Does Pulmonary Compliance Optimization Through PEEP Manipulations Reduces the Incidence of Postoperative Hypoxaemia in Bariatric Surgery?

Bariatric Surgery Clinical Trial

Official title:

Does Pulmonary Compliance Optimization Through PEEP Manipulations Reduces the Incidence of Postoperative Hypoxaemia in Bariatric Surgery?

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02579798
• Other study ID #: CHUB-CRF
• Status: Completed
• Phase: N/A
• First received: October 12, 2015
• Last updated: January 18, 2018
• Start date: July 2013
• Est. completion date: March 2016

Study information

• Verified date: January 2018
• Source: Brugmann University Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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 information / eligibility

• Status: Completed
• Enrollment: 100
• Est. completion date: March 2016
• Est. primary completion date: December 2015
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

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

Related Conditions & MeSH terms

• Bariatric Surgery
• Hypoxia

Intervention

Device:
• PEEP (positive end-expiratory pressure)

Locations

Country	Name	City	State
Belgium	CHU Brugmann	Brussels

Sponsors (1)

Lead Sponsor	Collaborator
Brugmann University Hospital

Country where clinical trial is conducted

Belgium, 

References & Publications (15)

Almarakbi WA, Fawzi HM, Alhashemi JA. Effects of four intraoperative ventilatory strategies on respiratory compliance and gas exchange during laparoscopic gastric banding in obese patients. Br J Anaesth. 2009 Jun;102(6):862-8. doi: 10.1093/bja/aep084. Epub 2009 Apr 29. — View Citation

Coussa M, Proietti S, Schnyder P, Frascarolo P, Suter M, Spahn DR, Magnusson L. Prevention of atelectasis formation during the induction of general anesthesia in morbidly obese patients. Anesth Analg. 2004 May;98(5):1491-5, table of contents. — View Citation

Eichenberger A, Proietti S, Wicky S, Frascarolo P, Suter M, Spahn DR, Magnusson L. Morbid obesity and postoperative pulmonary atelectasis: an underestimated problem. Anesth Analg. 2002 Dec;95(6):1788-92, table of contents. — View Citation

Futier E, Constantin JM, Pelosi P, Chanques G, Kwiatkoskwi F, Jaber S, Bazin JE. Intraoperative recruitment maneuver reverses detrimental pneumoperitoneum-induced respiratory effects in healthy weight and obese patients undergoing laparoscopy. Anesthesiology. 2010 Dec;113(6):1310-9. doi: 10.1097/ALN.0b013e3181fc640a. — View Citation

Gander S, Frascarolo P, Suter M, Spahn DR, Magnusson L. Positive end-expiratory pressure during induction of general anesthesia increases duration of nonhypoxic apnea in morbidly obese patients. Anesth Analg. 2005 Feb;100(2):580-4. — View Citation

Gattinoni L, Carlesso E, Brazzi L, Caironi P. Positive end-expiratory pressure. Curr Opin Crit Care. 2010 Feb;16(1):39-44. doi: 10.1097/MCC.0b013e3283354723. Review. — View Citation

Hans GA, Sottiaux TM, Lamy ML, Joris JL. Ventilatory management during routine general anaesthesia. Eur J Anaesthesiol. 2009 Jan;26(1):1-8. doi: 10.1097/EJA.0b000e000000f1fb. Review. — View Citation

Imberger G, McIlroy D, Pace NL, Wetterslev J, Brok J, Møller AM. Positive end-expiratory pressure (PEEP) during anaesthesia for the prevention of mortality and postoperative pulmonary complications. Cochrane Database Syst Rev. 2010 Sep 8;(9):CD007922. doi: 10.1002/14651858.CD007922.pub2. Review. Update in: Cochrane Database Syst Rev. 2014;6:CD007922. — View Citation

Maisch S, Reissmann H, Fuellekrug B, Weismann D, Rutkowski T, Tusman G, Bohm SH. Compliance and dead space fraction indicate an optimal level of positive end-expiratory pressure after recruitment in anesthetized patients. Anesth Analg. 2008 Jan;106(1):175-81, table of contents. doi: 10.1213/01.ane.0000287684.74505.49. — View Citation

Mercat A, Richard JC, Vielle B, Jaber S, Osman D, Diehl JL, Lefrant JY, Prat G, Richecoeur J, Nieszkowska A, Gervais C, Baudot J, Bouadma L, Brochard L; Expiratory Pressure (Express) Study Group. Positive end-expiratory pressure setting in adults with acute lung injury and acute respiratory distress syndrome: a randomized controlled trial. JAMA. 2008 Feb 13;299(6):646-55. doi: 10.1001/jama.299.6.646. — View Citation

