The Takeaway

“In patients who are planned to undergo open heart surgery, the initiation of DBEs with IS in the preoperative period may contribute to a reduction in the incidence of PPCs, the duration of MV, the length of stay in the ICU, the duration of hospitalisation, and an improvement in pre- and postoperative oxygenation“

Study Design

• A randomized controlled trial evaluating the impact of preoperative deep breathing exercises using an incentive spirometer on patients undergoing open-heart surgery.

Physiology Rewind

Impact of Open-Heart Surgery on Respiratory Physiology:

• Open-heart surgery, combined with general anesthesia, often leads to postoperative pulmonary complications (PPCs).
• These complications are largely due to atelectasis, reduced lung compliance, and impaired gas exchange.
• Cardiopulmonary bypass and surgical trauma can induce inflammatory responses and alter lung mechanics, further compromising respiratory function.

Role of General Anesthesia:

• Anesthesia contributes to reduced diaphragmatic tone and shallow breathing, leading to decreased alveolar ventilation.
• Mechanical ventilation during surgery can exacerbate alveolar collapse and impair mucociliary clearance, increasing the risk of infections.

Preoperative Deep Breathing and Incentive Spirometry:

• Deep breathing exercises promote alveolar recruitment, helping to maintain lung expansion and prevent atelectasis.
• Incentive spirometry provides visual feedback to encourage slow, deep inhalation, improving lung compliance and gas exchange.

Mechanisms of Improvement:

• Increased Functional Residual Capacity (FRC): Deep breathing maintains the volume of air remaining in the lungs after exhalation, preventing alveolar collapse.
• Improved Oxygenation: Enhanced alveolar ventilation leads to better oxygen delivery to tissues, reducing hypoxemia risk.

Clinical Relevance:

• By reducing the incidence of PPCs, these interventions minimize postoperative morbidity, shorten hospital stays, and improve overall recovery.
• Incorporating deep breathing exercises into preoperative care is a simple yet effective strategy to improve surgical outcomes.

Excerpts

Patients who have undergone cardiac surgery are at an elevated risk of developing postoperative pulmonary complications (PPCs)

approximately one-quarter of patients who have undergone cardiac surgery and do not have chronic pulmonary dysfunction develop a PPC.

PPCs range from a mild respiratory infection to acute respiratory failure, which may necessitate the use of oxygen therapy and invasive or non-invasive mechanical ventilation (MV) support.

Contributing factors have included surgical stress and anaesthesia, the systemic inflammatory response and oxidative stress from cardiopulmonary bypass, the type of surgery performed, inadequate pain management, the anaesthesia protocol employed, the use of blood products, and diaphragmatic dysfunction

In clinical practice, DBEs with IS is usually initiated in the post-operative period. However, it has been reported that inadequate physical adaptation and respiratory muscle weakness in the preoperative period are closely associated with PPCs leading to a prolonged hospital stay and increased mortality 

The aim of this study was to determine the effects of preoperative DBE and IS on respiratory parameters and complications in patients undergoing open-heart surgery.

Atelectasis is a well known complication of general anesthesia which may persist for several days for a variety of reasons. In this sense, DBEs have been shown to improve postoperative lung expansion and ventilation and reduce the occurrence and severity of PPCs 

In our study, preoperative DBE combined with IS had a statistically significant lower incidence of atelectasis in patients after open-heart surgery. This is similar to the findings of a meta-analysis which examined the effect of preoperative exercise training on PPCs in patients who underwent a major surgical intervention (cardiac, lung, esophageal, or abdominal surgery).

no atelectasis was seen in the patients in the deep breathing group, only one patient in the deep breathing group developed pneumonia, whereas most of the patients with PPCs in the control group developed atelectasis. 

MV duration was significantly shorter in patients in the deep breathing group than in the control group. This is consistent with other studies in CABG patients that have shown that the duration of MV was significantly shorter in patients who started DBE with IS preoperatively

It is important that patients stay in the hospital for a short time to avoid additional complications and increased healthcare costs. In our study, the duration of hospitalisation was found to be significantly shorter in the deep breathing group. A study of CABG patients showed that the length of hospital stay was significantly shorter in patients who underwent DBE with IS prior to surgery

In this study, the length of postoperative ICU stay was significantly shorter in the DBE and IS group as compared to the control group

Abstract

Background: Incentive spirometer is used in lung expansion therapy to maintain alveolar patency and improve pulmonary volumes in postoperative cardiac surgical patients. Deep breathing exercises with an incentive spirometer significantly reduce the development of postoperative pulmonary complications after open-heart cardiac surgery.

Aim: To determine the effect of deep breathing exercises with an incentive spirometer initiated in the preoperative period on respiratory parameters and complications in patients who underwent open-heart surgery.

Methods: This randomized controlled study was conducted with a total of 66 participants. The participants were randomized into a deep breathing group (n = 32) and a control group (n = 34). The control group received hospital routine physiotherapy, and the deep breathing group started to perform deep breathing exercises with an incentive spirometer in the preoperative period. Data were collected with the Sociodemographic and Medical Data Form and Patient Follow-up Form (respiratory rate, oxygen saturation (SpO₂) level, arterial blood gas parameters and posteroanterior chest X-ray were monitored with this form prepared by the investigators). The Medical Research Council Scale was used to determine the severity of dyspnea in the patients included in the study. Primary outcomes included respiratory rate, oxygen saturation, arterial blood gas parameters, posteroanterior chest X-ray, and evaluation of postoperative pulmonary complications development. Secondary outcomes included the mechanical ventilation time, length of intensive care unit stay, and length of hospital stay.

Results: The incidence of postoperative pulmonary complications was 3.1% and 23.5% (p < 0.05) in the deep breathing and control groups, respectively. The mechanical ventilation time, length of hospital stay, and length of stay in the intensive care unit were significantly shorter in the deep breathing group (p < 0.05). In the deep breathing group, the mean SpO₂ values evaluated before surgery, on the first day in the Cardiovascular Surgery Unit, and on the day of discharge were significantly higher than the control group (p < 0.05).

Conclusion: Deep breathing exercises with an incentive spirometer initiated in the preoperative period contribute to a reduction in postoperative pulmonary complication rates, shortening of mechanical ventilation time, length of stay in the intensive care unit, length of hospital stay, and improvement of pre- and postoperative oxygenation.

Citation

Öner Cengiz, H., Uluşan Özkan, Z. & Gani, E. The effect of preoperative deep breathing exercise with incentive spirometer initiated in the preoperative period on respiratory parameters and complications in patients underwent open heart surgery: a randomized controlled trial. BMC Anesthesiol 25, 36 (2025).a

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