The Effects of Subanesthetic Ketamine on Respiratory Stimulation and Transpulmonary Pressures in Mechanically Ventilated Critically Ill Patients
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 15
- 试验地点
- 4
- 主要终点
- Change in minute ventilation
研究概览
简要总结
Impairment of airway patency is a common cause of extubation failure and opioids and hypnotics can adversely affect airway patency. Ketamine, a noncompetitive antagonist of N-methyl-D-aspartate (NMDA), unlike other anesthetics activates respiratory effort and promotes bronchodilation. At subanesthetic plasma concentration, ketamine reduces both opioid and propofol requirements.
The purpose of this pharmaco-physiological interaction trial is to evaluate the effects of ketamine on breathing and electroencephalography in mechanically ventilated patients.
详细描述
Maintaining the patency of the upper airway in sedated and anesthetized patients is challenging especially when patients are ready to be weaned from mechanical ventilation. Spontaneous breathing trial (SBT) is used to expedite the weaning process, which oftentimes requires the reduction and/or discontinuation of sedatives and analgesics. In some surgical patients, reducing these medications can lead to pain associated agitation and inability to conduct SBTs, which may prolong the need for mechanical ventilation. Using medications with narcotic sparing effects and that do not cause respiratory depression may allow for the reduction or discontinuation of agents that depress respiratory drive and subsequently facilitate extubation.
Ketamine has been used for many years in critically ill patients for sedation and analgesia. This noncompetitive antagonist of N-methyl-D-aspartate (NMDA) is used as an anesthetic and analgesic and has been shown to reduce opioid consumption and to prevent the development of opioid tolerance. Unlike other anesthetics, ketamine activates respiratory effort and promotes bronchodilation. At subanesthetic plasma concentration, ketamine reduces both opioid and propofol requirements.
The goal of this pharmaco-physiological interaction trial is to evaluate the effects of ketamine at a subanesthetic dose on breathing and electroencephalography. The investigators hypothesize that ketamine drip at a subanesthetic infusion rate (low dose ketamine 5 - 10 mcg/kg/min) is associated with respiratory stimulating effects and does not markedly increase transpulmonary pressure in mechanically ventilated patients.
The primary outcome is respiratory function, assessed through peak inspiratory flow, tidal volume,respiratory rate, duty cycle, and minute ventilation measured 15 minutes prior to initiation of ketamine infusion (to serve as baseline), at 60 minutes of ketamine infusion at 5mcg/kg/min, at another 60 minutes of infusion at 10mcg/kg/min, at which point the infusion is stopped for 3 hours for a final set of measurements.
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
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
- •Age ≥ 18 years admitted to ICU requiring mechanical ventilation
- •Suitable for spontaneous breathing trial
- •Candidate to received low dose ketamine by the primary critical care team
排除标准
- •Esophageal injury
- •Allergic to ketamine
- •Known neurodegenerative disorders
- •Major neurologic disorders (elevated ICP)
研究组 & 干预措施
Cohort
Adult mechanically ventilated patients who are deemed eligible for a spontaneous breathing trial and are candidates to receive subanesthetic ketamine by the primary critical care team.
干预措施: Subanesthetic ketamine (Drug)
结局指标
主要结局
Change in minute ventilation
时间窗: Measured 15 minutes prior to initiation of ketamine infusion, at 60 minutes of ketamine infusion at 5mcg/kg/min, at another 60 minutes of infusion at 10mcg/kg/min, and at 2 hours after stopping the infusion
Measured using a pneumotach (Hans Rudolph Inc., Shawnee, KS) connected to the ventilation tubing of the patient during the spontaneous breathing trials.
Change in peak inspiratory flow
时间窗: Measured 15 minutes prior to initiation of ketamine infusion, at 60 minutes of ketamine infusion at 5mcg/kg/min, at another 60 minutes of infusion at 10mcg/kg/min, and at 2 hours after stopping the infusion
Measured using a pneumotach (Hans Rudolph Inc., Shawnee, KS) connected to the ventilation tubing of the patient during the spontaneous breathing trials.
Change in duty cycle
时间窗: Measured 15 minutes prior to initiation of ketamine infusion, at 60 minutes of ketamine infusion at 5mcg/kg/min, at another 60 minutes of infusion at 10mcg/kg/min, and at 2 hours after stopping the infusion
Measured using a pneumotach (Hans Rudolph Inc., Shawnee, KS) connected to the ventilation tubing of the patient during the spontaneous breathing trials.
Change in respiratory rate
时间窗: Measured 15 minutes prior to initiation of ketamine infusion, at 60 minutes of ketamine infusion at 5mcg/kg/min, at another 60 minutes of infusion at 10mcg/kg/min, and at 2 hours after stopping the infusion
Measured using a pneumotach (Hans Rudolph Inc., Shawnee, KS) connected to the ventilation tubing of the patient during the spontaneous breathing trials.
Change in tidal volume
时间窗: Measured 15 minutes prior to initiation of ketamine infusion, at 60 minutes of ketamine infusion at 5mcg/kg/min, at another 60 minutes of infusion at 10mcg/kg/min, and at 2 hours after stopping the infusion
Measured using a pneumotach (Hans Rudolph Inc., Shawnee, KS) connected to the ventilation tubing of the patient during the spontaneous breathing trials.
次要结局
- Changes in power spectrum densities(Continuously throughout the ketamine infusion until 3 hours after stopping the ketamine infusion.)
- Total narcotic consumption(3 hours after stopping the ketamine infusion)
- Number of days mechanically ventilated(3 hours after stopping the ketamine infusion)
- Critical care pain observation tool (CPOT)(3 hours after stopping the ketamine infusion)
- Confusion Assessment Measurement for the ICU (CAM-ICU)(3 hours after stopping the ketamine infusion)
- Richmond Agitation Sedation Scale (RASS)(3 hours after stopping the ketamine infusion)
- Transpulmonary pressure(Continuously throughout the study until stopping the ketamine infusion.)
- Changes in volumetric capnography(Periods of at least five minutes during steady state breathing before and after administration of ketamine.)
- Oxygen blood saturation(Continuously throughout the ketamine infusion until 3 hours after stopping the ketamine infusion.)
研究者
Lorenzo Berra, MD
Medical Director, Respiratory Care
Massachusetts General Hospital