Postoperative Atelectasis
Conditions
Keywords
Cardiac surgery, Coronary bypass, Heart valve replacement, Postoperative pulmonary complications
Brief summary
This study compares a novel breathing device, called the GO2 Mouthpiece, to the standard breathing tool called the incentive spirometer, thus improving respiratory dynamics of the postoperative patient.
Detailed description
Postoperative pulmonary complications (PPCs) are the principal cause of morbidity, mortality and prolonged hospitalizations in surgical patients, which results in a 50% increase in healthcare costs compared to postoperative cardiac complications. This is especially evident following cardiovascular surgery. One of the most common PPCs is atelectasis, resulting in dyspnea, tachypnea and hypoxemia. Postoperative atelectasis is a predictable consequence of anesthesia, surgical trauma, and pain associated with breathing. Methods aimed at increasing lung volume and treating atelectasis, commonly known as postoperative physiotherapy, play an important role in preventing PPCs. These methods include cough and deep breathing, continuous positive airway pressure (CPAP), postural drainage, incentive spirometry and positive end expiratory pressure (PEEP). Incentive spirometry has served as a convenient approach for the postoperative patient to sustain maximal inflations and encourage deep breathing. Although incentive spirometry is used commonly by post-operative patients, evidence fails to support its benefit. PEEP is a well-known pulmonary physiologic principle. There are on average 600 million alveoli in the lung. Each alveolus has surfactant to resist the natural propensity for these small air sacs to collapse during exhalation. Despite this surfactant, some alveoli will collapse and not be available for gas exchange. This atelectasis results in a ventilation/perfusion mismatch where alveolar units are perfused but not adequately ventilated. This is referred to as shunting and results in hypoxemia (decreased PaO2). PEEP decreases the propensity for the alveoli to collapse by increasing the air pressure in the lungs. This residual pressure in the lungs at the end of exhalation decreases shunting and allows for more complete gas exchange and improved oxygenation. In patients, PEEP is one of the safest ways to increase PaO2 and is used on almost all modern ventilator settings. The purpose of this study is to compare a novel breathing device, called the GO2 Mouthpiece, which uses the concept of PEEP, to the incentive spirometer in postoperative patients.
Interventions
DEVICEIncentive spirometer
The incentive spirometer is a device that measures how deeply a person can inhale (breathe in). It helps with taking slow, deep breaths to expand and fill the lungs with air, which helps prevent lung problems, such as pneumonia. The incentive spirometer is made up of a breathing tube, an air chamber, and an indicator to help users control their breathing.
DEVICEGO2 Mouthpiece
The GO2 Mouthpiece is a simple, comfortable, and straightforward silicone rubber-made, bidirectional oxygenation mouthpiece that effectively delivers PEEP with every breath.
Sponsors
PEEP Medical, LLC
Emory University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Single center, prospective, randomized controlled study
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
Inclusion criteria
1. Undergoing coronary artery bypass surgery (CABG) and/or valve replacement surgery 2. Able to provide written informed consent 3. Maintenance of an arterial line postoperatively
Exclusion criteria
1. Active smoking, within three months of surgery 2. Forced expiratory volume in one second (FEV1) \<75% predicted 3. Relative risk to develop pulmonary barotrauma as evident by history of pneumothorax or emphysema 4. Unable or unwilling to provide informed consent, cognitive impairment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Partial Pressure of Oxygen (PaO2 Level) | 1, 6, 12 and 24 hours postextubation | Partial pressure of oxygen is a measurement of oxygen pressure in arterial blood. It reflects how well oxygen is able to move from the lungs to the blood. Normal values are 80 to 100 millimeters of mercury (mmHg). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With Normal Atelectasis Score | Immediately postoperative, Postoperative days 1, 2, 3, 4 | Atelectasis is a lung condition that happens when the airways don't expand normally. Atelectasis is measured with the modified radiological atelectasis score (m-RAS). Each pulmonary lobe, including the lingula, is scored 0-3 (0=normal, 1=plate or minor infiltrate, 2= moderate atelectasis, 3= total atelectasis). The scores of the six lobes are then summed to give a total score ranging from 0 to 18 with higher scores being associated with worse outcomes. For this analysis, scores were categorized as 0 (normal) or greater than 0 (not normal). The count of participants with a normal atelectasis score at the indicated time point are presented here. |
