High flow nasal cannula oxygen therapy prevents hypoxia and hypercapnia even TOE insertion

Abstract

Introduction The use of transoesophageal ultrasound (TOE) is often cited as a limitation in TAVI under local anaesthesia and sedation. The reason is that moderate or deeper sedation is required when using TOE because of its invasiveness, and if deep sedation is used, its respiratory depression becomes stronger and airway and respiratory management become unstable. High flow nasal cannula oxygen therapy (HFNC) is a device that has recently been attracting attention as one that is expected to have oxygenation and ventilation assistance effects by using a high flow of humidified gas. We inserted TOE and managed by using HFNC in TAVI under local anaesthesia and sedation. After entering the room and securing various monitors and arterial pressure lines, HFNC was started with FiO2 40%, flow 40L. For induction of anaesthesia, fentanyl 0.5-1 mcg / kg and Propofol 20-30 mg were administered. After the disappearance of the eyelash reflex was confirmed, TOE was inserted after local anaesthesia to the pharynx with 8% Lidocaine spray. The state of anaesthesia was maintained at Propofol 2 mg / kg / hr and Remifentanil 0.01-0.03 mcg / kg / min. Methods A retrospective chart review was conducted from April 2017 to March 2018, and arterial blood gas analysis data at induction of anaesthesia (PaO2, PaCO2, BE), intubation event incidence rate and its breakdown were examined. Defects in the description were excluded. Results There were 88 cases in the period. Six cases were intubation cases, but 2 cases were intubated condition from before operation, 3 cases were extracorporeal circulation introduction due to hemodynamic instability, 1 case was due to coronary artery occlusion and There was no intubation and general anaesthesia due to anaesthesia related and patient movement control difficulty. Arterial blood gas analysis data were PaO 2 138.3 mmHg 95%CI[125.9, 150.7], PaCO 2 37.5 mmHg, 95%CI[35.7, 39.3], BE 0.09mEq/l, 95%CI[-0.60, 0.79]. Discussion Hypoxemia or hypercapnia did not occur even under moderate to deep sedation where TOE insertion did not cause movement. HFNC can suppress the occurrence of hypoxemia and hypercapnia even in moderate to deep sedation where TOE insertion is possible.