Does Pulmonary Compliance Optimization Through PEEP Manipulations Reduces the Incidence of Postoperative Hypoxaemia in Bariatric Surgery?
- Conditions
- Bariatric Surgery
- Registration Number
- NCT02579798
- Lead Sponsor
- Brugmann University Hospital
- Brief Summary
General anesthesia, even in patients in good health, impairs gas exchanges and ventilatory mechanics. These effects result primarily from atelectasis formation. They occur in 85-90% of healthy patients in the minutes following the induction when a positive end expiratory pressure (PEEP) is not used.
The functional residual capacity (FRC) of obese patients during general anesthesia is even smaller than the one of healthy patients. There is a direct relationship between the body mass index and the decrease of the functional residual capacity. Obese patients have therefore more atelectasis. The increased abdominal pressure during the pneumoperitoneum will increase the decrease of the CRF, and thus aggravate the formation of these atelectasis.
Atelectasis affect the peroperative gas exchanges and are likely to be involved in the worsening of postoperative hypoxemia episodes. In addition, atelectasis alter the clearance of secretions and the lymph flow, which predispose to lung infections.Taking all these factors into account, it is logical to think that the atelectasis presence can lead to an increase of the postsurgical morbidity (respiratory distress, infections). That is why actively fighting against the formation of these atelectasis is important.
There is a lack of scientific evidence to say that the strategies against atelectasis as PEEP have a significant impact on the patient's postoperative status. The expected clinical benefits balance (reduction of respiratory distress episodes, infections and mortality) versus the risks linked to the maneuvers done to reduce the development of atelectasis (barotraumas, cardiac complications) remains to be determined.
The primary goal of this study is to evaluate the impact of two different alveolar recruitment strategies on the incidence of postoperative hypoxemia in obese patients after bariatric surgery.
The secondary objectives of this study are to compare the number of recruitment maneuvers, the Pa02 / FI02 ratio (ratio of arterial oxygen partial pressure to fractional inspired oxygen), the dynamic compliance, the anatomic dead space and intraoperative PaCO2-EtCO2 gradient (arterial and end tidal gradient) between two alveolar recruitment strategies applied in obese patients during laparoscopic bariatric surgery (gastric bypass or sleeve gastrectomy).
The tertiary objectives of this study are to report the number of respiratory complications and postoperative wound infections at the 30th postoperative day.
- Detailed Description
General anesthesia, even in patients in good health, impairs gas exchanges and ventilatory mechanics. These effects result primarily from atelectasis formation. They occur in 85-90% of healthy patients in the minutes following the induction when a positive end expiratory pressure (PEEP) is not used.
These atelectasis are formed on one hand by the reduction of the functional residual capacity (FRC) following a compression mechanism (loss of the inspiratory muscle tone, which is accompanied by a chest wall configuration change and a diaphragm cephalic movement) and on the other hand by a denitrogenation absorption process (ventilation at high Fi02 (oxygen inspired fraction) causing complete absorption of O2 with lack of support for the alveolus, which then collapses).
The FRC of obese patients during general anesthesia is even smaller than the one of healthy patients. There is a direct relationship between the body mass index and the decrease of the functional residual capacity. Obese patients have therefore more atelectasis. The increased abdominal pressure during the pneumoperitoneum will increase the decrease of the CRF, and thus aggravate the formation of these atelectasis.
Atelectasis affect the peroperative gas exchanges and are likely to be involved in the worsening of postoperative hypoxemia episodes. In addition, atelectasis alter the clearance of secretions and the lymph flow, which predispose to lung infections.Taking all these factors into account, it is logical to think that the atelectasis presence can lead to an increase of the postsurgical morbidity (respiratory distress, infections). That is why actively fighting against the formation of these atelectasis is important.
Several strategies have been studied in order to improve respiratory mechanics and reduce impaired gas exchange during laparoscopic surgery in obese patients. The position called "chair", mechanical ventilation with PEEP, recruitment maneuvers followed by the PEEP, and spontaneous ventilation with CPAP before extubation, are all strategies that have proven effective to decrease development these atelectasis.
Currently, the scientific community agrees on the fact that PEEP improves intraoperative respiratory function (improved compliance, oxygenation) especially in conjunction with recruitment maneuvers.
