Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT05979129 |
| Other study ID # |
MD-65-2022 |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
August 6, 2023 |
| Est. completion date |
April 2024 |
Study information
| Verified date |
March 2024 |
| Source |
Kasr El Aini Hospital |
| Contact |
ahmed hasanin |
| Phone |
01095076954 |
| Email |
ahmedmohamedhasanin[@]gmail.com |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Gastric insufflation occurs when the inspiratory pressure exceeds the lower esophageal
sphincter pressure. Thus, it is desirable to avoid excessive positive pressure during mask
ventilation after induction of anesthesia and keeping the inspiratory pressure <15-20
cmH2O.In patients with obesity the lower compliance of the respiratory system usually
requires higher inspiratory pressures to maintain adequate ventilation making these patients
more prone to gastric insufflation. This high risk of gastric insufflation can be aggravated
by the use of positive end-expiratory pressure (PEEP) which is recommended to avoid lung
atelectasis. The application of PEEP during mask ventilation increases the risk of gastric
insufflation as it reduces the pressure threshold at which gastric insufflation occur The
optimum ventilatory strategy during mask ventilation should achieve the balance between
adequate lung ventilation and avoiding gastric insufflation. In obese patients, it is not
clear whether the use of PEEP during mask ventilation would increase the risk of gastric
insufflation or not.
We hypothesize that using zero end-expiratory pressure (ZEEP) or low PEEP during mask
ventilation would reduce the risk of gastric insufflation in comparison to high PEEP.
Description:
Upon arrival to the operating room, routine monitors (electrocardiogram, pulse oximetry, and
non-invasive blood pressure monitor) will be applied, intravenous line will be secured.
End-tidal CO2 monitoring will be initiated after induction of general anesthesia and starting
face-mask ventilation. All patients will be positioned in the ramped position (achieved by
elevation of the head and shoulders till achieving alignment of sternal notch and external
auditory meatus). Preoxygenation will be achieved by pressure support ventilation with 5
cmH2O and FiO2 of 0.8 without PEEP for three minutes. Induction of anesthesia will be
achieved using fentanyl (2 mcg/Kg lean body weight), propofol (2 mg/Kg lean body weight), and
rocuronium (0.6 mg/Kg ideal body weight). After loss of verbal response, mask ventilation
will be achieved by appropriate size face mask and oropharyngeal airway with 100% oxygen and
double hand jaw thrust head tilt maneuver. The included patients will be receiving
volume-controlled ventilation adjusted to deliver tidal volume of 8-10 mL/kg (ideal body
weight), at I:E ratio of 1:2, inspiratory pause of 0.5 s, respiratory rate of 12 breath per
minute, FiO2 of 0.8.
The 3 study groups will receive the planned ventilatory strategy for 120 seconds.
Assessment gastric insufflation during mask ventilation will be achieved by ultrasound
assessment of gastric antrum (at the sagittal plane between left lobe of the liver and
pancreas at level of the aorta). Gastric antral cross-sectional area (CSA) [ (longitudinal
diameter) X (anteroposterior diameter) X π /4] will be assessed in between contractions
before face mask ventilation and after insertion of endotracheal tube. [9] The proportion of
change in the CSA will be calculated as (delta CSA %= [CSA after intubation - baseline CSA] /
baseline CSA X 100). Significant gastric insufflation will be identified if the CSA increased
by > 30% after endotracheal intubation in relation to the baseline.
Intermittent gastric auscultation will be performed during mask ventilation at 30, 60, 90,
120 seconds by a blinded investigator (the presence of gastric insufflation will be defined
as a gurgling sound).
