Clinical Trial: Role of Lung Ultrasound Imaging for Intraoperative Monitoring of Atelectasis During Laparoscopic Surgery

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Role of Lung Ultrasound Imaging for Intraoperative Monitoring of Atelectasis During Laparoscopic Surgery

Brief Summary:

General anesthesia results in the development of atelectasis in the dependent areas of the lungs exposing patients to an increased risk of hypoxemia. During laparoscopic procedures, pneumoperitoneum increases already present atelectasis.

Several methods have been suggested to reduce the impact of atelectasis during surgery. However, few intraoperative modalities for the diagnosis and monitoring of atelectasis are available. Lung ultrasound imaging is a promising non-invasive, non-radiant, portable and easy to use tool that as yet to be studied in the intraoperative setting.

This observational study will aim to clarify the role of lung ultrasound imaging during laparoscopic surgery for the diagnostic and monitoring of atelectasis.

This study is designed to:

  • Demonstrate a link between the lung ultrasound aeration score, the partial pressure of oxygen in arterial blood (PaO2) / fraction of inspired oxygen (FiO2) ratio and the oxygenation index.
  • In the event of intraoperative desaturation, study the impact of positive end-expiratory pressure (PEEP) and/or increase of FiO2 on the aeration score.
  • Study the impact of pain on diaphragmatic function and the aeration score.

Our hypothesis is that lung ultrasound imaging allows detection of lung aeration changes associated with induction of general anesthesia, pneumoperitoneum, emergence from anesthesia and changes occurring during the stay in the recovery room.


Detailed Summary:

On arrival in the operating theatre, each patient will undergo a baseline lung ultrasound examination.

The anesthetic technique and monitoring will be standardized. The radial artery will be cannulated after induction of anesthesia for blood gas monitoring.

Lung ultrasound examinations will be performed 5 minutes following induction of general anesthesia and 5 minutes after insufflation of the abdomen with carbon dioxide. In the event of a desaturation needing an intervention (increase of FiO2 or PEEP), ultrasound imaging will be repeated before and after the intervention. Presence of a pneumothorax or endobronchial intubation will be assessed during each examination. Fifteen minutes after arrival and immediately before discharge from the recovery room, lung ultrasound examinations will also be performed.

FiO2 and vital signs will be recorded at each ultrasound examination. Arterial blood samples will be collected simultaneously. Pain rating using the visual analog scale and diaphragmatic function will be assessed during the preoperative ultrasound examination and before discharge from the recovery room.


Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)

Current Primary Outcome: Lung aeration [ Time Frame: From arrival in the operating theatre to immediately before discharge from the recovery room (Day 0) ]

Estimate lung aeration by ultrasound imaging using a four point aeration score (0 = normal lung, 1 = moderate aeration loss, 2 = severe aeration loss, 3 = complete aeration loss and consolidation)


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Gas exchange [ Time Frame: From 5 minutes following induction of anesthesia to immediately before discharge from the recovery room (Day 0) ]
    Assess the impact of the different stages of anesthesia and surgery on gas exchange by measuring arterial blood gases.
  • Diaphragmatic function [ Time Frame: On arrival in the operating theatre and immediately before discharge from the recovery room (Day 0) ]
    Assess diaphragmatic function by ultrasound imaging
  • Incidence of pneumothorax [ Time Frame: From 5 minutes following induction of anesthesia to immediately before discharge from the recovery room (Day 0) ]
    Estimate the incidence of pneumothorax by ultrasound imaging
  • Incidence of endobronchial intubation [ Time Frame: From 5 minutes following induction of anesthesia to immediately before discharge from the recovery room (Day 0) ]
    Estimate the incidence endobronchial intubation by ultrasound imaging


Original Secondary Outcome: Same as current

Information By: Centre hospitalier de l'Université de Montréal (CHUM)

Dates:
Date Received: December 12, 2012
Date Started: April 2013
Date Completion:
Last Updated: September 12, 2013
Last Verified: September 2013