Clinical trial NCT02579798: Does Pulmonary Compliance Optimization Through PEEP Manipulations Reduces the Incidence of Postoperative Hypoxaemia in Bariatric Surgery?
Official title: Does Pulmonary Compliance Optimization Through PEEP Manipulations Reduces the Incidence of Postoperative Hypoxaemia in Bariatric Surgery?
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Bariatric Surgery
Keywords: Bariatric surgery
Post-surgery hypoxemia
Obesity
Lead sponsor: Brugmann University Hospital
Sponsor class: OTHER
First posted: 2015-10-20
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

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.

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

Primary outcomes:
measure: Number of hypoxemia episodes (Sp02<90%)
timeFrame: continuously during 48h after surgery
measure: Number of hypoxemia episodes (Sp02<95%)
timeFrame: continuously during 48h after surgery
Secondary outcomes:
measure: Number of recruitment manoeuvers
timeFrame: From the beginning of the surgery till moment 1 (after induction/intubation, patient laying flat, without pneumoperitoneum)
measure: Number of recruitment manoeuvers
timeFrame: From moment 1 till moment 2 (after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation)
measure: Number of recruitment manoeuvers
timeFrame: From moment 2 till moment 3 (after pneumoperitoneum exsufflation - patient lying flat)
measure: Number of recruitment manoeuvers
timeFrame: From moment 3 till the end of the surgery (patient leaving the theater)
measure: Pulmonary dynamic compliance (Cd) - preoperative
timeFrame: Just before surgery, at ambient air contact
measure: Pulmonary dynamic compliance (Cd) - moment 1
timeFrame: just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory
measure: Pulmonary dynamic compliance (Cd) -moment 2
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Pulmonary dynamic compliance (Cd) -moment 3
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: Pulmonary dynamic compliance (Cd) -if recruitment manoeuvers
timeFrame: Five minutes after any recruitment manoeuver
measure: Anatomic dead space - preoperative
timeFrame: Just before surgery, at ambient air contact
measure: Anatomic dead space -moment 1
timeFrame: just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory
measure: Anatomic dead space -moment 2
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Anatomic dead space -moment 3
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: Anatomic dead space -if recruitment manoeuvers
timeFrame: Five minutes after any recruitment manoeuver
measure: PaO2/FiO2 ratio - preoperative
timeFrame: Just before surgery, at ambient air contact
measure: PaO2/FiO2 ratio - moment 1
timeFrame: just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory
measure: PaO2/FiO2 ratio - moment 2
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: PaO2/FiO2 ratio - moment 3
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: PaO2/FiO2 ratio - if recruitment manoeuvers
timeFrame: Five minutes after any recruitment manoeuver
measure: PaCO2-EtCO2 gradient - preoperative
timeFrame: Just before surgery, at ambient air contact
measure: PaCO2-EtCO2 gradient - moment 1
timeFrame: just after the anesthesia induction/intubation, patient laying flat, without pneumoperitory
measure: PaCO2-EtCO2 gradient - moment 2
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: PaCO2-EtCO2 gradient - moment 3
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: PaCO2-EtCO2 gradient - if recruitment manoeuvers
timeFrame: Five minutes after any recruitment manoeuver
measure: Number of respiratory complications
timeFrame: 30 days after surgery
measure: Number of postoperative wound infections
timeFrame: 30 days after surgery
measure: Pre-operative physiologic measures: cardiac frequency (FC)
timeFrame: Just before surgery, at ambient air contact
measure: Pre-operative physiologic measures: Arterial tension (TA)
timeFrame: Just before surgery, at ambient air contact
measure: Pre-operative physiologic measures: pH
timeFrame: Just before surgery, at ambient air contact
measure: Pre-operative physiologic measures: partial pressure of carbon dioxide in the arterial blood (PaCO2)
timeFrame: Just before surgery, at ambient air contact
measure: Operative physiologic measures - moment 1: FC
timeFrame: just after induction/intubation, patient laying flat, without pneumoperitoneum
measure: Operative physiologic measures - moment 1: PAM (Average arterial pressure)
timeFrame: just after induction/intubation, patient laying flat, without pneumoperitoneum
measure: Operative physiologic measures - moment 1: pH
timeFrame: just after induction/intubation, patient laying flat, without pneumoperitoneum
