COMPARISON OF CONVENTIONAL THERAPY WITH HIGH FLOW NASAL OXYGENATION IN MANAGEMENT OF HYPERCAPNEIC RESPIRATORY FAILURE

Oxygen therapy is one of the commonestintervention performed in ICU. Respiratory failure can be of two types: Type Ior hypoxemic Failure because of inadequate oxygen reaching the tissues and TypeII or hypercarbic failure because of inadequate carbon dioxide(CO2)transfer. Once the type of respiratory failure is diagnosed, the correcttreatment, 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 nasaloxygenation (HFNO) is a new non-invasive, easy-to-use respiratory device,displaying several advantages over conventional oxygenation systems .It  can deliverwarm, humidified flows up to 25  to 60 L/min through soft nasal canula.The active humidification along with warming  promotes physiologicmucociliary clearance and improves fluidity of respiratory secretions, thus,letting the patients to tolerate such high flows. Further, it has been seenthat the fraction of inspired oxygen (FiO2) remains stable and reliable asthere is minimal losses as well as negligible ambient air entrainment.. Tillnow there are very few reports, retrospective study(5) and patients involvingstable outdoor patients of chronic obstructive airway disease (COAD) (6), ortrials used for very short period (6,7) where HFNO was tried in patients ofCOAD. So, we designed this study to evaluate the effectiveness of HFNO inpatients of COAD  with predominantly Hypercapnic ( Type II) respiratoryfailure requiring ICU admission

Aim: To compare effectiveness of highFlow Nasal Oxygenation in patients with hypercapnic respiratory failure withconventional therapy. **Primary objective;**To compare changesin partial pressures of Carbon Dioxide between Conventional oxygentherapy  (COT)and High Flow Nasal Oxygenation (HFNO) groups.  Secondary Objective: Comparethe 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 readmissionand time to readmission.

METHODOLOGY

After obtaining approval from InstituteEthical Committee(IEC 67/19 ref5172 14/01/2020), this study will be conductedin the Intensive Care Unit of Dr Ram Manohar Lohia Institute of MedicalSciences, Lucknow. Written informed consent will be obtained from the patientor his nearest kin before enrolling for the study. Patients will have theliberty to withdraw from the study at any point without any adverse influencein his treatment. Patients of known COAD who are admitted because ofpredominant hypercapnic  respiratory failure fulfilling the inclusivecriteria will be enrolled for the study. Hypercapnia will be defined by PaCO2≥45mm Hg. Patients of HFNO will be managed by HFNO, starting with flow rates of0.25L/kg/min to 1L/kg/min. Data of conventional therapy will be obtained from historicalcontrols.

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  afterinstituting NIV/HFNO and will be repeated at 1 hour and 2 hours. Study willterminate after 2 hours or before if condition worsen and other intervention isrequired.