Peroperative Use of Positive End-expiratory Pressure Prevents Formation of Atelectasis as Studied by Computerised Tomography at End of Surgery

Atelectasis Clinical Trial

Official title:

Peroperative Use of Positive End-expiratory Pressure Prevents Formation of Atelectasis as Studied by Computerised Tomography at End of Surgery

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02548416
• Other study ID #: Dnr 2015/338
• Status: Completed
• Phase: N/A
• First received: September 1, 2015
• Last updated: November 19, 2017
• Start date: November 2015
• Est. completion date: November 2016

Study information

• Verified date: November 2016
• Source: Region Västmanland
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Atelectasis is common during and after general anaesthesia and a number of interventions have been suggested in order to prevent their formation. The use of Positive End Expiratory Pressure (PEEP) during general anaesthesia has in recent years been questioned.

The investigators hypothesize that the use of PEEP as a single intervention improves oxygenation and prevents atelectasis as investigated by computed tomography compared to a control group with zero PEEP.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 24
• Est. completion date: November 2016
• Est. primary completion date: November 2016
• Accepts healthy volunteers: No
• Gender: All
• Age group: 40 Years to 75 Years

Eligibility

Inclusion Criteria:

• Healthy subjects, American Society of Anesthesiology (ASA) I-II.

• Patients scheduled for non-abdominal day case surgery under general anaesthesia.

Exclusion Criteria:

• ASA class III or higher.

• Body Mass Index (BMI) 30 or higher.

• Arterial oxygen saturation (SpO2) <96% breathing air.

• Chronic Obstructive Pulmonary Disease (COPD).

• Ischaemic heart disease.

• Known or anticipated difficult airway.

• Active smokers and ex-smokers with a history of more than 6 pack years.

• Need for interscalene or supraclavicular plexus block for postoperative pain relief (risk of phrenic nerve paralysis).

Related Conditions & MeSH terms

• Atelectasis
• Pulmonary Atelectasis

Intervention

Procedure:
• Positive end-expiratory pressure
Induction of anaesthesia is performed in a conventional manner using a target controlled infusion of propofol and remifentanil. Intubation of the trachea is facilitated by rocuronium. As soon as correct position of the endotracheal tube is confirmed, controlled ventilation is started with a tidal volume of 7 mL/kg body weight and a respiratory frequency of 10. The fresh gas flow is set to 1 litre/min with an oxygen mixture of 40%, aiming for an inspired oxygen fraction (FiO2) of 30-35%. Positive end-expiratory pressure is set to 6 or 8 cm H20 (8 if BMI>25) in the intervention group. Unless the patient´s SpO2 falls below 90%, the FiO2 remains unchanged throughout the procedure.
• Control group, zero PEEP
Induction of anaesthesia is performed in a conventional manner using a target controlled infusion of propofol and remifentanil. Intubation of the trachea is facilitated by rocuronium. As soon as correct position of the endotracheal tube is confirmed, controlled ventilation is started with a tidal volume of 7 mL/kg body weight and a respiratory frequency of 10. The fresh gas flow is set to 1 litre/min with an oxygen mixture of 40%, aiming for an inspired oxygen fraction (FiO2) of 30-35%. Zero PEEP is used. Unless the patient´s SpO2 falls below 90%, the FiO2 remains unchanged throughout the procedure.

Locations

Country	Name	City	State
Sweden	Region Västmanland	Köping

Sponsors (1)

Lead Sponsor	Collaborator
Region Västmanland

Country where clinical trial is conducted

Sweden, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Area of atelectasis expressed as centimeter^2	The area of atelectasis in the lungs is assessed by computed tomography (CT) 5-10 mm above the dome of the right diaphragm and expressed in centimeter^2 and as a percentage of the total lung area in the particular scan.	Within 1-2 hours, just before emergence from anesthesia.The outcome measure (atelectasis) will be investigated at just one point i.e. end of surgery but before emergence from anaesthesia.
Primary	Measurement of aeras with different aeration in the particular CT scan.	The areas of different aeration are assessed by computed tomography (CT) 5-10 mm above the dome of the right diaphragm and expressed in centimeter^2 and as a percentage of the total lung area in the particular scan.	Within 1-2 hours, just before emergence from anesthesia.The outcome measure (atelectasis) will be investigated at just one point i.e. end of surgery but before emergence from anaesthesia.
Secondary	Oxygenation, oxygen tension in arterial blood expressed in kilo Pascal (kPa)	Arterial blood gas samples will be drawn and analyzed at the same time as the computed tomography scan will be undertaken.	Within 1-2 hours, just before emergence from anesthesia. At end of surgery but before emergence from anaesthesia, at the same time as the lungs are investigated by computed tomography.
Secondary	Oxygenation, oxygen tension in arterial blood expressed in kilo Pascal (kPa)	Arterial blood gas samples will be drawn and analyzed 15 minutes after emergence from anesthesia and extubation.	Within 2 hours perioperatively, 15 minutes after extubation.