measure: Operative physiologic measures - moment 1: PaCO2
timeFrame: just after induction/intubation, patient laying flat, without pneumoperitoneum
measure: Operative physiologic measures - moment 1: CO2
timeFrame: just after induction/intubation, patient laying flat, without pneumoperitoneum
measure: Operative physiologic measures - moment 2: FC
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Operative physiologic measures - moment 2: PAM
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Operative physiologic measures - moment 2: pH
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Operative physiologic measures - moment 2: PaCO2
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Operative physiologic measures - moment 2: CO2
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Operative physiologic measures - moment 3: FC
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: Operative physiologic measures - moment 3: PAM
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: Operative physiologic measures - moment 3: pH
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: Operative physiologic measures - moment 3: CO2
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: Operative physiologic measures - moment 3: PaCO2
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: Operative physiologic measures - if recruitment manoeuvers occurs: FC
timeFrame: Five minutes after any recruitment manoeuver
measure: Operative physiologic measures - if recruitment manoeuvers occurs: PAM
timeFrame: Five minutes after any recruitment manoeuver
measure: Operative physiologic measures - if recruitment manoeuvers occurs: SpO2
timeFrame: Five minutes after any recruitment manoeuver
measure: Operative physiologic measures - if recruitment manoeuvers occurs: pH
timeFrame: Five minutes after any recruitment manoeuver
measure: Operative physiologic measures - if recruitment manoeuvers occurs: PaCO2
timeFrame: Five minutes after any recruitment manoeuver
measure: Operative physiologic measures - if recruitment manoeuvers occurs: PaO2
timeFrame: Five minutes after any recruitment manoeuver
measure: Operative physiologic measures - if recruitment manoeuvers occurs: CO2
timeFrame: Five minutes after any recruitment manoeuver
measure: Pre-operative physiologic measures: partial pressure of oxygen in the arterial blood (PaO2)
timeFrame: Just before surgery, at ambient air contact
measure: Operative physiologic measures - moment 1: PaO2
timeFrame: just after induction/intubation, patient laying flat, without pneumoperitoneum
measure: Operative physiologic measures - moment 2: PaO2
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Operative physiologic measures - moment 3: PaO2
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
measure: Pre-operative physiologic measures: Oxygen Pulsated Saturation (SpO2)
timeFrame: Just before surgery, at ambient air contact
measure: Operative physiologic measures - moment 1: SpO2
timeFrame: just after induction/intubation, patient laying flat, without pneumoperitoneum
measure: Operative physiologic measures - moment 2: SpO2
timeFrame: just after peritoneal insufflation and anti-trendenlenbourg (anti-trent) implementation
measure: Operative physiologic measures - moment 3: SpO2
timeFrame: just after pneumoperitoneum exsufflation - patient lying flat
Other outcomes:
Locations:
city: Brussels
country: Belgium
facility: CHU Brugmann
Study officials:
affiliation: CHU Brugmann
name: Philippe Van der Linden, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: CHU Brugmann
name: Van Hecke Delphine, MD
role: PRINCIPAL_INVESTIGATOR
References:
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. doi: 10.1213/01.ane.0000111743.61132.99.
citation: 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.
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. doi: 10.1097/00000539-200212000-00060.
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. doi: 10.1213/01.ane.0000183655.57275.7a.
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.
citation: 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.
citation: 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.
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. doi: 10.1097/00000542-199911000-00011.
citation: 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.
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.
citation: 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.
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):580-584. doi: 10.1213/01.ANE.0000143339.40385.1B.
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.
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.
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.
citation: 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.