Can High-flow Nasal Oxygenation Improve Oxygen Saturation During Analgo-sedation in Obese Adults?

Summary

Obesity is omnipresent problem in everyday anesthesiology practice associated with low level of blood oxygen (hypoxemia) during analgo-sedation. Overweight outpatients are often scheduled for colonoscopy usually undergo analgo-sedation. In obese patients, intravenous analgo-sedation often diminish respiratory drive causing hypoxemia. To avoid hypoxemia, low-flow nasal oxygenation (LFNO) of 2-6 L/min is applied via standard nasal catheter to provide maximum 40 % of inspired fraction of oxygen (FiO2). LFNO comprises applying cold and dry oxygen which causes discomfort to nasal mucosa of patient. LFNO is often insufficient to provide satisfying oxygenation. Insufficient oxygenation adds to circulatory instability - heart rate (HR) and blood pressure (BP) disorder.

On the other side, high-flow nasal oxygenation (HFNO) brings 20 to 70 L/min of heated and humidified of O2/air mixture up to 100% FiO2 via specially designed nasal cannula. Heated and humidified O2/air mixture is much more agreeable to patient. HFNO brings noninvasive support to patients' spontaneous breathing by producing continuous positive pressure of 3-7 cmH2O in upper airways consequently enhancing oxygenation.

Investigators intend to analyze effect of HFNO vs. LFNO on oxygen saturation during procedural analgo-sedation for colonoscopy in obese adult patients.

Investigators expect that obese patients with preserved spontaneous breathing, oxygenized by HFNO vs. LFNO, will be less prone to hypoxemia thus more respiratory and circulatory stable during procedural analgo-sedation for colonoscopy.

Obese patients with applied HFNO should longer preserve: normal oxygen saturation, normal level of CO2 and O2, reflecting better respiratory stability. Investigators expect obese participnts to have more stable HR and BP, reflecting improved circulatory stability. There will be less interruption of breathing pattern of obese patients and less necessity for attending anesthesiologist to intervene.

Conditions

• Noninvasive Ventilation
• Respiratory Insufficiency
• Obesity
• Deep Sedation
• Hypoxia
• Airway Management
• Colonoscopy

Interventions

DEVICE

high-flow nasal oxygenation (HFNO)

Experimental HFNO: O2 flow 40L/min, FiO2 40%

DEVICE

low-flow nasal oxygenation (LFNO)

Active comparator (LFNO): O2 flow 5L/min, FiO2 40%

Sponsors & Collaborators

• General Hospital Dubrovnik

  collaborator OTHER

• University of Split, School of Medicine

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2018-10-30

Primary Completion

2019-10-30

Completion

2020-10-30