| Oxygen Requirement | Postextubation Hours 1, 6, 12 and 24, Postoperative Days 2, 3, and 4 | Oxygen was provided by a nasal cannula. The flow rate of supplemental oxygen that participants required after surgery is assessed as liters per minute. Higher flow rate indicates an increased need for supplemental oxygen. |
| Carbon Dioxide Level | Postextubation Hours 1, 6, 12 and 24 | Normal carbon dioxide (CO2) levels in blood range from 35.0 mmHg to 45.0 mmHg. |
| FEV1 | Preoperative and postoperative day 3 | Forced expiratory volume in one second (FEV1) is measured during a spirometry test, also known as a pulmonary function test, which involves forcefully breathing out into a mouthpiece connected to a spirometer machine. FEV1 is the amount of air forced from lungs in one second. To describe severity of pulmonary disease, FEV1 can be expressed as a percentage of the predicted value. Values 80% and and greater of the predicted value are considered normal. |
| Forced Vital Capacity (FVC) | Preoperative, Postoperative Day 3 | Forced vital capacity (FVC) is measured during a spirometry test, also known as a pulmonary function test, which involves forcefully breathing out into a mouthpiece connected to a spirometer machine. FVC is the total amount of air exhaled during the FEV test. FVC can be expressed as a percentage of the predicted value.The normal range for the percent of the predicted value is between 80% and 120%. |
| Respiratory Rate | Postextubation Hours 1, 6, 12 and 24, Postoperative Days 2, 3, and 4 | Respiratory rate is the number of breaths taken per minute. The normal respiration rate for an adult at rest is 16 to 20 breaths per minute. |
| Body Temperature | Immediately Postoperative, Postoperative Day 1, 2, 3, 4 | Measure of heat associated with the metabolism of the body. Normal range is between 36.5-37.5 degrees Celsius (°C). |
Countries
United States
Participant flow
Recruitment details
Participant enrollment began August 27, 2020 and all study follow up was completed January 31, 2021. Participants were enrolled at Emory Saint Joseph's Hospital in Atlanta, Georgia, USA.
Participants by arm
| Arm | Count |
|---|---|
| Incentive Spirometer Control Arm Participants using the incentive spirometer after surgery. | 10 |
| GO2 Mouthpiece Participants using the GO2 Mouthpiece after surgery. | 10 |
| Total | 20 |
Baseline characteristics
| Characteristic | Incentive Spirometer Control Arm | GO2 Mouthpiece | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 4 Participants | 6 Participants | 10 Participants |
| Age, Categorical Between 18 and 65 years | 6 Participants | 4 Participants | 10 Participants |
| Age, Continuous | 65.1 years STANDARD_DEVIATION 8.7 | 67.1 years STANDARD_DEVIATION 6.9 | 66.1 years STANDARD_DEVIATION 7.7 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants | 0 Participants | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 8 Participants | 10 Participants | 18 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 2 Participants | 1 Participants | 3 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 8 Participants | 9 Participants | 17 Participants |
| Region of Enrollment United States | 10 Participants | 10 Participants | 20 Participants |
| Sex: Female, Male Female | 2 Participants | 0 Participants | 2 Participants |
| Sex: Female, Male Male | 8 Participants | 10 Participants | 18 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 10 | 0 / 10 |
| other Total, other adverse events | 1 / 10 | 0 / 10 |
| serious Total, serious adverse events | 0 / 10 | 0 / 10 |
Outcome results
Primary
Partial Pressure of Oxygen (PaO2 Level)
Partial pressure of oxygen is a measurement of oxygen pressure in arterial blood. It reflects how well oxygen is able to move from the lungs to the blood. Normal values are 80 to 100 millimeters of mercury (mmHg).
