Effect of Inverse Ratio Ventilation During Induction of General Anesthesia on Safe Apnea Time in Obese Patients

Obesity Clinical Trial

Official title:

Effect of Inverse Ratio Ventilation During Induction of General Anesthesia on Safe Apnea Time in Obese Patients:A Randomized Controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04627883
• Other study ID #: 2020-718
• Status: Completed
• Phase: N/A
• Start date: April 1, 2020
• Est. completion date: August 1, 2020

Study information

• Verified date: October 2020
• Source: General Hospital of Ningxia Medical University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to investigate the clinical application value of inverse ratio ventilation in obese patients during induction of general anesthesia by studying the effect of inverse ratio ventilation on the safe apnea time.

Description:

Inverse ratio ventilation(IRV) can produce mean airway pressure(Pmean)similar to external positive end expiratory pressure(Peep) by increasing inspiratory time. Moreover, the increase of Pmean was not accompanied by the further increase of peak airway pressure (Ppeak) and airway plateau pressure (Pplat), while the application of external peep accompanied with the increase of Pplat increased the risk of barotrauma . High level of Peep increased cardiac load and decreased cardiac output. A number of studies have found that the hemodynamic stability of patients can be achieved when IRV regulates the inspiratory / expiratory ratio in an appropriate range (I: E < 2:1). Therefore, the inverse ratio is considered to be superior to Peep in terms of gas exchange and respiratory mechanics.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 40
• Est. completion date: August 1, 2020
• Est. primary completion date: August 1, 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• Obese patients, aged 18-65 years, of either gender, ASA grade II-III, body mass index (BMI) > 30 kg / m2, scheduled for general anesthesia under tracheal intubation, signed informed consent.

Exclusion Criteria:

• Patients who need rapid sequence induction (RSI); patients with expected difficult airway; severe chronic respiratory diseases, such as tuberculosis, bronchitis, bronchial asthma and COPD; patients with severe cardiovascular diseases, such as severe ischemic heart disease and pulmonary hypertension; patients with severe cerebrovascular diseases, such as cerebral hemorrhage and cerebral infarction; patients with abnormal basal metabolic rate, such as pregnancy, thyrotoxicosis, pheochromocytoma; and severe stomach reflux disease; patients with abnormal hemoglobin and hematocrit.

Related Conditions & MeSH terms

• Apnea
• Obesity

Intervention

Other:
• Inspiratory-to-expiratory (I : E) ratio of 1:2
After preoxygenation and induction of anesthesia, noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 1:2 for 5 min before endotracheal intubation.
• Inspiratory-to-expiratory (I : E) ratio of 2:1
After preoxygenation and induction of anesthesian, noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 2:1 for 5 min before endotracheal intubation.

Locations

Country	Name	City	State
China	General Hospital of Ningxia Medical University	General Hospital Of Ningxia Medical University	Ningxia
China	General Hospital of Ningxia Medical University	Yinchuan	Ningxia

Sponsors (1)

Lead Sponsor	Collaborator
General Hospital of Ningxia Medical University

Country where clinical trial is conducted

China, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Safe Apnea Time	The safe apnea time was defined as that period of time during which the arterial saturation as measured by pulse oximetry remained at or above 93% .	The arterial saturation as measured by pulse oximetry remained at or above 93% after endotracheal intubation immediately.
Secondary	EtO2	Fractional concentration of oxygen in end-tidal gas	After 3 minutes of preoxygenation After 5 minutes of noninvasive positive pressure ventilation
Secondary	EtO2	Fractional concentration of oxygen in end-tidal gas	After 3 minutes of noninvasive positive pressure ventilation
Secondary	EtO2	Fractional concentration of oxygen in end-tidal gas	After 5 minutes of noninvasive positive pressure ventilation