Does Pulmonary Compliance Optimization Through PEEP Manipulations Reduces the Incidence of Postoperative Hypoxaemia in Bariatric Surgery?
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Bariatric Surgery
- Sponsor
- Brugmann University Hospital
- Enrollment
- 100
- Locations
- 1
- Primary Endpoint
- Number of hypoxemia episodes (Sp02<90%)
- Status
- Completed
- Last Updated
- 8 years ago
Overview
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.
Investigators
Philippe VAN DER LINDEN
Head of clinic
Brugmann University Hospital
Eligibility Criteria
Inclusion Criteria
- •ASA score (American Society of Anesthesiologists ) of II or III
- •BMI \> 35 kg/m²
- •Elective laparoscopic bariatric surgery: gastric bypass or sleeve
Exclusion Criteria
- •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
Outcomes
Primary Outcomes
Number of hypoxemia episodes (Sp02<90%)
Time Frame: 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%)
Time Frame: 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 Outcomes
- Pulmonary dynamic compliance (Cd) - moment 1(just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory)
- Anatomic dead space -moment 1(just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory)
- Anatomic dead space -moment 2(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- PaO2/FiO2 ratio - preoperative(Just before surgery, at ambient air contact)
- Number of recruitment manoeuvers(From moment 3 till the end of the surgery (patient leaving the theater))
- Pulmonary dynamic compliance (Cd) -moment 3(just after pneumoperitoneum exsufflation - patient lying flat)
- Pulmonary dynamic compliance (Cd) -if recruitment manoeuvers(Five minutes after any recruitment manoeuver)
- Anatomic dead space -moment 3(just after pneumoperitoneum exsufflation - patient lying flat)
- PaCO2-EtCO2 gradient - moment 1(just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory)
- PaCO2-EtCO2 gradient - moment 2(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- PaCO2-EtCO2 gradient - moment 3(just after pneumoperitoneum exsufflation - patient lying flat)
- Number of respiratory complications(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)
- Operative physiologic measures - moment 1: FC(just after induction/intubation, patient laying flat, without pneumoperitoneum)
- Operative physiologic measures - moment 1: PaCO2(just after induction/intubation, patient laying flat, without pneumoperitoneum)
- Operative physiologic measures - moment 3: pH(just after pneumoperitoneum exsufflation - patient lying flat)
- Pulmonary dynamic compliance (Cd) - preoperative(Just before surgery, at ambient air contact)
- Pulmonary dynamic compliance (Cd) -moment 2(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- Anatomic dead space - preoperative(Just before surgery, at ambient air contact)
- Pre-operative physiologic measures: Arterial tension (TA)(Just before surgery, at ambient air contact)
- Pre-operative physiologic measures: pH(Just before surgery, at ambient air contact)
- Operative physiologic measures - moment 1: pH(just after induction/intubation, patient laying flat, without pneumoperitoneum)
- Operative physiologic measures - moment 2: FC(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- Operative physiologic measures - moment 3: CO2(just after pneumoperitoneum exsufflation - patient lying flat)
- Operative physiologic measures - moment 3: PaCO2(just after pneumoperitoneum exsufflation - patient lying flat)
- Operative physiologic measures - if recruitment manoeuvers occurs: PAM(Five minutes after any recruitment manoeuver)
- Operative physiologic measures - moment 2: PaO2(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- Pre-operative physiologic measures: Oxygen Pulsated Saturation (SpO2)(Just before surgery, at ambient air contact)
- Operative physiologic measures - moment 2: SpO2(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- Anatomic dead space -if recruitment manoeuvers(Five minutes after any recruitment manoeuver)
- PaO2/FiO2 ratio - moment 2(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- PaCO2-EtCO2 gradient - preoperative(Just before surgery, at ambient air contact)
- PaCO2-EtCO2 gradient - if recruitment manoeuvers(Five minutes after any recruitment manoeuver)
- Number of postoperative wound infections(30 days after surgery)
- Operative physiologic measures - moment 2: PAM(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- Operative physiologic measures - moment 2: pH(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- Operative physiologic measures - if recruitment manoeuvers occurs: FC(Five minutes after any recruitment manoeuver)
- Operative physiologic measures - if recruitment manoeuvers occurs: SpO2(Five minutes after any recruitment manoeuver)
- Operative physiologic measures - if recruitment manoeuvers occurs: PaCO2(Five minutes after any recruitment manoeuver)
- Pre-operative physiologic measures: partial pressure of oxygen in the arterial blood (PaO2)(Just before surgery, at ambient air contact)
- Operative physiologic measures - moment 1: SpO2(just after induction/intubation, patient laying flat, without pneumoperitoneum)
- PaO2/FiO2 ratio - moment 1(just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory)
- PaO2/FiO2 ratio - moment 3(just after pneumoperitoneum exsufflation - patient lying flat)
- PaO2/FiO2 ratio - if recruitment manoeuvers(Five minutes after any recruitment manoeuver)
- Pre-operative physiologic measures: cardiac frequency (FC)(Just before surgery, at ambient air contact)
- Operative physiologic measures - moment 1: CO2(just after induction/intubation, patient laying flat, without pneumoperitoneum)
- Operative physiologic measures - moment 3: PAM(just after pneumoperitoneum exsufflation - patient lying flat)
- Operative physiologic measures - if recruitment manoeuvers occurs: pH(Five minutes after any recruitment manoeuver)
- Operative physiologic measures - if recruitment manoeuvers occurs: PaO2(Five minutes after any recruitment manoeuver)
- Operative physiologic measures - moment 3: PaO2(just after pneumoperitoneum exsufflation - patient lying flat)
- Operative physiologic measures - moment 1: PAM (Average arterial pressure)(just after induction/intubation, patient laying flat, without pneumoperitoneum)
- Operative physiologic measures - moment 2: PaCO2(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- Operative physiologic measures - moment 2: CO2(just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
- Operative physiologic measures - moment 3: FC(just after pneumoperitoneum exsufflation - patient lying flat)
- Operative physiologic measures - if recruitment manoeuvers occurs: CO2(Five minutes after any recruitment manoeuver)
- Operative physiologic measures - moment 1: PaO2(just after induction/intubation, patient laying flat, without pneumoperitoneum)
- Operative physiologic measures - moment 3: SpO2(just after pneumoperitoneum exsufflation - patient lying flat)