///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-06:00

Comparison of volumes of air delivered and peak airway pressures generated using maximal and normal bimanual compressions of an adult Ambu® bag through two lengths of Frova intubation bougies into a standard adult lung compliance simulator: a pilot study

Abstract Number: T-11
Abstract Type: Original Research

Preeti Dewan MBBS, MD, FRCA1 ; Simon Massey MBBS,MD,FRCA,FRCPC2; Vit Gunka MBBS, MD, FRCPC3; Alison Dube BSc4

Introduction: Blade Assisted Bougie Cricothyroidotomy can be life saving in a “can’t intubate, can’t oxygenate” emergency1, 2.The Frova bougie (Cook medical) may be used as a temporizing device for oxygen delivery.

We aimed to demonstrate that it is possible to deliver significant volumes of air through a Frova bougie using bimanual compression of an Ambu® bag. We compared the volume of air delivered and the peak airway pressures generated using two lengths of Frova bougies. We hypothesized that there would be greater resistance to the flow of air through the longer Frova bougie resulting in smaller tidal volumes.

Methods: This prospective, randomized, and blinded observational study was conducted in the department of Anesthesia, BC Women’s and Children’s Hospital, Vancouver. Written informed consent was obtained from 22 anesthesiologists.

The proximal end of a Frova bougie was connected via a Rapi-fit® connector to an adult 2L Ambu® bag. The distal end was inserted via a universal adaptor into the measurement port of a flow analyser PF-300 fitted with a standard adult lung compliance simulator. The participants bimanually squeezed the Ambu® bag, connected to one of the Frova bougies (14G-70 cm; 14G-65 cm), with a maximum and a normal effort in a random order, using a computer generated randomisation table. Each participant was assessed three times per group, and the mean values were calculated. For each ventilatory effort, the volume of air delivered, the peak airway pressure generated, peak flow and inspiratory time were measured. Descriptive statistics were used for analysis.

Results: The volume of air delivered with a maximum and a normal effort with the 65cm and the 70cm Frova bougie were 980.8ml±133.5ml and 605.9±103.4ml versus 980.2±111.9ml and 585.5±128.9ml. The peak airway pressures for the two groups with a maximum and a normal effort were 40.5±11.5cm of water and 22.5±3.4cm of water versus 38.2±10.3cm of water and 22±2.9cm of water respectively.

Conclusion: Clinically significant volumes of air can be delivered through a Frova. Significantly larger volumes and peak pressures were seen in the short Frova bougie group (p<0.05). There was a significant increase, in these measurements, when a maximum effort was used, compared to the normal effort (p<0.05). Further study and discussion are required prior to recommending this technique for oxygenation.


1. Br. J. Anaesth. 2015; 115 (6): 827-848

2. Acad Emerg Med, 2012; 19 (7): 876–879

SOAP 2016