Pharyngeal and esophageal pressure measurements to evaluate respiratory mechanics in infants on high flow nasal cannula: A feasibility study

Abstract

High-flow humidified nasal cannula (HFNC) is often\ud used to relieve respiratory distress in children with acute\ud pulmonary disease, although its effects on respiratory mechanics\ud have not been objectively studied. The purpose of this study was\ud to test the feasibility of measuring pharyngeal (PP) and\ud esophageal (Pes) pressures of young children on HFNC oxygen\ud therapy through a specifically designed new monitoring,\ud acquisition, and elaboration system (MAES). Through MAES we\ud recorded and elaborated Pes and PP tracings obtained through\ud esophageal and pharyngeal catheters in a group of young children\ud hospitalized in a Pediatric Intensive Care Unit because of\ud respiratory distress. All traces were recorded during spontaneous\ud breathing and on HFNC 1 and 2 L/kg/min. To determine the\ud onset and the end of inspiration, the Pes and PP signals were\ud synchronized with the inspiratory flow obtained by a flow\ud transducer placed in the HFNC circuit. Direct measurement of\ud inspiratory flow by a face mask pneumotachograph also allowed\ud for inspiratory tidal volume (TV) measurement which was used\ud together with Pes curve to build Campbell’s diagram as well as\ud the static lung and chest wall recoil curves required for pressure\ud time product (PTP) evaluation. Using MAES we were able to\ud obtain: time interval between the beginning of inspiratory effort\ud and inspiration (Tdelay), TV, intrinsic positive end expiratory\ud pressure (PEEPi), total inspiratory Pes variation (ΔPes),\ud transpulmonary pressure at end of inspiration (Ptpei), dynamic\ud lung compliance (CLdyn), total lung resistance (RLtot) along with\ud all the relevant components of the inspiratory work of breathing\ud (WOB) and PTP. We believe that this new system will allow\ud clinicians for a bedside monitoring of respiratory distress in\ud infants treated with HFNC and to modify flow rates accordingly.\ud Index Terms—biological system modeling, biomedica

Expiratory braking defines the breathing patterns of asphyxiated neonates during therapeutic hypothermia

“…Flow was detected using a pneumotachograph (4,500 series, not heated, flow range 0–35 LPM; Hans Rudolph, Shawnee, Kansas) combined with a differential pressure transducer (SensorTechnics 144LU01D-PCB, SensorTechnics, Inc., Mansfield, CA), inserted into the facemask port. Pes, as a surrogate for pleural pressure, was measured with a single 1.3 mm (approximately 4 Ch) diameter solid-state pressure transducer at the catheter tip (CTO-1, Gaeltec, Dunvegan, Scotland) ( 23 ). Correct catheter placement in the lower third of the esophagus was confirmed using the occlusion technique ( 24 ).…”

“…Flow and Pes signals were sampled simultaneously using a portable oscilloscope (PicoScope 4,824, Pico Technology, UK), and acquired for off-line analysis ( 25 ). Flow and Pes tracings were combined to obtain data for respiratory mechanics (dynamic compliance, Cdyn, and inspiratory and expiratory airway resistances, Rinsp, Rexp, respectively) and respiratory effort (esophageal pressure-time product per minute, PTPes/min) indices using specific routines (MATLAB® software), as previously reported ( 23 , 25 ).…”

“…Neurological evaluations were performed daily using the Sarnat score. In accordance with the standard of care, neonates undergoing TH were routinely started on a continuous infusion of fentanyl at 1 mcg/kg/h modulated according to the Neonatal Infant Pain Scale (NIPS, target 0-2) (22). Fenanyl was temporarily discontinued if heart rate fell below 80 beats/min or the respiratory rate (RR) below 20 breaths/m.…”

Real-Time Optimal Flow Setting and Respiratory Profile Evaluation in Infants Treated with High-Flow Nasal Cannula (HFNC)

“…For this purpose, based on our previous experience [11], we specifically designed a new programmable data monitoring, acquisition, and elaboration system (Pro_HFNC) and tested its effectiveness on a series of young infants hospitalized in the Pediatric Intensive Care Unit (PICU) at Sapienza University of Rome (Italy) with mild to moderate acute respiratory failure treated with HFNC.…”

Monitoring the Occurrence of Alarms in IoT-Based HFNC With Analysis of Signal Increase Before Blockages Error Occurs (Pressure Parameters)

“…Giving HFNC to COVID-19 patients starts in the flow range of 30-50 LPM with an oxygen concentration of 92% [15]. The use of HFNC should be strictly monitored by nurses because when the patient is in the same condition or worsens the nurse is required to increase the flow rate given to the patient, this monitoring is carried out every hour so that nurses can know the results of giving HFNC and if the patient's condition remains then the flow is given to HFNC will be upgraded [16] [17], Therefore, during the administration of oxygen therapy using HFNC it must be monitored carefully, to monitor the dose of oxygen administration to the patient does not decrease or does not stop. [18].…”