size (13 patients) will be conducted to test feasibility and timing, and these patients will be excluded from the final analysis.

Eligible patients will be approached preoperatively to explain the study's purpose, benefits, and risks, and voluntary written informed consent will be obtained.

Implementation Phase:

Patients meeting the specific eligibility criteria will be enrolled. Preoperatively, baseline demographic attributes, clinical medical history, initial diagnostic studies (e.g., complete blood count, chest X-ray, arterial blood gas markers), and baseline vital signs will be documented. Patients allocated to the intervention arms will receive preoperative training on ACBT maneuvers and orientation regarding the postoperative position protocols.

During and immediately following surgery, operative variables such as extracorporeal circulation time, aortic cross-clamp time, and intraoperative blood transfusions will be extracted from anesthesia and surgical flow sheets. Patients will then be allocated into one of the four study groups. Group Interventions:

• Group 1 (Control Group): Participants receive only the standard, routine postoperative hospital care protocols.
• Group 2 (ACBT Group): Once hemodynamically stable on postoperative day 1 (POD 1), participants perform the active cycle of breathing technique (including breathing control, thoracic expansion exercises, and huffing). Sessions last 10-15 minutes, conducted three times daily across 5 postoperative days.
• Group 3 (Positioning Group): In the early postoperative phase (0-6 hours or until extubation), patients are managed with head elevation at $30-45^{\\circ}$ and head turning. Post-extubation/after 6 hours, they are maintained in a semi-recumbent position (approx60) during waking hours and 15-30 during sleep, with forward-leaning, postural drainage, and prone positioning integrated as tolerated.
• Group 4 (Combined Group): Participants receive the structured early head elevation and semi-recumbent positioning, followed by lateral or forward-leaning adjustments. Following extubation and stabilization, they initiate the ACBT sessions on the identical frequency and duration schedule as Group 2. Evaluation Phase:

Continuous daily monitoring of vital signs and clinical progress will be documented from POD 1 to POD 7. The incidence and clinical severity of PPCs will be evaluated daily using the Modified Kroenke Scoring System. Data collection will conclude on POD 7 or upon hospital discharge, whichever occurs first. Statistical analysis will compare the variations across the four groups to identify the most effective nursing practice.

Inclusion criteria

• Adult patients (aged from 20 years to 65 years old).
• Undergoing elective cardiac surgery (Coronary Artery bypass Grafting (CABG) or valves surgeries) via median sternotomy.
• Hemodynamically stable postoperatively (no high-dose vasopressor support).
• Fully conscious and capable of following complex verbal instructions.

Exclusion criteria

• • Patients undergoing emergency cardiac surgery.

• History of chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD), bronchial asthma, or bronchiectasis
• Pre-existing pulmonary complications (e.g., pneumonia, atelectasis, pleural effusion) prior to surgery
• Neuromuscular disorders affecting respiratory muscles
• Severe obesity (e.g., BMI ≥35 kg/m²)
• Cognitive impairment or inability to follow instructions
• Any contraindication to physiotherapy techniques (e.g., unstable sternum, severe pain not controlled)