Prashanth Bhat1, Janet L Peacock2, Gerrard F Rafferty1, Simon Hannam1, Anne Greenough3. 1. Division of Asthma, Allergy and Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK. 2. Division of Health and Social Care Research, King's College London, London, UK National Institute for Health Research (NIHR) Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK. 3. Division of Asthma, Allergy and Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London, UK National Institute for Health Research (NIHR) Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK.
Abstract
OBJECTIVE: The tension-time index of the diaphragm (TTdi) is a composite assessment of the load on and the capacity of the diaphragm. TTmus is a non-invasive tension-time index of the respiratory muscles. Our aim was to determine whether TTdi or TTmus predicted extubation outcome and performed better than respiratory muscle strength (Pimax, Pdimax), respiratory drive (P0.1) and work of breathing (transdiaphragmatic pressure-time product (PTPdi)) or routinely available clinical data. DESIGN: Prospective study. SETTING: Tertiary neonatal intensive care unit. PATIENTS: Sixty infants, median gestation age 35 (range 23-42) weeks and postnatal age of 55 (range 1-115) days. INTERVENTIONS: Airway occlusions were performed to measure Pimax, Pdimax and P0.1. TTdi and PTPdi were derived from measurements of transdiaphragmatic pressure. TTmus was derived from airway pressure measurements. Measurements were made within 6 h of extubation. MAIN OUTCOME MEASURES: Extubation failure defined as reintubation within 48 h of extubation. RESULTS: Twelve infants failed extubation. The infants who failed extubation were significantly more immature (medians 25 vs 37 weeks) and of greater postnatal age (23 vs 5 days) and had higher TTdi (0.15 vs 0.04) and TTmus (0.17 vs 0.08). TTdi and TTmus were only significantly better predictors than the peak inflation pressure immediately prior to extubation and did not perform significantly better than gestational age or birth weight. CONCLUSIONS: Assessment of TTdi and TTmus cannot be recommended for use in routine clinical practice. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
OBJECTIVE: The tension-time index of the diaphragm (TTdi) is a composite assessment of the load on and the capacity of the diaphragm. TTmus is a non-invasive tension-time index of the respiratory muscles. Our aim was to determine whether TTdi or TTmus predicted extubation outcome and performed better than respiratory muscle strength (Pimax, Pdimax), respiratory drive (P0.1) and work of breathing (transdiaphragmatic pressure-time product (PTPdi)) or routinely available clinical data. DESIGN: Prospective study. SETTING: Tertiary neonatal intensive care unit. PATIENTS: Sixty infants, median gestation age 35 (range 23-42) weeks and postnatal age of 55 (range 1-115) days. INTERVENTIONS: Airway occlusions were performed to measure Pimax, Pdimax and P0.1. TTdi and PTPdi were derived from measurements of transdiaphragmatic pressure. TTmus was derived from airway pressure measurements. Measurements were made within 6 h of extubation. MAIN OUTCOME MEASURES: Extubation failure defined as reintubation within 48 h of extubation. RESULTS: Twelve infants failed extubation. The infants who failed extubation were significantly more immature (medians 25 vs 37 weeks) and of greater postnatal age (23 vs 5 days) and had higher TTdi (0.15 vs 0.04) and TTmus (0.17 vs 0.08). TTdi and TTmus were only significantly better predictors than the peak inflation pressure immediately prior to extubation and did not perform significantly better than gestational age or birth weight. CONCLUSIONS: Assessment of TTdi and TTmus cannot be recommended for use in routine clinical practice. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Authors: Emma E Williams; Fahad M S Arattu Thodika; Imogen Chappelow; Nicole Chapman-Hatchett; Theodore Dassios; Anne Greenough Journal: Pediatr Res Date: 2022-05-06 Impact factor: 3.953
Authors: Wissam Shalish; Lara J Kanbar; Smita Rao; Carlos A Robles-Rubio; Lajos Kovacs; Sanjay Chawla; Martin Keszler; Doina Precup; Karen Brown; Robert E Kearney; Guilherme M Sant'Anna Journal: BMC Pediatr Date: 2017-07-17 Impact factor: 2.125