Time frame: 1, 6, 12 and 24 hours postextubation
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Incentive Spirometer Control Arm | Partial Pressure of Oxygen (PaO2 Level) | 1 hour postextubation | 95.4 mmHg | Standard Deviation 22.6 |
| Incentive Spirometer Control Arm | Partial Pressure of Oxygen (PaO2 Level) | 6 hours postextubation | 92.1 mmHg | Standard Deviation 28.1 |
| Incentive Spirometer Control Arm | Partial Pressure of Oxygen (PaO2 Level) | 12 hours postextubation | 91.0 mmHg | Standard Deviation 21.8 |
| Incentive Spirometer Control Arm | Partial Pressure of Oxygen (PaO2 Level) | 24 hours postextubation | 74.5 mmHg | Standard Deviation 17.2 |
| GO2 Mouthpiece | Partial Pressure of Oxygen (PaO2 Level) | 24 hours postextubation | 77.8 mmHg | Standard Deviation 14.6 |
| GO2 Mouthpiece | Partial Pressure of Oxygen (PaO2 Level) | 1 hour postextubation | 83.5 mmHg | Standard Deviation 18.3 |
| GO2 Mouthpiece | Partial Pressure of Oxygen (PaO2 Level) | 12 hours postextubation | 81.4 mmHg | Standard Deviation 17.9 |
| GO2 Mouthpiece | Partial Pressure of Oxygen (PaO2 Level) | 6 hours postextubation | 85.4 mmHg | Standard Deviation 22.3 |
Secondary
Body Temperature
Measure of heat associated with the metabolism of the body. Normal range is between 36.5-37.5 degrees Celsius (°C).
Time frame: Immediately Postoperative, Postoperative Day 1, 2, 3, 4
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Incentive Spirometer Control Arm | Body Temperature | Postoperative Day 1 | 38.0 °C | Standard Deviation 1.4 |
| Incentive Spirometer Control Arm | Body Temperature | Postoperative Day 3 | 37.3 °C | Standard Deviation 0.3 |
| Incentive Spirometer Control Arm | Body Temperature | Postoperative Day 2 | 37.5 °C | Standard Deviation 0.4 |
| Incentive Spirometer Control Arm | Body Temperature | Postoperative Day 4 | 37.2 °C | Standard Deviation 0.2 |
| Incentive Spirometer Control Arm | Body Temperature | Postoperative | 36.8 °C | Standard Deviation 0.2 |
| GO2 Mouthpiece | Body Temperature | Postoperative Day 4 | 37.2 °C | Standard Deviation 0.2 |
| GO2 Mouthpiece | Body Temperature | Postoperative | 36.8 °C | Standard Deviation 0.3 |
| GO2 Mouthpiece | Body Temperature | Postoperative Day 1 | 37.7 °C | Standard Deviation 0.4 |
| GO2 Mouthpiece | Body Temperature | Postoperative Day 2 | 37.4 °C | Standard Deviation 0.3 |
| GO2 Mouthpiece | Body Temperature | Postoperative Day 3 | 37.4 °C | Standard Deviation 0.3 |
Secondary
Carbon Dioxide Level
Normal carbon dioxide (CO2) levels in blood range from 35.0 mmHg to 45.0 mmHg.
Time frame: Postextubation Hours 1, 6, 12 and 24
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Incentive Spirometer Control Arm | Carbon Dioxide Level | Postextubation Hour 1 | 38.2 mmHg | Standard Deviation 2.9 |
| Incentive Spirometer Control Arm | Carbon Dioxide Level | Postextubation Hour 6 | 37.0 mmHg | Standard Deviation 4.8 |
| Incentive Spirometer Control Arm | Carbon Dioxide Level | Postextubation Hour 12 | 37.3 mmHg | Standard Deviation 5.1 |
| Incentive Spirometer Control Arm | Carbon Dioxide Level | Postextubation Hour 24 | 36.8 mmHg | Standard Deviation 5.1 |
| GO2 Mouthpiece | Carbon Dioxide Level | Postextubation Hour 24 | 38.1 mmHg | Standard Deviation 3.8 |
| GO2 Mouthpiece | Carbon Dioxide Level | Postextubation Hour 1 | 39 mmHg | Standard Deviation 3.3 |
| GO2 Mouthpiece | Carbon Dioxide Level | Postextubation Hour 12 | 36.9 mmHg | Standard Deviation 4.2 |
| GO2 Mouthpiece | Carbon Dioxide Level | Postextubation Hour 6 | 37.2 mmHg | Standard Deviation 4.4 |
Secondary
FEV1
Forced expiratory volume in one second (FEV1) is measured during a spirometry test, also known as a pulmonary function test, which involves forcefully breathing out into a mouthpiece connected to a spirometer machine. FEV1 is the amount of air forced from lungs in one second. To describe severity of pulmonary disease, FEV1 can be expressed as a percentage of the predicted value. Values 80% and and greater of the predicted value are considered normal.
