Airway Pressure Release Ventilation (APRV) Compared to ARDSnet Ventilation

Summary

Traditional modes of ventilation have failed to improve patient survival. Subsequent observations that elevated airway pressures observed in traditional forms of ventilation resulted in barotrauma and extension of ALI lead to the evolution of low volume cycled ventilation as a potentially better ventilatory modality for ARDS. Recent multicenter trials by the NIH-ARDS network have confirmed that low volume ventilation increases the number of ventilatory free days and improves overall patient survival. While reducing mean airway pressure has reduced barotrauma and improved patient survival, it has impaired attempts to improve alveolar recruitment. Alveolar recruitment is important as it improves V/Q mismatch, allows reduction in FIO2 earlier, and decreases the risk of oxygen toxicity. Airway pressure release ventilation (APRV) is a novel ventilatory modality that utilizes controlled positive airway pressure to maximize alveolar recruitment while minimizing barotrauma. In APRV, tidal ventilation occurs between the increase in lung volumes established by the application of CPAP and the relaxation of lung tissue following pressure release. Preliminary studies have suggested that APRV recruits collapsed alveoli and improves oxygenation through a restoration of pulmonary mechanics, but there are no studies indicating the potential overall benefit of APRV in recovery form ALI/ADRS.

Conditions

• Acute Lung Injury
• Adult Respiratory Distress Syndrome
• Kidney Injury

Interventions

DEVICE

Volume-Cycled Assist-Control (AC) mode

1. Patients ventilated with volume-cycled assist-control mode with PEEP and goal FIO2 \< 40% 2. Rate of mandatory time-cycled, pressure controlled breaths,initially at 12 per breaths/min 3. Initial tidal volume set at 8mL/kg using predicted body weight (PBW) with a goal of 6mL/kg \& setting positive end-expiratory pressure (PEEP) based on level of initial FiO2 4. Inspiratory to Expiratory ratio set at 1:1 to 1:3 5. If frequency of triggered breaths increased greater than 10 per min sedation will be increased. If needed,rate of mandatory breaths increased 6. Mgmt of PEEP will be conducted as per the ARDSnet Protocol 7. Oxygenation goal PaO2: PaO2-55-80 mm Hg O2 Sat: 88-95% 8. Tidal volume and respiratory rate adjusted to the desired pH and plateau pressures per ARDSnet protocol

DEVICE

Airway Pressure Release Ventilation (APRV) mode

1. Ventilation uses Drager Model X1 2. Spontaneous breathing allowed throughout ventilatory cycle at 2 airway pressure levels 3. Time periods for the high \& low pressure levels can be set independently 4. Duration of the lower pressure level will be adjusted to allow expiratory flow to decay to 75% of total volume 5. Duration of higher pressure levels will be adjusted to produce 12 pressure shifts per min 6. Spontaneous frequency will be targeted for 6 to 18 breaths/per min 7. If spontaneous breathing is achieved,level of sedation will be decreased 8. If spontaneous respirations are \>20 breaths/min, sedation will be increased 9. If spontaneous breathing frequency increased greater than 20/per min, sedation was increased and if needed the mechanical frequency increased

Sponsors & Collaborators

• University of Tennessee, Chattanooga

  lead OTHER

Principal Investigators

• James A Tumlin, MD · University of Tennessee

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

85 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-11-02

Primary Completion

2020-11-02

Completion

2020-11-02

Countries

• United States

Study Locations