Ventilation Strategy for the Elderly Patients in Prone Position

Not Applicable

• Conditions: Ventilators, Mechanical
• Interventions: Procedure: ventilator setting vcv with pause; Procedure: ventilator setting pcv-vg; Procedure: ventilator setting vcv

• Registration Number: NCT04520893
• Lead Sponsor: Eunhee Chun

Brief Summary

The investigators compare three ventilation modes; volume controlled ventilation, volume guaranteed pressure controlled ventilation and volume controlled ventilation with pause during spine surgery for the elderly patients. The investigators can reveal that how lung collapse can be reduced by optimizing the inspiratory flow pattern under general anesthesia.

Detailed Description

\<Protocol\>

1. All patients were ventilated by an anaesthesia ventilator (Zeus, Dräger, Lübeck, Germany) under general anesthesia.

2. Ventilation strategy:

* Pressure controlled ventilation volume guaranteed (PCV-VG) mode or volume control ventilation (VCV) mode

* tidal volume 6-8 mL/kg (predicted body weight)

* Inspiratory/expiratory (I/E) ratio 1:1.5

* Inspired oxygen concentration (FIO2) 0.5 with air

* 3.0 L/min of inspiratory fresh gas flow

* Positive end-expiratory pressure (PEEP) of 5 cm H2O

* Respiratory rate (RR) of 10 to 14 min-1

3. After prone positioning and hemodynamic condition was stabilized, patients were ventilated with VCV, PCV-VG mode, VCV with pause following a randomized order, previously determined for each patient. Before each ventilator setting was started, lung recruitment maneuvers were performed to set the lungs to a defined baseline status.

* ventilation order : one of the following examples is taken by randomization.

VCV 15 min -- VCV pause 15min -- PCV-VG 15min

VCV 15 min -- PCV-VG 15min -- VCV pause 15min

VCV pause 15min -- VCV 15 min -- PCV-VG 15min

VCV pause 15min -- PCV-VG 15min -- VCV 15 min

PCV-VG 15min -- VCV 15 min -- VCV pause 15min

PCV-VG 15min -- VCV pause 15min -- VCV 15 min

Study Timeline

• Study First Submitted: 2020-08-17
• Study First Submitted QC: 2020-08-19
• Study First Posted: 2020-08-20
• Study Start: 2020-10-22
• Primary Completion: 2021-01-07
• Status Verified: 2021-02
• Last Update Submitted: 2021-02-17
• Last Update Posted: 2021-02-18
• Study Completion: 2021-03

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 45

Inclusion Criteria

• patients undergoing elective spine surgery under general anesthesia

Exclusion Criteria

• obesity (body mass index >35 kg/m2)
• chronic obstructive pulmonary disease
• respiratory infection

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
VCV pause	ventilator setting vcv with pause	volume controlled ventilation with pause time 30%
PCV-VG	ventilator setting pcv-vg	pressure controlled ventilation - volume guaranteed
VCV	ventilator setting vcv	volume controlled ventilation (without pause)

Primary Outcome Measures

Name	Time	Method
MVCO2	ventilation 15 min later	minute CO2 production (ml/min), a parameter of Drager ventilator, displayed in the Primus model and software

Secondary Outcome Measures

Name	Time	Method
airway compliance	ventilation 15 min later	Respiratory dynamic compliance (ml/cmH2O; displayed in the ventilator)
airway pressure	ventilation 15 min later	peak airway pressure (cmH2O; displayed in the ventilator), plateau pressure (cmH2O; diaplayed in the ventilator), driving pressure(cmH2O, plateau pressure minus peak airway pressure)

Trial Locations

Locations (1)

Hallym University Kangnam Sacred Hospital; 🇰🇷 Seoul, Korea, Republic of