Pelosi P, Ravagnan I, Giurati G, Panigada M, Bottino N, Tredici S, Eccher G, Gattinoni L. Positive end-expiratory pressure improves respiratory function in obese but not in normal subjects during anesthesia and paralysis. Anesthesiology. 1999 Nov;91(5):1221-31. — View Citation

Reinius H, Jonsson L, Gustafsson S, Sundbom M, Duvernoy O, Pelosi P, Hedenstierna G, Fredén F. Prevention of atelectasis in morbidly obese patients during general anesthesia and paralysis: a computerized tomography study. Anesthesiology. 2009 Nov;111(5):979-87. doi: 10.1097/ALN.0b013e3181b87edb. — View Citation

Strang CM, Hachenberg T, Fredén F, Hedenstierna G. Development of atelectasis and arterial to end-tidal PCO2-difference in a porcine model of pneumoperitoneum. Br J Anaesth. 2009 Aug;103(2):298-303. doi: 10.1093/bja/aep102. Epub 2009 May 13. — View Citation

Tusman G, Böhm SH, Suarez-Sipmann F, Turchetto E. Alveolar recruitment improves ventilatory efficiency of the lungs during anesthesia. Can J Anaesth. 2004 Aug-Sep;51(7):723-7. — View Citation

Whalen FX, Gajic O, Thompson GB, Kendrick ML, Que FL, Williams BA, Joyner MJ, Hubmayr RD, Warner DO, Sprung J. The effects of the alveolar recruitment maneuver and positive end-expiratory pressure on arterial oxygenation during laparoscopic bariatric surgery. Anesth Analg. 2006 Jan;102(1):298-305. Erratum in: Anesth Analg. 2006 Mar;102(3):881. — View Citation

