Comparison Between NAVA and PSV in Neurocritical Patients: a Pilot Study
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 20
- 试验地点
- 2
- 主要终点
- NAVA safety- Change in cranial blood flow velocity
研究概览
简要总结
Partial assisted mechanical ventilation modes are widely used to manage respiratory failure. It has been demonstrated that they can reduce complications related to mechanical ventilation and neuromuscular blocking agents administration.
During partially assisted ventilation, there is no predefined respiratory rate and the patient must trigger each breath.
One of the most used partial assisted mode is pressure support ventilation (PSV), which plays a key role in weaning from mechanical ventilation, especially in neuro-cranial diseases.
Neurally adjusted ventilatory assist mode (NAVA) has been introduced in clinical practice in recent years. It has been widely demonstrated that NAVA is able to guarantee gas exchange in the same way as PSV in patients admitted to ICU for respiratory failure.
Thus, NAVA can improve patient-ventilator interaction reducing the incidence of asynchronous events and favoring the patient's own ventilatory pattern. Nevertheless, NAVA does not appear to have been applied in neuro ICU patients. In a study conducted on non-neurosurgical infants has been demonstrated negative effects of asynchronous events on cerebral blood flow velocities, examined with transcranial Doppler technique.
In the present pilot study, the investigators would like to compare NAVA and PSV ventilation influence on cranial blood flow, evaluated with Trans-Cranial Color Doppler, in patients admitted to ICU for neurological injuries.
详细描述
The aim of this pilot study is to compare NAVA and PSV in order to establish their influence on cranial blood flow, assessed in the mean cerebral artery (M1 tract bilaterally). Secondarily, it will be evaluated the effectiveness in guaranteeing the gas exchange and patient-ventilator interaction during each ventilation mode.
Patients will be evaluated in order to establish their readiness for assisted mechanical ventilation.
The following clinical criteria must be respected:
- a heart rate of less than 120 bpm, blood pressure between 90 and 180 mmHg;
- dopamine/dobutamine less than 5 mcg/kg/minute, norepinephrine less than 0.25 mcg/kg/min;
- PaO2/FiO2 > 150;
- PEEP (positive end-expiratory pressure) minor or equal to 10 cmH2O;
- Vt between 6 and 8 ml/kg;
- respiratory rate less than 35 breaths per minutes and without respiratory distress signs;
- blood pH between 7.35 and 7.45; Afterward, patients will be submitted to three different mechanical ventilation trials in partially assisted modes: the first one in PSV mode, the second one in NAVA mode and the third one in PSV mode again. Each trial will last 30 minutes. PSV will have PEEP set by clinician and pressure support will be set in order to obtain Vt between 6 and 8 ml/kg. NAVA will have the same PEEP as PSV and NAVA level will be set to obtain the same peak of Inspiratory pressure of PSV.
The expiratory trigger will be adjusted to the 50% of the inspiratory flow peak in PSV. During NAVA, the expiratory trigger is fixed to 75% of diaphragmatic electrical activity. The inspiratory fraction of oxygen (FiO2) will be set in order to obtain a peripheral oxygen saturation of more than 94%.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
盲法说明
the ultrasonography examiner is blind on the ventilatory mode
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Every ICU patient sedated and intubated, admitted for intracranial disease (neuromuscular disease and head trauma);
- •intracranial pressure monitoring
- •Mechanical ventilation for more than 48 hours
- •Readiness for assisted mechanical ventilation at the screening
排除标准
- •intracranial pressure instability more than 15 cmH2O;
- •symptomatic vasospasm;
- •average cerebral flow velocity at transcranial basal doppler in M1 more than 120 cm/sec
- •hemodynamic instability;
- •gastro-esophageal surgery in the previous 12 months;
- •gastro-esophageal bleeding in the previous 30 days;
- •history of esophageal varices;
- •maxillofacial trauma or surgery;
- •body temperature more than 38° C at the time of the study;
- •coagulation disorders;
- •PaCO2 not included in the basal range (between 35 and 45 mmHg) or paCo2 variation more than +/- 20% obtained in partially assisted mode compared to baseline;
- •pregnancy;
- •inclusion in other research projects;
结局指标
主要结局
NAVA safety- Change in cranial blood flow velocity
时间窗: After ventilatory modes is applied, a time range of 20 minutes will be considered necessary to assess cerebral blood flow. This evaluation will be performed over time range of 5-15 seconds (in any case the time of 3 doppler signal beats)
Ultrasound evaluation, using trans cranial doppler technique will be performed to evaluate the blood cerebral flow speed (average/systolic speed) near the point of emergency, in the middle tract and at the bifurcation of M1 bilaterally.
次要结局
- Gas exchange - pH(After ventilatory modes is applied, a time range of 20 minutes will be considered necessary to assess arterial blood gas analysis. this evaluation will be run at the end of each trial for a total of)
- Patient-ventilator interaction 1(After ventilatory modes is applied, a time range of 20 minutes will be considered necessary to assess arterial blood gas analysis. this evaluation will be run at the end of each trial for a total of 3 times per hour.)
- Patient-ventilator interaction 2(After ventilatory modes is applied, a time range of 20 minutes will be considered necessary to assess arterial blood gas analysis. this evaluation will be run at the end of each trial for a total of 3 times per hour.)
- Gas exchange - arterial oxygen tension(After ventilatory modes is applied, a time range of 20 minutes will be considered necessary to assess arterial blood gas analysis. this evaluation will be run at the end of each trial for a total of 3 sample in 60 minutes.)
- Patient-ventilator interaction 3(After ventilatory modes is applied, a time range of 20 minutes will be considered necessary to assess arterial blood gas analysis. this evaluation will be run at the end of each trial for a total of 3 times per hour.)
- Gas exchange - arterial carbon dioxide tension(After ventilatory modes is applied, a time range of 20 minutes will be considered necessary to assess arterial blood gas analysis. this evaluation will be run at the end of each trial for a total of 3 sample in 60 minutes.)
研究者
Gianmaria Cammarota
Principal investigator
Azienda Ospedaliero Universitaria Maggiore della Carita