Effect of Box Breathing Before Chest Tube Removal After Open-Heart Surgery

Chest tube removal is a routine procedure following open-heart surgery; however, it may cause pain, anxiety, dyspnea, and changes in hemodynamic parameters. Nonpharmacological interventions that are simple, safe, and easy to apply may contribute to symptom management during this procedure.

This prospective, two-arm, parallel-group randomized controlled trial will evaluate the effects of box breathing performed before chest tube removal in patients undergoing open-heart surgery. A total of 86 eligible patients will be randomly assigned in a 1:1 ratio to the intervention group (n=43) or control group (n=43) using block randomization.

Participants assigned to the intervention group will receive routine care and perform the box breathing technique approximately five minutes before chest tube removal. The technique consists of four phases of equal duration: inhaling for 4 seconds, holding the breath for 4 seconds, exhaling for 4 seconds, and holding after exhalation for 4 seconds. Participants will perform 15 consecutive cycles for approximately five minutes under the verbal guidance of the researcher. The exercise will be completed immediately before chest tube removal. Participants in the control group will receive routine clinical care without an additional nonpharmacological intervention.

Pain intensity will be assessed using the Visual Analog Scale (VAS), anxiety using the Visual Analog Scale for Anxiety (VAS-A), and dyspnea using the Visual Analog Scale for Dyspnea (VAS-D). Hemodynamic parameters will include systolic blood pressure, diastolic blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation (SpO2).

Assessments will be performed at five time points: before the box breathing intervention (T0), immediately after chest tube removal (T1), and at 5 minutes (T2), 15 minutes (T3), and 30 minutes (T4) after chest tube removal. Both groups will continue to receive routine medical treatment and nursing care throughout the study.

The primary outcome is pain intensity associated with chest tube removal. Secondary outcomes are anxiety, dyspnea, systolic blood pressure, diastolic blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation.

• Box breathing (Behavioral): Participants will perform the 4-4-4-4 box breathing technique approximately five minutes before chest tube removal. The technique consists of inhaling through the nose for 4 seconds, holding the breath for 4 seconds, exhaling for 4 seconds, and holding after exhalation for 4 seconds. Participants will perform 15 consecutive cycles for approximately five minutes under the verbal guidance of the researcher. The intervention will be completed immediately before chest tube removal. Routine medical treatment and nursing care will continue throughout the intervention.

Primary outcomes

• Pain Intensity [Before the intervention, immediately after chest tube removal, and 5, 15, and 30 minutes after chest tube removal.]: Pain intensity will be assessed using a 10-cm Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst possible pain). Higher scores indicate greater pain intensity.

Secondary outcomes

• Anxiety Level [Before the intervention, immediately after chest tube removal, and 5, 15, and 30 minutes after chest tube removal.]: Anxiety will be assessed using the 10-cm Visual Analog Scale for Anxiety (VAS-A), ranging from 0 (no anxiety) to 10 (highest possible anxiety). Higher scores indicate greater anxiety.
• Dyspnea Level [Before the intervention, immediately after chest tube removal, and 5, 15, and 30 minutes after chest tube removal.]: Dyspnea will be assessed using the 10-cm Visual Analog Scale for Dyspnea (VAS-D), ranging from 0 (no dyspnea) to 10 (worst imaginable dyspnea). Higher scores indicate greater dyspnea.
• Systolic Blood Pressure [Before the intervention, immediately after chest tube removal, and 5, 15, and 30 minutes after chest tube removal.]: Systolic blood pressure will be measured using a bedside patient monitor and recorded in millimeters of mercury (mmHg).
• Diastolic Blood Pressure [Before the intervention, immediately after chest tube removal, and 5, 15, and 30 minutes after chest tube removal.]: Diastolic blood pressure will be measured using a bedside patient monitor and recorded in millimeters of mercury (mmHg).
• Heart Rate [Before the intervention, immediately after chest tube removal, and 5, 15, and 30 minutes after chest tube removal.]: Heart rate will be measured using a bedside patient monitor and recorded as beats per minute (beats/min).
• Respiratory Rate [Before the intervention, immediately after chest tube removal, and 5, 15, and 30 minutes after chest tube removal.]: Respiratory rate will be assessed by the researcher by observing and counting chest movements for one minute and will be recorded as breaths per minute.
• Peripheral Oxygen Saturation (SpO2) [Before the intervention, immediately after chest tube removal, and 5, 15, and 30 minutes after chest tube removal.]: Peripheral oxygen saturation (SpO2) will be measured using a bedside patient monitor and recorded as a percentage (%).

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Patients who have undergone open-heart surgery and have a chest tube
* Aged 18 years or older
* Willing to participate in the study and providing written informed consent
* Conscious, oriented, and cooperative
* Able to read and understand Turkish
* Clinically and hemodynamically stable
* Having no more than three chest tubes (up to two mediastinal and one thoracic chest tube)
* No diagnosed psychiatric disorder
* Not receiving psychiatric medications and/or local neuromuscular blocking agents

Exclusion Criteria:

* Patients who have not undergone open-heart surgery
* Unconscious, disoriented, or uncooperative patients
* Unable to read and understand Turkish
* Intubated patients
* Receiving additional analgesic medication other than routine analgesia
* Receiving local anesthesia at the chest tube insertion site
* Having four chest tubes (two mediastinal and two thoracic)
* Unwilling to participate in the study
* Having a diagnosed psychiatric disorder or mental health condition

• McAllister MJ, Martaindale MH, Sutton N, Andersen JP. Box breathing and prolonged exhalation reduces markers of physiological stress reactivity in response to a virtual trier social stress test. Compr Psychoneuroendocrinol. 2026 Jun 25;27:100360. doi: 10.1016/j.cpnec.2026.100360. eCollection 2026 Aug. PMID 42388906
• Jarrah MI, Hweidi IM, Al-Dolat SA, Alhawatmeh HN, Al-Obeisat SM, Hweidi LI, Hweidi AI, Alkouri OA. The effect of slow deep breathing relaxation exercise on pain levels during and post chest tube removal after coronary artery bypass graft surgery. Int J Nurs Sci. 2022 Mar 15;9(2):155-161. doi: 10.1016/j.ijnss.2022.03.001. eCollection 2022 Apr. PMID 35509699

• Tuğba ÇAM YANIK, Principal investigator, Mersin University