But there is a lack of scientific evidence to say that the strategies against atelectasis as PEEP have a significant impact on the patient's postoperative status. The expected clinical benefits balance (reduction of respiratory distress episodes, infections and mortality) versus the risks linked to the maneuvers done to reduce the development of atelectasis (barotraumas, cardiac complications) remains to be determined.
The primary goal of this study is to evaluate the impact of two different alveolar recruitment strategies on the incidence of postoperative hypoxemia in obese patients after bariatric surgery.
The secondary objectives of this study are to compare the number of recruitment maneuvers, the Pa02 / FI02 ratio, the dynamic compliance, the anatomic dead space and intraoperative PaCO2-EtCO2 gradient between two alveolar recruitment strategies applied in obese patients during laparoscopic bariatric surgery (gastric bypass or sleeve gastrectomy).
The tertiary objectives of this study are to report the number of respiratory complications and postoperative wound infections at the 30th postoperative day.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 100
- ASA score (American Society of Anesthesiologists ) of II or III
- BMI > 35 kg/m²
- Elective laparoscopic bariatric surgery: gastric bypass or sleeve
- Restrictive (CPT <65%) or obstructive (VEMS/CV < 69%) chronic lung disease
- Increase of the intracranial pressure
- History of smoking with chronic obstructive disease (VEMS/CV)
- Active tabagism
- Ongoing pregnancy
- History of heart failure (NYHA III or IV) or coronary artery disease
- Urgent surgery
- Allergy to a drug used within the study
- Lack of written informed consent
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Primary Outcome Measures
Name Time Method Number of hypoxemia episodes (Sp02<90%) continuously during 48h after surgery This will be monitored by a portable saturometer (OxyTrue A, Bluepoint, Germany). This saturometer will allow the investigators to count the number of hypoxemia episodes (Sp02\<90%) and their duration in obese patients, in the postoperative period.
Number of hypoxemia episodes (Sp02<95%) continuously during 48h after surgery This will be monitored by a portable saturometer (OxyTrue A, Bluepoint, Germany). This saturometer will allow the investigators to count the number of hypoxemia episodes (Sp02\<95%) and their duration in obese patients, in the postoperative period.
- Secondary Outcome Measures
Name Time Method Pulmonary dynamic compliance (Cd) - moment 1 just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O
Anatomic dead space -moment 1 just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)
Anatomic dead space -moment 2 just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)
PaO2/FiO2 ratio - preoperative Just before surgery, at ambient air contact Arterial oxygen partial pressure to fractional inspired oxygen ratio
Number of recruitment manoeuvers From moment 3 till the end of the surgery (patient leaving the theater) Recruitment manoeuver are performed if patient saturation drops below 95%.
Pulmonary dynamic compliance (Cd) -moment 3 just after pneumoperitoneum exsufflation - patient lying flat This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O
Pulmonary dynamic compliance (Cd) -if recruitment manoeuvers Five minutes after any recruitment manoeuver This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O
Anatomic dead space -moment 3 just after pneumoperitoneum exsufflation - patient lying flat This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)
PaCO2-EtCO2 gradient - moment 1 just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory The gradient between the partial pressure of carbon dioxide in the arterial blood (PaCO2) and the CO2 end-tidal partial pressure (EtCO2) is used to evaluate the effectiveness of alveolar recruitment.
PaCO2-EtCO2 gradient - moment 2 just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation The gradient between the partial pressure of carbon dioxide in the arterial blood (PaCO2) and the CO2 end-tidal partial pressure (EtCO2) is used to evaluate the effectiveness of alveolar recruitment.
PaCO2-EtCO2 gradient - moment 3 just after pneumoperitoneum exsufflation - patient lying flat The gradient between the partial pressure of carbon dioxide in the arterial blood (PaCO2) and the CO2 end-tidal partial pressure (EtCO2) is used to evaluate the effectiveness of alveolar recruitment.
Number of respiratory complications 30 days after surgery Number of hospitalisations due to respiratory complications within 30 days after surgery.
Pre-operative physiologic measures: partial pressure of carbon dioxide in the arterial blood (PaCO2) Just before surgery, at ambient air contact The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens).
