The effects of airway resistance compensation on oxygen consumption in patients of the intensive care ward

In the mechanically ventilated patient, the single greatest cause of imposed work of breathing (WOB) is the resistance caused by the endotracheal tube (ETT). However, a special mode of ventilatory support called automatic tube compensation (ATC) delivers exactly the amount of pressure necessary to overcome the resistive load imposed by the ETT for the flow measured at the time (so-called variable pressure support). Materials and methods: 21 patients were included in our study who were on mechanical ventilation CPAP/PSV with tracheostomy tube of 8.0 mm. Pulse, BP, SpO2, Ppeak, PS, PEEP, FiO2, VO2, VCO2, EE, RQ, RSBI were monitored. 100% ARC compensation was given. Duration of observation was 60 minutes for each patient. Observation study was stopped if patients' condition deteriorated. Results: it was observed that mean BR before ARC was 20.3 ± 4.6 & mean BR after ARC was 20.8 ± 5.4, mean VO2 before ARC was 238 ± 72.5 & mean VO2 after ARC was 235.6 ± 70.7, in addition to that we observed that there was a rise in Ppeak of about 3 mm water column. Conclusion: ATC mode did not reduce the work of breathing as all the other measured parameters such as pulse, BR, RSBI, VO2, VCO2 didn't have a significant change. .