* Note: There are 15 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Number of hypoxemia episodes (Sp02<90%)	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.	continuously during 48h after surgery
Primary	Number of hypoxemia episodes (Sp02<95%)	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.	continuously during 48h after surgery
Secondary	Number of recruitment manoeuvers	Recruitment manoeuver are performed if patient saturation drops below 95%.	From the beginning of the surgery till moment 1 (after induction/intubation, patient laying flat, without pneumoperitoneum)
Secondary	Number of recruitment manoeuvers	Recruitment manoeuver are performed if patient saturation drops below 95%.	From moment 1 till moment 2 (after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
Secondary	Number of recruitment manoeuvers	Recruitment manoeuver are performed if patient saturation drops below 95%.	From moment 2 till moment 3 (after pneumoperitoneum exsufflation - patient lying flat)
Secondary	Number of recruitment manoeuvers	Recruitment manoeuver are performed if patient saturation drops below 95%.	From moment 3 till the end of the surgery (patient leaving the theater)
Secondary	Pulmonary dynamic compliance (Cd) - preoperative	This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O	Just before surgery, at ambient air contact
Secondary	Pulmonary dynamic compliance (Cd) - moment 1	This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O	just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory
Secondary	Pulmonary dynamic compliance (Cd) -moment 2	This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Pulmonary dynamic compliance (Cd) -moment 3	This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	Pulmonary dynamic compliance (Cd) -if recruitment manoeuvers	This will be determined by the following formula: Cd = Vt/P(peak)-PEEP and expressed in mL/cmH2O	Five minutes after any recruitment manoeuver
Secondary	Anatomic dead space - preoperative	This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)	Just before surgery, at ambient air contact
Secondary	Anatomic dead space -moment 1	This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)	just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory
Secondary	Anatomic dead space -moment 2	This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Anatomic dead space -moment 3	This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	Anatomic dead space -if recruitment manoeuvers	This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)	Five minutes after any recruitment manoeuver
Secondary	PaO2/FiO2 ratio - preoperative	Arterial oxygen partial pressure to fractional inspired oxygen ratio	Just before surgery, at ambient air contact
Secondary	PaO2/FiO2 ratio - moment 1	Arterial oxygen partial pressure to fractional inspired oxygen ratio	just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory
Secondary	PaO2/FiO2 ratio - moment 2	Arterial oxygen partial pressure to fractional inspired oxygen ratio	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	PaO2/FiO2 ratio - moment 3	Arterial oxygen partial pressure to fractional inspired oxygen ratio	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	PaO2/FiO2 ratio - if recruitment manoeuvers	Arterial oxygen partial pressure to fractional inspired oxygen ratio	Five minutes after any recruitment manoeuver
Secondary	PaCO2-EtCO2 gradient - preoperative	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.	Just before surgery, at ambient air contact
Secondary	PaCO2-EtCO2 gradient - moment 1	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.	just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory
Secondary	PaCO2-EtCO2 gradient - moment 2	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.	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	PaCO2-EtCO2 gradient - moment 3	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.	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	PaCO2-EtCO2 gradient - if recruitment manoeuvers	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.	Five minutes after any recruitment manoeuver
Secondary	Number of respiratory complications	Number of hospitalisations due to respiratory complications within 30 days after surgery.	30 days after surgery
Secondary	Number of postoperative wound infections	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).	30 days after surgery
Secondary	Pre-operative physiologic measures: cardiac frequency (FC)	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	Just before surgery, at ambient air contact
Secondary	Pre-operative physiologic measures: Arterial tension (TA)	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	Just before surgery, at ambient air contact
Secondary	Pre-operative physiologic measures: pH	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	Just before surgery, at ambient air contact
Secondary	Pre-operative physiologic measures: partial pressure of carbon dioxide in the arterial blood (PaCO2)	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens).	Just before surgery, at ambient air contact
Secondary	Operative physiologic measures - moment 1: FC	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after induction/intubation, patient laying flat, without pneumoperitoneum
Secondary	Operative physiologic measures - moment 1: PAM (Average arterial pressure)	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after induction/intubation, patient laying flat, without pneumoperitoneum
Secondary	Operative physiologic measures - moment 1: pH	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after induction/intubation, patient laying flat, without pneumoperitoneum
Secondary	Operative physiologic measures - moment 1: PaCO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after induction/intubation, patient laying flat, without pneumoperitoneum
Secondary	Operative physiologic measures - moment 1: CO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after induction/intubation, patient laying flat, without pneumoperitoneum
Secondary	Operative physiologic measures - moment 2: FC	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Operative physiologic measures - moment 2: PAM	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Operative physiologic measures - moment 2: pH	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Operative physiologic measures - moment 2: PaCO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Operative physiologic measures - moment 2: CO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Operative physiologic measures - moment 3: FC	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	Operative physiologic measures - moment 3: PAM	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	Operative physiologic measures - moment 3: pH	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	Operative physiologic measures - moment 3: CO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	Operative physiologic measures - moment 3: PaCO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	Operative physiologic measures - if recruitment manoeuvers occurs: FC	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	Five minutes after any recruitment manoeuver
Secondary	Operative physiologic measures - if recruitment manoeuvers occurs: PAM	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	Five minutes after any recruitment manoeuver
Secondary	Operative physiologic measures - if recruitment manoeuvers occurs: SpO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	Five minutes after any recruitment manoeuver
Secondary	Operative physiologic measures - if recruitment manoeuvers occurs: pH	The hemodynamic and respiratory parameters of the patient are measured by means of a Datex-Ohmeda Acertys machine (Aisys type).	Five minutes after any recruitment manoeuver
Secondary	Operative physiologic measures - if recruitment manoeuvers occurs: PaCO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	Five minutes after any recruitment manoeuver
Secondary	Operative physiologic measures - if recruitment manoeuvers occurs: PaO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	Five minutes after any recruitment manoeuver
Secondary	Operative physiologic measures - if recruitment manoeuvers occurs: CO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	Five minutes after any recruitment manoeuver
Secondary	Pre-operative physiologic measures: partial pressure of oxygen in the arterial blood (PaO2)	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	Just before surgery, at ambient air contact
Secondary	Operative physiologic measures - moment 1: PaO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after induction/intubation, patient laying flat, without pneumoperitoneum
Secondary	Operative physiologic measures - moment 2: PaO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Operative physiologic measures - moment 3: PaO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after pneumoperitoneum exsufflation - patient lying flat
Secondary	Pre-operative physiologic measures: Oxygen Pulsated Saturation (SpO2)	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	Just before surgery, at ambient air contact
Secondary	Operative physiologic measures - moment 1: SpO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after induction/intubation, patient laying flat, without pneumoperitoneum
Secondary	Operative physiologic measures - moment 2: SpO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
Secondary	Operative physiologic measures - moment 3: SpO2	The gasometric parameters of the patient are analyzed with a Rapidlab 1265 machine (Siemens)	just after pneumoperitoneum exsufflation - patient lying flat