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

NCT02548416 | Completed

• 1 other identifier: Dnr 2015/338
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Atelectasis

Keywords

Atelectasis; Positive End-Expiratory Pressure; Oxygenation; Anaesthesia; Computed tomography

Outcome Measures

Primary Outcomes (2)

• 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.

• 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 Outcomes (2)

• Oxygenation, oxygen tension in arterial blood expressed in kilo Pascal (kPa)

  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.

• Oxygenation, oxygen tension in arterial blood expressed in kilo Pascal (kPa)

  Within 2 hours perioperatively, 15 minutes after extubation.

Study Arms (2)

PEEP group

ACTIVE COMPARATOR

Induction and maintenance of anaesthesia in a conventional manner. Peroperative ventilatory settings using positive end-expiratory pressure.

Procedure: Positive end-expiratory pressure

Control group zero PEEP

ACTIVE COMPARATOR

Induction and maintenance of anaesthesia in a conventional manner. Peroperative ventilatory settings using zero end-expiratory pressure.

Procedure: Control group, zero PEEP

Interventions

Positive end-expiratory pressure PROCEDURE

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.

PEEP group

Control group, zero PEEP PROCEDURE

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.

Control group zero PEEP

Eligibility Criteria

• Age: 40 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy subjects, American Society of Anesthesiology (ASA) I-II.
• Patients scheduled for non-abdominal day case surgery under general anaesthesia.

You may not qualify if:

• 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).

Sponsors & Collaborators

• Region Västmanland: lead

Study Sites (1)

Region Västmanland

Köping, Sweden

Location

MeSH Terms

Conditions

Pulmonary Atelectasis

Interventions

Positive-Pressure Respiration; Control Groups

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Respiration, Artificial; Airway Management; Therapeutics; Respiratory Therapy; Epidemiologic Research Design; Epidemiologic Methods; Investigative Techniques; Research Design; Methods

Study Officials

• Lennart Edmark

  Region Västmanland

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: M.D.

Study Record Dates

• First Submitted: September 1, 2015
• First Posted: September 14, 2015
• Study Start: November 1, 2015
• Primary Completion: November 1, 2016
• Study Completion: November 1, 2016
• Last Updated: November 21, 2017

Record last verified: 2016-11

Locations

SE (1)