Obesity, PEEP and Postoperative Oxygenation

Oxygenation Clinical Trial

— ZAPPAII  

Official title:

Zero Positive End-expiratory Pressure Before Emergence Improves Postoperative Oxygenation in Obese Patients Undergoing Laparoscopic Surgery - a Randomized Clinical Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04150276
• Other study ID #: Dnr 2019/04860
• Status: Completed
• Phase: N/A
• Start date: December 3, 2019
• Est. completion date: January 25, 2023

Study information

• Verified date: January 2023
• Source: Region Västmanland
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

A study on overweight patients undergoing anesthesia for laparoscopic surgery.

• evaluation of positive end-expiratory pressure versus zero positive end-expiratory pressure during awakening on oxygenation in the early postoperative period.

Description:

Positive end-expiratory pressure (PEEP) is often used during mechanical ventilation to preserve end-expiratory lung volume. After emergence and extubation, this volume will diminish instantly. Some patients will have difficulties to restore functional residual capacity (FRC) during the early phase of recovery. If routine high FIO2 is being delivered together with maintained PEEP prior to extubation, several important prerequisites are established for the development of postoperative atelectasis. The investigators hypothesize that establishing zero positive end-expiratory pressure (ZEEP) immediately prior to emergence preoxygenation, will prevent gas with high oxygen concentration from entering dorso-basal areas of the lungs, and thereby diminishing postoperative atelectasis formation and improve oxygenation.

This randomized controlled study will study overweight patients undergoing general anesthesia for laparoscopic surgery. The patients in the two study groups will receive mechanical ventilation with identical settings, comprising low TV, PEEP, and no RM. Randomization will occur at the end of surgery, before awakening. The patients will be allocated to zero PEEP (ZEEP) or maintained PEEP during emergence preoxygenation and extubation. Importantly, the intervention group will have ZEEP established while still having low ETO2 levels, prior to any preoxygenation. Arterial blood gases will be collected before, during and after anaesthesia. Primary endpoint measure will be change in oxygenation from before awakening to after awakening.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 60
• Est. completion date: January 25, 2023
• Est. primary completion date: January 25, 2023
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

• Obese patients scheduled for elective laparocopic surgery.

• American Society of Anesthesiologists functional class I-III

• Body Mass Index 35-50 kg/m2

Exclusion Criteria:

• Body Mass Index =50 kg/m2

• Peripheral oxygen saturation (SpO2) breathing air <94 %

• Symtomatic asthma, COPD or heart failure

• Ischemic heart disease

• Hemoglobin < 100g/l

• Smokers and ex-smokers that stopped smoking < 9 months ago

• Need for peroperative RM and PEEP higher than in study protocol, as indicated by SpO2 <92% despite the stipulated FiO2 0.30-0.35.

• Obstructive sleep apnea syndrome on home-CPAP

Related Conditions & MeSH terms

• Oxygenation

Intervention

Procedure:
• ZEEP during awakening
ZEEP will be established 2 min prior to the start of emergence preoxygenation and awakening.
• PEEP during awakening
PEEP will be maintained throughout emergence preoxygenation and awakening.

Locations

Country	Name	City	State
Sweden	Dep. of Anaesthesia and Intensive Care	Västerås	Region Västmanland

Sponsors (1)

Lead Sponsor	Collaborator
Region Västmanland

Country where clinical trial is conducted

Sweden, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in oxygenation	Arterial blood samples will be collected for measurement of arterial oxygen partial pressure.	Bloodgases will be obtained 5 minutes before the start of the awakening procedure and 30 minutes after awakening and extubation.
Secondary	Need for postoperative supplemental oxygen	Number of patients and amount of oxygen needed in the respective group postoperatively.	First 3 hours postoperatively.