Time frame: Preoperative and postoperative day 3
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Incentive Spirometer Control Arm | FEV1 | Preoperative | 86.4 percentage of the predicted FEV1 value | Standard Deviation 10.1 |
| Incentive Spirometer Control Arm | FEV1 | Postoperative Day 3 | 35.9 percentage of the predicted FEV1 value | Standard Deviation 8 |
| GO2 Mouthpiece | FEV1 | Preoperative | 93.7 percentage of the predicted FEV1 value | Standard Deviation 8.9 |
| GO2 Mouthpiece | FEV1 | Postoperative Day 3 | 43.1 percentage of the predicted FEV1 value | Standard Deviation 10.7 |
Secondary
Forced Vital Capacity (FVC)
Forced vital capacity (FVC) is measured during a spirometry test, also known as a pulmonary function test, which involves forcefully breathing out into a mouthpiece connected to a spirometer machine. FVC is the total amount of air exhaled during the FEV test. FVC can be expressed as a percentage of the predicted value.The normal range for the percent of the predicted value is between 80% and 120%.
Time frame: Preoperative, Postoperative Day 3
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Incentive Spirometer Control Arm | Forced Vital Capacity (FVC) | Preoperative | 85.7 percentage of the predicted FVC value | Standard Deviation 9.8 |
| Incentive Spirometer Control Arm | Forced Vital Capacity (FVC) | Postoperative Day 3 | 38.0 percentage of the predicted FVC value | Standard Deviation 9.9 |
| GO2 Mouthpiece | Forced Vital Capacity (FVC) | Preoperative | 90.1 percentage of the predicted FVC value | Standard Deviation 8.3 |
| GO2 Mouthpiece | Forced Vital Capacity (FVC) | Postoperative Day 3 | 41.6 percentage of the predicted FVC value | Standard Deviation 10.5 |
Secondary
Number of Participants With Normal Atelectasis Score
Atelectasis is a lung condition that happens when the airways don't expand normally. Atelectasis is measured with the modified radiological atelectasis score (m-RAS). Each pulmonary lobe, including the lingula, is scored 0-3 (0=normal, 1=plate or minor infiltrate, 2= moderate atelectasis, 3= total atelectasis). The scores of the six lobes are then summed to give a total score ranging from 0 to 18 with higher scores being associated with worse outcomes. For this analysis, scores were categorized as 0 (normal) or greater than 0 (not normal). The count of participants with a normal atelectasis score at the indicated time point are presented here.
Time frame: Immediately postoperative, Postoperative days 1, 2, 3, 4
Population: This analysis includes participants who completed the chest x-ray at the indicated visits. The atelectasis score could not be determined for one participant at postoperative day 3 and two participants at postoperative day 4 because chest x-rays were not performed.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Incentive Spirometer Control Arm | Number of Participants With Normal Atelectasis Score | Postoperative Day 1 | 0 Participants |
| Incentive Spirometer Control Arm | Number of Participants With Normal Atelectasis Score | Postoperative Day 3 | 0 Participants |
| Incentive Spirometer Control Arm | Number of Participants With Normal Atelectasis Score | Postoperative Day 2 | 0 Participants |
| Incentive Spirometer Control Arm | Number of Participants With Normal Atelectasis Score | Postoperative Day 4 | 2 Participants |
| Incentive Spirometer Control Arm | Number of Participants With Normal Atelectasis Score | Immediately Postoperative | 0 Participants |
| GO2 Mouthpiece | Number of Participants With Normal Atelectasis Score | Postoperative Day 4 | 0 Participants |
| GO2 Mouthpiece | Number of Participants With Normal Atelectasis Score | Immediately Postoperative | 2 Participants |
| GO2 Mouthpiece | Number of Participants With Normal Atelectasis Score | Postoperative Day 1 | 0 Participants |
| GO2 Mouthpiece | Number of Participants With Normal Atelectasis Score | Postoperative Day 2 | 0 Participants |
| GO2 Mouthpiece | Number of Participants With Normal Atelectasis Score | Postoperative Day 3 | 0 Participants |
Secondary
Oxygen Requirement
Oxygen was provided by a nasal cannula. The flow rate of supplemental oxygen that participants required after surgery is assessed as liters per minute. Higher flow rate indicates an increased need for supplemental oxygen.
