Acute Respiratory Distress Syndrome, Mechanical Ventilation Complication, Sedation Complication
Conditions
Brief summary
This study will investigate how different types of routine sedation may affect patient's breathing whilst on a ventilator in the Intensive Care Unit (ICU). There are different approaches to sedation which may have advantages and disadvantages. During the study patients will receive both intravenous and inhaled volatile sedation (similar to anaesthetic 'gases' used for general anaesthesia) and the drive to breath, breathing efforts and function of the lung will be assessed.
Detailed description
It is routine for patients to be sedated for their comfort and safety whilst on a ventilator in the Intensive Care Unit (ICU). Conventionally sedatives are given intravenously, however inhaled volatile sedation is becoming more popular. Inhaled sedation has recently been approved by the National Institute for Health and Clinical Excellence (NICE) in the United Kingdom (UK). Whilst being on a ventilator can be life-saving, it can cause potential problems. It is important that the patient interacts well with the ventilator and that their own breathing efforts are well regulated. There is evidence that inhaled sedation can specifically help the lungs when patients have the Acute Respiratory Distress Syndrome (ARDS) and in particular, inhaled sedation does not appear to suppress patient's own breathing as much as conventional sedation. Greater spontaneous breathing by the patient is usually positive but needs to be carefully understood to ensure it is not excessive or damaging to the patient's already injured lungs. This study of 20 patients is designed to carefully measure the impact of inhaled sedation on the patient's breathing and lung function, in comparison to intravenous sedation. Measurements will be taken whilst on intravenous sedation before the patient is switched to an equivalent level of inhaled sedation for six hours, when the measurements will be repeated. Finally, the patient will go back to their original intravenous sedation and the measurements taken again. This is called a 'cross-over' study and is a good way to evaluate the effect of the drug.
Interventions
DRUGPropofol
Standard care, propofol sedation - 2 hour periods of observation before and after inhaled volatile sedation
DRUGIsoflurane
Inhaled volatile sedation for 6 hours - 2 hours wash in / wash out, followed by 4 hours of observations
Sponsors
Guy's and St Thomas' NHS Foundation Trust
Sedana Medical
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Masking description
None, open label, physiological study
Intervention model description
Prospective, cross-over trial design comparing intravenous versus inhaled volatile sedation
Eligibility
Sex/Gender
ALL
Age
17 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adult patients admitted to the Intensive Care Unit (ICU) * ARDS * Invasive mechanical ventilation (IMV) * Spontaneous breathing in pressures support mode (PSV) for less than or equal to 48 hours * Sedated with intravenous sedation (ie. propofol and / or midazolam and fentanyl or alternate short acting opioid) * Anticipated to remain on IMV and PSV and with a stable sedation score for a further 24 hours without planned sedation interruption / spontaneous breathing trial or other significant change in the level of ventilator support * Not receiving / anticipated to receive paralysis * In supine position
Exclusion criteria
* Personal or family history of malignant hyperpyrexia * Known or suspected elevated intracranial pressure * High dose vasopressors (ie. Noradrenaline \> 0.3mcg/kg/min or equivalent) * Contra-indication to oesophageal balloon (i.e. oesophageal / upper gastro-intestinal pathology) * Pregnancy * High dose oral sedatives (e.g. benzodiazepines) or opioids (e.g. oxycodone / oral morphine) which may affect respiratory drive
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Respiratory drive (P0.1) | 8 hours | Negative pressure in the first 100milliseconds of inspiration (P0.1) - Physiological parameter |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Respiratory effort (Pmus) | 8 hours | End expiratory occlusion pressure (Pmus) - Physiological parameter |
| Respiratory effort (PMI) | 8 hours | Pressure Muscle Index (PMI) - Physiological parameter |
| Respiratory effort (Oesophageal pressure swings) | 8 hours | Oesophageal pressure swings - Physiological parameter |
| Gas exchange (PaO2:FiO2 ratio) | 8 hours | Ratio of arterial partial pressure of oxygen to fractional inspired concentration of oxygen (PaO2:FiO2) - Physiological parameter |
| Gas exchange (pulmonary shunt fraction (Qs/Qt)) | 8 hours | Pulmonary shunt fraction (Qs/Qt) - Physiological parameter |
| Gas exchange ( ratio of ventilatory 'dead space' to tidal volume (Vd/Vt)) | 8 hours | ratio of ventilatory 'dead space' to tidal volume (Vd/Vt) - Physiological parameter |
| Gas exchange (volume of carbon dioxide breathed out (VCO2)) | 8 hours | volume of carbon dioxide breathed out (VCO2) - Physiological parameter |
Countries
United Kingdom
Contacts
CONTACTGuy Glover
CONTACTGill Radcliffe
PRINCIPAL_INVESTIGATORGuy Glover
Guy's and St Thomas' NHS Foundation Trust
Outcome results
None listed