Oxygen therapy is one of the commonest intervention performed in ICU. Respiratory failure can be of two types: Type I or hypoxemic Failure because of inadequate oxygen reaching the tissues and Type II or hypercarbic failure because of inadequate carbon dioxide(CO₂) transfer. Once the type of respiratory failure is diagnosed, the correct treatment, based on oxygen support and/or ventilation should be instituted(1). The conventional treatment is initially oxygen therapy by various masks, followed by non invasive or invasive mechanical ventilation

High flow nasal oxygenation (HFNO) is a new non-invasive, easy-to-use respiratory device, displaying several advantages over conventional oxygenation systems .It  can deliver warm, humidified flows up to 25  to 60 L/min through soft nasal canula. The active humidification along with warming  promotes physiologic mucociliary clearance and improves fluidity of respiratory secretions, thus, letting the patients to tolerate such high flows. Further, it has been seen that the fraction of inspired oxygen (FiO2) remains stable and reliable as there is minimal losses as well as negligible ambient air entrainment.. Till now there are very few reports, retrospective study(5) and patients involving stable outdoor patients of chronic obstructive airway disease (COAD) (6), or trials used for very short period (6,7) where HFNO was tried in patients of COAD. So, we designed this study to evaluate the effectiveness of HFNO in patients of COAD  with predominantly Hypercapnic ( Type II) respiratory failure requiring ICU admission

Aim: To compare effectiveness of high Flow Nasal Oxygenation in patients with hypercapnic respiratory failure with conventional therapy. Primary objective; To compare changes in partial pressures of Carbon Dioxide between Conventional oxygen therapy  (COT)and High Flow Nasal Oxygenation (HFNO) groups.  Secondary Objective: Compare the change in (1)   Partial pressure of oxygen (2) Incidence of need for mechanical ventilation (3)  Time to discharge from ICU (4)Time to discharge from hospital (5)   Rate of readmission and time to readmission.

METHODOLOGY

After obtaining approval from Institute Ethical Committee(IEC 67/19 ref5172 14/01/2020), this study will be conducted in the Intensive Care Unit of Dr Ram Manohar Lohia Institute of Medical Sciences, Lucknow. Written informed consent will be obtained from the patient or his nearest kin before enrolling for the study. Patients will have the liberty to withdraw from the study at any point without any adverse influence in his treatment. Patients of known COAD who are admitted because of predominant hypercapnic  respiratory failure fulfilling the inclusive criteria will be enrolled for the study. Hypercapnia will be defined by PaCO ₂ â‰¥45 mm Hg. Patients of HFNO will be managed by HFNO, starting with flow rates of 0.25L/kg/min to 1L/kg/min. Data of conventional therapy will be obtained from historical controls.

All patients will be monitored by  ECG, Heart rate(HR), Respiratory Rate(RR), systolic blood pressure(SBP) diastolic blood pressure and mean arterial pressure(MAP)  ,  pH, partial pressures of oxygen, carbon dioxide,  at base line  after instituting NIV/HFNO and will be repeated at 1 hour and 2 hours. Study will terminate after 2 hours or before if condition worsen and other intervention is required.