Intensive Inspiratory Training and Post-CABG Pulmonary Complications - Intensive Inspiratory Training and Post-CABG Pulmonary Complications


The goal of the trial was to evaluate preoperative intensive inspiratory muscle training (IMT) compared with usual care and postoperative pulmonary complications (PPCs) among patients undergoing coronary artery bypass graft (CABG) surgery.

Study Design

Study Design:

Patients Enrolled: 655
Mean Follow Up: Hospital discharge
Mean Patient Age: Mean age 67 years
Female: 22

Patient Populations:

Scheduled for primary elective CABG surgery and high risk of developing PPCs


Surgery performed within 2 weeks of initial contact; a history of cerebrovascular accident; use of immunosuppressive medication for 30 days before surgery; and presence of a neuromuscular disorder, cardiovascular instability, or an aneurysm

Primary Endpoints:

Incidence of PPCs

Secondary Endpoints:

Duration of postoperative hospitalization

Drug/Procedures Used:

Patients at a single center in the Netherlands were randomized preoperatively to either preoperative IMT (n = 140) or usual care (n = 139). The intervention consisted of 20 minutes of individualized IMT exercises, including incentive spirometry, education in active cycle of breathing techniques, and forced expiration techniques. Training was done 7 days per week for ≥2 weeks prior to surgery, once a week with supervision by a physical therapist, and 6 days independently. The usual care group received instructions the day prior to surgery on deep breathing maneuvers, coughing, and early mobilization.

Principal Findings:

Baseline characteristics were well-matched between groups, with 35% of patients smokers, a history of chronic obstructive pulmonary disease in 20%, and productive coughing in 29%. On-pump surgery was performed in 82% of cases, with mean cardiopulmonary bypass time of ~90 minutes. Median time of waiting for surgery was 8.2 weeks in the IMT group and 7.0 weeks in the usual care group. Duration of exercise in the IMT group was 29.7 days. Mean inspiratory muscle strength increased from baseline in the IMT group (from 81.1 cm H2O to 95.6 cm H2O, p < 0.001), but did not change in the usual care group. Likewise, respiratory muscle endurance increased in the IMT group (from 48.8% to 56.0%, p < 0.001), but did not change in the usual care group.

The primary endpoint of post-surgery PPCs occurred less frequently in the IMT group compared with the usual care group (18.0% vs. 35.0%, odds ratio [OR] 0.52, p = 0.02). Pneumonia also occurred less frequently in the IMT group (6.5% vs. 16.1%, OR 0.40, p = 0.01). Duration of postoperative hospitalization was shorter in the IMT group than the usual care group (median 7 days vs. 8 days, p = 0.02).


Among patients undergoing elective CABG who were at high risk of developing PPCs, preoperative intensive IMT was associated with a reduction in PPCs by hospital discharge, including a reduction in pneumonia.

In addition to the reduction in PPCs with IMT therapy, length of hospitalization was also a median of 1 day shorter in the IMT group, likely due in part to the lower postoperative complication rate. While the results of the present study were very favorable for preoperative IMT, the length of time waiting for CABG was quite long (7-8 weeks) and it is unclear if similar results would occur in a shorter time frame, since it is likely that most US patients undergo CABG more quickly.


Hulzebos EH, Helders PJ, Favie NJ, De Bie RA, Brutel De La Riviere A, Van Meeteren NL. Preoperative intensive inspiratory muscle training to prevent postoperative pulmonary complications in high-risk patients undergoing CABG surgery: a randomized clinical trial. JAMA 2006;296:1851-7.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention

Keywords: Respiratory Muscles, Motivation, Postoperative Complications, Odds Ratio, Pulmonary Disease, Chronic Obstructive, Early Ambulation, Pneumonia, Spirometry, Muscle Strength, Coronary Disease, Coronary Artery Bypass

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