Ventilation Strategy for the Elderly Patients in Prone Position

Eunhee Chun

Status: Unknown

Conditions: Ventilators, Mechanical

Treatments: Procedure: ventilator setting vcv; Procedure: ventilator setting pcv-vg; Procedure: ventilator setting vcv with pause

Study type: Interventional

Funder types: Other

Identifiers

NCT04520893

2020-03-010

Details and patient eligibility

About

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.

Full 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

Enrollment: 45 estimated patients

Sex: All

Ages: 65 to 85 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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45 participants in 3 patient groups

VCV pause

Experimental group

Description:

volume controlled ventilation with pause time 30%

Treatment:

Procedure: ventilator setting vcv with pause

VCV

Active Comparator group

Description:

volume controlled ventilation (without pause)

Treatment:

Procedure: ventilator setting vcv

PCV-VG

Active Comparator group

Description:

pressure controlled ventilation - volume guaranteed

Treatment:

Procedure: ventilator setting pcv-vg