Operative physiologic measures - moment 1: FC just after induction/intubation, patient laying flat, without pneumoperitoneum The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - moment 1: PaCO2 just after induction/intubation, patient laying flat, without pneumoperitoneum The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 3: pH just after pneumoperitoneum exsufflation - patient lying flat The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Pulmonary dynamic compliance (Cd) - preoperative Just before surgery, at ambient air contact This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O
Pulmonary dynamic compliance (Cd) -moment 2 just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O
Anatomic dead space - preoperative Just before surgery, at ambient air contact This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)
Pre-operative physiologic measures: Arterial tension (TA) Just before surgery, at ambient air contact The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Pre-operative physiologic measures: pH Just before surgery, at ambient air contact The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - moment 1: pH just after induction/intubation, patient laying flat, without pneumoperitoneum The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - moment 2: FC just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - moment 3: CO2 just after pneumoperitoneum exsufflation - patient lying flat The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 3: PaCO2 just after pneumoperitoneum exsufflation - patient lying flat The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - if recruitment manoeuvers occurs: PAM Five minutes after any recruitment manoeuver The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - moment 2: PaO2 just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Pre-operative physiologic measures: Oxygen Pulsated Saturation (SpO2) Just before surgery, at ambient air contact The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 2: SpO2 just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Anatomic dead space -if recruitment manoeuvers Five minutes after any recruitment manoeuver This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)
PaO2/FiO2 ratio - moment 2 just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation Arterial oxygen partial pressure to fractional inspired oxygen ratio
PaCO2-EtCO2 gradient - preoperative Just before surgery, at ambient air contact The gradient between the partial pressure of carbon dioxide in the arterial blood (PaCO2) and the CO2 end-tidal partial pressure (EtCO2) is used to evaluate the effectiveness of alveolar recruitment.
PaCO2-EtCO2 gradient - if recruitment manoeuvers Five minutes after any recruitment manoeuver The gradient between the partial pressure of carbon dioxide in the arterial blood (PaCO2) and the CO2 end-tidal partial pressure (EtCO2) is used to evaluate the effectiveness of alveolar recruitment.
Number of postoperative wound infections 30 days after surgery All patients are seen at the surgical consultation on day 30 after surgery. The anamnesis performed during that consultation enables the investigators to identify patients with wound infections (defined as a need for local or oral antibiotics, additional hospitalisation or abnormal cicatrisation).
Operative physiologic measures - moment 2: PAM just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - moment 2: pH just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - if recruitment manoeuvers occurs: FC Five minutes after any recruitment manoeuver The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - if recruitment manoeuvers occurs: SpO2 Five minutes after any recruitment manoeuver The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - if recruitment manoeuvers occurs: PaCO2 Five minutes after any recruitment manoeuver The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Pre-operative physiologic measures: partial pressure of oxygen in the arterial blood (PaO2) Just before surgery, at ambient air contact The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 1: SpO2 just after induction/intubation, patient laying flat, without pneumoperitoneum The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
PaO2/FiO2 ratio - moment 1 just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory Arterial oxygen partial pressure to fractional inspired oxygen ratio
PaO2/FiO2 ratio - moment 3 just after pneumoperitoneum exsufflation - patient lying flat Arterial oxygen partial pressure to fractional inspired oxygen ratio
PaO2/FiO2 ratio - if recruitment manoeuvers Five minutes after any recruitment manoeuver Arterial oxygen partial pressure to fractional inspired oxygen ratio
Pre-operative physiologic measures: cardiac frequency (FC) Just before surgery, at ambient air contact The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - moment 1: CO2 just after induction/intubation, patient laying flat, without pneumoperitoneum The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 3: PAM just after pneumoperitoneum exsufflation - patient lying flat The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - if recruitment manoeuvers occurs: pH Five minutes after any recruitment manoeuver The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - if recruitment manoeuvers occurs: PaO2 Five minutes after any recruitment manoeuver The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 3: PaO2 just after pneumoperitoneum exsufflation - patient lying flat The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 1: PAM (Average arterial pressure) just after induction/intubation, patient laying flat, without pneumoperitoneum The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - moment 2: PaCO2 just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 2: CO2 just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 3: FC just after pneumoperitoneum exsufflation - patient lying flat The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).
Operative physiologic measures - if recruitment manoeuvers occurs: CO2 Five minutes after any recruitment manoeuver The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 1: PaO2 just after induction/intubation, patient laying flat, without pneumoperitoneum The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Operative physiologic measures - moment 3: SpO2 just after pneumoperitoneum exsufflation - patient lying flat The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)
Trial Locations
- Locations (1)
CHU Brugmann
🇧🇪Brussels, Belgium
CHU Brugmann🇧🇪Brussels, Belgium