Time frame: Postextubation Hours 1, 6, 12 and 24, Postoperative Days 2, 3, and 4
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Incentive Spirometer Control Arm | Oxygen Requirement | Postextubation Hour 24 | 2.4 liters of oxygen per minute | Standard Deviation 2.8 |
| Incentive Spirometer Control Arm | Oxygen Requirement | Postextubation Hour 1 | 3.7 liters of oxygen per minute | Standard Deviation 1.26 |
| Incentive Spirometer Control Arm | Oxygen Requirement | Postoperative Day 2 | 2.0 liters of oxygen per minute | Standard Deviation 1.6 |
| Incentive Spirometer Control Arm | Oxygen Requirement | Postextubation Hour 12 | 2.2 liters of oxygen per minute | Standard Deviation 1.5 |
| Incentive Spirometer Control Arm | Oxygen Requirement | Postoperative Day 3 | 1.1 liters of oxygen per minute | Standard Deviation 1.2 |
| Incentive Spirometer Control Arm | Oxygen Requirement | Postoperative Day 4 | 0.6 liters of oxygen per minute | Standard Deviation 1 |
| Incentive Spirometer Control Arm | Oxygen Requirement | Postextubation Hour 6 | 2.3 liters of oxygen per minute | Standard Deviation 0.7 |
| GO2 Mouthpiece | Oxygen Requirement | Postoperative Day 4 | 0.5 liters of oxygen per minute | Standard Deviation 1.1 |
| GO2 Mouthpiece | Oxygen Requirement | Postextubation Hour 1 | 3.7 liters of oxygen per minute | Standard Deviation 1.7 |
| GO2 Mouthpiece | Oxygen Requirement | Postextubation Hour 6 | 2.4 liters of oxygen per minute | Standard Deviation 0.8 |
| GO2 Mouthpiece | Oxygen Requirement | Postextubation Hour 12 | 2.1 liters of oxygen per minute | Standard Deviation 0.3 |
| GO2 Mouthpiece | Oxygen Requirement | Postextubation Hour 24 | 2.3 liters of oxygen per minute | Standard Deviation 0.7 |
| GO2 Mouthpiece | Oxygen Requirement | Postoperative Day 2 | 2.3 liters of oxygen per minute | Standard Deviation 1.1 |
| GO2 Mouthpiece | Oxygen Requirement | Postoperative Day 3 | 1.7 liters of oxygen per minute | Standard Deviation 0.9 |
Secondary
Respiratory Rate
Respiratory rate is the number of breaths taken per minute. The normal respiration rate for an adult at rest is 16 to 20 breaths per minute.
Time frame: Postextubation Hours 1, 6, 12 and 24, Postoperative Days 2, 3, and 4
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Incentive Spirometer Control Arm | Respiratory Rate | Postextubation Hour 6 | 21.2 breaths per minute | Standard Deviation 5.5 |
| Incentive Spirometer Control Arm | Respiratory Rate | Postextubation Hour 24 | 20.7 breaths per minute | Standard Deviation 3.8 |
| Incentive Spirometer Control Arm | Respiratory Rate | Postextubation Hour 1 | 21.3 breaths per minute | Standard Deviation 4 |
| Incentive Spirometer Control Arm | Respiratory Rate | Postoperative Day 2 | 21.7 breaths per minute | Standard Deviation 4.9 |
| Incentive Spirometer Control Arm | Respiratory Rate | Postextubation Hour 12 | 21.0 breaths per minute | Standard Deviation 3.9 |
| Incentive Spirometer Control Arm | Respiratory Rate | Postoperative Day 3 | 18.4 breaths per minute | Standard Deviation 1.3 |
| Incentive Spirometer Control Arm | Respiratory Rate | Postoperative Day 4 | 18.0 breaths per minute | Standard Deviation 1.7 |
| GO2 Mouthpiece | Respiratory Rate | Postextubation Hour 12 | 19.2 breaths per minute | Standard Deviation 3.3 |
| GO2 Mouthpiece | Respiratory Rate | Postoperative Day 3 | 18.4 breaths per minute | Standard Deviation 1.3 |
| GO2 Mouthpiece | Respiratory Rate | Postextubation Hour 1 | 20.5 breaths per minute | Standard Deviation 5.8 |
| GO2 Mouthpiece | Respiratory Rate | Postextubation Hour 6 | 17.9 breaths per minute | Standard Deviation 4.8 |
| GO2 Mouthpiece | Respiratory Rate | Postoperative Day 4 | 18.6 breaths per minute | Standard Deviation 1.3 |
| GO2 Mouthpiece | Respiratory Rate | Postextubation Hour 24 | 18.9 breaths per minute | Standard Deviation 3.2 |
| GO2 Mouthpiece | Respiratory Rate | Postoperative Day 2 | 20.6 breaths per minute | Standard Deviation 3.4 |