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

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.

Study Overview

• Status: Completed
• Conditions: Bariatric Surgery
• Intervention / Treatment: Device: PEEP (positive end-expiratory pressure)

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.

• Study Type: Interventional
• Enrollment (Actual): 100
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Brussels, Belgium, 1020
    • CHU Brugmann

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PEEP 10 cmH20; In this group, a PEEP of 10 cmH20 is applied for the duration of the intervention and a recruitment maneuver is applied each time the SpO2 (oxygen pulsated saturation) drops below 95%.	Device: PEEP (positive end-expiratory pressure)
Active Comparator: optimal PEEP; In this group, 10 cmH20 PEEP is applied immediately. Then the "optimal PEEP" is sought at three key moments. It is determined by the best value of lung compliance found in the patient. It is sought by increasing or decreasing the value of the PEEP by increments or decrements of 2 cmH20. If after 6 respiratory cycles, the value of the compliance is increased, the investigator continues to increase the value of the PEEP. On the other hand, if the value of compliance is reduced, the investigator reduces the value of PEEP. The value of the PEEP selected shall in no event exceed the set pressure range (maximum pressure plate of 30 cmH20 and maximum inspiratory peak pressure 40cmH20). A recruitment maneuver is applied each time the SpO2 drops below 95%, as in the PEEP 10cmH2O group.	Device: PEEP (positive end-expiratory pressure)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
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)
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)
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)
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)
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
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
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
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
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
Anatomic dead space - preoperative	This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)	Just before surgery, at ambient air contact
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
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
Anatomic dead space -moment 3	This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)	just after pneumoperitoneum exsufflation - patient lying flat
Anatomic dead space -if recruitment manoeuvers	This will be determined by this formula: VD = VT (1-PEtCO2/PaC02)	Five minutes after any recruitment manoeuver
PaO2/FiO2 ratio - preoperative	Arterial oxygen partial pressure to fractional inspired oxygen ratio	Just before surgery, at ambient air contact
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
PaO2/FiO2 ratio - moment 2	Arterial oxygen partial pressure to fractional inspired oxygen ratio	just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
PaO2/FiO2 ratio - moment 3	Arterial oxygen partial pressure to fractional inspired oxygen ratio	just after pneumoperitoneum exsufflation - patient lying flat
PaO2/FiO2 ratio - if recruitment manoeuvers	Arterial oxygen partial pressure to fractional inspired oxygen ratio	Five minutes after any recruitment manoeuver
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
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
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
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
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
Number of respiratory complications	Number of hospitalisations due to respiratory complications within 30 days after surgery.	30 days after surgery
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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

Collaborators and Investigators

• Sponsor: Brugmann University Hospital
• Investigators: Principal Investigator: Van Hecke Delphine, MD, CHU Brugmann

Publications and helpful links

General Publications

• 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. doi: 10.1213/01.ane.0000111743.61132.99.
• 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):580-584. doi: 10.1213/01.ANE.0000143339.40385.1B.
• Reinius H, Jonsson L, Gustafsson S, Sundbom M, Duvernoy O, Pelosi P, Hedenstierna G, Freden 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.
• 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.
• 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. doi: 10.1097/00000539-200212000-00060.
• 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. doi: 10.1213/01.ane.0000183655.57275.7a. Erratum In: Anesth Analg. 2006 Mar;102(3):881.
• 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. doi: 10.1097/00000542-199911000-00011.
• Imberger G, McIlroy D, Pace NL, Wetterslev J, Brok J, Moller 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.
• 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.
• 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.
• Tusman G, Bohm 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. doi: 10.1007/BF03018433.
• Strang CM, Hachenberg T, Freden 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.
• 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.
• 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.
• 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.
• Van Hecke D, Bidgoli JS, Van der Linden P. Does Lung Compliance Optimization Through PEEP Manipulations Reduce the Incidence of Postoperative Hypoxemia in Laparoscopic Bariatric Surgery? A Randomized Trial. Obes Surg. 2019 Apr;29(4):1268-1275. doi: 10.1007/s11695-018-03662-x.

Study record dates

Study Major Dates

• Study Start: July 1, 2013
• Primary Completion (Actual): December 1, 2015
• Study Completion (Actual): March 1, 2016

Study Registration Dates

• First Submitted: October 12, 2015
• First Submitted That Met QC Criteria: October 16, 2015
• First Posted (Estimate): October 20, 2015

Study Record Updates

• Last Update Posted (Actual): January 19, 2018
• Last Update Submitted That Met QC Criteria: January 18, 2018
• Last Verified: January 1, 2018

More Information

Terms related to this study

• Keywords: Obesity; Bariatric surgery; Post-surgery hypoxemia
• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Hypoxia
• Other Study ID Numbers: CHUB-CRF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No