Physiology Regarding Apnoeic Oxygenation During Nasal Cannula Therapy at Different Flow Rates

• Status: Completed
• Trial end date: 2019-12-31
• Target enrollment: 0
• Participant gender: All

Summary

This study compares under controlled conditions if different flow rates affect apnoea time after induction of anaesthesia and how CO2 clearance is influenced. Furthermore, this study enables to quantify the effects of increased pCO2 on vital parameters (e.g. blood pressure, cardiac output, cerebral perfusion, etc.) The investigators will enroll patients undergoing elective surgery at the University Hospital of Bern, Switzerland.

Once anesthesia has been induced, apnoea will set it. During this period, the investigators will compare different methods of apnoeic oxygenation for a maximum of 15 or 30 minutes.

Before discharge, an interview will be conducted, assessing complications and patient satisfaction.

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University Hospital Inselspital, Berne

Criteria

Inclusion Criteria:

• > 18 years

• Written informed consent

• Undergoing elective surgery

• Requiring general anesthesia

Exclusion Criteria:

• Any Indication for fibre optic intubation

• Expected impossible mask ventilation

• Known coronary heart disease

• Known heart failure, NYHA classification ≥ 2

• Therapy including β-receptor antagonists

• Arrhythmias in need of anti-arrhythmic therapy (e.g. implanted cardio defibrillator)

• Peripheral occlusive arterial disease, Fontaine ≥ 2b

• Known stenosis of the (common or internal) carotid or vertebral arteries

• BMI > 35kg/m2 and BMI < 16kg/m2

• Hyperkalaemia (K > 5.5 mmol/l)

• Known COPD Gold classification ≥ 2

• Known pulmonary arterial hypertension, systolic > 35mmHg

• Known obstructive sleep apnoea syndrome in need of therapy

• High risk of aspiration (requiring rapid sequence induction intubation)

• Increased intracranial pressure

• Intracranial surgery

• Limited knowledge of German language

• Absent power of judgement

• Anaemia, Hb < 100 g/l

• Pregnancy (pregnancy test in all female patients)

• Neuromuscular disorder

• Known or suspected cervical spine instability

• Nasal obstruction, impossibility of nasal ventilation (both sides patent)

• Allergies or contra-indications to one or more of the used anaesthesia agents